Science.gov

Sample records for airplane critical systems

  1. MLS: Airplane system modeling

    NASA Technical Reports Server (NTRS)

    Thompson, A. D.; Stapleton, B. P.; Walen, D. B.; Rieder, P. F.; Moss, D. G.

    1981-01-01

    Analysis, modeling, and simulations were conducted as part of a multiyear investigation of the more important airplane-system-related items of the microwave landing system (MLS). Particular emphasis was placed upon the airplane RF system, including the antenna radiation distribution, the cabling options from the antenna to the receiver, and the overall impact of the airborne system gains and losses upon the direct-path signal structure. In addition, effort was expended toward determining the impact of the MLS upon the airplane flight management system and developing the initial stages of a fast-time MLS automatic control system simulation model. Results ot these studies are presented.

  2. Airplane takeoff and landing performance monitoring system

    NASA Technical Reports Server (NTRS)

    Middleton, David B. (Inventor); Srivatsan, Raghavachari (Inventor); Person, Lee H. (Inventor)

    1989-01-01

    The invention is a real-time takeoff and landing performance monitoring system which provides the pilot with graphic and metric information to assist in decisions related to achieving rotation speed (V sub R) within the safe zone of the runway or stopping the aircraft on the runway after landing or take off abort. The system processes information in two segments: a pretakeoff segment and a real-time segment. One-time inputs of ambient conditions and airplane configuration information are used in the pretakeoff segment to generate scheduled performance data. The real-time segment uses the scheduled performance data, runway length data and transducer measured parameters to monitor the performance of the airplane throughout the takeoff roll. An important feature of this segment is that it updates the estimated runway rolling friction coefficient. Airplane performance predictions also reflect changes in headwind occurring as the takeoff roll progresses. The system displays the position of the airplane on the runway, indicating runway used and runway available, summarizes the critical information into a situation advisory flag, flags engine failures and off-nominal acceleration performance, and indicates where on the runway particular events such as decision speed (V sub 1), rotation speed (V sub R) and expected stop points will occur based on actual or predicted performance. The display also indicates airspeed, wind vector, engine pressure ratios, second segment climb speed, and balanced field length (BFL). The system detects performance deficiencies by comparing the airplane's present performance with a predicted nominal performance based upon the given conditions.

  3. 78 FR 73995 - Special Conditions: Cessna Model 680 Series Airplanes; Aircraft Electronic System Security...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-10

    ...These special conditions are issued for the Cessna Model 680 series airplanes. These airplanes will have novel or unusual design features associated with connectivity of the passenger service computer systems to the airplane critical systems and data networks. The network architecture is composed of several connected networks including the following: 1. Flight-Safety related control and......

  4. 78 FR 4038 - Critical Parts for Airplane Propellers

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-18

    ..., FAA published a notice of proposed rulemaking titled ``Critical Parts for Airplane Propellers'' (76 FR... parts, and establish engineering, manufacturing, and maintenance processes for propeller critical parts... prescribing regulations promoting safe flight of civil aircraft in air commerce by prescribing regulations...

  5. 78 FR 45052 - Critical Parts for Airplane Propellers; Correction

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-26

    .... SUMMARY: The FAA is correcting a final rule published on January 18, 2013 (78 FR 4038). In that rule, the... 18, 2013, the FAA published a final rule titled, ``Critical Parts for Airplane Propellers'' (78 FR... unintentional error was introduced in Sec. 35.15 when we revised paragraph (d). We did not intend to...

  6. 76 FR 36861 - Special Conditions: Gulfstream Model GVI Airplane; Electronic Systems Security Isolation or...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-23

    ... Gulfstream GVI airplanes was published in the Federal Register on February 25, 2011 (76 FR 10528). Only one... features associated with connectivity of the passenger domain computer systems to the airplane ] critical... connected networks. The proposed architecture and network configuration may be used for, or interfaced...

  7. Planetary Airplane Extraction System Development and Subscale Testing

    NASA Technical Reports Server (NTRS)

    Teter, John E., Jr.

    2006-01-01

    The Aerial Regional-scale Environmental Survey (ARES) project employs an airplane as the science platform from which to collect science data in the previously inaccessible, thin atmosphere of Mars. In order for the airplane to arrive safely in the Martian atmosphere a number of sequences must occur. A critical element in the entry sequence at Mars is an extraction maneuver to separate the airplane quickly (in less than a second) from its protective backshell to reduce the possibility of re-contact, potentially leading to mission failure. This paper describes the development, testing, and lessons learned from building a 1/3 scale model of this airplane extraction system. This design, based on the successful Mars Exploration Rover (MER) extraction mechanism, employs a series of trucks rolling along tracks located on the surface of the central parachute can. Numerous tests using high speed video were conducted at the Langley Research Center (LaRC) to validate this concept. One area of concern was that that although the airplane released cleanly, a pitching moment could be introduced. While targeted for a Mars mission, this concept will enable environmental surveys by aircraft in other planetary bodies with a sensible atmosphere such as Venus or Saturn s moon, Titan.

  8. Planetary Airplane Extraction System Development and Subscale Testing

    NASA Technical Reports Server (NTRS)

    Teter, John E., Jr.

    2006-01-01

    The Aerial Regional-scale Environmental Survey (ARES) project will employ an airplane as the science platform from which to collect science data in the previously inaccessible, thin atmosphere of Mars. In order for the airplane to arrive safely in the Martian atmosphere, a number of sequences must occur. A critical element in the entry sequence at Mars is an extraction maneuver to separate the airplane quickly (in less than a second) from its protective backshell to reduce the possibility of re-contact, potentially leading to mission failure. This paper describes the development, testing, and lessons learned from building a 1/3 scale model of this airplane extraction system. This design, based on the successful Mars Exploration Rover (MER) extraction mechanism, employs a series of trucks rolling along tracks located on the surface of the central parachute can. Numerous tests using high speed video were conducted at the Langley Research Center to validate this concept. One area of concern was that that although the airplane released cleanly, a pitching moment could be introduced. While targeted for a Mars mission, this concept will enable environmental surveys by aircraft in other planetary bodies with a sensible atmosphere such as Venus or Saturn's moon, Titan.

  9. Airplane takeoff and landing performance monitoring system

    NASA Technical Reports Server (NTRS)

    Middleton, David B. (Inventor); Srivatsan, Raghavachari (Inventor); Person, Jr., Lee H. (Inventor)

    1996-01-01

    The invention is a real-time takeoff and landing performance monitoring system for an aircraft which provides a pilot with graphic and metric information to assist in decisions related to achieving rotation speed (V.sub.R) within the safe zone of a runway, or stopping the aircraft on the runway after landing or take-off abort. The system processes information in two segments: a pretakeoff segment and a real-time segment. One-time inputs of ambient conditions and airplane configuration information are used in the pretakeoff segment to generate scheduled performance data. The real-time segment uses the scheduled performance data, runway length data and transducer measured parameters to monitor the performance of the airplane throughout the takeoff roll. Airplane acceleration and engine-performance anomalies are detected and annunciated. A novel and important feature of this segment is that it updates the estimated runway rolling friction coefficient. Airplane performance predictions also reflect changes in head wind occurring as the takeoff roll progresses. The system provides a head-down display and a head-up display. The head-up display is projected onto a partially reflective transparent surface through which the pilot views the runway. By comparing the present performance of the airplane with a continually predicted nominal performance based upon given conditions, performance deficiencies are detected by the system and conveyed to pilot in form of both elemental information and integrated information.

  10. Airplane takeoff and landing performance monitoring system

    NASA Technical Reports Server (NTRS)

    Middleton, David B. (Inventor); Srivatsan, Raghavachari (Inventor); Person, Lee H., Jr. (Inventor)

    1994-01-01

    The invention is a real-time takeoff and landing performance monitoring system for an aircraft which provides a pilot with graphic and metric information to assist in decisions related to achieving rotation speed (VR) within the safe zone of a runway, or stopping the aircraft on the runway after landing or take-off abort. The system processes information in two segments: a pretakeoff segment and a real-time segment. One-time inputs of ambient conditions and airplane configuration information are used in the pretakeoff segment to generate scheduled performance data. The real-time segment uses the scheduled performance data, runway length data and transducer measured parameters to monitor the performance of the airplane throughout the takeoff roll. Airplane acceleration and engine-performance anomalies are detected and annunciated. A novel and important feature of this segment is that it updates the estimated runway rolling friction coefficient. Airplane performance predictions also reflect changes in head wind occurring as the takeoff roll progresses. The system provides a head-down display and a head-up display. The head-up display is projected onto a partially reflective transparent surface through which the pilot views the runway. By comparing the present performance of the airplane with a continually predicted nominal performance based upon given conditions, performance deficiencies are detected by the system and conveyed to pilot in form of both elemental information and integrated information.

  11. Airplane takeoff and landing performance monitoring system

    NASA Technical Reports Server (NTRS)

    Middleton, David B. (Inventor); Srivatsan, Raghavachari (Inventor); Person, Jr., Lee H. (Inventor)

    1991-01-01

    The invention is a real-time takeoff and landing performance monitoring system for an aircraft which provides a pilot with graphic and metric information to assist in decisions related to achieving rotation speed (V.sub.R) within the safe zone of a runway, or stopping the aircraft on the runway after landing or take-off abort. The system processes information in two segments: a pretakeoff segment and a real-time segment. One-time inputs of ambient conditions and airplane configuration information are used in the pretakeoff segment to generate scheduled performance data. The real-time segment uses the scheduled performance data, runway length data and transducer measured parameters to monitor the performance of the airplane throughout the takeoff roll. Airplane and engine performance deficiencies are detected and annunciated. A novel and important feature of this segment is that it updates the estimated runway rolling friction coefficient. Airplane performance predictions also reflect changes in head wind occurring as the takeoff roll progresses. The system provides a head-down display and a head-up display. The head-up display is projected onto a partially reflective transparent surface through which the pilot views the runway. By comparing the present performance of the airplane with a predicted nominal performance based upon given conditions, performance deficiencies are detected by the system.

  12. Wind-tunnel procedure for determination of critical stability and control characteristics of airplanes

    NASA Technical Reports Server (NTRS)

    Goett, Harry J; Jackson, Roy P; Belsley, Steven E

    1944-01-01

    This report outlines the flight conditions that are usually critical in determining the design of components of an airplane which affect its stability and control characteristics. The wind-tunnel tests necessary to determine the pertinent data for these conditions are indicated, and the methods of computation used to translate these data into characteristics which define the flying qualities of the airplane are illustrated.

  13. Wind-Tunnel Procedure for Determination of Critical Stability and Control Characteristics of Airplanes

    NASA Technical Reports Server (NTRS)

    Goett, Harry J.; Jackson, Roy P.; Belsley, Steven E.

    1944-01-01

    This report outlines the flight conditions that are usually critical in determining the design of components of an airplane which affect its stability and control characteristics. The wind-tunnel tests necessary to determine the pertinent data for these conditions are indicated, and the methods of computation used to translate these data into characteristics which define the flying qualities of the airplane are illustrated.

  14. 78 FR 73993 - Special Conditions: Cessna Model 680 Series Airplanes; Aircraft Electronic System Security...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-10

    ...These special conditions are issued for the Cessna Model 680 Series airplanes. These airplanes will have a novel or unusual design feature associated with the architecture and connectivity capabilities of the airplanes' computer systems and networks. Connectivity to, or access by, external systems and networks may result in security vulnerabilities to the airplanes' systems. The proposed......

  15. 75 FR 28463 - Airworthiness Directives; BAE SYSTEMS (Operations) Limited Model BAe 146 Airplanes and Model Avro...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-21

    ...-16301; AD 2010-10-22] RIN 2120-AA64 Airworthiness Directives; BAE SYSTEMS (Operations) Limited Model BAe 146 Airplanes and Model Avro 146-RJ Airplanes AGENCY: Federal Aviation Administration (FAA... airworthiness directive (AD), which applies to Model BAe 146 airplanes and Model Avro 146-RJ airplanes. That...

  16. 75 FR 65052 - Consensus Standards, Standard Practice for Maintenance of Airplane Electrical Wiring Systems

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-21

    ... TRANSPORTATION Federal Aviation Administration Consensus Standards, Standard Practice for Maintenance of Airplane... Practice for Maintenance of Airplane Electrical Wiring Systems (Standard Practice) as an acceptable means... FAA finds the standards to be acceptable methods and procedures for maintenance of electrical...

  17. Gust alleviation system to improve ride comfort of light airplanes

    NASA Technical Reports Server (NTRS)

    Stewart, E. C.; Phillips, W. H.; Hewes, D. E.

    1975-01-01

    System consists of movable auxiliary aerodynamic sensors mounted on fuselage and connected to trailing-edge flaps by rigid mechanical linkages. System achieves alleviation by reducing lift-curve slope of airplane to such a small value that gust-induced angles of attack will result in small changes in lift.

  18. 78 FR 46303 - Airworthiness Directives; Fokker Services B.V. Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-31

    ... fuel system; and revising the airplane maintenance program by incorporating critical design... switch and subsequently, the implementation of the associated Critical Design Configuration Control...'' (66 FR 23086, May 7, 2001). In addition to new airworthiness standards for transport airplanes and...

  19. System for Better Spacing of Airplanes En Route

    NASA Technical Reports Server (NTRS)

    Green, Steven; Erzberger, Heinz

    2004-01-01

    An improved method of computing the spacing of airplanes en route, and software to implement the method, have been invented. The purpose of the invention is to help air-traffic controllers minimize those deviations of the airplanes from the trajectories preferred by their pilots that are needed to make the airplanes comply with miles-in-trail spacing requirements. The software is meant to be a modular component of the Center TRACON Automation System (CTAS) (TRACON signifies "terminal radar approach control"). The invention reduces controllers workloads and reduces fuel consumption by reducing the number of corrective clearances needed to achieve conformance with specified flow rates, without causing conflicts, while providing for more efficient distribution of spacing workload upstream and across air-traffic-control sectors.

  20. 75 FR 76647 - Special Conditions: Boeing Model 747-8 Airplanes, Systems and Data Networks Security-Isolation or...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-09

    ... passenger domain computer systems to the airplane critical systems and data networks. The applicable...: Digital systems architecture composed of several connected networks. The proposed network architecture... Domain), and 4. The capability to allow access to or by external network sources. Discussion The...

  1. Boeing Satellite Television Airplane Receiving System (STARS) performance

    NASA Technical Reports Server (NTRS)

    Vertatschitsch, Edward J.; Fitzsimmons, George W.

    1995-01-01

    Boeing Defense and Space Group is developing a Satellite Television Airplane Receiving System (STARS) capable of delivering Direct Broadcast Satellite (DBS) television to an aircraft in-flight. This enables a new service for commercial airplanes that will make use of existing and future DBS systems. The home entertainment satellites, along with STARS, provide a new mobile satellite communication application. This paper will provide a brief background of the antenna issues associated with STARS for commercial airplanes and then describe the innovative Boeing phased-array solution to these problems. The paper then provides a link budget of the STARS using the Hughes DBS as an example, but the system will work with all of the proposed DBS satellites in the 12.2-12.7 GHz band. It concludes with operational performance calculations of the STARS system, supported by measured test data of an operational 16-element subarray. Although this system is being developed for commercial airplanes, it is well suited for a wide variety of mobile military and other commercial communications systems in air, on land and at sea. The applications include sending high quality video for the digital battlefield and large volumes of data on the information superhighway at rates in excess of 350 Mbps.

  2. Rotor systems research aircraft airplane configuration flight-test results

    NASA Technical Reports Server (NTRS)

    Painter, W. D.; Erickson, R. E.

    1984-01-01

    The rotor systems research aircraft (RSRA) has undergone ground and flight tests, primarily as a compound aircraft. The purpose was to train pilots and to check out and develop the design flight envelope. The preparation and flight test of the RSRA in the airplane, or fixed-wind, configuration are reviewed and the test results are discussed.

  3. 76 FR 74749 - Critical Parts for Airplane Propellers

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-01

    ... (65 FR 19477-19478), as well as at http://DocketsInfo.dot.gov . Docket: Background documents or.... Consequently, there are no requirements for design, manufacture, maintenance, or management of propeller... provide information concerning propeller critical part design, manufacture, or maintenance. Background...

  4. Blended Buffet-Load-Alleviation System for Fighter Airplane

    NASA Technical Reports Server (NTRS)

    Moses, Robert W.

    2005-01-01

    The capability of modern fighter airplanes to sustain flight at high angles of attack and/or moderate angles of sideslip often results in immersion of part of such an airplane in unsteady, separated, vortical flow emanating from its forebody or wings. The flows from these surfaces become turbulent and separated during flight under these conditions. These flows contain significant levels of energy over a frequency band coincident with that of low-order structural vibration modes of wings, fins, and control surfaces. The unsteady pressures applied to these lifting surfaces as a result of the turbulent flows are commonly denoted buffet loads, and the resulting vibrations of the affected structures are known as buffeting. Prolonged exposure to buffet loads has resulted in fatigue of structures on several airplanes. Damage to airplanes caused by buffeting has led to redesigns of airplane structures and increased support costs for the United States Air Force and Navy as well as the armed forces of other countries. Time spent inspecting, repairing, and replacing structures adversely affects availability of aircraft for missions. A blend of rudder-control and piezoelectric- actuator engineering concepts was selected as a basis for the design of a vertical-tail buffet-load-alleviation system for the F/A-18 airplane. In this system, the rudder actuator is used to control the response of the first tail vibrational mode (bending at a frequency near 15 Hz), while directional patch piezoelectric actuators are used to control the second tail vibrational mode (tip torsion at a frequency near 45 Hz). This blend of two types of actuator utilizes the most effective features of each. An analytical model of the aeroservoelastic behavior of the airplane equipped with this system was validated by good agreement with measured results from a full-scale ground test, flight-test measurement of buffet response, and an in-flight commanded rudder frequency sweep. The overall performance of the

  5. A Study of Transport Airplane Crash-Resistant Fuel Systems

    NASA Technical Reports Server (NTRS)

    Jones, Lisa (Technical Monitor); Robertson, S. H.; Johnson, N. B.; Hall, D. S.; Rimson, I. J.

    2002-01-01

    This report presents the results of a study, funded by the Federal Aviation Administration (FAA), of transport airplane crash-resistant fuel system (CRFS). The report covers the historical studies related to aircraft crash fires and fuel containment concepts undertaken by the FAA, NASA, and the U.S. Army, which ultimately led to the current state of the art in CRFS technology. It describes the basic research, testing, field investigations and production efforts which have led to the highly successful military CRFS, which has saved many lives and reduced costs of accidents. Current CRFS technology used in transport category airplanes is defined and compared to the available state-of-the-art technology. The report provides information to the FAA and other government organizations which can help them plan their efforts to improve the state of crash fire protection in the transport airplane fleet. The report provides guidance to designers looking for information about CRFS design problems, analysis tools to use for product improvement, and a summary of current and proposed regulations for transport category airplane fuel systems.

  6. 78 FR 63847 - Special Conditions: Embraer S.A., Model EMB-550 Airplanes; Airplane Electronic System Security...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-25

    ... be found in the Federal Register published on April 11, 2000 (65 FR 19477-19478), as well as at http... design feature associated with the architecture and connectivity capabilities of the airplanes' computer systems and networks, which may allow access to or by external computer systems and networks....

  7. 76 FR 8316 - Special Conditions: Gulfstream Model GVI Airplane; Interaction of Systems and Structures

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-14

    ... systems that affect the structural capability of the airplane. The applicable airworthiness regulations do... are systems that may affect the airplane's structural performance, either directly or as a result of... conditions, and thereby affect its structural capability. These systems may also affect the...

  8. 76 FR 36863 - Special Conditions: Gulfstream Model GVI Airplane; Electronic Systems Security Protection From...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-23

    ... airplanes was published in the Federal Register on February 25, 2011 (76 FR 10529). Only one comment was... architecture and connectivity capabilities of the airplane's computer systems and networks, which may allow access by external computer systems and networks. Connectivity by external systems and networks...

  9. 76 FR 9265 - Special Conditions: Gulfstream Model GVI Airplane; Electronic Flight Control System: Control...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-17

    ... Model GVI Airplane; Electronic Flight Control System: Control Surface Position Awareness AGENCY: Federal... transport category airplanes. These design features include an electronic flight control system. The..., include with your comments a self-addressed, stamped postcard on which you have written the docket...

  10. 76 FR 36865 - Special Conditions: Gulfstream Model GVI Airplane; Interaction of Systems and Structures

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-23

    ... Federal Register on February 14, 2011 (76 FR 8316). Only one comment was received. Clarification of GVI... that affect the structural capability of the airplane. The applicable airworthiness regulations do not... unusual design features. These features are systems that may affect the airplane's structural...

  11. Investigation of Icing Characteristics of Typical Light Airplane Engine Induction Systems

    NASA Technical Reports Server (NTRS)

    Coles, W. D.

    1949-01-01

    The icing characteristics of two typical light-airplane engine induction systems were investigated using the carburetors and manifolds of engines in the horsepower ranges from 65 to 85 and 165 to 185. The smaller system consisted of a float-type carburetor with an unheated manifold and the larger system consisted of a single-barrel pressure-type carburetor with an oil-jacketed manifold. Carburetor-air temperature and humidity limits of visible and serious Icing were determined for various engine power conditions. Several.methods of achieving ice-free induction systems are discussed along with estimates of surface heating requirements of the various induct ion-system components. A study was also made of the icing characteristics of a typical light-airplane air scoop with an exposed filter and a modified system that provided a normal ram inlet with the filter located in a position to Induce inertia separation of the free water from the charge air. The principle of operation of float-type carburetors is proved to make them inherently more susceptible to icing at the throttle plate than pressure-type carburetors.. The results indicated that proper jacketing and heating of all parts exposed to the fuel spray can satisfactorily reduce or eliminate icing in the float-type carburetor and the manifold. Pressure-type carburetors can be protected from serious Icing by proper location of the fuel-discharge nozzle combined with suitable application of heat to critical parts.

  12. Tradeoff studies in multiobjective insensitive design of airplane control systems

    NASA Technical Reports Server (NTRS)

    Schy, A. A.; Giesy, D. P.

    1983-01-01

    A computer aided design method for multiobjective parameter-insensitive design of airplane control systems is described. Methods are presented for trading off nominal values of design objectives against sensitivities of the design objectives to parameter uncertainties, together with guidelines for designer utilization of the methods. The methods are illustrated by application to the design of a lateral stability augmentation system for two supersonic flight conditions of the Shuttle Orbiter. Objective functions are conventional handling quality measures and peak magnitudes of control deflections and rates. The uncertain parameters are assumed Gaussian, and numerical approximations of the stochastic behavior of the objectives are described. Results of applying the tradeoff methods to this example show that stochastic-insensitive designs are distinctly different from deterministic multiobjective designs. The main penalty for achieving significant decrease in sensitivity is decreased speed of response for the nominal system.

  13. Optimizing Mars Airplane Trajectory with the Application Navigation System

    NASA Technical Reports Server (NTRS)

    Frumkin, Michael; Riley, Derek

    2004-01-01

    Planning complex missions requires a number of programs to be executed in concert. The Application Navigation System (ANS), developed in the NAS Division, can execute many interdependent programs in a distributed environment. We show that the ANS simplifies user effort and reduces time in optimization of the trajectory of a martian airplane. We use a software package, Cart3D, to evaluate trajectories and a shortest path algorithm to determine the optimal trajectory. ANS employs the GridScape to represent the dynamic state of the available computer resources. Then, ANS uses a scheduler to dynamically assign ready task to machine resources and the GridScape for tracking available resources and forecasting completion time of running tasks. We demonstrate system capability to schedule and run the trajectory optimization application with efficiency exceeding 60% on 64 processors.

  14. 75 FR 77569 - Special Conditions: Gulfstream Model GVI Airplane; Electronic Flight Control System Mode...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-13

    ...; Electronic Flight Control System Mode Annunciation AGENCY: Federal Aviation Administration (FAA), DOT. ACTION... design features include an electronic flight control system. The applicable airworthiness regulations do... INFORMATION CONTACT: Joe Jacobsen, FAA, Airplane and Flight Crew Interface Branch, ANM-111,...

  15. 76 FR 10529 - Special Conditions: Gulfstream Model GVI Airplane; Electronic Systems Security Protection From...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-25

    ... associated with the architecture and connectivity capabilities of the airplane's computer systems and networks, which may allow access by external computer systems and networks. Connectivity by external... architecture composed of several connected networks. The proposed architecture and network configuration may...

  16. An Investigation of a Thermal Ice-Prevention System for a Twin-Engine Transport Airplane

    NASA Technical Reports Server (NTRS)

    Jones, Alun R

    1946-01-01

    Several previously published reports on a comprehensive investigation of a thermal ice-prevention system for a typical twin-engine transport airplane are correlated with some unpublished data to present the entire investigation in one publication. Several previously published reports on a comprehensive investigation of a thermal ice-prevention system for a typical twin-engine transport airplane are correlated with some unpublished data to present the entire investigation in one publication. The thermal system investigated was based upon the transfer of heat from the engine exhaust gas to air, which is then caused to flow along the inner surface of any portion of the airplane for which protection is desired.

  17. Flight test evaluation of a separate surface attitude command control system on a Beech 99 airplane

    NASA Technical Reports Server (NTRS)

    Gee, S. W.; Jenks, G. E.; Roskam, J.; Stone, R. L.

    1976-01-01

    A joint NASA/university/industry program was conducted to flight evaluate a potentially low cost separate surface implementation of attitude command in a Beech 99 airplane. Saturation of the separate surfaces was the primary cause of many problems during development. Six experienced professional pilots who made simulated instrument flight evaluations experienced improvements in airplane handling qualities in the presence of turbulence and a reduction in pilot workload. For ride quality, quantitative data show that the attitude command control system results in all cases of airplane motion being removed from the uncomfortable ride region.

  18. 78 FR 75289 - Airworthiness Directives; BAE Systems (Operations) Limited Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-11

    ... rule'' under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); 3. Will not... may view this referenced service information at the FAA, Transport Airplane Directorate, 1601...

  19. Tradeoff methods in multiobjective insensitive design of airplane control systems

    NASA Technical Reports Server (NTRS)

    Schy, A. A.; Giesy, D. P.

    1984-01-01

    The latest results of an ongoing study of computer-aided design of airplane control systems are given. Constrained minimization algorithms are used, with the design objectives in the constraint vector. The concept of Pareto optimiality is briefly reviewed. It is shown how an experienced designer can use it to find designs which are well-balanced in all objectives. Then the problem of finding designs which are insensitive to uncertainty in system parameters are discussed, introducing a probabilistic vector definition of sensitivity which is consistent with the deterministic Pareto optimal problem. Insensitivity is important in any practical design, but it is particularly important in the design of feedback control systems, since it is considered to be the most important distinctive property of feedback control. Methods of tradeoff between deterministic and stochastic-insensitive (SI) design are described, and tradeoff design results are presented for the example of the a Shuttle lateral stability augmentation system. This example is used because careful studies have been made of the uncertainty in Shuttle aerodynamics. Finally, since accurate statistics of uncertain parameters are usually not available, the effects of crude statistical models on SI designs are examined.

  20. Analytical study of the performance of a gust alleviation system for a STOL airplane

    NASA Technical Reports Server (NTRS)

    Oehman, W. I.

    1973-01-01

    An analytical study has shown that a gust alleviation system for a STOL airplane in a cruise condition could reduce the root mean square of the normal acceleration of the airplane flying in random turbulence by as much as 50 percent. This alleviation is obtained by driving the flaps in response to normal acceleration and by moving the elevator in proportion to the commanded flap deflection angle and to a pitch-rate signal.

  1. Nuclear criticality information system

    SciTech Connect

    Koponen, B.L.; Hampel, V.E.

    1981-11-30

    The nuclear criticality safety program at LLNL began in the 1950's with a critical measurements program which produced benchmark data until the late 1960's. This same time period saw the rapid development of computer technology useful for both computer modeling of fissile systems and for computer-aided management and display of the computational benchmark data. Database management grew in importance as the amount of information increased and as experimental programs were terminated. Within the criticality safety program at LLNL we began at that time to develop a computer library of benchmark data for validation of computer codes and cross sections. As part of this effort, we prepared a computer-based bibliography of criticality measurements on relatively simple systems. However, it is only now that some of these computer-based resources can be made available to the nuclear criticality safety community at large. This technology transfer is being accomplished by the DOE Technology Information System (TIS), a dedicated, advanced information system. The NCIS database is described.

  2. Flight evaluation of advanced control systems and displays on a general aviation airplane

    NASA Technical Reports Server (NTRS)

    Loschke, P. C.; Barber, M. R.; Enevoldson, E. K.; Mcmurtry, T. C.

    1974-01-01

    A flight-test program was conducted to determine the effect of advanced flight control systems and displays on the handling qualities of a light twin-engined airplane. A flight-director display and an attitude-command control system, used separately and in combination, transformed a vehicle with poor handling qualities during ILS approaches in turbulent air into a vehicle with good handling qualities. The attitude-command control system also improved the ride qualities of the airplane. A rate-command control system made only small improvements to the airplane's ILS handling qualities in turbulence. Both the rate- and the attitude-command control systems reduced stall warning in the test airplane, increasing the likelihood of inadvertent stalls. The final approach to the point of flare was improved by both the rate- and the attitude-command control systems. However, the small control wheel deflections necessary to flare were unnatural and tended to cause overcontrolling during flare. Airplane handling qualities are summarized for each control-system and display configuration.

  3. Preliminary design-lift/cruise fan research and technology airplane flight control system

    NASA Technical Reports Server (NTRS)

    Gotlieb, P.; Lewis, G. E.; Little, L. J.

    1976-01-01

    This report presents the preliminary design of a stability augmentation system for a NASA V/STOL research and technology airplane. This stability augmentation system is postulated as the simplest system that meets handling qualities levels for research and technology missions flown by NASA test pilots. The airplane studied in this report is a T-39 fitted with tilting lift/cruise fan nacelles and a nose fan. The propulsion system features a shaft interconnecting the three variable pitch fans and three power plants. The mathematical modeling is based on pre-wind tunnel test estimated data. The selected stability augmentation system uses variable gains scheduled with airspeed. Failure analysis of the system illustrates the benign effect of engine failure. Airplane rate sensor failure must be solved with redundancy.

  4. A spin-recovery parachute system for light general-aviation airplanes

    NASA Technical Reports Server (NTRS)

    Bradshaw, C.

    1980-01-01

    A tail mounted spin recovery parachute system was designed and developed for use on light general aviation airplanes. The system was designed for use on typical airplane configurations, including low wing, high wing, single engine and twin engine designs. A mechanically triggered pyrotechnic slug gun is used to forcibly deploy a pilot parachute which extracts a bag that deploys a ring slot spin recovery parachute. The total system weighs 8.2 kg. System design factors included airplane wake effects on parachute deployment, prevention of premature parachute deployment, positive parachute jettison, compact size, low weight, system reliability, and pilot and ground crew safety. Extensive ground tests were conducted to qualify the system. The recovery parachute was used successfully in flight 17 times.

  5. Low-temperature fuel cell systems for commercial airplane auxiliary power.

    SciTech Connect

    Curgus, Dita Brigitte; Pratt, Joseph William; Akhil, Abbas Ali; Klebanoff, Leonard E.

    2010-11-01

    This presentation briefly describes the ongoing study of fuel cell systems on-board a commercial airplane. Sandia's current project is focused on Proton Exchange Membrane (PEM) fuel cells applied to specific on-board electrical power needs. They are trying to understand how having a fuel cell on an airplane would affect overall performance. The fuel required to accomplish a mission is used to quantify the performance. Our analysis shows the differences between the base airplane and the airplane with the fuel cell. There are many ways of designing a system, depending on what you do with the waste heat. A system that requires ram air cooling has a large mass penalty due to increased drag. The bottom-line impact can be expressed as additional fuel required to complete the mission. Early results suggest PEM fuel cells can be used on airplanes with manageable performance impact if heat is rejected properly. For PEMs on aircraft, we are continuing to perform: (1) thermodynamic analysis (investigate configurations); (2) integrated electrical design (with dynamic modeling of the micro grid); (3) hardware assessment (performance, weight, and volume); and (4) galley and peaker application.

  6. 75 FR 70092 - Special Conditions: Bombardier Inc. Model CL-600-2E25 Airplane, Interaction of Systems and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-17

    ...-2D24. The CL-600-2E25 will have a CBW rudder-control system that will affect the structural performance... effects of this system and its failures on structural performance. The special conditions defined herein... that will affect the structural performance of the airplane. The airplane will use a CBW Rudder...

  7. 75 FR 2433 - Special Conditions: Boeing Model 747-8/-8F Airplanes, Systems and Data Networks Security...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-15

    ... Federal Register on October 2, 2009 (74 FR 50926). No comments were received. Applicability As discussed... Administration 14 CFR Part 25 Special Conditions: Boeing Model 747-8/-8F Airplanes, Systems and Data Networks Security--Protection of Airplane Systems and Data Networks From Unauthorized External Access...

  8. Highly integrated digital engine control system on an F-15 airplane

    NASA Technical Reports Server (NTRS)

    Burcham, F. W., Jr.; Haering, E. A., Jr.

    1984-01-01

    The Highly Integrated Digital Electronic Control (HIDEC) program will demonstrate and evaluate the improvements in performance and mission effectiveness that result from integrated engine/airframe control systems. This system is being used on the F-15 airplane. An integrated flightpath management mode and an integrated adaptive engine stall margin mode are implemented into the system. The adaptive stall margin mode is a highly integrated mode in which the airplane flight conditions, the resulting inlet distortion, and the engine stall margin are continuously computed; the excess stall margin is used to uptrim the engine for more thrust. The integrated flightpath management mode optimizes the flightpath and throttle setting to reach a desired flight condition. The increase in thrust and the improvement in airplane performance is discussed.

  9. Highly integrated digital engine control system on an F-15 airplane

    NASA Technical Reports Server (NTRS)

    Burcham, F. W., Jr.; Haering, E. A., Jr.

    1984-01-01

    The highly integrated digital electronic control (HIDEC) program will demonstrate and evaluate the improvements in performance and mission effectiveness that result from integrated engine-airframe control systems. This system is being used on the F-15 airplane at the Dryden Flight Research Facility of NASA Ames Research Center. An integrated flightpath management mode and an integrated adaptive engine stall margin mode are being implemented into the system. The adaptive stall margin mode is a highly integrated mode in which the airplane flight conditions, the resulting inlet distortion, and the engine stall margin are continuously computed; the excess stall margin is used to uptrim the engine for more thrust. The integrated flightpath management mode optimizes the flightpath and throttle setting to reach a desired flight condition. The increase in thrust and the improvement in airplane performance is discussed in this paper.

  10. Critical Infrastructure Modeling System

    2004-10-01

    The Critical Infrastructure Modeling System (CIMS) is a 3D modeling and simulation environment designed to assist users in the analysis of dependencies within individual infrastructure and also interdependencies between multiple infrastructures. Through visual cuing and textual displays, a use can evaluate the effect of system perturbation and identify the emergent patterns that evolve. These patterns include possible outage areas from a loss of power, denial of service or access, and disruption of operations. Method ofmore » Solution: CIMS allows the user to model a system, create an overlay of information, and create 3D representative images to illustrate key infrastructure elements. A geo-referenced scene, satellite, aerial images or technical drawings can be incorporated into the scene. Scenarios of events can be scripted, and the user can also interact during run time to alter system characteristics. CIMS operates as a discrete event simulation engine feeding a 3D visualization.« less

  11. Critical Infrastructure Modeling System

    SciTech Connect

    2004-10-01

    The Critical Infrastructure Modeling System (CIMS) is a 3D modeling and simulation environment designed to assist users in the analysis of dependencies within individual infrastructure and also interdependencies between multiple infrastructures. Through visual cuing and textual displays, a use can evaluate the effect of system perturbation and identify the emergent patterns that evolve. These patterns include possible outage areas from a loss of power, denial of service or access, and disruption of operations. Method of Solution: CIMS allows the user to model a system, create an overlay of information, and create 3D representative images to illustrate key infrastructure elements. A geo-referenced scene, satellite, aerial images or technical drawings can be incorporated into the scene. Scenarios of events can be scripted, and the user can also interact during run time to alter system characteristics. CIMS operates as a discrete event simulation engine feeding a 3D visualization.

  12. A Parametric Study of Accelerations of an Airplane Due to a Wake Vortex System

    NASA Technical Reports Server (NTRS)

    Stewart, Eric C.

    1999-01-01

    A study was conducted using strip theory to systematically investigate the effects of progressively more complete descriptions of the interaction of an airplane with a wake vortex system. The emphasis was in roll-dominant, parallel, vortex encounters. That is, the simulated airplane's longitudinal axis was nearly parallel to the rotation axis of the vortex system for most of the results presented. The study began with a drag-less rectangular wing in the flow field of a single vortex and progressed to a complete airplane with aerodynamic surfaces possessing taper, sweep, dihedral, and stalling and immersed in the flow field of a vortex pair in ground effect. The effects of the pitch, roll, and yaw attitudes of the airplane on the calculated accelerations were also investigated. The airplane had the nominal characteristics of a Boeing 757, and the vortex flow field had the nominal characteristics of the wake of a Boeing 767. The Bumham-Hallock model of a vortex flow field was used throughout the study. The data are presented mainly in terms of contours of equal acceleration in a two-dimensional area centered on the vortex pair and having dimensions of 300 feet by 300 feet.

  13. Flight test evaluation of a separate surface attitude command control system on a Beech 99 airplane

    NASA Technical Reports Server (NTRS)

    Gee, S. W.; Jenks, G. E.; Roskam, J.; Stone, R. L.

    1976-01-01

    A joint NASA/university/industry program was conducted to flight evaluate a potentially low cost separate surface implementation of attitude command in a Beech 99 airplane. Saturation of the separate surfaces was the primary cause of many problems during development. Six experienced professional pilots made simulated instrument flight evaluations in light-to-moderate turbulence. They were favorably impressed with the system, particularly with the elimination of control force transients that accompanied configuration changes. For ride quality, quantitative data showed that the attitude command control system resulted in all cases of airplane motion being removed from the uncomfortable ride region.

  14. 78 FR 75453 - Special Conditions: Cessna Model 750 Series Airplanes; Aircraft Electronic System Security...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-12

    ... Privacy Act Statement can be found in the Federal Register published on April 11, 2000 (65 FR 19477-19478... Airplanes; Aircraft Electronic System Security Isolation or Protection From Internal Access AGENCY: Federal... control and navigation systems, 2. Operator business and administrative support, and 3....

  15. 78 FR 11553 - Special Conditions: Embraer S.A., Model EMB-550 Airplane; Electronic Flight Control System...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-19

    ...These special conditions are issued for the Embraer S.A. Model EMB-550 airplane. This airplane will have a novel or unusual design feature(s) associated with the control surface awareness and mode annunciation of the electronic flight control system. The applicable airworthiness regulations do not contain adequate or appropriate safety standards for this design feature. These special......

  16. 76 FR 14794 - Special Conditions: Boeing Model 747-8 Airplanes, Systems and Data Networks Security-Isolation or...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-18

    ... Boeing Model 747-8 airplane was published in the Federal Register on December 9, 2010 (75 FR 76647). No... design features associated with connectivity of the passenger domain computer systems to the airplane... connected networks. The network architecture would be used for a diverse set of functions, including:...

  17. Flight testing a propulsion-controlled aircraft emergency flight control system on an F-15 airplane

    NASA Technical Reports Server (NTRS)

    Burcham, F. W., Jr.; Burken, John; Maine, Trindel A.

    1994-01-01

    Flight tests of a propulsion-controlled aircraft (PCA) system on an F-15 airplane have been conducted at the NASA Dryden Flight Research Center. The airplane was flown with all flight control surfaces locked both in the manual throttles-only mode and in an augmented system mode. In the latter mode, pilot thumbwheel commands and aircraft feedback parameters were used to position the throttles. Flight evaluation results showed that the PCA system can be used to land an airplane that has suffered a major flight control system failure safely. The PCA system was used to recover the F-15 airplane from a severe upset condition, descend, and land. Pilots from NASA, U.S. Air Force, U.S. Navy, and McDonnell Douglas Aerospace evaluated the PCA system and were favorably impressed with its capability. Manual throttles-only approaches were unsuccessful. This paper describes the PCA system operation and testing. It also presents flight test results and pilot comments.

  18. 76 FR 41041 - Special Conditions: Gulfstream Aerospace LP (GALP) Model G250 Airplane, Interaction of Systems...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-13

    ... effects on structural ] performance of this system and its failures. Discussion Active flight control... controls and are given sufficient control authority to maneuver the airplane to its structural design.... Therefore, it is necessary to determine the structural factors of safety and operating margins such that...

  19. 78 FR 65153 - Special Conditions: Learjet Model 45 Series Airplanes; Aircraft Electronic System Security...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-31

    ... Privacy Act Statement can be found in the Federal Register published on April 11, 2000 (65 FR 19477-19478... design feature associated with the architecture and connectivity capabilities of the airplanes' computer... systems architecture composed of several connected networks. The proposed architecture and...

  20. An automated airplane detection system for the safeguard against airplane illumination from the laser guide star beacons at the MMT

    NASA Astrophysics Data System (ADS)

    Snyder, Miguel; Lloyd-Hart, Michael

    2007-09-01

    Laser beams for guide star generation are a potential hazard for aircraft. At the MMT telescope located on Mt. Hopkins in Southern Arizona, a constellation of five Rayleigh guide stars is created with a total of 25 W of projected power at 532 nm wavelength. We report operational results from an automatic system deployed at the MMT that is designed to detect aircraft and shut down the lasers if a collision with the beams appears likely. The system, building on a previous prototype, uses a wide-angle CCD camera mounted with a minimally unobstructed view to the optical support structure at the top of the telescope. A computer program reads the camera once every two seconds and calculates the difference between adjacent image pairs. The anti-collision beacons required on all aircraft by the Federal Aviation Administration appear as streaks in the field. If an airplane is detected, it is located in the field relative to the laser beam and its path is projected. If aircraft are detected near or appear that they will approach the beam, the laser's safety shutter is closed and warning messages are sent to the laser operator. Failsafe operation is assured by a "heart beat" signal continuously sent from the detection system to the laser controller, and by the fact that the safety shutter must be energized to open. In the event of a power failure, the system must be manually reset by the Laser Safety Officer before the laser beam can again be propagated.

  1. Summary of design considerations for airplane spin-recovery parachute systems

    NASA Technical Reports Server (NTRS)

    Burk, S. M., Jr.

    1972-01-01

    A compilation of design considerations applicable to spin-recovery parachute systems for military airplanes has been made so that the information will be readily available to persons responsible for the design of such systems. This information was obtained from a study of available documents and from discussions with persons in both government and industry experienced in parachute technology, full-scale and model spin testing, and related systems.

  2. 78 FR 65155 - Special Conditions: Learjet Model 45 Series Airplanes; Isolation or Security Protection of the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-31

    ... be found in the Federal Register published on April 11, 2000 (65 FR 19477-19478), as well as at http... associated with connectivity of the passenger service computer systems to the airplane critical systems and... perform functions required for the safe operation of the airplane. This proposed data network and...

  3. Predicted performance benefits of an adaptive digital engine control system of an F-15 airplane

    NASA Technical Reports Server (NTRS)

    Burcham, F. W., Jr.; Myers, L. P.; Ray, R. J.

    1985-01-01

    The highly integrated digital electronic control (HIDEC) program will demonstrate and evaluate the improvements in performance and mission effectiveness that result from integrating engine-airframe control systems. Currently this is accomplished on the NASA Ames Research Center's F-15 airplane. The two control modes used to implement the systems are an integrated flightpath management mode and in integrated adaptive engine control system (ADECS) mode. The ADECS mode is a highly integrated mode in which the airplane flight conditions, the resulting inlet distortion, and the available engine stall margin are continually computed. The excess stall margin is traded for thrust. The predicted increase in engine performance due to the ADECS mode is presented in this report.

  4. Predicted performance benefits of an adaptive digital engine control system on an F-15 airplane

    NASA Technical Reports Server (NTRS)

    Burcham, F. W., Jr.; Myers, L. P.; Ray, R. J.

    1985-01-01

    The highly integrated digital electronic control (HIDEC) program will demonstrate and evaluate the improvements in performance and mission effectiveness that result from integrating engine-airframe control systems. Currently this is accomplished on the NASA Ames Research Center's F-15 airplane. The two control modes used to implement the systems are an integrated flightpath management mode and an integrated adaptive engine control system (ADECS) mode. The ADECS mode is a highly integrated mode in which the airplane flight conditions, the resulting inlet distortion, and the available engine stall margin are continually computed. The excess stall margin is traded for thrust. The predicted increase in engine performance due to the ADECS mode is presented in this report.

  5. 75 FR 10701 - Airworthiness Directives; BAE SYSTEMS (Operations) Limited Model BAe 146 Airplanes and Model Avro...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-09

    ... (Operations) Limited Model BAe 146 Airplanes and Model Avro 146-RJ Airplanes AGENCY: Federal Aviation... directive (AD) that applies to all Model BAe 146 airplanes and Model Avro 146-RJ airplanes. The original.... ADDRESSES: You may send comments by any of the following methods: Federal eRulemaking Portal: Go to...

  6. Flutter analysis of an airplane with multiple structural nonlinearities in the control system

    NASA Technical Reports Server (NTRS)

    Breitbach, E. J.

    1980-01-01

    Experience has shown that the flutter prediction process for airplanes can be greatly affected by strong concentrated nonlinearities which may be localized in the linking elements of the control mechanism, in the pivot joints of variable-sweep-wing systems, and in the connecting points between wing and pylon-mounted external stores. The principle of equivalent linearization offers an efficent possibility for solving the related nonlinear flutter equations in the frequency domain as a complement to the well-known time domain procedures. Taking as an example an airplane with nonlinear control characteristics, it is demonstrated how the equivalent linearization approach can be extended to rather complicated systems with multiple sets of strongly interacting, concentrated nonlinearities.

  7. A flight-test evaluation of a go-around control system for a twin engine powered-lift STOL airplane

    NASA Technical Reports Server (NTRS)

    Watson, D. M.; Hardy, G. H.

    1983-01-01

    An automatic go-around control system was evaluated on the Augmentor Wing Jet Short Takeoff and Landing (STOL) Research Airplane (AWJSRA) as part of a study of an automatic landing system for a powered-lift STOL airplane. The results of the evaluation indicate that the go-around control system can successfully transition the airplane to a climb configuration from any initiation point during the glide-slope track or the flare maneuver prior to touchdown.

  8. Capabilities and applications of a computer program system for dynamic loads analyses of flexible airplanes with active controls /DYLOFLEX/

    NASA Technical Reports Server (NTRS)

    Perry, B., III; Goetz, R. C.; Kroll, R. I.; Miller, R. D.

    1979-01-01

    This paper describes and illustrates the capabilities of the DYLOFLEX Computer Program System. DYLOFLEX is an integrated system of computer programs for calculating dynamic loads of flexible airplanes with active control systems. A brief discussion of the engineering formulation for each of the nine DYLOFLEX programs is described. The capabilities of the system are illustrated by the analyses of two example configurations.

  9. Preliminary Flight Results of a Fly-by-throttle Emergency Flight Control System on an F-15 Airplane

    NASA Technical Reports Server (NTRS)

    Burcham, Frank W., Jr.; Maine, Trindel A.; Fullerton, C. Gordon; Wells, Edward A.

    1993-01-01

    A multi-engine aircraft, with some or all of the flight control system inoperative, may use engine thrust for control. NASA Dryden has conducted a study of the capability and techniques for this emergency flight control method for the F-15 airplane. With an augmented control system, engine thrust, along with appropriate feedback parameters, is used to control flightpath and bank angle. Extensive simulation studies were followed by flight tests. The principles of throttles only control, the F-15 airplane, the augmented system, and the flight results including actual landings with throttles-only control are discussed.

  10. Preliminary flight test results of a fly-by-throttle emergency flight control system on an F-15 airplane

    NASA Technical Reports Server (NTRS)

    Burcham, Frank W., Jr.; Maine, Trindel A.; Fullerton, C. G.; Wells, Edward A.

    1993-01-01

    A multi-engine aircraft, with some or all of the flight control system inoperative, may use engine thrust for control. NASA Dryden has conducted a study of the capability and techniques for this emergency flight control method for the F-15 airplane. With an augmented control system, engine thrust, along with appropriate feedback parameters, is used to control flightpath and bank angle. Extensive simulation studies have been followed by flight tests. This paper discusses the principles of throttles-only control, the F-15 airplane, the augmented system, and the flight results including landing approaches with throttles-only control to within 10 ft of the ground.

  11. Development and Flight Test of an Emergency Flight Control System Using Only Engine Thrust on an MD-11 Transport Airplane

    NASA Technical Reports Server (NTRS)

    Burcham, Frank W., Jr.; Burken, John J.; Maine, Trindel A.; Fullerton, C. Gordon

    1997-01-01

    An emergency flight control system that uses only engine thrust, called the propulsion-controlled aircraft (PCA) system, was developed and flight tested on an MD-11 airplane. The PCA system is a thrust-only control system, which augments pilot flightpath and track commands with aircraft feedback parameters to control engine thrust. The PCA system was implemented on the MD-11 airplane using only software modifications to existing computers. Results of a 25-hr flight test show that the PCA system can be used to fly to an airport and safely land a transport airplane with an inoperative flight control system. In up-and-away operation, the PCA system served as an acceptable autopilot capable of extended flight over a range of speeds, altitudes, and configurations. PCA approaches, go-arounds, and three landings without the use of any normal flight controls were demonstrated, including ILS-coupled hands-off landings. PCA operation was used to recover from an upset condition. The PCA system was also tested at altitude with all three hydraulic systems turned off. This paper reviews the principles of throttles-only flight control, a history of accidents or incidents in which some or all flight controls were lost, the MD-11 airplane and its systems, PCA system development, operation, flight testing, and pilot comments.

  12. Development and Flight Test of an Augmented Thrust-Only Flight Control System on an MD-11 Transport Airplane

    NASA Technical Reports Server (NTRS)

    Burcham, Frank W., Jr.; Maine, Trindel A.; Burken, John J.; Pappas, Drew

    1996-01-01

    An emergency flight control system using only engine thrust, called Propulsion-Controlled Aircraft (PCA), has been developed and flight tested on an MD-11 airplane. In this thrust-only control system, pilot flight path and track commands and aircraft feedback parameters are used to control the throttles. The PCA system was installed on the MD-11 airplane using software modifications to existing computers. Flight test results show that the PCA system can be used to fly to an airport and safely land a transport airplane with an inoperative flight control system. In up-and-away operation, the PCA system served as an acceptable autopilot capable of extended flight over a range of speeds and altitudes. The PCA approaches, go-arounds, and three landings without the use of any non-nal flight controls have been demonstrated, including instrument landing system-coupled hands-off landings. The PCA operation was used to recover from an upset condition. In addition, PCA was tested at altitude with all three hydraulic systems turned off. This paper reviews the principles of throttles-only flight control; describes the MD-11 airplane and systems; and discusses PCA system development, operation, flight testing, and pilot comments.

  13. The shock-absorbed system of the airplane landing gear

    NASA Technical Reports Server (NTRS)

    Callerio, Pietro

    1940-01-01

    A discussion is given of the behavior of the shock-absorbing system, consisting of elastic struts and tires, under landing, take-off, and taxying conditions, and a general formula derived for obtaining the minimum stroke required to satisfy the conditions imposed on the landing gear. Finally, the operation of some typical shock-absorbing systems are examined and the necessity brought out for taking into account, in dynamic landing-gear tests, the effect of the wing lift at the instant of contact with the ground.

  14. 78 FR 58960 - Airworthiness Directives; BAE SYSTEMS (OPERATIONS) LIMITED Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-25

    ... Policies and Procedures (44 FR 11034, February 26, 1979); 3. Will not affect intrastate aviation in Alaska... inspection of certain engine and auxiliary power unit (APU) fire extinguishers to determine if the fire... system to extinguish fires in the engine or APU fire zones, possibly resulting in damage to the...

  15. An analytical study and wind tunnel tests of an aeromechanical gust-alleviation system for a light airplane

    NASA Technical Reports Server (NTRS)

    Stewart, E. C.

    1976-01-01

    The results of an analytical study of a system using stability derivatives determined in static wind tunnel tests of a 1/6 scale model of a popular, high wing, light airplane equipped with the gust alleviation system are reported. The longitudinal short period mode dynamics of the system are analyzed, and include the following: (1) root loci, (2) airplane frequency responses to vertical gusts, (3) power spectra of the airplane responses in a gust spectrum, (4) time history responses to vertical gusts, and (5) handling characteristics. The system reduces the airplane's normal acceleration response to vertical gusts while simultaneously increasing the pitching response and reducing the damping of the longitudinal short period mode. The normal acceleration response can be minimized by using the proper amount of static alleviation and a fast response system with a moderate amount of damping. The addition of a flap elevator interconnect or a pitch damper system further increases the alleviation while moderating the simultaneous increase in pitching response. The system provides direct lift control and may reduce the stick fixed longitudinal static stability.

  16. Design of a Mars Airplane Propulsion System for the Aerial Regional-Scale Environmental Survey (ARES) Mission Concept

    NASA Technical Reports Server (NTRS)

    Kuhl. Christopher A.

    2009-01-01

    The Aerial Regional-Scale Environmental Survey (ARES) is a Mars exploration mission concept with the goal of taking scientific measurements of the atmosphere, surface, and subsurface of Mars by using an airplane as the payload platform. ARES team first conducted a Phase-A study for a 2007 launch opportunity, which was completed in May 2003. Following this study, significant efforts were undertaken to reduce the risk of the atmospheric flight system, under the NASA Langley Planetary Airplane Risk Reduction Project. The concept was then proposed to the Mars Scout program in 2006 for a 2011 launch opportunity. This paper summarizes the design and development of the ARES airplane propulsion subsystem beginning with the inception of the ARES project in 2002 through the submittal of the Mars Scout proposal in July 2006.

  17. Self-Organized Criticality Systems

    NASA Astrophysics Data System (ADS)

    Aschwanden, M. J.

    2013-07-01

    Contents: (1) Introduction - Norma B. Crosby --- (2) Theoretical Models of SOC Systems - Markus J. Aschwanden --- (3) SOC and Fractal Geometry - R. T. James McAteer --- (4) Percolation Models of Self-Organized Critical Phenomena - Alexander V. Milovanov --- (5) Criticality and Self-Organization in Branching Processes: Application to Natural Hazards - Álvaro Corral, Francesc Font-Clos --- (6) Power Laws of Recurrence Networks - Yong Zou, Jobst Heitzig, Jürgen Kurths --- (7) SOC computer simolations - Gunnar Pruessner --- (8) SOC Laboratory Experiments - Gunnar Pruessner --- (9) Self-Organizing Complex Earthquakes: Scaling in Data, Models, and Forecasting - Michael K. Sachs et al. --- (10) Wildfires and the Forest-Fire Model - Stefan Hergarten --- (11) SOC in Landslides - Stefan Hergarten --- (12) SOC and Solar Flares - Paul Charbonneau --- (13) SOC Systems in Astrophysics - Markus J. Aschwanden ---

  18. General airplane performance

    NASA Technical Reports Server (NTRS)

    Rockfeller, W C

    1939-01-01

    Equations have been developed for the analysis of the performance of the ideal airplane, leading to an approximate physical interpretation of the performance problem. The basic sea-level airplane parameters have been generalized to altitude parameters and a new parameter has been introduced and physically interpreted. The performance analysis for actual airplanes has been obtained in terms of the equivalent ideal airplane in order that the charts developed for use in practical calculations will for the most part apply to any type of engine-propeller combination and system of control, the only additional material required consisting of the actual engine and propeller curves for propulsion unit. Finally, a more exact method for the calculation of the climb characteristics for the constant-speed controllable propeller is presented in the appendix.

  19. 78 FR 76980 - Special Conditions: Airbus, A350-900 Series Airplane; Interaction of Systems and Structures

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-20

    ... Privacy Act Statement can be found in the Federal Register published on April 11, 2000 (65 FR 19477-19478... structural performance. The applicable airworthiness regulations do not contain adequate or appropriate... features: Systems that affect the airplane's structural performance, either directly or as a result...

  20. 77 FR 70941 - Special Conditions: Embraer S.A., Model EMB-550 Airplane; Interaction of Systems and Structures

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-28

    ... the Federal Register published on April 11, 2000 (65 FR 19477-19478), as well as at http://DocketsInfo..., affect its structural performance. Current regulations do not take into account loads for the airplane due to the effects of systems on structural performance including normal operation and...

  1. 78 FR 11556 - Special Conditions: Embraer S.A., Model EMB-550 Airplane; Interaction of Systems and Structures

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-19

    ... was published in the Federal Register on November 28, 2012, (77 FR 70941). No comments were received..., affect its structural performance. Current regulations do not take into account loads for the airplane due to the effects of systems on structural performance including normal operation and...

  2. Simulator evaluation of a flight-path-angle control system for a transport airplane with direct lift control

    NASA Technical Reports Server (NTRS)

    Kelley, W. W.

    1978-01-01

    A piloted simulator was used to evaluate the flight path angle control capabilities of a system that employs spoiler direct lift control. The system was designated the velocity vector control system and was compared with a baseline flight path angle control system which used elevator for control. The simulated airplane was a medium jet transport. Research pilots flew a manual instrument landing system glide slope tracking task and a variable flight path angle task in the landing configuration to obtain comparative performance data.

  3. Development and Flight Evaluation of an Emergency Digital Flight Control System Using Only Engine Thrust on an F-15 Airplane

    NASA Technical Reports Server (NTRS)

    Burcham, Frank W., Jr.; Maine, Trindel A.; Fullerton, C. Gordon; Webb, Lannie Dean

    1996-01-01

    A propulsion-controlled aircraft (PCA) system for emergency flight control of aircraft with no flight controls was developed and flight tested on an F-15 aircraft at the NASA Dryden Flight Research Center. The airplane has been flown in a throttles-only manual mode and with an augmented system called PCA in which pilot thumbwheel commands and aircraft feedback parameters were used to drive the throttles. Results from a 36-flight evaluation showed that the PCA system can be used to safety land an airplane that has suffered a major flight control system failure. The PCA system was used to recover from a severe upset condition, descend, and land. Guest pilots have also evaluated the PCA system. This paper describes the principles of throttles-only flight control; a history of loss-of-control accidents; a description of the F-15 aircraft; the PCA system operation, simulation, and flight testing; and the pilot comments.

  4. 76 FR 53348 - Airworthiness Directives; BAE SYSTEMS (Operations) Limited Model BAe 146 Airplanes and Model Avro...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-26

    ... (Operations) Limited Model BAe 146 Airplanes and Model Avro 146-RJ Airplanes AGENCY: Federal Aviation... send comments by any of the following methods: Federal eRulemaking Portal: Go to http://www.regulations... proposed AD. Discussion On May 3, 2010, we issued AD 2010-10-22, Amendment 39-16301 (75 FR 28463, May...

  5. 76 FR 2281 - Airworthiness Directives; BAE SYSTEMS (OPERATIONS) LIMITED Model BAe 146 Airplanes, and Model...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-13

    ... (OPERATIONS) LIMITED Model BAe 146 Airplanes, and Model Avro 146-RJ Airplanes AGENCY: Federal Aviation... comments by any of the following methods: Federal eRulemaking Portal: Go to http://www.regulations.gov... this proposed AD. Discussion On June 14, 2005, we issued AD 2005-13-19, Amendment 39-14156 (70 FR...

  6. The Scale Effect in Towing Tests with Airplane-float Systems

    NASA Technical Reports Server (NTRS)

    Schmidt, Rudolph

    1937-01-01

    The present report includes a description of the making of three-component measurements on a full-size float mounted on an actual airplane and the comparison of the results with those from two models of the same form but of different size which had been tested in the towing tank. The purpose of the comparison is to determine the effect of the Reynolds Number on the results of model tank tests. Following a brief discussion of previous tests intended to elucidate the problem of scale effect on float systems and a description of the testing equipment, the choice of the reference quantities to be used in the comparison is discussed. The selection of load, speed, and trim as a basis of comparison seems best suited to the practical operation of making this comparison. The quantities affected by scale are then: resistance, trimming moment, and their derivatives; planing number (resistance/weight on water); and position of center of pressure.

  7. Flight and analytical investigations of a structural mode excitation system on the YF-12A airplane

    NASA Technical Reports Server (NTRS)

    Goforth, E. A.; Murphy, R. C.; Beranek, J. A.; Davis, R. A.

    1987-01-01

    A structural excitation system, using an oscillating canard vane to generate force, was mounted on the forebody of the YF-12A airplane. The canard vane was used to excite the airframe structural modes during flight in the subsonic, transonic, and supersonic regimes. Structural modal responses generated by the canard vane forces were measured at the flight test conditions by airframe-mounted accelerometers. Correlations of analytical and experimental aeroelastic results were made. Doublet lattice, steady state double lattice with uniform lag, Mach box, and piston theory all produced acceptable analytical aerodynamic results within the restrictions that apply to each. In general, the aerodynamic theory methods, carefully applied, were found to predict the dynamic behavior of the YF-12A aircraft adequately.

  8. Hydrothermal mineralising systems as critical systems

    NASA Astrophysics Data System (ADS)

    Hobbs, Bruce

    2015-04-01

    Hydrothermal mineralising systems as critical systems. Bruce E Hobbs1,2, Alison Ord1 and Mark A. Munro1. 1. Centre for Exploration Targeting, The University of Western Australia, M006, 35 Stirling Highway, Crawley, WA 6009, Australia. 2. CSIRO Earth and Resource Engineering, Bentley, WA, Australia Hydrothermal mineralising systems are presented as large, open chemical reactors held far from equilibrium during their life-time by the influx of heat, fluid and dissolved chemical species. As such they are nonlinear dynamical systems and need to be analysed using the tools that have been developed for such systems. Hydrothermal systems undergo a number of transitions during their evolution and this paper focuses on methods for characterising these transitions in a quantitative manner and establishing whether they resemble first or second (critical) phase transitions or whether they have some other kind of nature. Critical phase transitions are characterised by long range correlations for some parameter characteristic of the system, power-law probability distributions so that there is no characteristic length scale and a high sensitivity to perturbations; as one approaches criticality, characteristic parameters for the system scale in a power law manner with distance from the critical point. The transitions undergone in mineralised hydrothermal systems are: (i) widespread, non-localised mineral alteration involving exothermic mineral reactions that produce hydrous silicate phases, carbonates and iron-oxides, (ii) strongly localised veining, brecciation and/or stock-work formation, (iii) a series of endothermic mineral reactions involving the formation of non-hydrous silicates, sulphides and metals such as gold, (iv) multiple repetitions of transitions (ii) and (iii). We have quantified aspects of these transitions in gold deposits from the Yilgarn craton of Western Australia using wavelet transforms. This technique is convenient and fast. It enables one to establish if

  9. Design of a Mars Airplane Propulsion System for the Aerial Regional-Scale Environmental Survey (ARES) Mission Concept

    NASA Technical Reports Server (NTRS)

    Kuhl, Christopher A.

    2008-01-01

    The Aerial Regional-Scale Environmental Survey (ARES) is a Mars exploration mission concept that utilizes a rocket propelled airplane to take scientific measurements of atmospheric, surface, and subsurface phenomena. The liquid rocket propulsion system design has matured through several design cycles and trade studies since the inception of the ARES concept in 2002. This paper describes the process of selecting a bipropellant system over other propulsion system options, and provides details on the rocket system design, thrusters, propellant tank and PMD design, propellant isolation, and flow control hardware. The paper also summarizes computer model results of thruster plume interactions and simulated flight performance. The airplane has a 6.25 m wingspan with a total wet mass of 185 kg and has to ability to fly over 600 km through the atmosphere of Mars with 45 kg of MMH / MON3 propellant.

  10. Description of an experimental (hydrogen peroxide) rocket system and its use in measuring aileron and rudder effectiveness of a light airplane

    NASA Technical Reports Server (NTRS)

    Obryan, T. C.; Goode, M. W.; Gregory, F. D.; Mayo, M. H.

    1980-01-01

    A hydrogen peroxide fueled rocket system, which is to be used as a research tool in flight studies of stall and spin maneuvers, was installed on a light, four place general aviation airplane. The pilot controlled rocket system produces moments about either the roll or the yaw body axis to augment or oppose the aerodynamic forces and inertial moments acting on the airplane during various flight maneuvers, including the spin. These controlled moments of a known magnitude can be used in various ways to help analyze and interpret the importance of the various factors which influence airplane maneuvers. The rocket system and its installation in the airplane are described, and the results of flight rests used to measure rudder and aileron effectiveness at airspeeds above the stall are presented. These tests also serve to demonstrate the operational readiness of the rocket system for future research operations.

  11. Piloted simulator study of allowable time delay in pitch flight control system of a transport airplane with negative static stability

    NASA Technical Reports Server (NTRS)

    Grantham, William D.; Smith, Paul M.; Person, Lee H., Jr.; Meyer, Robert T.; Tingas, Stephen A.

    1987-01-01

    A piloted simulation study was conducted to determine the permissible time delay in the flight control system of a 10-percent statically unstable transport airplane during cruise flight conditions. The math model used for the simulation was a derivative Lockheed L-1011 wide-body jet transport. Data were collected and analyzed from a total of 137 cruising flights in both calm- and turbulent-air conditions. Results of this piloted simulation study verify previous findings that show present military specifications for allowable control-system time delay may be too stringent when applied to transport-size airplanes. Also, the degree of handling-qualities degradation due to time delay is shown to be strongly dependent on the source of the time delay in an advanced flight control system. Maximum allowable time delay for each source of time delay in the control system, in addition to a less stringent overall maximum level of time delay, should be considered for large aircraft. Preliminary results also suggest that adverse effects of control-system time delay may be at least partially offset by variations in control gearing. It is recommended that the data base include different airplane baselines, control systems, and piloting tasks with many pilots participating, so that a reasonable set of limits for control-system time delay can be established to replace the military specification limits currently being used.

  12. An improved criticality alarm system

    SciTech Connect

    Tyree, W.H.; Gilpin, H.E.; Balmer, D.K.; Vennitti, D.A.

    1991-12-31

    The Rocky Flats Plant near Golden, Colorado is the primary facility for the production of plutonium components used in the US arsenal of nuclear weapons. It is operated by EG&G under contract to the US Department of Energy (DOE). There are ten production buildings on plant site with neutron based criticality alarm systems. These systems have been in operation for the past seventeen years. Changes in the interpretation of A.N.S.I. standards and DOE orders have precipitated an evaluation of detector sensitivity and placement criteria. As a result of this evaluation, improvements in detector design and calibration have improved detector sensitivity by a factor of six. Testing performed on the design defined a minimum sensitivity as required by A.N.S.I. 8.3 and provided information for saturation and survivability for a fission event of up to 1 {times} 10{sup 17} fissions in 80 microseconds. A rigorous testing and calibration program has been developed and is in place. Neutron sensitivity is certified at a nearby reactor which is traceable to N.I.S.T.. 4 refs.

  13. Some effects of adverse weather conditions on performance of airplane antiskid braking systems

    NASA Technical Reports Server (NTRS)

    Horne, W. B.; Mccarty, J. L.; Tanner, J. A.

    1976-01-01

    The performance of current antiskid braking systems operating under adverse weather conditions was analyzed in an effort to both identify the causes of locked-wheel skids which sometimes occur when the runway is slippery and to find possible solutions to this operational problem. This analysis was made possible by the quantitative test data provided by recently completed landing research programs using fully instrumented flight test airplanes and was further supported by tests performed at the Langley aircraft landing loads and traction facility. The antiskid system logic for brake control and for both touchdown and locked-wheel protection is described and its response behavior in adverse weather is discussed in detail with the aid of available data. The analysis indicates that the operational performance of the antiskid logic circuits is highly dependent upon wheel spin-up acceleration and can be adversely affected by certain pilot braking inputs when accelerations are low. Normal antiskid performance is assured if the tire-to-runway traction is sufficient to provide high wheel spin-up accelerations or if the system is provided a continuous, accurate ground speed reference. The design of antiskid systems is complicated by the necessity for tradeoffs between tire braking and cornering capabilities, both of which are necessary to provide safe operations in the presence of cross winds, particularly under slippery runway conditions.

  14. Flight test of a propulsion controlled aircraft system on the NASA F-15 airplane

    NASA Technical Reports Server (NTRS)

    Burcham, Frank W., Jr.; Maine, Trindel A.

    1995-01-01

    Flight tests of the propulsion controlled aircraft (PCA) system on the NASA F-15 airplane evolved as a result of a long series of simulation and flight tests. Initially, the simulation results were very optimistic. Early flight tests showed that manual throttles-only control was much more difficult than the simulation, and a flight investigation was flown to acquire data to resolve this discrepancy. The PCA system designed and developed by MDA evolved as these discrepancies were found and resolved, requiring redesign of the PCA software and modification of the flight test plan. Small throttle step inputs were flown to provide data for analysis, simulation update, and control logic modification. The PCA flight tests quickly revealed less than desired performance, but the extensive flexibility built into the flight PCA software allowed rapid evaluation of alternate gains, filters, and control logic, and within 2 weeks, the PCA system was functioning well. The initial objective of achieving adequate control for up-and-away flying and approaches was satisfied, and the option to continue to actual landings was achieved. After the PCA landings were accomplished, other PCA features were added, and additional maneuvers beyond those originally planned were flown. The PCA system was used to recover from extreme upset conditions, descend, and make approaches to landing. A heading mode was added, and a single engine plus rudder PCA mode was also added and flown. The PCA flight envelope was expanded far beyond that originally designed for. Guest pilots from the USAF, USN, NASA, and the contractor also flew the PCA system and were favorably impressed.

  15. Critical areas: Satellite power systems concepts

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Critical Areas are defined and discussed in the various areas pertinent to satellite power systems. The presentation is grouped into five areas (General, Space Systems, Solar Energy Conversion, Microwave Systems, and Environment/Ecology) with a sixth area (Power Relay) considered separately in an appendix. Areas for Future Consideration as critical areas are discussed in a second appendix.

  16. Annoyance caused by propeller airplane flyover noise

    NASA Technical Reports Server (NTRS)

    Mccurdy, D. A.; Powell, C. A.

    1984-01-01

    Laboratory experiments were conducted to provide information on quantifying the annoyance response of people to propeller airplane noise. The items of interest were current noise metrics, tone corrections, duration corrections, critical band corrections, and the effects of engine type, operation type, maximum takeoff weight, blade passage frequency, and blade tip speed. In each experiment, 64 subjects judged the annoyance of recordings of propeller and jet airplane operations presented at d-weighted sound pressure levels of 70, 80, and 90 dB in a testing room which simulates the outdoor acoustic environment. The first experiment examined 11 propeller airplanes with maximum takeoff weights greater than or equal to 5700 kg. The second experiment examined 14 propeller airplanes weighting 5700 kg or less. Five jet airplanes were included in each experiment. For both the heavy and light propeller airplanes, perceived noise level and perceived level (Stevens Mark VII procedure) predicted annoyance better than other current noise metrics.

  17. 76 FR 64788 - Airworthiness Directives; BAE SYSTEMS (Operations) Limited Model 4101 Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-19

    ... (Operations) Limited Model 4101 Airplanes AGENCY: Federal Aviation Administration (FAA), Department of... by reference of certain other publications listed in this AD as of June 11, 2009 (74 FR 21246, May 7... April 8, 2011 (76 FR 19716), and proposed to supersede AD 2009-10-02, Amendment 39-15897 (74 FR...

  18. 78 FR 75451 - Special Conditions: Cessna Model 750 Series Airplanes; Aircraft Electronic System Security...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-12

    ... be found in the Federal Register published on April 11, 2000 (65 FR 19477-19478), as well as at http... design feature associated with the architecture and connectivity capabilities of the airplanes' computer...; facsimile 425-227-1149. SUPPLEMENTARY INFORMATION: The proposed network architecture includes the...

  19. Flight-test of the glide-slope track and flare-control laws for an automatic landing system for a powered-lift STOL airplane

    NASA Technical Reports Server (NTRS)

    Watson, D. M.; Hardy, G. H.; Warner, D. N., Jr.

    1983-01-01

    An automatic landing system was developed for the Augmentor Wing Jet STOL Research Airplane to establish the feasibility and examine the operating characteristics of a powered-lift STOL transport flying a steep, microwave landing system (MLS) glide slope to automatically land on a STOL port. The flight test results address the longitudinal aspects of automatic powered lift STOL airplane operation including glide slope tracking on the backside of the power curve, flare, and touchdown. Three different autoland control laws were evaluated to demonstrate the tradeoff between control complexity and the resulting performance. The flight test and simulation methodology used in developing conventional jet transport systems was applied to the powered-lift STOL airplane. The results obtained suggest that an automatic landing system for a powered-lift STOL airplane operating into an MLS-equipped STOL port is feasible. However, the airplane must be provided with a means of rapidly regulation lift to satisfactorily provide the glide slope tracking and control of touchdown sink rate needed for automatic landings.

  20. Piloted simulation study of the effects of an automated trim system on flight characteristics of a light twin-engine airplane with one engine inoperative

    NASA Technical Reports Server (NTRS)

    Stewart, E. C.; Brown, P. W.; Yenni, K. R.

    1986-01-01

    A simulation study was conducted to investigate the piloting problems associated with failure of an engine on a generic light twin-engine airplane. A primary piloting problem for a light twin-engine airplane after an engine failure is maintaining precise control of the airplane in the presence of large steady control forces. To address this problem, a simulated automatic trim system which drives the trim tabs as an open-loop function of propeller slipstream measurements was developed. The simulated automatic trim system was found to greatly increase the controllability in asymmetric powered flight without having to resort to complex control laws or an irreversible control system. However, the trim-tab control rates needed to produce the dramatic increase in controllability may require special design consideration for automatic trim system failures. Limited measurements obtained in full-scale flight tests confirmed the fundamental validity of the proposed control law.

  1. Flight evaluations of the effect of advanced control systems and displays on the handling qualities of a general aviation airplane.

    NASA Technical Reports Server (NTRS)

    Loschke, P. C.; Barber, M. R.; Jarvis, C. R.; Enevoldson, E. K.

    1972-01-01

    Flight tests have shown that, by means of improved displays and advanced control systems, it is possible to transform a typical light airplane into a flying machine that borders on being perfect from a handling-qualities standpoint. A flight-director display and an attitude-command control system used in combination transformed a vehicle with poor handling qualities during ILS approaches in turbulent air into a vehicle with extremely good handling qualities. The attitude-command control system also improved the ride qualities of the airplane. A rate-command control system was less beneficial than an attitude-command control system. Although this paper deals primarily with general aviation aircraft, the results presented pertain to other types of aircraft. Short-takeoff-and-landing (STOL) aircraft would be a natural application of the control systems because, as a result of their low speeds, they encounter many of the handling-qualities problems noted on light aircraft. The improved ride qualities should be of interest to all airline operations, and for STOL aircraft in particular, because of their prolonged exposure to low-altitude turbulence.

  2. Critical infrastructure systems of systems assessment methodology.

    SciTech Connect

    Sholander, Peter E.; Darby, John L.; Phelan, James M.; Smith, Bryan; Wyss, Gregory Dane; Walter, Andrew; Varnado, G. Bruce; Depoy, Jennifer Mae

    2006-10-01

    Assessing the risk of malevolent attacks against large-scale critical infrastructures requires modifications to existing methodologies that separately consider physical security and cyber security. This research has developed a risk assessment methodology that explicitly accounts for both physical and cyber security, while preserving the traditional security paradigm of detect, delay, and respond. This methodology also accounts for the condition that a facility may be able to recover from or mitigate the impact of a successful attack before serious consequences occur. The methodology uses evidence-based techniques (which are a generalization of probability theory) to evaluate the security posture of the cyber protection systems. Cyber threats are compared against cyber security posture using a category-based approach nested within a path-based analysis to determine the most vulnerable cyber attack path. The methodology summarizes the impact of a blended cyber/physical adversary attack in a conditional risk estimate where the consequence term is scaled by a ''willingness to pay'' avoidance approach.

  3. NCIS - a Nuclear Criticality Information System (overview)

    SciTech Connect

    Koponen, B.L.; Hampel, V.E.

    1983-07-01

    A Nuclear Criticality Information System (NCIS) is being established at the Lawrence Livermore National Laboratory (LLNL) in order to serve personnel responsible for safe storage, transport, and handling of fissile materials and those concerned with the evaluation and analysis of nuclear, critical experiments. Public concern for nuclear safety provides the incentive for improved access to nuclear safety information.

  4. 77 FR 38467 - Special Conditions: Gulfstream Aerospace LP (GALP), Model Gulfstream G280 Airplane; Isolation or...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-28

    ... the Federal Register published on April 11, 2000 (65 FR 19477-19478), as well as at http://DocketsInfo... connectivity of the passenger service computer systems to the airplane critical systems and data networks. The.... The proposed architecture and network configuration may be used for, or interfaced with, a diverse...

  5. Bifurcation of critical periods of polynomial systems

    NASA Astrophysics Data System (ADS)

    Ferčec, Brigita; Levandovskyy, Viktor; Romanovski, Valery G.; Shafer, Douglas S.

    2015-10-01

    We describe a general approach to studying bifurcations of critical periods based on a complexification of the system and algorithms of computational algebra. Using this approach we obtain upper bounds on the number of critical periods of several families of cubic systems. In some cases we overcome the problem of nonradicality of a relevant ideal by moving it to a subalgebra generated by invariants of a group of linear transformations.

  6. Critical Mineralising Plumbing Systems - Analysis Using Wavelets

    NASA Astrophysics Data System (ADS)

    Ord, Alison; Hobbs, Bruce

    2013-04-01

    Crustal plumbing systems consist of an interconnected set of fractures. Recently, fracture systems have been viewed as examples of critical systems (Perez-Reche et al., 2008). Various styles of critical systems can be distinguished. The classical form of critical behaviour occurs when some tuning parameter (such as elastic modulus or stress) reaches a critical value that initiates fracture. This is expressed as a single catastrophic event which is repeated as the system reloads. Another extreme in behaviour is self-organised criticality (SOC) where the system fails through the development of small avalanches of fractures with continuous forcing. Perez-Reche et al. (2008) discuss systems that can evolve from classical criticality to self-organised criticality or to other regimes. Each regime is characterised spatially by a range in the fractal dimension, D. Massive catastrophic behaviour (called SNAP), in two dimensions, is characterised by1 ˜ D ˜ 1.5. SOC has D ? 1.5whereas distributed small avalanches (called POP) are characterised by1.5 ˜ D ˜ 2. The aim is to distinguish SNAP terrains from POP terrains which seem highly probable mineralising plumbing systems based on previous modelling (Miller and Nur, 2000) and work by Sibson (1992), Cox (1999) and Cox et al. (2001) that portrays the evolution of the plumbing system as a swarm of seismic aftershocks; this constitutes a typical POP regime. We explore whether or not the plumbing systems for hydrothermal systems have fractal dimensions in the POP-range for critical systems, and whether or not there is more diagnostic information to be obtained from the multi-fractal spectrum. The hypothesis is that fracture systems analysed using wavelets define multifractal patterns which are diagnostic of hydrothermal systems. References Cox SF. Deformational controls on the dynamics of fluid flow in mesothermal gold systems. In: McCaffrey K, Lonergan L, Wilkinson J, editors. Fractures, Fluid Flow and Mineralization

  7. Stress Analysis of B-52B and B-52H Air-Launching Systems Failure-Critical Structural Components

    NASA Technical Reports Server (NTRS)

    Ko, William L.

    2005-01-01

    The operational life analysis of any airborne failure-critical structural component requires the stress-load equation, which relates the applied load to the maximum tangential tensile stress at the critical stress point. The failure-critical structural components identified are the B-52B Pegasus pylon adapter shackles, B-52B Pegasus pylon hooks, B-52H airplane pylon hooks, B-52H airplane front fittings, B-52H airplane rear pylon fitting, and the B-52H airplane pylon lower sway brace. Finite-element stress analysis was performed on the said structural components, and the critical stress point was located and the stress-load equation was established for each failure-critical structural component. The ultimate load, yield load, and proof load needed for operational life analysis were established for each failure-critical structural component.

  8. The Nuclear Criticality Information System: An update

    SciTech Connect

    Koponen, B.L.

    1991-07-01

    The US Department of Energy`s Nuclear Criticality Information System (NCIS) has served the criticality community for the past ten years with publications and with an online information system. NCIS provides a mean for widely distributed nuclear criticality specialists to communicate and work together instantly. Users of the system may receive assistance from all members of the NCIS community, which provides a much broader base of support than is available at any single site. When unified by NCIS, these diverse specialists provide a resource that has proven to be very useful in the safe handling of fissile material. NCIS also is a source of current nuclear criticality safety information; the rapid access of such up-to-date information on the handling of fissile materials outside of nuclear reactors is international in scope, extending beyond political and geographical boundaries.

  9. The Nuclear Criticality Information System: An update

    SciTech Connect

    Koponen, B.L.

    1991-07-01

    The US Department of Energy's Nuclear Criticality Information System (NCIS) has served the criticality community for the past ten years with publications and with an online information system. NCIS provides a mean for widely distributed nuclear criticality specialists to communicate and work together instantly. Users of the system may receive assistance from all members of the NCIS community, which provides a much broader base of support than is available at any single site. When unified by NCIS, these diverse specialists provide a resource that has proven to be very useful in the safe handling of fissile material. NCIS also is a source of current nuclear criticality safety information; the rapid access of such up-to-date information on the handling of fissile materials outside of nuclear reactors is international in scope, extending beyond political and geographical boundaries.

  10. Conceptual Design for a Dual-Bell Rocket Nozzle System Using a NASA F-15 Airplane as the Flight Testbed

    NASA Technical Reports Server (NTRS)

    Jones, Daniel S.; Ruf, Joseph H.; Bui, Trong T.; Martinez, Martel; St. John, Clinton W.

    2014-01-01

    The dual-bell rocket nozzle was first proposed in 1949, offering a potential improvement in rocket nozzle performance over the conventional-bell nozzle. Despite the performance advantages that have been predicted, both analytically and through static test data, the dual-bell nozzle has still not been adequately tested in a relevant flight environment. In 2013 a proposal was constructed that offered a NASA F-15 airplane as the flight testbed, with the plan to operate a dual-bell rocket nozzle during captive-carried flight. If implemented, this capability will permit nozzle operation into an external flow field similar to that of a launch vehicle, and facilitate an improved understanding of dual-bell nozzle plume sensitivity to external flow-field effects. More importantly, this flight testbed can be utilized to help quantify the performance benefit with the dual-bell nozzle, as well as to advance its technology readiness level. This presentation provides highlights of a technical paper that outlines this ultimate goal, including plans for future flights to quantify the external flow field of the airplane near the nozzle experiment, as well as details on the conceptual design for the dual-bell nozzle cold-flow propellant feed system integration within the NASA F-15 Propulsion Flight Test Fixture. The current study shows that this concept of flight research is feasible, and could result in valuable flight data for the dual-bell nozzle.

  11. Conceptual Design for a Dual-Bell Rocket Nozzle System Using a NASA F-15 Airplane as the Flight Testbed

    NASA Technical Reports Server (NTRS)

    Jones, Daniel S.; Ruf, Joseph H.; Bui, Trong T.; Martinez, Martel; St. John, Clinton W.

    2014-01-01

    The dual-bell rocket nozzle was first proposed in 1949, offering a potential improvement in rocket nozzle performance over the conventional-bell nozzle. Despite the performance advantages that have been predicted, both analytically and through static test data, the dual-bell nozzle has still not been adequately tested in a relevant flight environment. In 2013 a proposal was constructed that offered a NASA F-15 airplane as the flight testbed, with the plan to operate a dual-bell rocket nozzle during captive-carried flight. If implemented, this capability will permit nozzle operation into an external flow field similar to that of a launch vehicle, and facilitate an improved understanding of dual-bell nozzle plume sensitivity to external flow-field effects. More importantly, this flight testbed can be utilized to help quantify the performance benefit with the dual-bell nozzle, as well as to advance its technology readiness level. Toward this ultimate goal, this paper provides plans for future flights to quantify the external flow field of the airplane near the nozzle experiment, as well as details on the conceptual design for the dual-bell nozzle cold-flow propellant feed system integration within the NASA F-15 Propulsion Flight Test Fixture. The current study shows that this concept of flight research is feasible, and could result in valuable flight data for the dual-bell nozzle.

  12. Conceptual Design for a Dual-Bell Rocket Nozzle System Using a NASA F-15 Airplane as the Flight Testbed

    NASA Technical Reports Server (NTRS)

    Jones, Daniel S.; Ruf, Joseph H.; Bui, Trong T.; Martinez, Martel; St. John, Clinton W.

    2014-01-01

    The dual-bell rocket nozzle was first proposed in 1949, offering a potential improvement in rocket nozzle performance over the conventional-bell nozzle. Despite the performance advantages that have been predicted, both analytically and through static test data, the dual-bell nozzle has still not been adequately tested in a relevant flight environment. In 2013 a proposal was constructed that offered a National Aeronautics and Space Administration (NASA) F-15 airplane as the flight testbed, with the plan to operate a dual-bell rocket nozzle during captive-carried flight. If implemented, this capability will permit nozzle operation into an external flow field similar to that of a launch vehicle, and facilitate an improved understanding of dual-bell nozzle plume sensitivity to external flow-field effects. More importantly, this flight testbed can be utilized to help quantify the performance benefit with the dual-bell nozzle, as well as to advance its technology readiness level. Toward this ultimate goal, this report provides plans for future flights to quantify the external flow field of the airplane near the nozzle experiment, as well as details on the conceptual design for the dual-bell nozzle cold-flow propellant feed system integration within the NASA F-15 Propulsion Flight Test Fixture. The current study shows that this concept of flight research is feasible, and could result in valuable flight data for the dual-bell nozzle.

  13. Flight Calibration of four airspeed systems on a swept-wing airplane at Mach numbers up to 1.04 by the NACA radar-phototheodolite method

    NASA Technical Reports Server (NTRS)

    Thompson, Jim Rogers; Bray, Richard S; COOPER GEORGE E

    1950-01-01

    The calibrations of four airspeed systems installed in a North American F-86A airplane have been determined in flight at Mach numbers up to 1.04 by the NACA radar-phototheodolite method. The variation of the static-pressure error per unit indicated impact pressure is presented for three systems typical of those currently in use in flight research, a nose boom and two different wing-tip booms, and for the standard service system installed in the airplane. A limited amount of information on the effect of airplane normal-force coefficient on the static-pressure error is included. The results are compared with available theory and with results from wind-tunnel tests of the airspeed heads alone. Of the systems investigated, a nose-boom installation was found to be most suitable for research use at transonic and low supersonic speeds because it provided the greatest sensitivity of the indicated Mach number to a unit change in true Mach number at very high subsonic speeds, and because it was least sensitive to changes in airplane normal-force coefficient. The static-pressure error of the nose-boom system was small and constant above a Mach number of 1.03 after passage of the fuselage bow shock wave over the airspeed head.

  14. Critical care nursing: Embedded complex systems.

    PubMed

    Trinier, Ruth; Liske, Lori; Nenadovic, Vera

    2016-01-01

    Variability in parameters such as heart rate, respiratory rate and blood pressure defines healthy physiology and the ability of the person to adequately respond to stressors. Critically ill patients have lost this variability and require highly specialized nursing care to support life and monitor changes in condition. The critical care environment is a dynamic system through which information flows. The critical care unit is typically designed as a tree structure with generally one attending physician and multiple nurses and allied health care professionals. Information flow through the system allows for identification of deteriorating patient status and timely interventionfor rescue from further deleterious effects. Nurses provide the majority of direct patient care in the critical care setting in 2:1, 1:1 or 1:2 nurse-to-patient ratios. The bedside nurse-critically ill patient relationship represents the primary, real-time feedback loop of information exchange, monitoring and treatment. Variables that enhance information flow through this loop and support timely nursing intervention can improve patient outcomes, while barriers can lead to errors and adverse events. Examining patient information flow in the critical care environment from a dynamic systems perspective provides insights into how nurses deliver effective patient care and prevent adverse events. PMID:27047997

  15. 77 FR 52201 - Airworthiness Directives; The Boeing Company Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-29

    ... installing Aero-Engine database (AEDB) software in the airplane information management system (AIMS) hardware... installing AEDB software in the airplane AIMS hardware. Comments We gave the public the opportunity to... large pieces of the T/R or adjacent components departing the airplane. A separated T/R piece...

  16. Airplane Balance

    NASA Technical Reports Server (NTRS)

    Huguet, L

    1921-01-01

    The authors argue that the center of gravity has a preponderating influence on the longitudinal stability of an airplane in flight, but that manufacturers, although aware of this influence, are still content to apply empirical rules to the balancing of their airplanes instead of conducting wind tunnel tests. The author examines the following points: 1) longitudinal stability, in flight, of a glider with coinciding centers; 2) the influence exercised on the stability of flight by the position of the axis of thrust with respect to the center of gravity and the whole of the glider; 3) the stability on the ground before taking off, and the influence of the position of the landing gear. 4) the influence of the elements of the glider on the balance, the possibility of sometimes correcting defective balance, and the valuable information given on this point by wind tunnel tests; 5) and a brief examination of the equilibrium of power in horizontal flight, where the conditions of stability peculiar to this kind of flight are added to previously existing conditions of the stability of the glider, and interfere in fixing the safety limits of certain evolutions.

  17. A revolutionary approach to composite construction and flight management systems for small, general aviation airplanes

    NASA Technical Reports Server (NTRS)

    Roskam, Jan; Wenninger, ED

    1992-01-01

    The design studies for two composite general aviation airplanes are presented. The main consideration for both of the designs was to avoid the typical 'metal replacement' philosophy that has hindered the widespread use of composites in general aviation aircraft. The first design is for a low wing aircraft based on the Smith Aircraft Corporation GT-3 Global Trainer. The second aircraft is a composite version of the Cessna 152. The project was conducted as a graduate level design class under the auspices of the KU/NASA/USRA Advanced Design Program in aeronautics. The results obtained from the Fall semester of 1991 and the Spring semester of 1992 are presented.

  18. Criticality alarm system for plutonium process operations

    SciTech Connect

    Tyree, W H; Urano, H

    1981-05-25

    A criticality alarm system using neutron detection is described. The system includes a neutron detection unit with an internal operational testing mode. The unit uses a Li/sup 6/F foil for the production of alpha particles from a thermal neturon flux, a thorium-230 alpha particle source for the continuous monitoring of the raidation detection circuits, and an internal clock which produces an alarmed condition if the detector amplifier circuit fails. This neutron detector unit is designed to replace the existing neutron detector in the criticality alarm systems at Rocky Flats. Coincidence circuits, interface system and audio signal generators used in the output of the alarm system are described. The system meets the criteria for the American National Standards and the USDOE Manual Chapter for detection, alarm, and signal output requirements.

  19. Flight Investigation of a Mechanical Feel Device in an Irreversible Elevator Control System of a Large Airplane

    NASA Technical Reports Server (NTRS)

    Brown, B Porter; Chilton, Robert G; Whitten, James B

    1952-01-01

    Report presents the results of measurements of the longitudinal stability and control characteristics of a large airplane using a mechanical feel device in combination with a booster incorporated in the elevator-control system. Tests were made to investigate the feasibility of eliminating the aerodynamic control forces through use of a booster and of providing control-feel forces mechanically. The feel device consisted of a centering spring which restrained the control stick through a linkage which was changed as a function of the dynamic pressure. Provisions were made for trimming and for manual adjustment of the force gradient. The system was designed to approximate the control-force characteristics that would result with a conventional elevator control with linear hinge-moment characteristics.

  20. 77 FR 69573 - Special Conditions: Embraer S.A., Model EMB-550 Airplane; Electronic Flight Control System...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-20

    ... Statement can be found in the Federal Register published on April 11, 2000 (65 FR 19477-19478), as well as...-135 (76 FR 74654, December 1, 2011), effective January 30, 2012. (This amendment is not in the Model... Model EMB-550 airplane. The Model EMB-550 airplane is the first of a new family of jet...

  1. 76 FR 36398 - Airworthiness Directives; BAE SYSTEMS (OPERATIONS) LIMITED Model BAe 146 and Avro 146-RJ Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-22

    ... review copies of the referenced service information at the FAA, Transport Airplane Directorate, 1601 Lind..., Transport Airplane Directorate, FAA, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425... Order 12866; 2. Is not a ``significant rule'' under the DOT Regulatory Policies and Procedures (44...

  2. Use of active control systems to improve bending and rotor flapping response of a tilt rotor VTOL airplane

    NASA Technical Reports Server (NTRS)

    Whitaker, H. P.; Cheng, Y.

    1975-01-01

    The results are summarized of an analytical study of the use of active control systems for the purpose of reducing the root mean square response of wing vertical bending and rotor flapping to atmospheric turbulence for a tilt-rotor VTOL airplane. Only the wing/rotor assembly was considered so that results of a wind tunnel test program would be applicable in a subsequent phase of the research. The capabilities and limitations of simple single feedback configurations were identified, and the most promising multiloop feedback configurations were then investigated. Design parameters were selected so as to minimize either wing bending or rotor flapping response. Within the constraints imposed by practical levels of feedback gains and complexity and by considerations of safety, reduction in response due to turbulence of the order of 30 to 50 percent is predicted using the rotor longitudinal cyclic and a trailing edge wing flap as control effectors.

  3. Security for safety critical space borne systems

    NASA Technical Reports Server (NTRS)

    Legrand, Sue

    1987-01-01

    The Space Station contains safety critical computer software components in systems that can affect life and vital property. These components require a multilevel secure system that provides dynamic access control of the data and processes involved. A study is under way to define requirements for a security model providing access control through level B3 of the Orange Book. The model will be prototyped at NASA-Johnson Space Center.

  4. Percolation systems away from the critical point

    NASA Astrophysics Data System (ADS)

    Dhar, Deepak

    2002-02-01

    This article reviews some effects of disorder in percolation systems away from the critical density pc. For densities below pc, the statistics of large clusters defines the animals problem. Its relation to the directed animals problem and the Lee--Yang edge singularity problem is described. Rare compact clusters give rise to Griffiths singularities in the free energy of diluted ferromagnets, and lead to a very slow relaxation of magnetization. In biased diffusion on percolation clusters, trapping in dead-end branches leads to asymptotic drift velocity becoming zero for strong bias, and very slow relaxation of velocity near the critical bias field.

  5. Bad Actors Criticality Assessment for Pipeline system

    NASA Astrophysics Data System (ADS)

    Nasir, Meseret; Chong, Kit wee; Osman, Sabtuni; Siaw Khur, Wee

    2015-04-01

    Failure of a pipeline system could bring huge economic loss. In order to mitigate such catastrophic loss, it is required to evaluate and rank the impact of each bad actor of the pipeline system. In this study, bad actors are known as the root causes or any potential factor leading to the system downtime. Fault Tree Analysis (FTA) is used to analyze the probability of occurrence for each bad actor. Bimbaum's Importance and criticality measure (BICM) is also employed to rank the impact of each bad actor on the pipeline system failure. The results demonstrate that internal corrosion; external corrosion and construction damage are critical and highly contribute to the pipeline system failure with 48.0%, 12.4% and 6.0% respectively. Thus, a minor improvement in internal corrosion; external corrosion and construction damage would bring significant changes in the pipeline system performance and reliability. These results could also be useful to develop efficient maintenance strategy by identifying the critical bad actors.

  6. The Light Airplane

    NASA Technical Reports Server (NTRS)

    Driggs, Ivan H.

    1925-01-01

    This report begins with a review and analysis of the work being done to develop light airplanes in the U.S. and abroad. A technical discussion of the construction and innovations in light airplanes is then presented.

  7. Critical Systems Engineering Accelerator: Aerospace Demonstrator

    NASA Astrophysics Data System (ADS)

    Moreno, Ricardo; Fernandez, Gonzalo; Regada, Raul; Basanta, Luis; Alana, Elena; Del Carmen Lomba, Maria

    2014-08-01

    Nowadays, the complexity and functionality of space systems is increasing more and more. Safety critical systems have to guarantee strong safety and dependability constraints. This paper presents CRYSTAL (Critical sYSTem engineering AcceLeration), a cross-domain ARTEMIS project for increasing the efficiency of the embedded software development in the industry through the definition of an integrated tool chain. CRYSTAL involves four major application domains: Aerospace, Automotive, Rail and Medical Healthcare. The impact in the Space Domain will be evaluated through a demonstrator implemented using CRYSTAL framework: the Low Level Software for an Avionics Control Unit, capable to run Application SW for autonomous navigation, image acquisition control, data compression and/or data handling. Finally, the results achieved will be evaluated taking into account the ECSS (European Committee for Space Standardization) standards and procedures.

  8. SILENE Benchmark Critical Experiments for Criticality Accident Alarm Systems

    SciTech Connect

    Miller, Thomas Martin; Reynolds, Kevin H.

    2011-01-01

    In October 2010 a series of benchmark experiments was conducted at the Commissariat a Energie Atomique et aux Energies Alternatives (CEA) Valduc SILENE [1] facility. These experiments were a joint effort between the US Department of Energy (DOE) and the French CEA. The purpose of these experiments was to create three benchmarks for the verification and validation of radiation transport codes and evaluated nuclear data used in the analysis of criticality accident alarm systems (CAASs). This presentation will discuss the geometric configuration of these experiments and the quantities that were measured and will present some preliminary comparisons between the measured data and calculations. This series consisted of three single-pulsed experiments with the SILENE reactor. During the first experiment the reactor was bare (unshielded), but during the second and third experiments it was shielded by lead and polyethylene, respectively. During each experiment several neutron activation foils and thermoluminescent dosimeters (TLDs) were placed around the reactor, and some of these detectors were themselves shielded from the reactor by high-density magnetite and barite concrete, standard concrete, and/or BoroBond. All the concrete was provided by CEA Saclay, and the BoroBond was provided by Y-12 National Security Complex. Figure 1 is a picture of the SILENE reactor cell configured for pulse 1. Also included in these experiments were measurements of the neutron and photon spectra with two BICRON BC-501A liquid scintillators. These two detectors were provided and operated by CEA Valduc. They were set up just outside the SILENE reactor cell with additional lead shielding to prevent the detectors from being saturated. The final detectors involved in the experiments were two different types of CAAS detectors. The Babcock International Group provided three CIDAS CAAS detectors, which measured photon dose and dose rate with a Geiger-Mueller tube. CIDAS detectors are currently in

  9. Icing Protection for a Turbojet Transport Airplane: Heating Requirements, Methods of Protection, and Performance Penalties

    NASA Technical Reports Server (NTRS)

    Gelder, Thomas F.; Lewis, James P.; Koutz, Stanley L.

    1953-01-01

    The problems associated with providing icing protection for the critical components of a typical turbojet transport airplane operating over a range of probable icing conditions are analyzed and discussed. Heating requirements for several thermal methods of protection are evaluated and the airplane performance penalties associated with providing this protection from various energy sources are assessed. The continuous heating requirements for icing protection and the associated airplane performance penalties for the turbojet transport are considerably increased over those associated with lower-speed aircraft. Experimental results show that the heating requirements can be substantially reduced by the deve1opment of a satisfactory cyclic deicing system. The problem of providing protection can be minimized by employing a proper energy source since the airplane performance penalties vary considerably with the source of energy employed. The optimum icing protection system for the turbojet transport or for any other particular aircraft cannot be generally specified; the choice of the optimum system is dependent upon the specific characteristics of the airplane and engine, the flight plan, the probable icing conditions, and the performance requirements of the aircraft.

  10. Slow Relaxation in Anderson Critical Systems

    NASA Astrophysics Data System (ADS)

    Choi, Soonwon; Yao, Norman; Choi, Joonhee; Kucsko, Georg; Lukin, Mikhail

    2016-05-01

    We study the single particle dynamics in disordered systems with long range hopping, focusing on the critical cases, i.e., the hopping amplitude decays as 1 /rd in d-dimension. We show that with strong on-site potential disorder, the return probability of the particle decays as power-law in time. As on-site potential disorder decreases, the temporal profile smoothly changes from a simple power-law to the sum of multiple power-laws with exponents ranged from 0 to νmax. We analytically compute the decay exponents using a simple resonance counting argument, which quantitatively agrees with exact numerical results. Our result implies that the dynamics in Anderson Critical systems are dominated by resonances. Harvard-MIT CUA, Kwanjeong Educational Fellowship, AFOSR MURI, Samsung Scholarship.

  11. A Comparison of Bus Architectures for Safety-Critical Embedded Systems

    NASA Technical Reports Server (NTRS)

    Rushby, John; Miner, Paul S. (Technical Monitor)

    2003-01-01

    We describe and compare the architectures of four fault-tolerant, safety-critical buses with a view to deducing principles common to all of them, the main differences in their design choices, and the tradeoffs made. Two of the buses come from an avionics heritage, and two from automobiles, though all four strive for similar levels of reliability and assurance. The avionics buses considered are the Honeywell SAFEbus (the backplane data bus used in the Boeing 777 Airplane Information Management System) and the NASA SPIDER (an architecture being developed as a demonstrator for certification under the new DO-254 guidelines); the automobile buses considered are the TTTech Time-Triggered Architecture (TTA), recently adopted by Audi for automobile applications, and by Honeywell for avionics and aircraft control functions, and FlexRay, which is being developed by a consortium of BMW, DaimlerChrysler, Motorola, and Philips.

  12. Effect on Longitudinal Stability and Control Characteristics of a Boeing B-29 Airplane of Variations in Stick-Force and Control-Rate Characteristics Obtained Through Use of a Booster in the Elevator-Control System

    NASA Technical Reports Server (NTRS)

    Mathews, Charles W; Talmage, Donald B; Whitten, James B

    1952-01-01

    A longitudinal stability and control characteristics of a Boeing B-29 airplane have been measured with a booster incorporated in the elevator-control system. Tests were made to determine the effects on the handling qualities of the test airplane of variations in the pilot's control-force gradients as well as the effects of variations in the maximum rate of control motion supplied by the booster. The results of the control-rate investigation indicate that large airplanes may have satisfactory handling qualities with the booster adjusted to give much lower rates of control motion than those normally used by pilots.

  13. Longitudinal Stability and Control Characteristics of a B-29 Airplane with a Booster Incorporated in the Elevator Control System to Provide Various Stick-Force and Control-Rate Characteristics

    NASA Technical Reports Server (NTRS)

    Mathews, Charles W.; Talmage, Donald B.; Whitten, James B.

    1948-01-01

    The longitudinal stability and control characteristics of a B-29 airplane have been measured with a booster incorporated in the elevator control system. Tests were made to determine the effects on the handling qualities of the test airplane of variations in pilots control-force gradients as well as the effects of variations in the maximum rate of control motion supplied by the booster system.

  14. Chemical dosimetry system for criticality accidents.

    PubMed

    Miljanić, Saveta; Ilijas, Boris

    2004-01-01

    Ruder Bosković Institute (RBI) criticality dosimetry system consists of a chemical dosimetry system for measuring the total (neutron + gamma) dose, and a thermoluminescent (TL) dosimetry system for a separate determination of the gamma ray component. The use of the chemical dosemeter solution chlorobenzene-ethanol-trimethylpentane (CET) is based on the radiolytic formation of hydrochloric acid, which protonates a pH indicator, thymolsulphonphthalein. The high molar absorptivity of its red form at 552 nm is responsible for a high sensitivity of the system: doses in the range 0.2-15 Gy can be measured. The dosemeter has been designed as a glass ampoule filled with the CET solution and inserted into a pen-shaped plastic holder. For dose determinations, a newly constructed optoelectronic reader has been used. The RBI team took part in the International Intercomparison of Criticality Accident Dosimetry Systems at the SILENE Reactor, Valduc, June 2002, with the CET dosimetry system. For gamma ray dose determination TLD-700 TL detectors were used. The results obtained with CET dosemeter show very good agreement with the reference values. PMID:15353694

  15. Dynamic Response of Control Servo System Installed in NAES-Equipped SB2C-5 Airplane (BuAer No. 83135)

    NASA Technical Reports Server (NTRS)

    Smaus, Louis H.; Stewart, Elwood C.

    1950-01-01

    Dynamic--response measurements for various conditions of displacement and rate signal input, sensitivity setting, and simulated hinge moment were made of the three control-surface servo systems of an NAES-equipped remote-controlled airplane while on the ground. The basic components of the servo systems are those of the General Electric Company type G-1 autopilot using electrical signal. sources, solenoid-operated valves, and hydraulic pistons. The test procedures and difficulties are discussed, Both frequency and transient-response data, are presented and comparisons are made. The constants describing the servo system, the undamped natural frequency, and the damping ratio, are determined by several methods. The response of the system with the addition of airframe rate signal is calculated. The transfer function of the elevator surface, linkage, and cable system is obtained. The agreement between various methods of measurement and calculation is considered very good. The data are complete enough and in such form that they may be used directly with the frequency-response data of an airplane to predict the stability of the autopilot-airplane combination.

  16. 78 FR 11560 - Special Conditions: Embraer S.A., Model EMB-550 Airplane; Electronic Flight Control System...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-19

    ...-135 (76 FR 74654, December 1, 2011), effective January 30, 2012. (This amendment is not in the Model.... Model EMB-550 airplanes was published in the Federal Register on November 20, 2012 (77 FR 69573)....

  17. Building the airplane in flight: an auditing approach to quality management system development.

    PubMed

    Burson, M C

    2001-01-01

    In June of 2000, Maine DEP (in company with the other five New England states) found itself under EPA pressure to develop and document a quality management system by the end of the calendar year. In the frenzy that followed, the Department decided to use a private sector model for system development that called for a prospectively-focused QM plan that would be implemented through formal auditing. That is, instead of trying in advance to identify all the deficits in departmental quality management, and then assigning individuals and task groups to create structures to fill the gaps, Maine's QMP specifies the future desired system in broad terms. ME-DEP then uses its own cadre of trained auditors to assess current practice against the "condition expected" in the QMP, knowing that in many cases basic quality management practices will need to be developed. This approach assists program managers, particularly (but not exclusively) in areas sensitive to environmental data standards, in creating systems and practices that are rooted in reality, and that are perceived to add value to the Department's core work instead of just additional paperwork. Audit reports create a continuous feedback loop assuring that written procedures document actual operations. Finally, the results of auditing identify areas in which the QM system (and its plan) should be elaborated or refined, which leads to an iterative process by which quality approaches are infused in all areas of DEP operations. In the twelve months following EPA-Region I's initial approval of Maine's QMP, a total of seven audits were completed at various program levels, including two focused on critical QMP elements: Documents and Records; and Computer Hardware/Software. This paper will briefly describe the background and implementation of this approach; identify some of the factors which led to success; and describe, using selected examples, some of the early outcomes of the program. PMID:12553076

  18. General problem of the airplane

    NASA Technical Reports Server (NTRS)

    Richard, Maurice; Richard, Paul

    1922-01-01

    A series of equations relating to airplanes are given and examples listed. Some of the equations listed include: the speed, altitude and carrying capacity of various airplanes; weight of an airplane; weight of various parts of an airplane; the polars of the wings; speeds of airplanes; radius of action.

  19. Critical issues in NASA information systems

    NASA Technical Reports Server (NTRS)

    1987-01-01

    The National Aeronautics and Space Administration has developed a globally-distributed complex of earth resources data bases since LANDSAT 1 was launched in 1972. NASA envisages considerable growth in the number, extent, and complexity of such data bases, due to the improvements expected in its remote sensing data rates, and the increasingly multidisciplinary nature of its scientific investigations. Work already has begun on information systems to support multidisciplinary research activities based on data acquired by the space station complex and other space-based and terrestrial sources. In response to a request from NASA's former Associate Administrator for Space Science and Applications, the National Research Council convened a committee in June 1985 to identify the critical issues involving information systems support to space science and applications. The committee has suggested that OSSA address four major information systems issues; centralization of management functions, interoperability of user involvement in the planning and implementation of its programs, and technology.

  20. Effects on Longitudinal Stability and Control Characteristics of a B-29 Airplane of Variations in Stick-force and Control-rate Characteristics Obtained Through Use of a Booster in the Elevator-control System

    NASA Technical Reports Server (NTRS)

    Mathews, Charles W; Talmage, Donald B; Whitten, James B

    1951-01-01

    The longitudinal stability and control characteristics of a B-29 airplane have been measured with a control surface booster incorporated in the elevator-control system. The measurements were obtained with the booster operating to provide various control-force gradients and various maximum rates of control motion. Results are presented which show the effect of these booster parameters on the handling qualities of the test airplane.

  1. Simulator study of the effectiveness of an automatic control system designed to improve the high-angle-of-attack characteristics of a fighter airplane

    NASA Technical Reports Server (NTRS)

    Gilbert, W. P.; Nguyen, L. T.; Vangunst, R. W.

    1976-01-01

    A piloted, fixed-base simulation was conducted to study the effectiveness of some automatic control system features designed to improve the stability and control characteristics of fighter airplanes at high angles of attack. These features include an angle-of-attack limiter, a normal-acceleration limiter, an aileron-rudder interconnect, and a stability-axis yaw damper. The study was based on a current lightweight fighter prototype. The aerodynamic data used in the simulation were measured on a 0.15-scale model at low Reynolds number and low subsonic Mach number. The simulation was conducted on the Langley differential maneuvering simulator, and the evaluation involved representative combat maneuvering. Results of the investigation show the fully augmented airplane to be quite stable and maneuverable throughout the operational angle-of-attack range. The angle-of-attack/normal-acceleration limiting feature of the pitch control system is found to be a necessity to avoid angle-of-attack excursions at high angles of attack. The aileron-rudder interconnect system is shown to be very effective in making the airplane departure resistant while the stability-axis yaw damper provided improved high-angle-of-attack roll performance with a minimum of sideslip excursions.

  2. Automated visual inspection of an airplane exterior

    NASA Astrophysics Data System (ADS)

    Jovančević, Igor; Orteu, Jean-José; Sentenac, Thierry; Gilblas, Rémi

    2015-04-01

    This paper deals with the inspection of an airplane using a Pan-Tilt-Zoom camera mounted on a mobile robot moving around the airplane. We present image processing methods for detection and inspection of four different types of items on the airplane exterior. Our detection approach is focused on the regular shapes such as rounded corner rectangles and ellipses, while inspection relies on clues such as uniformity of isolated image regions, convexity of segmented shapes and periodicity of the image intensity signal. The initial results are promising and demonstrate the feasibility of the envisioned robotic system.

  3. Handling qualities of a wide-body transport airplane utilizing Pitch Active Control Systems (PACS) for relaxed static stability application

    NASA Technical Reports Server (NTRS)

    Grantham, William D.; Person, Lee H., Jr.; Brown, Philip W.; Becker, Lawrence E.; Hunt, George E.; Rising, J. J.; Davis, W. J.; Willey, C. S.; Weaver, W. A.; Cokeley, R.

    1985-01-01

    Piloted simulation studies have been conducted to evaluate the effectiveness of two pitch active control systems (PACS) on the flying qualities of a wide-body transport airplane when operating at negative static margins. These two pitch active control systems consisted of a simple 'near-term' PACS and a more complex 'advanced' PACS. Eight different flight conditions, representing the entire flight envelope, were evaluated with emphasis on the cruise flight conditions. These studies were made utilizing the Langley Visual/Motion Simulator (VMS) which has six degrees of freedom. The simulation tests indicated that (1) the flying qualities of the baseline aircraft (PACS off) for the cruise and other high-speed flight conditions were unacceptable at center-of-gravity positions aft of the neutral static stability point; (2) within the linear static stability flight envelope, the near-term PACS provided acceptable flying qualities for static stabilty margins to -3 percent; and (3) with the advanced PACS operative, the flying qualities were demonstrated to be good (satisfactory to very acceptable) for static stabilty margins to -20 percent.

  4. Are Biological Systems Poised at Criticality?

    NASA Astrophysics Data System (ADS)

    Mora, Thierry; Bialek, William

    2011-07-01

    Many of life's most fascinating phenomena emerge from interactions among many elements—many amino acids determine the structure of a single protein, many genes determine the fate of a cell, many neurons are involved in shaping our thoughts and memories. Physicists have long hoped that these collective behaviors could be described using the ideas and methods of statistical mechanics. In the past few years, new, larger scale experiments have made it possible to construct statistical mechanics models of biological systems directly from real data. We review the surprising successes of this "inverse" approach, using examples from families of proteins, networks of neurons, and flocks of birds. Remarkably, in all these cases the models that emerge from the data are poised near a very special point in their parameter space—a critical point. This suggests there may be some deeper theoretical principle behind the behavior of these diverse systems.

  5. Summary of V-G and VGH Data Collected on Lockheed Electra Airplanes During Airplane Operations

    NASA Technical Reports Server (NTRS)

    Jewel, Joseph W., Jr.; Fetner, Mary W.

    1961-01-01

    Data obtained by NASA VGH and V-G recorders on several Lockheed Electra airplanes operated over three domestic routes have been analyzed to determine the in-flight accelerations, airspeed practices, and landing accelerations experienced by this particular airplane. The results indicate that the accelerations caused by gusts and maneuvers are comparable to corresponding results for piston-engine transport airplanes. Oscillatory accelerations (apparently caused by the autopilot or control system) appear to occur about one-tenth as frequently as accelerations due to gusts. Airspeed operating practices in rough air generally follow the trends shown by piston-engine transports in that there is no significant difference between the average airspeed in rough or smooth air. Placard speeds were exceeded more frequently by the Electra airplane than by piston-engine transport airplanes. Generally, the landing-impact accelerations were higher than those for piston-engine transports.

  6. Precision controllability of the F-15 airplane

    NASA Technical Reports Server (NTRS)

    Sisk, T. R.; Matheny, N. W.

    1979-01-01

    A flying qualities evaluation conducted on a preproduction F-15 airplane permitted an assessment to be made of its precision controllability in the high subsonic and low transonic flight regime over the allowable angle of attack range. Precision controllability, or gunsight tracking, studies were conducted in windup turn maneuvers with the gunsight in the caged pipper mode and depressed 70 mils. This evaluation showed the F-15 airplane to experience severe buffet and mild-to-moderate wing rock at the higher angles of attack. It showed the F-15 airplane radial tracking precision to vary from approximately 6 to 20 mils over the load factor range tested. Tracking in the presence of wing rock essentially doubled the radial tracking error generated at the lower angles of attack. The stability augmentation system affected the tracking precision of the F-15 airplane more than it did that of previous aircraft studied.

  7. 76 FR 19716 - Airworthiness Directives; BAE SYSTEMS (Operations) Limited Model 4101 Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-08

    ... AD. Discussion On April 27, 2009, we issued AD 2009-10-02, Amendment 39-15897 (74 FR 21246, May 7... Maintenance Requirements'', and, --05-10-30 ``Critical Design Configuration Control Limitations (CDCCL)--Fuel... 12866; 2. Is not a ``significant rule'' under the DOT Regulatory Policies and Procedures (44 FR...

  8. Nuclear Criticality Information System. Database examples

    SciTech Connect

    Foret, C.A.

    1984-06-01

    The purpose of this publication is to provide our users with a guide to using the Nuclear Criticality Information System (NCIS). It is comprised of an introduction, an information and resources section, a how-to-use section, and several useful appendices. The main objective of this report is to present a clear picture of the NCIS project and its available resources as well as assisting our users in accessing the database and using the TIS computer to process data. The introduction gives a brief description of the NCIS project, the Technology Information System (TIS), online user information, future plans and lists individuals to contact for additional information about the NCIS project. The information and resources section outlines the NCIS database and describes the resources that are available. The how-to-use section illustrates access to the NCIS database as well as searching datafiles for general or specific data. It also shows how to access and read the NCIS news section as well as connecting to other information centers through the TIS computer.

  9. 76 FR 8319 - Special Conditions: Gulfstream Model GVI Airplane; Design Roll Maneuver Requirement for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-14

    ... Roll Maneuver Requirement for Electronic Flight Controls AGENCY: Federal Aviation Administration (FAA... airplanes. These design features include an electronic flight control system that provides roll control of the airplane through pilot inputs to the flight ] computers. These proposed special conditions...

  10. The Airplane Experiment.

    ERIC Educational Resources Information Center

    Larson, Lee; Grant, Roderick

    1991-01-01

    Presents an experiment to investigate centripetal force and acceleration that utilizes an airplane suspended on a string from a spring balance. Investigates the possibility that lift on the wings of the airplane accounts for the differences between calculated tension and measured tension on the string. (MDH)

  11. Metal Airplane Construction

    NASA Technical Reports Server (NTRS)

    1926-01-01

    It has long been thought that metal construction of airplanes would involve an increase in weight as compared with wood construction. Recent experience has shown that such is not the case. This report describes the materials used, treatment of, and characteristics of metal airplane construction.

  12. Criticality and Chaos in Systems of Communities

    NASA Astrophysics Data System (ADS)

    Ostilli, Massimo; Figueiredo, Wagner

    2016-01-01

    We consider a simple model of communities interacting via bilinear terms. After analyzing the thermal equilibrium case, which can be described by an Hamiltonian, we introduce the dynamics that, for Ising-like variables, reduces to a Glauber-like dynamics. We analyze and compare four different versions of the dynamics: flow (differential equations), map (discretetime dynamics), local-time update flow, and local-time update map. The presence of only bilinear interactions prevent the flow cases to develop any dynamical instability, the system converging always to the thermal equilibrium. The situation is different for the map when unfriendly couplings are involved, where period-two oscillations arise. In the case of the map with local-time updates, oscillations of any period and chaos can arise as a consequence of the reciprocal “tension” accumulated among the communities during their sleeping time interval. The resulting chaos can be of two kinds: true chaos characterized by positive Lyapunov exponent and bifurcation cascades, or marginal chaos characterized by zero Lyapunov exponent and critical continuous regions.

  13. Brake control system modification, augmentor Wing Jet STOL Research Airplane (AWJSRA)

    NASA Technical Reports Server (NTRS)

    Amberg, R. L.; Arline, J. A.; Jenny, R. W.

    1974-01-01

    The braking system for a short takeoff aircraft is discussed and the deficiencies are described. The installation of a Boeing 727 aircraft brake system was made to correct the deficiencies. Tests of the modified system were conducted using an analog computer/hardware simulator. Actual performance tests were conducted and the characteristics of the system were satisfactory.

  14. The Nuclear Criticality Information System`s project to archive unpublished critical experiment data

    SciTech Connect

    Koponen, B.L.; Clayton, E.D.; Doherty, A.L.

    1991-07-01

    Critical experiment facilities produced a large amount of important data during the past forty-five years. However, much useful data remains unpublished. The unpublished material exists in the form of experimenters` logbooks, notes, photographs, material descriptions, etc. These data could be important for computer code validation, understanding the physics of criticality, facility design, or for setting process limits. In the past, criticality specialists have been able to obtain unpublished details by direct contact with the experimenters. Obviously, this will not be possible indefinitely. Most of the US critical experiment facilities are now closed, the experimenters are moving the other jobs, retiring, or otherwise becoming unavailable for this informal assistance. The closure of the facilities and the loss of personnel is likely to lead to the loss of the facility records unless an effort is made to assure that the records are preserved. It has been recognized for some time that the unpublished records of critical experiment facilities comprise a valuable resource, thus the Nuclear Criticality Information System (NCIS) is working to insure that the records are preserved and made available via NCIS. As a first step in the archiving project, we identified criteria to help judge which series of experiments should be considered for archiving. Data that are used for validating calculations or the basis for subcritical limits in standards, handbooks, and guides are of particular importance. In this paper we will discuss the criteria for archiving, the priority list of experiments for archiving, and progress in developing an NCIS image database using current CD-ROM technology.

  15. Variable-Structure Control of a Model Glider Airplane

    NASA Technical Reports Server (NTRS)

    Waszak, Martin R.; Anderson, Mark R.

    2008-01-01

    A variable-structure control system designed to enable a fuselage-heavy airplane to recover from spin has been demonstrated in a hand-launched, instrumented model glider airplane. Variable-structure control is a high-speed switching feedback control technique that has been developed for control of nonlinear dynamic systems.

  16. Why Mission-Critical Systems Are Critical to the Future of Academic Libraries

    ERIC Educational Resources Information Center

    Oberlander, Cyril

    2012-01-01

    A mission-critical system is one that is so intertwined with the operation of an organization that the organization can scarcely function without it. Just as in corporations, mission-critical library systems offer the capability to unlock talent and time. They are essential to the transformation of higher education and the learning environment. A…

  17. 75 FR 5146 - Hewlett Packard Company Business Critical Systems, Mission Critical Business Software Division...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-01

    ... Register November 5, 2009 (74 FR 57341). At the request of the State Agency, the Department reviewed the... Business Software Division, OpenVMS Operating System Development Group, Including Employees Working Off... Business Critical Systems, Mission Critical Business Software Division, OpenVMS Operating...

  18. Landing performance of an air cushion landing system installed on a 1/10-scale dynamic model on the C-8 Buffalo airplane

    NASA Technical Reports Server (NTRS)

    Thompson, W. C.

    1973-01-01

    An experimental study was conducted to evaluate the landing behavior of a 1/10-scale dynamic model of the C-8 Buffalo airplane equipped with an air-cushion landing system (ACLS) on a variety of surfaces including both calm and rough water and a smooth hard surface. Taxi runs were made on the hard surface over several obstacles. Landings were made with the model at various pitch and roll attitudes and vertical velocities and at one nominal horizontal velocity. Data from the landings include time histories of the trunk and air-cushion pressures and accelerations at selected locations on the model.

  19. 76 FR 31456 - Special Conditions: Gulfstream Model GVI Airplane; Electronic Flight Control System: Control...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-01

    ... Federal Register on February 17, 2011 (76 FR 9265). One supportive comment was received and these special...; Electronic Flight Control System: Control Surface Position Awareness AGENCY: Federal Aviation Administration... design features include an electronic flight control system. The applicable airworthiness regulations...

  20. 76 FR 14795 - Special Conditions: Gulfstream Model GVI Airplane; Electronic Flight Control System Mode...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-18

    ... December 13, 2010 (75 FR 77569). Only one comment was received. Clarification of Conditions That Should Be...; Electronic Flight Control System Mode Annunciation. AGENCY: Federal Aviation Administration (FAA), DOT... electronic flight control system. The applicable airworthiness regulations do not contain adequate...

  1. 78 FR 77611 - Special Conditions: Airbus, A350-900 Series Airplane; High Speed Protection System

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-24

    ... April 11, 2000 (65 FR 19477-19478), as well as at http://DocketsInfo.dot.gov/ . Docket: Background... Speed Protection System AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed... high-speed protection system. The applicable airworthiness regulations do not contain adequate...

  2. Application of high-alpha control system concepts to a variable-sweep fighter airplane

    NASA Technical Reports Server (NTRS)

    Nguyen, L. T.; Gilbert, W. P.; Gera, J.; Iliff, K. W.; Enevoldson, E. K.

    1980-01-01

    The use of control system design to enhance high-angle-of-attack flying qualities and departure/spin resistance has become an accepted and widely used approach for modern fighter aircraft. NASA and the Navy are currently conducting a joint research program to investigate the application of this technology to the F-14. The paper discusses the results of this program within the context of its contributions to advancing high-alpha control system technology. General topics covered include (1) analysis and design tools, (2) control system design approach, and (3) flight test approach and results.

  3. Airplane Superchargers

    NASA Technical Reports Server (NTRS)

    Noack, W G

    1921-01-01

    Discussed here are the principles and operation of aircraft engine superchargers used to maintain and increase engine power as aircraft encounter decreases in the density of air as altitude rises. Details are given on the design and operation of the centrifugal compressors. A method is given for calculating the amount of power needed to drive a compressor. The effects of the use of a compressor on fuel system operation and design are discussed. Several specific superchargers that were in operation are described.

  4. Performance improvements of a highly integrated digital electronic control system for an F-15 airplane

    NASA Technical Reports Server (NTRS)

    Putnam, T. W.; Burcham, F. W., Jr.; Andries, M. G.; Kelly, J. B.

    1985-01-01

    The NASA highly integrated digital electronic control (HIDEC) program is structured to conduct flight research into the benefits of integrating an aircraft flight control system with the engine control system. A brief description of the HIDEC system installed on an F-15 aircraft is provided. The adaptive engine control system (ADECS) mode is described in detail, together with simulation results and analyses that show the significant excess thrust improvements achievable with the ADECS mode. It was found that this increased thrust capability is accompanied by reduced fan stall margin and can be realized during flight conditions where engine face distortion is low. The results of analyses and simulations also show that engine thrust response is improved and that fuel consumption can be reduced. Although the performance benefits that accrue because of airframe and engine control integration are being demonstrated on an F-15 aircraft, the principles are applicable to advanced aircraft such as the advanced tactical fighter and advanced tactical aircraft.

  5. 14 CFR 91.219 - Altitude alerting system or device: Turbojet-powered civil airplanes.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... determine proper operation of the alerting signals; and (5) Accept necessary barometric pressure settings if the system or device operates on barometric pressure. However, for operation below 3,000 feet AGL,...

  6. 14 CFR 91.219 - Altitude alerting system or device: Turbojet-powered civil airplanes.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... determine proper operation of the alerting signals; and (5) Accept necessary barometric pressure settings if the system or device operates on barometric pressure. However, for operation below 3,000 feet AGL,...

  7. 14 CFR 91.219 - Altitude alerting system or device: Turbojet-powered civil airplanes.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... determine proper operation of the alerting signals; and (5) Accept necessary barometric pressure settings if the system or device operates on barometric pressure. However, for operation below 3,000 feet AGL,...

  8. 14 CFR 91.219 - Altitude alerting system or device: Turbojet-powered civil airplanes.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... determine proper operation of the alerting signals; and (5) Accept necessary barometric pressure settings if the system or device operates on barometric pressure. However, for operation below 3,000 feet AGL,...

  9. 14 CFR 91.219 - Altitude alerting system or device: Turbojet-powered civil airplanes.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... determine proper operation of the alerting signals; and (5) Accept necessary barometric pressure settings if the system or device operates on barometric pressure. However, for operation below 3,000 feet AGL,...

  10. Gordon Bennett Airplane Cup

    NASA Technical Reports Server (NTRS)

    Margoulis, W

    1921-01-01

    The characteristics of the airplanes built for the Gordon Bennet Airplane Cup race that took place on September 28, 1920 are described. The airplanes are discussed from a aerodynamical point of view, with a number of new details concerning the French machines. Also discussed is the regulation of future races. The author argues that there should be no limitations on the power of the aircraft engines. He reasons that in the present state of things, liberty with regard to engine power does not lead to a search for the most powerful engine, but for one which is reliable and light, thus leading to progress.

  11. Criticality accident alarm system at the Fernald Environmental Management Project

    SciTech Connect

    Marble, R.C.; Brown, T.D.; Wooldridge, J.C.

    1994-12-31

    This paper describes the staus of the Fernald Environmental Management Project (FEMP) criticality alarm system. A new radiation detection alarm system was installed in 1990. The anunciation system, calibration and maintenance, and detector placement is described.

  12. Preliminary flight results of an adaptive engine control system of an F-15 airplane

    NASA Technical Reports Server (NTRS)

    Myers, Lawrence P.; Walsh, Kevin R.

    1987-01-01

    Results of the flight demonstration of the adaptive engine control system (ADECS), an integrated flight and propulsion control system, are reported. The ADECS system provides additional engine thrust by increasing engine pressure ratio (EPR) at intermediate and afterburning power, with the amount of EPR uptrim modulated in accordance with the maneuver requirements, flight conditions, and engine information. As a result of EPR uptrimming, engine thrust has increased by as much as 10.5 percent, rate of climb has increased by 10 percent, and the time to climb from 10,000 to 40,000 ft has been reduced by 12.5 percent. Increases in acceleration of 9.3 and 13 percent have been obtained at intermediate and maximum power, respectively. No engine anomalies have been detected for EPR increases up to 12 percent.

  13. Observing scale-invariance in non-critical dynamical systems

    NASA Astrophysics Data System (ADS)

    Gros, C.; Marković, D.

    2013-01-01

    Recent observation for scale invariant neural avalanches in the brain have been discussed in details in the scientific literature. We point out, that these results do not necessarily imply that the properties of the underlying neural dynamics are also scale invariant. The reason for this discrepancy lies in the fact that the sampling statistics of observations and experiments is generically biased by the size of the basins of attraction of the processes to be studied. One has hence to precisely define what one means with statements like 'the brain is critical' . We recapitulate the notion of criticality, as originally introduced in statistical physics for second order phase transitions, turning then to the discussion of critical dynamical systems. We elucidate in detail the difference between a 'critical system', viz a system on the verge of a phase transition, and a 'critical state', viz state with scaleinvariant correlations, stressing the fact that the notion of universality is linked to critical states. We then discuss rigorous results for two classes of critical dynamical systems, the Kauffman net and a vertex routing model, which both have non-critical states. However, an external observer that samples randomly the phase space of these two critical models, would find scale invariance. We denote this phenomenon as 'observational criticality' and discuss its relevance for the response properties of critical dynamical systems.

  14. 78 FR 78701 - Airworthiness Directives; The Boeing Company Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-27

    ...We are adopting a new airworthiness directive (AD) for certain The Boeing Company Model 737-300, -400, and -500 series airplanes. This AD was prompted by fuel system reviews conducted by the manufacturer. This AD requires, depending on airplane configuration, replacing fuel pump power control relays with new relays having a ground fault interrupter (GFI) feature, installing ground studs and a......

  15. Measurement of the handling characteristics of two light airplanes

    NASA Technical Reports Server (NTRS)

    1980-01-01

    A flight investigation of the handling characteristics of two single engine general aviation airplanes, one a high wing and the other a low wing, included a variety of measurements of different characteristics of the airplanes. The characteristics included those of the control systems, performance, longitudinal and lateral responses, and stall motions.

  16. 77 FR 16488 - Airworthiness Directives; Bombardier, Inc. Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-21

    ... rule'' under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); 3. Will not...-100, DHC-8-200, and DHC-8-300 series airplanes. This proposed AD was prompted by reports of hydraulic... caps, which could result in loss of the number 2 hydraulic system and damage to airplane...

  17. 76 FR 10528 - Special Conditions: Gulfstream Model GVI Airplane; Electronic Systems Security Isolation or...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-25

    ... unusual design features associated with connectivity of the passenger domain computer systems to the... and network configuration may be used for, or interfaced with, a diverse set of functions, including... sources. Discussion of Proposed Special Conditions The proposed Model GVI integrated network...

  18. AIRID: an application of the KAS/Prospector expert system builder to airplane identification

    SciTech Connect

    Aldridge, J.P.

    1984-01-01

    The Knowledge Acquisition System/Prospector expert system building tool developed by SRI, International, has been used to construct an expert system to identify aircraft on the basis of observables such as wing shape, engine number/location, fuselage shape, and tail assembly shape. Additional detailed features are allowed to influence the identification as other favorable features. Constraints on the observations imposed by bad weather and distant observations have been included as contexts to the models. Models for Soviet and US fighter aircraft have been included. Inclusion of other types of aircraft such as bombers, transports, and reconnaissance craft is straightforward. Two models permit exploration of the interaction of semantic and taxonomic networks with the models. A full set of text data for fluid communication with the user has been included. The use of demons as triggered output responses to enhance utility to the user has been explored. This paper presents discussion of the ease of building the expert system using this powerful tool and problems encountered in the construction process.

  19. Flight evaluation of a digital electronic engine control system in an F-15 airplane

    NASA Technical Reports Server (NTRS)

    Myers, L. P.; Mackall, K. G.; Burcham, F. W., Jr.; Walter, W. A.

    1982-01-01

    Benefits provided by a full-authority digital engine control are related to improvements in engine efficiency, performance, and operations. An additional benefit is the capability of detecting and accommodating failures in real time and providing engine-health diagnostics. The digital electronic engine control (DEEC), is a full-authority digital engine control developed for the F100-PW-100 turbofan engine. The DEEC has been flight tested on an F-15 aircraft. The flight tests had the objective to evaluate the DEEC hardware and software over the F-15 flight envelope. A description is presented of the results of the flight tests, which consisted of nonaugmented and augmented throttle transients, airstarts, and backup control operations. The aircraft, engine, DEEC system, and data acquisition and reduction system are discussed.

  20. English airplane construction

    NASA Technical Reports Server (NTRS)

    Schwencke, D

    1930-01-01

    English airplane construction is presented with a particular emphasis on metal construction techniques. Steel rib and fuselage construction are discussed as well as the use of duralumin in construction.

  1. The Bristol "Badminton" Airplane

    NASA Technical Reports Server (NTRS)

    1926-01-01

    The Bristol Badminton, Type 99 airplane has a radial aircooled engine (a Bristol Jupiter 9 cylinder 450 HP.) and three fuel tanks. It is a single seat biplane weighing 1,840 lbs. empty and 2,460 lbs. loaded.

  2. Airplane Stress Analysis

    NASA Technical Reports Server (NTRS)

    Zahm, A F; Crook, L H

    1918-01-01

    Report presents stress analysis of individual components of an airplane. Normal and abnormal loads, sudden loads, simple stresses, indirect simple stresses, resultant unit stress, repetitive and equivalent stress, maximum steady load and stress are considered.

  3. 78 FR 63845 - Special Conditions: Embraer S.A., Model EMB-550 Airplanes; Isolation or Airplane Electronic...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-25

    ..., 2000 (65 FR 19477-19478), as well as at http://DocketsInfo.dot.gov/ . Docket: Background documents or...; Isolation or Airplane Electronic System Security Protection From Unauthorized Internal Access AGENCY... control surfaces. The Model EMB-550 airplane is designed for 8 passengers, with a maximum of 12...

  4. 75 FR 39804 - Airworthiness Directives; The Boeing Company Model 757 Airplanes, Model 767 Airplanes, and Model...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-13

    ... Model 757 Airplanes, Model 767 Airplanes, and Model 777-200 and -300 Series Airplanes AGENCY: Federal... directive (AD) for certain Model 757 airplanes, Model 767 airplanes, and Model 777-200 and -300 series...) that would apply to certain Model 757 airplanes, Model 767 airplanes, and Model 777-200 and -300...

  5. Stall-proof Airplanes

    NASA Technical Reports Server (NTRS)

    Lachmann, G

    1927-01-01

    My lecture has to do with the following questions. Is the danger of stalling necessarily inherent in the airplane in its present form and structure, or can it be diminished or eliminated by suitable means? Do we possess such means or devices and how must they operate? In this connection I will devote special attention to the exhibition of stall-proof airplanes by Fokker under the auspices of the English Air Ministry, which took place in Croyden last April.

  6. Flight evaluation of modifications to a digital electronic engine control system in an F-15 airplane

    NASA Technical Reports Server (NTRS)

    Burcham, F. W., Jr.; Myers, L. P.; Zeller, J. R.

    1983-01-01

    The third phase of a flight evaluation of a digital electronic engine control system in an F-15 has recently been completed. It was found that digital electronic engine control software logic changes and augmentor hardware improvements resulted in significant improvements in engine operation. For intermediate to maximum power throttle transients, an increase in altitude capability of up to 8000 ft was found, and for idle to maximum transients, an increase of up to 4000 ft was found. A nozzle instability noted in earlier flight testing was investigated on a test engine at NASA Lewis Research Center, a digital electronic engine control software logic change was developed and evaluated, and no instability occurred in the Phase 3 flight evaluation. The backup control airstart modification was evaluated, and gave an improvement of airstart capability by reducing the minimum airspeed for successful airstarts by 50 to 75 knots.

  7. Status, plans, and capabilities of the Nuclear Criticality Information System

    SciTech Connect

    Koponen, B.L.

    1984-01-06

    The Nuclear Criticality Information System (NCIS), in preparation since 1981, has substantially evolved and now contains a growing number of resources pertinent to nuclear criticality safety. These resources include bibliographic compilations, experimental data, communications media, and the International Directory of Nuclear Criticality Safety Personnel. These resources are part of the LLNL Technology Information System (TIS) which provides the host computer for NCIS. The TIS provides nationwide access to authorized members of the nuclear criticality community via interactive dial-up from computer terminals that utilize communication facilities such as commercial and federal telephone networks, toll-free WATS lines, TYMNET, and the ARPANET/MILNET computer network.

  8. Precision controllability of the YF-17 airplane

    NASA Technical Reports Server (NTRS)

    Sisk, T. R.; Mataeny, N. W.

    1980-01-01

    A flying qualities evaluation conducted on the YF-17 airplane permitted assessment of its precision controllability in the transonic flight regime over the allowable angle of attack range. The precision controllability (tailchase tracking) study was conducted in constant-g and windup turn tracking maneuvers with the command augmentation system (CAS) on, automatic maneuver flaps, and the caged pipper gunsight depressed 70 mils. This study showed that the YF-17 airplane tracks essentially as well at 7 g's to 8 g's as earlier fighters did at 4 g's to 5 g's before they encountered wing rock. The pilots considered the YF-17 airplane one of the best tracking airplanes they had flown. Wing rock at the higher angles of attack degraded tracking precision, and lack of control harmony made precision controllability more difficult. The revised automatic maneuver flap schedule incorporated in the airplane at the time of the tests did not appear to be optimum. The largest tracking errors and greatest pilot workload occurred at high normal load factors at low angles of attack. The pilots reported that the high-g maneuvers caused some tunnel vision and that they found it difficult to think clearly after repeated maneuvers.

  9. Sensor Systems Collect Critical Aerodynamics Data

    NASA Technical Reports Server (NTRS)

    2010-01-01

    With the support of Small Business Innovation Research (SBIR) contracts with Dryden Flight Research Center, Tao of Systems Integration Inc. developed sensors and other components that will ultimately form a first-of-its-kind, closed-loop system for detecting, measuring, and controlling aerodynamic forces and moments in flight. The Hampton, Virginia-based company commercialized three of the four planned components, which provide sensing solutions for customers such as Boeing, General Electric, and BMW and are used for applications such as improving wind turbine operation and optimizing air flow from air conditioning systems. The completed system may one day enable flexible-wing aircraft with flight capabilities like those of birds.

  10. Class 2 design update for the family of commuter airplanes

    NASA Technical Reports Server (NTRS)

    Creighton, Thomas R.; Hendrich, Louis J.

    1987-01-01

    This is the final report of seven on the design of a family of commuter airplanes. This design effort was performed in fulfillment of NASA/USRA grant NGT-8001. Its contents are as follows: (1) the class 1 baseline designs for the commuter airplane family; (2) a study of takeoff weight penalties imposed on the commuter family due to implementing commonality objectives; (3) component structural designs common to the commuter family; (4) details of the acquisition and operating economics of the commuter family, i.e., savings due to production commonality and handling qualities commonality are determined; (5) discussion of the selection of an advanced turboprop propulsion system for the family of commuter airplanes, and (6) a proposed design for an SSSA controller design to achieve similar handling for all airplanes. Final class 2 commuter airplane designs are also presented.

  11. Life prediction systems for critical rotating components

    NASA Technical Reports Server (NTRS)

    Cunningham, Susan E.

    1993-01-01

    With the advent of advanced materials in rotating gas turbine engine components, the methodologies for life prediction of these parts must also increase in sophistication and capability. Pratt & Whitney's view of generic requirements for composite component life prediction systems are presented, efforts underway to develop these systems are discussed, and industry participation in key areas requiring development is solicited.

  12. Critical Propulsion Components. Volume 1; Summary, Introduction, and Propulsion Systems Studies

    NASA Technical Reports Server (NTRS)

    2005-01-01

    Several studies have concluded that a supersonic aircraft, if environmentally acceptable and economically viable, could successfully compete in the 21st century marketplace. However, before industry can commit to what is estimated as a 15 to 20 billion dollar investment, several barrier issues must be resolved. In an effort to address these barrier issues, NASA and Industry teamed to form the High-Speed Research (HSR) program. As part of this program, the Critical Propulsion Components (CPC) element was created and assigned the task of developing those propulsion component technologies necessary to: (1) reduce cruise emissions by a factor of 10 and (2) meet the ever-increasing airport noise restrictions with an economically viable propulsion system. The CPC-identified critical components were ultra-low emission combustors, low-noise/high-performance exhaust nozzles, low-noise fans, and stable/high-performance inlets. Propulsion cycle studies (coordinated with NASA Langley Research Center sponsored airplane studies) were conducted throughout this CPC program to help evaluate candidate components and select the best concepts for the more complex and larger scale research efforts. The propulsion cycle and components ultimately selected were a mixed-flow turbofan (MFTF) engine employing a lean, premixed, prevaporized (LPP) combustor coupled to a two-dimensional mixed compression inlet and a two-dimensional mixer/ejector nozzle. Due to the large amount of material presented in this report, it was prepared in four volumes; Volume 1: Summary, Introduction, and Propulsion System Studies, Volume 2: Combustor, Volume 3: Exhaust Nozzle, and Volume 4: Inlet and Fan/ Inlet Acoustic Team.

  13. Solar Airplanes and Regenerative Fuel Cells

    NASA Technical Reports Server (NTRS)

    Bents, David J.

    2007-01-01

    A solar electric aircraft with the potential to "fly forever" has captured NASA's interest, and the concept for such an aircraft was pursued under Aeronautics Environmental Research Aircraft and Sensor Technology (ERAST) project. Feasibility of this aircraft happens to depend on the successful development of solar power technologies critical to NASA's Exploration Initiatives; hence, there was widespread interest throughout NASA to bring these technologies to a flight demonstration. The most critical is an energy storage system to sustain mission power during night periods. For the solar airplane, whose flight capability is already limited by the diffuse nature of solar flux and subject to latitude and time of year constraints, the feasibility of long endurance flight depends on a storage density figure of merit better than 400-600 watt-hr per kilogram. This figure of merit is beyond the capability of present day storage technologies (other than nuclear) but may be achievable in the hydrogen-oxygen regenerative fuel cell (RFC). This potential has led NASA to undertake the practical development of a hydrogen-oxygen regenerative fuel cell, initially as solar energy storage for a high altitude UAV science platform but eventually to serve as the primary power source for NASAs lunar base and other planet surface installations. Potentially the highest storage capacity and lowest weight of any non-nuclear device, a flight-weight RFC aboard a solar-electric aircraft that is flown continuously through several successive day-night cycles will provide the most convincing demonstration that this technology's widespread potential has been realized. In 1998 NASA began development of a closed cycle hydrogen oxygen PEM RFC under the Aeronautics Environmental Research Aircraft and Sensor Technology (ERAST) project and continued its development, originally for a solar electric airplane flight, through FY2005 under the Low Emissions Alternative Power (LEAP) project. Construction of

  14. Motion simulator study of longitudinal stability requirements for large delta wing transport airplanes during approach and landing with stability augmentation systems failed

    NASA Technical Reports Server (NTRS)

    Snyder, C. T.; Fry, E. B.; Drinkwater, F. J., III; Forrest, R. D.; Scott, B. C.; Benefield, T. D.

    1972-01-01

    A ground-based simulator investigation was conducted in preparation for and correlation with an-flight simulator program. The objective of these studies was to define minimum acceptable levels of static longitudinal stability for landing approach following stability augmentation systems failures. The airworthiness authorities are presently attempting to establish the requirements for civil transports with only the backup flight control system operating. Using a baseline configuration representative of a large delta wing transport, 20 different configurations, many representing negative static margins, were assessed by three research test pilots in 33 hours of piloted operation. Verification of the baseline model to be used in the TIFS experiment was provided by computed and piloted comparisons with a well-validated reference airplane simulation. Pilot comments and ratings are included, as well as preliminary tracking performance and workload data.

  15. Self limiting features of accidental criticality in a solution system

    SciTech Connect

    Malenfant, R.E.

    1988-01-01

    Experience with the SHEBA solution critical assembly during validation testing of accidental criticality alarm detectors provided several insights into the character of potential accidental excursions. Two observations were of particular interest. First, it is nearly impossible to maintain a solution system, particularly one employing low-enrichment material, in a constant state. If super-critical, the system will heat up, expand (or form bubbles), return to a sub-critical state, and shut down of its own accord without going into short period oscillations. Second, a very slow change in the system could produce a long ''pulse'' resulting in lengthy exposures, a high dose, but a low dose rate. The experiments dramatically contradicted the popular contention that accidental criticality is characterized by a blue flash, a clap of thunder, and violet expulsion of material. 5 refs., 3 figs., 4 tabs.

  16. Minimum time and fuel flight profiles for an F-15 airplane with a Highly Integrated Digital Electronic Control (HIDEC) system

    NASA Technical Reports Server (NTRS)

    Haering, E. A., Jr.; Burcham, F. W., Jr.

    1984-01-01

    A simulation study was conducted to optimize minimum time and fuel consumption paths for an F-15 airplane powered by two F100 Engine Model Derivative (EMD) engines. The benefits of using variable stall margin (uptrim) to increase performance were also determined. This study supports the NASA Highly Integrated Digital Electronic Control (HIDEC) program. The basis for this comparison was minimum time and fuel used to reach Mach 2 at 13,716 m (45,000 ft) from the initial conditions of Mach 0.15 at 1524 m (5000 ft). Results were also compared to a pilot's estimated minimum time and fuel trajectory determined from the F-15 flight manual and previous experience. The minimum time trajectory took 15 percent less time than the pilot's estimate for the standard EMD engines, while the minimum fuel trajectory used 1 percent less fuel than the pilot's estimate for the minimum fuel trajectory. The F-15 airplane with EMD engines and uptrim, was 23 percent faster than the pilot's estimate. The minimum fuel used was 5 percent less than the estimate.

  17. Systemic trade risk of critical resources.

    PubMed

    Klimek, Peter; Obersteiner, Michael; Thurner, Stefan

    2015-11-01

    In the wake of the 2008 financial crisis, the role of strongly interconnected markets in causing systemic instability has been increasingly acknowledged. Trade networks of commodities are susceptible to cascades of supply shocks that increase systemic trade risks and pose a threat to geopolitical stability. We show that supply risk, scarcity, and price volatility of nonfuel mineral resources are intricately connected with the structure of the worldwide trade networks spanned by these resources. At the global level, we demonstrate that the scarcity of a resource is closely related to the susceptibility of the trade network with respect to cascading shocks. At the regional level, we find that, to some extent, region-specific price volatility and supply risk can be understood by centrality measures that capture systemic trade risk. The resources associated with the highest systemic trade risk indicators are often those that are produced as by-products of major metals. We identify significant strategic shortcomings in the management of systemic trade risk, in particular in the European Union. PMID:26702431

  18. Non-Systemic Drugs: A Critical Review

    PubMed Central

    Charmot, Dominique

    2012-01-01

    Non-systemic drugs act within the intestinal lumen without reaching the systemic circulation. The first generation included polymeric resins that sequester phosphate ions, potassium ions, or bile acids for the treatment of electrolyte imbalances or hypercholesteremia. The field has evolved towards non-absorbable small molecules or peptides targeting luminal enzymes or transporters for the treatment of mineral metabolism disorders, diabetes, gastrointestinal (GI) disorders, and enteric infections. From a drug design and development perspective, non-systemic agents offer novel opportunities to address unmet medical needs while minimizing toxicity risks, but also present new challenges, including developing a better understanding and control of non-transcellular leakage pathways into the systemic circulation. The pharmacokinetic-pharmacodynamic relationship of drugs acting in the GI tract can be complex due to the variability of intestinal transit, interaction with chyme, and the complex environment of the surface epithelia. We review the main classes of non-absorbable agents at various stages of development, and their therapeutic potential and limitations. The rapid progress in the identification of intestinal receptors and transporters, their functional characterization and role in metabolic and inflammatory disorders, will undoubtedly renew interest in the development of novel, safe, non-systemic therapeutics. PMID:22300258

  19. Systemic trade risk of critical resources

    PubMed Central

    Klimek, Peter; Obersteiner, Michael; Thurner, Stefan

    2015-01-01

    In the wake of the 2008 financial crisis, the role of strongly interconnected markets in causing systemic instability has been increasingly acknowledged. Trade networks of commodities are susceptible to cascades of supply shocks that increase systemic trade risks and pose a threat to geopolitical stability. We show that supply risk, scarcity, and price volatility of nonfuel mineral resources are intricately connected with the structure of the worldwide trade networks spanned by these resources. At the global level, we demonstrate that the scarcity of a resource is closely related to the susceptibility of the trade network with respect to cascading shocks. At the regional level, we find that, to some extent, region-specific price volatility and supply risk can be understood by centrality measures that capture systemic trade risk. The resources associated with the highest systemic trade risk indicators are often those that are produced as by-products of major metals. We identify significant strategic shortcomings in the management of systemic trade risk, in particular in the European Union. PMID:26702431

  20. Involving family systems in critical care nursing: challenges and opportunities.

    PubMed

    Leon, Ana M; Knapp, Sandra

    2008-01-01

    The literature indicates that involvement of families in critical care settings is effective in meeting the needs of families and patients during a medical crisis. This article presents basic concepts from family systems theory, including cultural considerations useful in developing nursing care plans that integrate family involvement in the care of critically ill patients. PMID:18953193

  1. Systems approach critical to agroecosystems management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sustainable dryland agriculture in the semi-arid Great Plains of the U.S. depends on achieving economic yields while maintaining soil resources. The traditional system of conventional tillage wheat-fallow was vulnerable to excessive soil erosion which resulted in excessive organic matter loss. No-...

  2. Applying face identification to detecting hijacking of airplane

    NASA Astrophysics Data System (ADS)

    Luo, Xuanwen; Cheng, Qiang

    2004-09-01

    That terrorists hijacked the airplanes and crashed the World Trade Center is disaster to civilization. To avoid the happening of hijack is critical to homeland security. To report the hijacking in time, limit the terrorist to operate the plane if happened and land the plane to the nearest airport could be an efficient way to avoid the misery. Image processing technique in human face recognition or identification could be used for this task. Before the plane take off, the face images of pilots are input into a face identification system installed in the airplane. The camera in front of pilot seat keeps taking the pilot face image during the flight and comparing it with pre-input pilot face images. If a different face is detected, a warning signal is sent to ground automatically. At the same time, the automatic cruise system is started or the plane is controlled by the ground. The terrorists will have no control over the plane. The plane will be landed to a nearest or appropriate airport under the control of the ground or cruise system. This technique could also be used in automobile industry as an image key to avoid car stealth.

  3. Fuzzy Logic Decoupled Lateral Control for General Aviation Airplanes

    NASA Technical Reports Server (NTRS)

    Duerksen, Noel

    1997-01-01

    It has been hypothesized that a human pilot uses the same set of generic skills to control a wide variety of aircraft. If this is true, then it should be possible to construct an electronic controller which embodies this generic skill set such that it can successfully control different airplanes without being matched to a specific airplane. In an attempt to create such a system, a fuzzy logic controller was devised to control aileron or roll spoiler position. This controller was used to control bank angle for both a piston powered single engine aileron equipped airplane simulation and a business jet simulation which used spoilers for primary roll control. Overspeed, stall and overbank protection were incorporated in the form of expert systems supervisors and weighted fuzzy rules. It was found that by using the artificial intelligence techniques of fuzzy logic and expert systems, a generic lateral controller could be successfully used on two general aviation aircraft types that have very different characteristics. These controllers worked for both airplanes over their entire flight envelopes. The controllers for both airplanes were identical except for airplane specific limits (maximum allowable airspeed, throttle ]ever travel, etc.). This research validated the fact that the same fuzzy logic based controller can control two very different general aviation airplanes. It also developed the basic controller architecture and specific control parameters required for such a general controller.

  4. Fuzzy Logic Decoupled Longitudinal Control for General Aviation Airplanes

    NASA Technical Reports Server (NTRS)

    Duerksen, Noel

    1996-01-01

    It has been hypothesized that a human pilot uses the same set of generic skills to control a wide variety of aircraft. If this is true, then it should be possible to construct an electronic controller which embodies this generic skill set such that it can successfully control difference airplanes without being matched to a specific airplane. In an attempt to create such a system, a fuzzy logic controller was devised to control throttle position and another to control elevator position. These two controllers were used to control flight path angle and airspeed for both a piston powered single engine airplane simulation and a business jet simulation. Overspeed protection and stall protection were incorporated in the form of expert systems supervisors. It was found that by using the artificial intelligence techniques of fuzzy logic and expert systems, a generic longitudinal controller could be successfully used on two general aviation aircraft types that have very difference characteristics. These controllers worked for both airplanes over their entire flight envelopes including configuration changes. The controllers for both airplanes were identical except for airplane specific limits (maximum allowable airspeed, throttle lever travel, etc.). The controllers also handled configuration changes without mode switching or knowledge of the current configuration. This research validated the fact that the same fuzzy logic based controller can control two very different general aviation airplanes. It also developed the basic controller architecture and specific control parameters required for such a general controller.

  5. Medicare's prospective payment system: A critical appraisal

    PubMed Central

    Coulam, Robert F.; Gaumer, Gary L.

    1992-01-01

    Implementation of the Medicare prospective payment system (PPS) for hospital payment has produced major changes in the hospital industry and in the way hospital services are used by physicians and their patients. The substantial published literature that examines these changes is reviewed in this article. This literature suggests that most of the intended effects of PPS on costs and intensity of care have been realized. But the literature fails to answer fundamental questions about the effectiveness and equity of administered pricing as a policy tool for cost containment. The literature offers some hope that the worst fears about the effects of PPS on quality of care and the health of the hospital industry have not materialized. But because of data lags, the studies done to date seem to tell us more about the effects of the early, more generous period of PPS than about the opportunity costs of reducing hospital cost inflation. PMID:25372306

  6. Computational methods for criticality safety analysis within the scale system

    SciTech Connect

    Parks, C.V.; Petrie, L.M.; Landers, N.F.; Bucholz, J.A.

    1986-01-01

    The criticality safety analysis capabilities within the SCALE system are centered around the Monte Carlo codes KENO IV and KENO V.a, which are both included in SCALE as functional modules. The XSDRNPM-S module is also an important tool within SCALE for obtaining multiplication factors for one-dimensional system models. This paper reviews the features and modeling capabilities of these codes along with their implementation within the Criticality Safety Analysis Sequences (CSAS) of SCALE. The CSAS modules provide automated cross-section processing and user-friendly input that allow criticality safety analyses to be done in an efficient and accurate manner. 14 refs., 2 figs., 3 tabs.

  7. 77 FR 63264 - Airworthiness Directives; Airbus Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-16

    ... structure and airplane systems. The related investigative actions include an inspection to determine the... rule'' under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); 3. Will not... AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed rulemaking (NPRM)....

  8. Program computes single-point failures in critical system designs

    NASA Technical Reports Server (NTRS)

    Brown, W. R.

    1967-01-01

    Computer program analyzes the designs of critical systems that will either prove the design is free of single-point failures or detect each member of the population of single-point failures inherent in a system design. This program should find application in the checkout of redundant circuits and digital systems.

  9. Assessing Reliability: Critical Corrections for a Critical Examination of the Rorschach Comprehensive System.

    ERIC Educational Resources Information Center

    Meyer, Gregory J.

    1997-01-01

    In reply to criticism of the Rorschach Comprehensive System (CS) by J. Wood, M. Nezworski, and W. Stejskal (1996), this article presents a meta-analysis of published data indicating that the CS has excellent chance-corrected interrater reliability. It is noted that the erroneous assumptions of Wood et al. make their assertions about validity…

  10. Flight Test of a Propulsion-Based Emergency Control System on the MD-11 Airplane with Emphasis on the Lateral Axis

    NASA Technical Reports Server (NTRS)

    Burken, John J.; Burcham, Frank W., Jr.; Maine, Trindel A.; Feather, John; Goldthorpe, Steven; Kahler, Jeffrey A.

    1996-01-01

    A large, civilian, multi-engine transport MD-11 airplane control system was recently modified to perform as an emergency backup controller using engine thrust only. The emergency backup system, referred to as the propulsion-controlled aircraft (PCA) system, would be used if a major primary flight control system fails. To allow for longitudinal and lateral-directional control, the PCA system requires at least two engines and is implemented through software modifications. A flight-test program was conducted to evaluate the PCA system high-altitude flying characteristics and to demonstrate its capacity to perform safe landings. The cruise flight conditions, several low approaches and one landing without any aerodynamic flight control surface movement, were demonstrated. This paper presents results that show satisfactory performance of the PCA system in the longitudinal axis. Test results indicate that the lateral-directional axis of the system performed well at high attitude but was sluggish and prone to thermal upsets during landing approaches. Flight-test experiences and test techniques are also discussed with emphasis on the lateral-directional axis because of the difficulties encountered in flight test.

  11. The evolution of airplanes

    NASA Astrophysics Data System (ADS)

    Bejan, A.; Charles, J. D.; Lorente, S.

    2014-07-01

    The prevailing view is that we cannot witness biological evolution because it occurred on a time scale immensely greater than our lifetime. Here, we show that we can witness evolution in our lifetime by watching the evolution of the flying human-and-machine species: the airplane. We document this evolution, and we also predict it based on a physics principle: the constructal law. We show that the airplanes must obey theoretical allometric rules that unite them with the birds and other animals. For example, the larger airplanes are faster, more efficient as vehicles, and have greater range. The engine mass is proportional to the body size: this scaling is analogous to animal design, where the mass of the motive organs (muscle, heart, lung) is proportional to the body size. Large or small, airplanes exhibit a proportionality between wing span and fuselage length, and between fuel load and body size. The animal-design counterparts of these features are evident. The view that emerges is that the evolution phenomenon is broader than biological evolution. The evolution of technology, river basins, and animal design is one phenomenon, and it belongs in physics.

  12. A Cost Effective System Design Approach for Critical Space Systems

    NASA Technical Reports Server (NTRS)

    Abbott, Larry Wayne; Cox, Gary; Nguyen, Hai

    2000-01-01

    NASA-JSC required an avionics platform capable of serving a wide range of applications in a cost-effective manner. In part, making the avionics platform cost effective means adhering to open standards and supporting the integration of COTS products with custom products. Inherently, operation in space requires low power, mass, and volume while retaining high performance, reconfigurability, scalability, and upgradability. The Universal Mini-Controller project is based on a modified PC/104-Plus architecture while maintaining full compatibility with standard COTS PC/104 products. The architecture consists of a library of building block modules, which can be mixed and matched to meet a specific application. A set of NASA developed core building blocks, processor card, analog input/output card, and a Mil-Std-1553 card, have been constructed to meet critical functions and unique interfaces. The design for the processor card is based on the PowerPC architecture. This architecture provides an excellent balance between power consumption and performance, and has an upgrade path to the forthcoming radiation hardened PowerPC processor. The processor card, which makes extensive use of surface mount technology, has a 166 MHz PowerPC 603e processor, 32 Mbytes of error detected and corrected RAM, 8 Mbytes of Flash, and I Mbytes of EPROM, on a single PC/104-Plus card. Similar densities have been achieved with the quad channel Mil-Std-1553 card and the analog input/output cards. The power management built into the processor and its peripheral chip allows the power and performance of the system to be adjusted to meet the requirements of the application, allowing another dimension to the flexibility of the Universal Mini-Controller. Unique mechanical packaging allows the Universal Mini-Controller to accommodate standard COTS and custom oversized PC/104-Plus cards. This mechanical packaging also provides thermal management via conductive cooling of COTS boards, which are typically

  13. Network Randomization and Dynamic Defense for Critical Infrastructure Systems

    SciTech Connect

    Chavez, Adrian R.; Martin, Mitchell Tyler; Hamlet, Jason; Stout, William M.S.; Lee, Erik

    2015-04-01

    Critical Infrastructure control systems continue to foster predictable communication paths, static configurations, and unpatched systems that allow easy access to our nation's most critical assets. This makes them attractive targets for cyber intrusion. We seek to address these attack vectors by automatically randomizing network settings, randomizing applications on the end devices themselves, and dynamically defending these systems against active attacks. Applying these protective measures will convert control systems into moving targets that proactively defend themselves against attack. Sandia National Laboratories has led this effort by gathering operational and technical requirements from Tennessee Valley Authority (TVA) and performing research and development to create a proof-of-concept solution. Our proof-of-concept has been tested in a laboratory environment with over 300 nodes. The vision of this project is to enhance control system security by converting existing control systems into moving targets and building these security measures into future systems while meeting the unique constraints that control systems face.

  14. Simulation of Dynamics of a Flexible Miniature Airplane

    NASA Technical Reports Server (NTRS)

    Waszak, Martin R.

    2005-01-01

    A short report discusses selected aspects of the development of the University of Florida micro-aerial vehicle (UFMAV) basically, a miniature airplane that has a flexible wing and is representative of a new class of airplanes that would operate autonomously or under remote control and be used for surveillance and/or scientific observation. The flexibility of the wing is to be optimized such that passive deformation of the wing in the presence of aerodynamic disturbances would reduce the overall response of the airplane to disturbances, thereby rendering the airplane more stable as an observation platform. The aspect of the development emphasized in the report is that of computational simulation of dynamics of the UFMAV in flight, for the purpose of generating mathematical models for use in designing control systems for the airplane. The simulations are performed by use of data from a wind-tunnel test of the airplane in combination with commercial software, in which are codified a standard set of equations of motion of an airplane, and a set of mathematical routines to compute trim conditions and extract linear state space models.

  15. Optimization and self-organized criticality in a magnetic system

    NASA Astrophysics Data System (ADS)

    Onody, Roberto N.; de Castro, Paulo A.

    2003-05-01

    We propose a kind of Bak-Sneppen dynamics as a general optimization technique to treat magnetic systems. The resulting dynamics shows self-organized criticality with power-law scaling of the spatial and temporal correlations. An alternative method of the extremal optimization (EO) is also analyzed here. We provided a numerical confirmation that, for any possible value of its free parameter τ, the EO dynamics exhibits a non-critical behavior with an infinite spatial range and exponential decay of the avalanches. Using the chiral clock model as our test system, we compare the efficiency of the two dynamics with regard to their abilities to find the system's ground state.

  16. Critical Casimir forces in a magnetic system: An experimental protocol

    NASA Astrophysics Data System (ADS)

    Lopes Cardozo, David; Jacquin, Hugo; Holdsworth, Peter C. W.

    2014-11-01

    We numerically test an experimentally realizable method for the extraction of the critical Casimir force based on its thermodynamic definition as the derivative of the excess free energy with respect to system size. Free energy differences are estimated for different system sizes by integrating the order parameter along an isotherm. The method could be developed for experiments on magnetic systems and could give access to the critical Casimir force for any universality class. By choosing an applied field that opposes magnetic ordering at the boundaries, the Casimir force is found to increase by an order of magnitude over zero-field results.

  17. Traceability of Software Safety Requirements in Legacy Safety Critical Systems

    NASA Technical Reports Server (NTRS)

    Hill, Janice L.

    2007-01-01

    How can traceability of software safety requirements be created for legacy safety critical systems? Requirements in safety standards are imposed most times during contract negotiations. On the other hand, there are instances where safety standards are levied on legacy safety critical systems, some of which may be considered for reuse for new applications. Safety standards often specify that software development documentation include process-oriented and technical safety requirements, and also require that system and software safety analyses are performed supporting technical safety requirements implementation. So what can be done if the requisite documents for establishing and maintaining safety requirements traceability are not available?

  18. Critical experiments analysis by ABBN-90 constant system

    SciTech Connect

    Tsiboulia, A.; Nikolaev, M.N.; Golubev, V.

    1997-06-01

    The ABBN-90 is a new version of the well-known Russian group-constant system ABBN. Included constants were calculated based on files of evaluated nuclear data from the BROND-2, ENDF/B-VI, and JENDL-3 libraries. The ABBN-90 is intended for the calculation of different types of nuclear reactors and radiation shielding. Calculations of criticality safety and reactivity accidents are also provided by using this constant set. Validation of the ABBN-90 set was made by using a computerized bank of evaluated critical experiments. This bank includes the results of experiments conducted in Russia and abroad of compact spherical assemblies with different reflectors, fast critical assemblies, and fuel/water-solution criticalities. This report presents the results of the calculational analysis of the whole collection of critical experiments. All calculations were produced with the ABBN-90 group-constant system. Revealed discrepancies between experimental and calculational results and their possible reasons are discussed. The codes and archives INDECS system is also described. This system includes three computerized banks: LEMEX, which consists of evaluated experiments and their calculational results; LSENS, which consists of sensitivity coefficients; and LUND, which consists of group-constant covariance matrices. The INDECS system permits us to estimate the accuracy of neutronics calculations. A discussion of the reliability of such estimations is finally presented. 16 figs.

  19. Annoyance Caused by Propeller Airplane Flyover Noise: Preliminary Results

    NASA Technical Reports Server (NTRS)

    Mccurdy, D. A.; Powell, C. A.

    1981-01-01

    The annoyance response of people to the noise of propeller airplane flyovers was examined. The specific items of interest were: (1) the annoyance prediction ability of current noise metrics; (2) the effect of tone corrections on prediction ability; (3) the effect of duration corrections on prediction ability; and (4) the effect of 'critical band' corrections on the prediction ability of perceived noise level. Preliminary analyses of the data obtained from two experiments are presented. The first experiment examined 11 propeller airplanes with maximum takeoff weights greater than or equal to 5700 kg. The second experiment examined 14 propeller airplanes weighting 5700 kg or less. Also included in each experiment were five different commercial service jet airplanes. Each airplane noise was presented at D-weighted sound pressure levels of 70, 80, and 90 dB to subjects in a testing room which simulates the outdoor acoustic environment. Subjects judged 108 stimuli in the first experiment and 132 stimuli in the second experiment. Perceived noise level predicted annoyance better than A, D, or E-weighted sound pressure level. Corrections for tones greater than of equal to 500 Hz generally improved prediction ability for the heavier propeller airplanes.

  20. Critical quasienergy states in driven many-body systems

    NASA Astrophysics Data System (ADS)

    Bastidas Valencia, Victor Manuel; Engelhardt, Georg; Perez-Fernandez, Pedro; Vogl, Malte; Brandes, Tobias

    2015-03-01

    A quantum phase transition (QPT) is characterized by non-analyticities of ground-state properties at the critical points. Recently it has been shown that quantum criticality emerges also in excited states of the system, which is referred to as an excited-state quantum phase transition (ESQPT). This kind of quantum criticality is intimately related to a level clustering at critical energies, which results in a logarithmic singularity in the density of states. Most of the previous studies on quantum criticality in excited states have been focused on time independent systems. Here we study spectral singularities that appear in periodically-driven many-body systems and show how the external control allows one to engineer geometrical features of the quasienergy landscape. In particular, we study singularities in the quasienergy spectrum of a fully-connected network consisting of two-level systems with time-dependent interactions. We discuss the characteristic signatures of these singularities in observables like the magnetization, which should be measurable with current technology. The authors gratefully acknowledge financial support by the DFG via grants BRA 1528/7, BRA 1528/8, SFB 910 (V.M.B., T.B.), the Spanish Ministerio de Ciencia e Innovacion (Grants No. FIS2011-28738-C02-01) and Junta de Andalucia (Grants No. FQM160).

  1. The Nuclear Criticality Information System's project to archive unpublished critical experiment data

    SciTech Connect

    Koponen, B.L. ); Clayton, E.D.; Doherty, A.L. )

    1991-07-01

    Critical experiment facilities produced a large amount of important data during the past forty-five years. However, much useful data remains unpublished. The unpublished material exists in the form of experimenters' logbooks, notes, photographs, material descriptions, etc. These data could be important for computer code validation, understanding the physics of criticality, facility design, or for setting process limits. In the past, criticality specialists have been able to obtain unpublished details by direct contact with the experimenters. Obviously, this will not be possible indefinitely. Most of the US critical experiment facilities are now closed, the experimenters are moving the other jobs, retiring, or otherwise becoming unavailable for this informal assistance. The closure of the facilities and the loss of personnel is likely to lead to the loss of the facility records unless an effort is made to assure that the records are preserved. It has been recognized for some time that the unpublished records of critical experiment facilities comprise a valuable resource, thus the Nuclear Criticality Information System (NCIS) is working to insure that the records are preserved and made available via NCIS. As a first step in the archiving project, we identified criteria to help judge which series of experiments should be considered for archiving. Data that are used for validating calculations or the basis for subcritical limits in standards, handbooks, and guides are of particular importance. In this paper we will discuss the criteria for archiving, the priority list of experiments for archiving, and progress in developing an NCIS image database using current CD-ROM technology.

  2. The search for quantum critical scaling in a classical system

    NASA Astrophysics Data System (ADS)

    Lamsal, Jagat; Gaddy, John; Petrovic, Marcus; Montfrooij, Wouter; Vojta, Thomas

    2009-04-01

    Order-disorder phase transitions in magnetic metals that occur at zero temperature have been studied in great detail. Theorists have advanced scenarios for these quantum critical systems in which the unusual response can be seen to evolve from a competition between ordering and disordering tendencies, driven by quantum fluctuations. Unfortunately, there is a potential disconnect between the real systems that are being studied experimentally, and the idealized systems that theoretical scenarios are based upon. Here we discuss how disorder introduces a change in morphology from a three-dimensional system to a collection of magnetic clusters, and we present neutron scattering data on a classical system, Li[Mn1.96Li0.04]O4, that show how magnetic clusters by themselves can lead to scaling laws that mimic those observed in quantum critical systems.

  3. Progress report of the critical equipment monitoring system

    SciTech Connect

    Pantis, M.J.

    1984-05-01

    The Philadelphia Electric Company has contracted with Energy Data Systems to develop a Critical Equipment Monitoring System for its Peach Bottom Nuclear Plant. This computerized system is designed to acquire and maintain accurate and timely status information on plant equipment. It will provide auditable record of plant and equipment transactions. Positive equipment identification and location will be provided. Errors in complex logical checking will be minimized. This system should reduce operator loading and improve operator communicatin with the plant personnel. Phase I of this system was installed at Peach Bottom Nuclear Station May 1982. It provides the necessary hardware and software to do check-off lists on critical plant systems. This paper describes some of the start-up and operational problems encountered.

  4. Critical issues in process control system security : DHS spares project.

    SciTech Connect

    Hernandez, Jacquelynne; McIntyre, Annie; Henrie, Morgan

    2010-10-01

    The goals of this event are: (1) Discuss the next-generation issues and emerging risks in cyber security for control systems; (2) Review and discuss common control system architectures; (3) Discuss the role of policy, standards, and supply chain issues; (4) Interact to determine the most pertinent risks and most critical areas of the architecture; and (5) Merge feedback from Control System Managers, Engineers, IT, and Auditors.

  5. Formal methods in the development of safety critical software systems

    SciTech Connect

    Williams, L.G.

    1991-11-15

    As the use of computers in critical control systems such as aircraft controls, medical instruments, defense systems, missile controls, and nuclear power plants has increased, concern for the safety of those systems has also grown. Much of this concern has focused on the software component of those computer-based systems. This is primarily due to historical experience with software systems that often exhibit larger numbers of errors than their hardware counterparts and the fact that the consequences of a software error may endanger human life, property, or the environment. A number of different techniques have been used to address the issue of software safety. Some are standard software engineering techniques aimed at reducing the number of faults in a software protect, such as reviews and walkthroughs. Others, including fault tree analysis, are based on identifying and reducing hazards. This report examines the role of one such technique, formal methods, in the development of software for safety critical systems. The use of formal methods to increase the safety of software systems is based on their role in reducing the possibility of software errors that could lead to hazards. The use of formal methods in the development of software systems is controversial. Proponents claim that the use of formal methods can eliminate errors from the software development process, and produce programs that are probably correct. Opponents claim that they are difficult to learn and that their use increases development costs unacceptably. This report discusses the potential of formal methods for reducing failures in safety critical software systems.

  6. Automated airplane surface generation

    SciTech Connect

    Smith, R.E.; Cordero, Y.; Jones, W.

    1996-12-31

    An efficient methodology and software axe presented for defining a class of airplane configurations. A small set of engineering design parameters and grid control parameters govern the process. The general airplane configuration has wing, fuselage, vertical tall, horizontal tail, and canard components. Wing, canard, and tail surface grids axe manifested by solving a fourth-order partial differential equation subject to Dirichlet and Neumann boundary conditions. The design variables are incorporated into the boundary conditions, and the solution is expressed as a Fourier series. The fuselage is described by an algebraic function with four design parameters. The computed surface grids are suitable for a wide range of Computational Fluid Dynamics simulation and configuration optimizations. Both batch and interactive software are discussed for applying the methodology.

  7. Software Safety Risk in Legacy Safety-Critical Computer Systems

    NASA Technical Reports Server (NTRS)

    Hill, Janice; Baggs, Rhoda

    2007-01-01

    Safety-critical computer systems must be engineered to meet system and software safety requirements. For legacy safety-critical computer systems, software safety requirements may not have been formally specified during development. When process-oriented software safety requirements are levied on a legacy system after the fact, where software development artifacts don't exist or are incomplete, the question becomes 'how can this be done?' The risks associated with only meeting certain software safety requirements in a legacy safety-critical computer system must be addressed should such systems be selected as candidates for reuse. This paper proposes a method for ascertaining formally, a software safety risk assessment, that provides measurements for software safety for legacy systems which may or may not have a suite of software engineering documentation that is now normally required. It relies upon the NASA Software Safety Standard, risk assessment methods based upon the Taxonomy-Based Questionnaire, and the application of reverse engineering CASE tools to produce original design documents for legacy systems.

  8. Evolution Towards Critical Fluctuations in a System of Accidental Pathogens

    NASA Astrophysics Data System (ADS)

    Ghaffari, Peyman; Jansen, Vincent; Stollenwerk, Nico

    2011-09-01

    Some time ago a model for accidental pathogens was developed to describe large fluctuations in the epidemiology of some diseases where the pathogen mostly lives with its host as a commensal and only rarely causes disease, leading to a disadvantage of the mutants which cause disease more often. By now the simplest version of this scenario is known as Stollenwerk-Jansen (SJ) model, showing that the critical exponents of the large fluctuations are of the type of the voter model (which by itself has an evolutionary biologists predecessor) but no further attempt was made there to investigate in more detail the mechanism leading the system to evolve towards small pathogenicity. We investigate an extended version of the SJ model, the SJ model version II in which we find the system to evolve to low pathogenicity causing large critical fluctuations without tuning the control parameter, a self-organization of criticality.

  9. Testing airplane fabrics

    NASA Technical Reports Server (NTRS)

    Proll, A

    1924-01-01

    The following considerations determine the strength of airplane fabrics: 1. maximum air forces acting on the surfaces (including local stresses); 2. tensions produced in the fabrics, in the directions of both warp and filling; 3. factor of safety required. The question of the permissible depression of the fabric as affecting the aerodynamic requirements in regard to the maintenance of shape of the section, the tenacity and extensibility of the layer of dope, its strength and its permeability to water is almost as important.

  10. Airplane dopes and doping

    NASA Technical Reports Server (NTRS)

    Smith, W H

    1919-01-01

    Cellulose acetate and cellulose nitrate are the important constituents of airplane dopes in use at the present time, but planes were treated with other materials in the experimental stages of flying. The above compounds belong to the class of colloids and are of value because they produce a shrinking action on the fabric when drying out of solution, rendering it drum tight. Other colloids possessing the same property have been proposed and tried. In the first stages of the development of dope, however, shrinkage was not considered. The fabric was treated merely to render it waterproof. The first airplanes constructed were covered with cotton fabric stretched as tightly as possible over the winds, fuselage, etc., and flying was possible only in fine weather. The necessity of an airplane which would fly under all weather conditions at once became apparent. Then followed experiments with rubberized fabrics, fabrics treated with glue rendered insoluble by formaldehyde or bichromate, fabrics treated with drying and nondrying oils, shellac, casein, etc. It was found that fabrics treated as above lost their tension in damp weather, and the oil from the motor penetrated the proofing material and weakened the fabric. For the most part the film of material lacked durability. Cellulose nitrate lacquers, however were found to be more satisfactory under varying weather conditions, added less weight to the planes, and were easily applied. On the other hand, they were highly inflammable, and oil from the motor penetrated the film of cellulose nitrate, causing the tension of the fabric to be relaxed.

  11. 77 FR 50644 - Airworthiness Directives; Cessna Airplane Company Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-22

    ... 1134104-5 air conditioning (A/C) compressor motor; and (2) are certificated in any category. (d) Subject... certain Cessna Airplane Company Model 525 airplanes equipped with certain part number (P/N) air conditioning (A/C) compressor motors. This proposed AD was prompted by reports of smoke and/or fire in...

  12. Airplane stability calculations and their verification by flight tests

    NASA Technical Reports Server (NTRS)

    Rota, Augusto

    1922-01-01

    For some time, the designers of airplanes have begun to occupy themselves with the question of longitudinal stability. In their quest to simplify calculation and data collection, the designers have attached the greatest importance to the coefficient of initial longitudinal stability. In this study a diagram was constructed from the data of the tunnel tests, which depends neither on the position of the center of gravity nor of the angle of deflection of the elevators. This diagram is constructed by means of straight lines drawn through the metacenters of the complete airplane, in a direction parallel to the tangents to the polar of the airplane relative to a system of axes fixed with reference to the airplane.

  13. Bolted Flanged Connection for Critical Plant/Piping Systems

    SciTech Connect

    Efremov, Anatoly

    2006-07-01

    A novel type of Bolted Flanged Connection with bolts and gasket manufactured on a basis of advanced Shape Memory Alloys is examined. Presented approach combined with inverse flexion flange design of plant/piping joint reveals a significant increase of internal pressure under conditions of a variety of operating temperatures relating to critical plant/piping systems. (author)

  14. Los Alamos personnel and area criticality dosimeter systems

    SciTech Connect

    Vasilik, D.G.; Martin, R.W.

    1981-06-01

    Fissionable materials are handled and processed at the Los Alamos National Laboratory. Although the probability of a nuclear criticality accident is very remote, it must be considered. Los Alamos maintains a broad spectrum of dose assessment capabilities. This report describes the methods employed for personnel neutron, area neutron, and photon dose evaluations with passive dosimetry systems.

  15. Termini of calving glaciers as self-organized critical systems

    NASA Astrophysics Data System (ADS)

    Åström, J. A.; Vallot, D.; Schäfer, M.; Welty, E. Z.; O'Neel, S.; Bartholomaus, T. C.; Liu, Yan; Riikilä, T. I.; Zwinger, T.; Timonen, J.; Moore, J. C.

    2014-12-01

    Over the next century, one of the largest contributions to sea level rise will come from ice sheets and glaciers calving ice into the ocean. Factors controlling the rapid and nonlinear variations in calving fluxes are poorly understood, and therefore difficult to include in prognostic climate-forced land-ice models. Here we analyse globally distributed calving data sets from Svalbard, Alaska (USA), Greenland and Antarctica in combination with simulations from a first-principles, particle-based numerical calving model to investigate the size and inter-event time of calving events. We find that calving events triggered by the brittle fracture of glacier ice are governed by the same power-law distributions as avalanches in the canonical Abelian sandpile model. This similarity suggests that calving termini behave as self-organized critical systems that readily flip between states of sub-critical advance and super-critical retreat in response to changes in climate and geometric conditions. Observations of sudden ice-shelf collapse and tidewater glacier retreat in response to gradual warming of their environment are consistent with a system fluctuating around its critical point in response to changing external forcing. We propose that self-organized criticality provides a yet unexplored framework for investigations into calving and projections of sea level rise.

  16. 'One physical system': Tansley's ecosystem as Earth's critical zone.

    PubMed

    Richter, Daniel deB; Billings, Sharon A

    2015-05-01

    Integrative concepts of the biosphere, ecosystem, biogeocenosis and, recently, Earth's critical zone embrace scientific disciplines that link matter, energy and organisms in a systems-level understanding of our remarkable planet. Here, we assert the congruence of Tansley's (1935) venerable ecosystem concept of 'one physical system' with Earth science's critical zone. Ecosystems and critical zones are congruent across spatial-temporal scales from vegetation-clad weathering profiles and hillslopes, small catchments, landscapes, river basins, continents, to Earth's whole terrestrial surface. What may be less obvious is congruence in the vertical dimension. We use ecosystem metabolism to argue that full accounting of photosynthetically fixed carbon includes respiratory CO₂ and carbonic acid that propagate to the base of the critical zone itself. Although a small fraction of respiration, the downward diffusion of CO₂ helps determine rates of soil formation and, ultimately, ecosystem evolution and resilience. Because life in the upper portions of terrestrial ecosystems significantly affects biogeochemistry throughout weathering profiles, the lower boundaries of most terrestrial ecosystems have been demarcated at depths too shallow to permit a complete understanding of ecosystem structure and function. Opportunities abound to explore connections between upper and lower components of critical-zone ecosystems, between soils and streams in watersheds, and between plant-derived CO₂ and deep microbial communities and mineral weathering. PMID:25731586

  17. 75 FR 46868 - Airworthiness Directives; The Boeing Company Model 747 Airplanes and Model 767 Airplanes Equipped...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-04

    ... airplanes. That original NPRM was published in the Federal Register on April 7, 2008 (73 FR 18721). That... Relevant Rulemaking Related NPRM, Docket FAA-2008-0403, Directorate Identifier 2007-NM- 166-AD (73 FR 18719... Global Supply Systems (Global) requests that we revise AD 2007-12- 07, Amendment 39-15085 (72 FR...

  18. Application of SAE ARP4754A to Flight Critical Systems

    NASA Technical Reports Server (NTRS)

    Peterson, Eric M.

    2015-01-01

    This report documents applications of ARP4754A to the development of modern computer-based (i.e., digital electronics, software and network-based) aircraft systems. This study is to offer insight and provide educational value relative to the guidelines in ARP4754A and provide an assessment of the current state-of-the- practice within industry and regulatory bodies relative to development assurance for complex and safety-critical computer-based aircraft systems.

  19. Robust requirements specifications for safety-critical systems

    NASA Astrophysics Data System (ADS)

    Saeed, A.; Anderson, T.; Delemos, R.

    1993-10-01

    Experience in safety-critical systems has shown that deviations from assumed behavior can and do cause accidents. This suggests that the development of requirements specifications for such systems should be supported with a risk analysis. In this paper, we present an approach to the development of robust requirements specifications (i.e. specifications that are adequate for the risks involved), based on qualitative and quantitative analyses.

  20. Seminar in Critical Inquiry Twenty-first Century Nuclear Systems

    SciTech Connect

    LeMone, D. V.

    2002-02-25

    Critical Inquiry, has not only been successful in increasing university student retention rate but also in improving student academic performance beyond the initial year of transition into the University. The seminar course herein reviewed is a balanced combination of student personal and academic skill development combined with a solid background in modern nuclear systems. It is a valid premise to assume that entering students as well as stakeholders of the general public demonstrate equal levels of capability. Nuclear systems is designed to give a broad and basic knowledge of nuclear power, medical, industrial, research, and military systems (nuclear systems) in 20-25 hours.

  1. Critical event management with geographic information system technology

    NASA Astrophysics Data System (ADS)

    Booth, John F.; Young, Jeffrey M.

    1997-02-01

    Critical event management at the Los Angeles County Regional Criminal Information Clearinghouse (LACRCIC) provides for the deconfliction of operations, such as reverse stings, arrests, undercover buys/busts, searches, surveillances, and site surveys in the Los Angeles, Orange, Riverside, and San Bernardino county area. During these operations, the opportunity for officer-to-officer confrontation is high, possibly causing a worse case scenario -- officers drawing on each other resulting in friendly fire injuries or casualties. In order to prevent local, state, and federal agencies in the Los Angeles area from experiencing this scenario, the LACRCIC provides around the clock critical event management services via its secure war room. The war room maintains a multicounty detailed street-level map base and geographic information system (GIS) application to support this effort. Operations are telephoned in by the participating agencies and posted in the critical event management system by war room analysts. The application performs both a proximity search around the address and a commonality of suspects search. If a conflict is found, the system alerts the analyst by sounding an audible alarm and flashing the conflicting events on the automated basemap. The analyst then notifies the respective agencies of the conflicting critical events so coordination or rescheduling can occur.

  2. Trend of airplane flight characteristics

    NASA Technical Reports Server (NTRS)

    Von Koppen, Joachim

    1933-01-01

    This report describes the development of airplane characteristics since the war and indicates the direction development should take in the immediate future. Some of the major topics include: the behavior of an airplane about its lateral, vertical, and longitudinal axes. Behavior at large angles of attack and landing characteristics are also included.

  3. Semiparametric energy-based models of systems exhibiting criticality

    NASA Astrophysics Data System (ADS)

    Humplik, Jan; Tkacik, Gasper

    Over the last decade, several empirical studies have found evidence that many biological and natural systems exhibit critical fluctuations analogous to those observed during second-order phase transitions in equilibrium systems. In many cases, these fluctuations were shown to be equivalent to a thermodynamic version of Zipf's law-if the system is sufficiently large, then a log-log plot of the probability of a state vs. its rank yields a straight line with slope - 1 . Because the origin of critical fluctuations cannot be traced to a unique mechanism, it is important that data-driven phenomenological models of natural systems are flexible enough so as to easily capture any kind of criticality. Here we study a class of models with exactly this property. This class consists of energy-based models in which the exponential Boltzmann factor is replaced by an arbitrary nonlinear function. We demonstrate the usefulness of our method by modeling the spiking activity of a population of retinal neurons, and the distribution of light intensities in small patches of natural images. In light of recent work on models with hidden variables, the proposed method can separate interactions induced by an unknown fluctuating environment from interactions intrinsic to the system.

  4. Neural Network Based Intrusion Detection System for Critical Infrastructures

    SciTech Connect

    Todd Vollmer; Ondrej Linda; Milos Manic

    2009-07-01

    Resiliency and security in control systems such as SCADA and Nuclear plant’s in today’s world of hackers and malware are a relevant concern. Computer systems used within critical infrastructures to control physical functions are not immune to the threat of cyber attacks and may be potentially vulnerable. Tailoring an intrusion detection system to the specifics of critical infrastructures can significantly improve the security of such systems. The IDS-NNM – Intrusion Detection System using Neural Network based Modeling, is presented in this paper. The main contributions of this work are: 1) the use and analyses of real network data (data recorded from an existing critical infrastructure); 2) the development of a specific window based feature extraction technique; 3) the construction of training dataset using randomly generated intrusion vectors; 4) the use of a combination of two neural network learning algorithms – the Error-Back Propagation and Levenberg-Marquardt, for normal behavior modeling. The presented algorithm was evaluated on previously unseen network data. The IDS-NNM algorithm proved to be capable of capturing all intrusion attempts presented in the network communication while not generating any false alerts.

  5. 14 CFR 23.3 - Airplane categories.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Airplane categories. 23.3 Section 23.3... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES General § 23.3 Airplane categories. (a) The normal category is limited to airplanes that have a seating configuration, excluding...

  6. 14 CFR 23.3 - Airplane categories.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Airplane categories. 23.3 Section 23.3... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES General § 23.3 Airplane categories. (a) The normal category is limited to airplanes that have a seating configuration, excluding...

  7. 14 CFR 23.3 - Airplane categories.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Airplane categories. 23.3 Section 23.3... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES General § 23.3 Airplane categories... airplanes that have a seating configuration, excluding pilot seats, of nine or less, a maximum...

  8. 14 CFR 23.3 - Airplane categories.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Airplane categories. 23.3 Section 23.3... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES General § 23.3 Airplane categories. (a) The normal category is limited to airplanes that have a seating configuration, excluding...

  9. 14 CFR 23.3 - Airplane categories.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Airplane categories. 23.3 Section 23.3... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES General § 23.3 Airplane categories. (a) The normal category is limited to airplanes that have a seating configuration, excluding...

  10. Testbeds for Assessing Critical Scenarios in Power Control Systems

    NASA Astrophysics Data System (ADS)

    Dondossola, Giovanna; Deconinck, Geert; Garrone, Fabrizio; Beitollahi, Hakem

    The paper presents a set of control system scenarios implemented in two testbeds developed in the context of the European Project CRUTIAL - CRitical UTility InfrastructurAL Resilience. The selected scenarios refer to power control systems encompassing information and communication security of SCADA systems for grid teleoperation, impact of attacks on inter-operator communications in power emergency conditions, impact of intentional faults on the secondary and tertiary control in power grids with distributed generators. Two testbeds have been developed for assessing the effect of the attacks and prototyping resilient architectures.

  11. 14 CFR 121.293 - Special airworthiness requirements for nontransport category airplanes type certificated after...

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... warning system that meets the requirements of 14 CFR 25.703. However, the takeoff warning system does not... nontransport category airplanes type certificated after December 31, 1964. 121.293 Section 121.293 Aeronautics... nontransport category airplanes type certificated after December 31, 1964. No certificate holder may operate...

  12. Description of Fracture Systems for External Criticality Reports

    SciTech Connect

    Jean-Philippe Nicot

    2001-09-21

    The purpose of this Analysis/Model Report (AMR) is to describe probabilistically the main features of the geometry of the fracture system in the vicinity of the repository. They will be used to determine the quantity of fissile material that could accumulate in the fractured rock underneath a waste package as it degrades. This AMR is to feed the geochemical calculations for external criticality reports. This AMR is done in accordance with the technical work plan (BSC (Bechtel SAIC Company) 2001 b). The scope of this AMR is restricted to the relevant parameters of the fracture system. The main parameters of interest are fracture aperture and fracture spacing distribution parameters. The relative orientation of the different fracture sets is also important because of its impact on criticality, but they will be set deterministically. The maximum accumulation of material depends primarily on the fracture porosity, combination of the fracture aperture, and fracture intensity. However, the fracture porosity itself is not sufficient to characterize the potential for accumulation of a fracture system. The fracture aperture is also important because it controls both the flow through the fracture and the potential plugging of the system. Other features contributing to the void space such as lithophysae are also investigated. On the other hand, no analysis of the matrix porosity is done. The parameters will be used in sensitivity analyses of geochemical calculations providing actinide accumulations and in the subsequent Monte Carlo criticality analyses.

  13. Software Safety Risk in Legacy Safety-Critical Computer Systems

    NASA Technical Reports Server (NTRS)

    Hill, Janice L.; Baggs, Rhoda

    2007-01-01

    Safety Standards contain technical and process-oriented safety requirements. Technical requirements are those such as "must work" and "must not work" functions in the system. Process-Oriented requirements are software engineering and safety management process requirements. Address the system perspective and some cover just software in the system > NASA-STD-8719.13B Software Safety Standard is the current standard of interest. NASA programs/projects will have their own set of safety requirements derived from the standard. Safety Cases: a) Documented demonstration that a system complies with the specified safety requirements. b) Evidence is gathered on the integrity of the system and put forward as an argued case. [Gardener (ed.)] c) Problems occur when trying to meet safety standards, and thus make retrospective safety cases, in legacy safety-critical computer systems.

  14. Software Reliability Issues Concerning Large and Safety Critical Software Systems

    NASA Technical Reports Server (NTRS)

    Kamel, Khaled; Brown, Barbara

    1996-01-01

    This research was undertaken to provide NASA with a survey of state-of-the-art techniques using in industrial and academia to provide safe, reliable, and maintainable software to drive large systems. Such systems must match the complexity and strict safety requirements of NASA's shuttle system. In particular, the Launch Processing System (LPS) is being considered for replacement. The LPS is responsible for monitoring and commanding the shuttle during test, repair, and launch phases. NASA built this system in the 1970's using mostly hardware techniques to provide for increased reliability, but it did so often using custom-built equipment, which has not been able to keep up with current technologies. This report surveys the major techniques used in industry and academia to ensure reliability in large and critical computer systems.

  15. 77 FR 15291 - Airworthiness Directives; Airbus Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-15

    ... rule'' under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); 3. Will not... B4-622R airplanes; Model A300 C4-605R Variant F airplanes; and Model A300 F4-600R series airplanes... B4-603, B4-605R, and B4- 622R airplanes; Model A300 C4-605R Variant F airplanes; and Model A300...

  16. A Project Manager's View of Safety-Critical Systems

    NASA Astrophysics Data System (ADS)

    Docker, Thomas

    This paper presents a project manager's view that safety-critical systems are not a special case or category of product development, but is one dimension that is a requirement in increasingly more systems. As with any product development, the degree to which a safety-critical product is tested or proved should be based on 'cost of failure' that, in the final analysis, is a commercial decision based on benefits and business risk. It is argued that with the emphasis on cost of failure, project teams can be more effective in producing safer products, particularly in terms of focusing testing. With effectiveness in mind, an approach to linking benefits to products is described, along with how this relates to requirements and acceptance criteria. Possible impacts of the use of standards in a project are also discussed. Case studies are used to reinforce concepts and highlight concerns.

  17. Spacecraft System Integration and Test: SSTI Lewis critical design audit

    NASA Technical Reports Server (NTRS)

    Brooks, R. P.; Cha, K. K.

    1995-01-01

    The Critical Design Audit package is the final detailed design package which provides a comprehensive description of the SSTI mission. This package includes the program overview, the system requirements, the science and applications activities, the ground segment development, the assembly, integration and test description, the payload and technology demonstrations, and the spacecraft bus subsystems. Publication and presentation of this document marks the final requirements and design freeze for SSTI.

  18. Analyzing Software Requirements Errors in Safety-Critical, Embedded Systems

    NASA Technical Reports Server (NTRS)

    Lutz, Robyn R.

    1993-01-01

    This paper analyzes the root causes of safety-related software errors in safety-critical, embedded systems. The results show that software errors identified as potentially hazardous to the system tend to be produced by different error mechanisms than non- safety-related software errors. Safety-related software errors are shown to arise most commonly from (1) discrepancies between the documented requirements specifications and the requirements needed for correct functioning of the system and (2) misunderstandings of the software's interface with the rest of the system. The paper uses these results to identify methods by which requirements errors can be prevented. The goal is to reduce safety-related software errors and to enhance the safety of complex, embedded systems.

  19. Evaluating Models of Human Performance: Safety-Critical Systems Applications

    NASA Technical Reports Server (NTRS)

    Feary, Michael S.

    2012-01-01

    This presentation is part of panel discussion on Evaluating Models of Human Performance. The purpose of this panel is to discuss the increasing use of models in the world today and specifically focus on how to describe and evaluate models of human performance. My presentation will focus on discussions of generating distributions of performance, and the evaluation of different strategies for humans performing tasks with mixed initiative (Human-Automation) systems. I will also discuss issues with how to provide Human Performance modeling data to support decisions on acceptability and tradeoffs in the design of safety critical systems. I will conclude with challenges for the future.

  20. Verification and Validation for Flight-Critical Systems (VVFCS)

    NASA Technical Reports Server (NTRS)

    Graves, Sharon S.; Jacobsen, Robert A.

    2010-01-01

    On March 31, 2009 a Request for Information (RFI) was issued by NASA s Aviation Safety Program to gather input on the subject of Verification and Validation (V & V) of Flight-Critical Systems. The responses were provided to NASA on or before April 24, 2009. The RFI asked for comments in three topic areas: Modeling and Validation of New Concepts for Vehicles and Operations; Verification of Complex Integrated and Distributed Systems; and Software Safety Assurance. There were a total of 34 responses to the RFI, representing a cross-section of academic (26%), small & large industry (47%) and government agency (27%).

  1. An agent-based microsimulation of critical infrastructure systems

    SciTech Connect

    BARTON,DIANNE C.; STAMBER,KEVIN L.

    2000-03-29

    US infrastructures provide essential services that support the economic prosperity and quality of life. Today, the latest threat to these infrastructures is the increasing complexity and interconnectedness of the system. On balance, added connectivity will improve economic efficiency; however, increased coupling could also result in situations where a disturbance in an isolated infrastructure unexpectedly cascades across diverse infrastructures. An understanding of the behavior of complex systems can be critical to understanding and predicting infrastructure responses to unexpected perturbation. Sandia National Laboratories has developed an agent-based model of critical US infrastructures using time-dependent Monte Carlo methods and a genetic algorithm learning classifier system to control decision making. The model is currently under development and contains agents that represent the several areas within the interconnected infrastructures, including electric power and fuel supply. Previous work shows that agent-based simulations models have the potential to improve the accuracy of complex system forecasting and to provide new insights into the factors that are the primary drivers of emergent behaviors in interdependent systems. Simulation results can be examined both computationally and analytically, offering new ways of theorizing about the impact of perturbations to an infrastructure network.

  2. Radiated Emissions from a Remote-Controlled Airplane-Measured in a Reverberation Chamber

    NASA Technical Reports Server (NTRS)

    Ely, Jay J.; Koppen, Sandra V.; Nguyen, Truong X.; Dudley, Kenneth L.; Szatkowski, George N.; Quach, Cuong C.; Vazquez, Sixto L.; Mielnik, John J.; Hogge, Edward F.; Hill, Boyd L.; Strom, Thomas H.

    2011-01-01

    A full-vehicle, subscale all-electric model airplane was tested for radiated emissions, using a reverberation chamber. The mission of the NASA model airplane is to test in-flight airframe damage diagnosis and battery prognosis algorithms, and provide experimental data for other aviation safety research. Subscale model airplanes are economical experimental tools, but assembling their systems from hobbyist and low-cost components may lead to unforseen electromagnetic compatibility problems. This report provides a guide for accommodating the on-board radio systems, so that all model airplane systems may be operated during radiated emission testing. Radiated emission data are provided for on-board systems being operated separately and together, so that potential interferors can be isolated and mitigated. The report concludes with recommendations for EMI/EMC best practices for subscale model airplanes and airships used for research.

  3. Sleep dynamics: A self-organized critical system

    NASA Astrophysics Data System (ADS)

    Comte, J. C.; Ravassard, P.; Salin, P. A.

    2006-05-01

    In psychiatric and neurological diseases, sleep is often perturbed. Moreover, recent works on humans and animals tend to show that sleep plays a strong role in memory processes. Reciprocally, sleep dynamics following a learning task is modified [Hubert , Nature (London) 02663, 1 (2004), Peigneux , Neuron 44, 535 (2004)]. However, sleep analysis in humans and animals is often limited to the total sleep and wake duration quantification. These two parameters are not fully able to characterize the sleep dynamics. In mammals sleep presents a complex organization with an alternation of slow wave sleep (SWS) and paradoxical sleep (PS) episodes. Moreover, it has been shown recently that these sleep episodes are frequently interrupted by micro-arousal (without awakening). We present here a detailed analysis of the basal sleep properties emerging from the mechanisms underlying the vigilance states alternation in an animal model. These properties present a self-organized critical system signature and reveal the existence of two W, two SWS, and a PS structure exhibiting a criticality as met in sand piles. We propose a theoretical model of the sleep dynamics based on several interacting neuronal populations. This new model of sleep dynamics presents the same properties as experimentally observed, and explains the variability of the collected data. This experimental and theoretical study suggests that sleep dynamics shares several common features with critical systems.

  4. Mobile healthcare applications: system design review, critical issues and challenges.

    PubMed

    Baig, Mirza Mansoor; GholamHosseini, Hamid; Connolly, Martin J

    2015-03-01

    Mobile phones are becoming increasingly important in monitoring and delivery of healthcare interventions. They are often considered as pocket computers, due to their advanced computing features, enhanced preferences and diverse capabilities. Their sophisticated sensors and complex software applications make the mobile healthcare (m-health) based applications more feasible and innovative. In a number of scenarios user-friendliness, convenience and effectiveness of these systems have been acknowledged by both patients as well as healthcare providers. M-health technology employs advanced concepts and techniques from multidisciplinary fields of electrical engineering, computer science, biomedical engineering and medicine which benefit the innovations of these fields towards healthcare systems. This paper deals with two important aspects of current mobile phone based sensor applications in healthcare. Firstly, critical review of advanced applications such as; vital sign monitoring, blood glucose monitoring and in-built camera based smartphone sensor applications. Secondly, investigating challenges and critical issues related to the use of smartphones in healthcare including; reliability, efficiency, mobile phone platform variability, cost effectiveness, energy usage, user interface, quality of medical data, and security and privacy. It was found that the mobile based applications have been widely developed in recent years with fast growing deployment by healthcare professionals and patients. However, despite the advantages of smartphones in patient monitoring, education, and management there are some critical issues and challenges related to security and privacy of data, acceptability, reliability and cost that need to be addressed. PMID:25476753

  5. The GH/IGF-1 System in Critical Illness

    PubMed Central

    Elijah, Itoro; Branski, Ludwik K.; Finnerty, Celeste F.; Herndon, David N.

    2013-01-01

    The Growth Hormone and Insulin-like Growth Factor-1 axis plays a pivotal role in critical illness, with a derangement leading to profound changes in metabolism. Protein wasting with skeletal muscle loss, delayed wound healing, and impaired recovery of organ systems are some of the most feared consequences. The use of human recombinant Growth Hormone (rhGH) and Insulin-like Growth Factor-1 (IGF-1) - alone and in combination - has been studied extensively in preclinical and clinical trials. This article reviews the current knowlegde and clinical practice of the use of rhGh and IGF-1 in critically ill patients, with a special focus on the trauma and burns patient population. PMID:21925076

  6. Practical variational tomography for critical one-dimensional systems

    NASA Astrophysics Data System (ADS)

    Lee, Jong Yeon; Landon-Cardinal, Olivier

    2015-06-01

    We improve upon a recently introduced efficient quantum state reconstruction procedure targeted to states well approximated by the multiscale entanglement renormalization ansatz (MERA), e.g., ground states of critical models. We show how to numerically select a subset of experimentally accessible measurements which maximize information extraction about renormalized particles, thus dramatically reducing the required number of physical measurements. We numerically estimate the number of measurements required to characterize the ground state of the critical one-dimensional Ising (resp. XX) model and find that MERA tomography on 16-qubit (resp. 24-qubit) systems requires the same experimental effort as brute-force tomography on 8 qubits. We derive a bound computable from experimental data which certifies the distance between the experimental and reconstructed states.

  7. Critical Path-Based Thread Placement for NUMA Systems

    SciTech Connect

    Su, C Y; Li, D; Nikolopoulos, D S; Grove, M; Cameron, K; de Supinski, B R

    2011-11-01

    Multicore multiprocessors use a Non Uniform Memory Architecture (NUMA) to improve their scalability. However, NUMA introduces performance penalties due to remote memory accesses. Without efficiently managing data layout and thread mapping to cores, scientific applications, even if they are optimized for NUMA, may suffer performance loss. In this paper, we present algorithms and a runtime system that optimize the execution of OpenMP applications on NUMA architectures. By collecting information from hardware counters, the runtime system directs thread placement and reduces performance penalties by minimizing the critical path of OpenMP parallel regions. The runtime system uses a scalable algorithm that derives placement decisions with negligible overhead. We evaluate our algorithms and runtime system with four NPB applications implemented in OpenMP. On average the algorithms achieve between 8.13% and 25.68% performance improvement compared to the default Linux thread placement scheme. The algorithms miss the optimal thread placement in only 8.9% of the cases.

  8. 14 CFR Appendix B to Part 135 - Airplane Flight Recorder Specifications

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Airplane Flight Recorder Specifications B Appendix B to Part 135 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION.... B Appendix B to Part 135—Airplane Flight Recorder Specifications Parameters Range Installed system...

  9. 78 FR 11609 - Special Conditions: Embraer S.A., Model EMB-550 Airplane; Landing Pitchover Condition

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-19

    ...This action proposes special conditions for the Embraer S.A. Model EMB-550 airplane. This airplane will have a novel or unusual design feature(s) associated with landing loads due to the automatic braking system. The applicable airworthiness regulations do not contain adequate or appropriate safety standards for this design feature. These proposed special conditions contain the additional......

  10. Critical behavior in light nuclear systems: Experimental aspects

    SciTech Connect

    Ma, Y.G.; Natowitz, J.B.; Wada, R.; Hagel, K.; Wang, J.; Qin, L.; Smith, P.; Keksis, A.; Makeev, A.; Martin, E.; Ruangma, A.; Shetty, D.V.; Souliotis, G.; Veselsky, M.; Winchester, E.M.; Yennello, S.J.; Keutgen, T.; El Masri, Y.; Majka, Z.; Staszel, P.

    2005-05-01

    An extensive experimental survey of the features of the disassembly of a small quasiprojectile system with A{approx}36, produced in the reactions of 47 MeV/nucleon {sup 40}Ar + {sup 27}Al, {sup 48}Ti, and {sup 58}Ni, has been carried out. Nuclei in the excitation energy range of 1-9 MeV/nucleon have been investigated employing a new method to reconstruct the quasiprojectile source. At an excitation energy {approx}5.6 MeV/nucleon many observables indicate the presence of maximal fluctuations in the deexcitation processes. These include the normalized second moments of the Campi plot and normalized variances of the distributions of order parameters such as the atomic number of the heaviest fragment Z{sub max} and the total kinetic energy. The evolution of the correlation of the atomic number of the heaviest fragment with that of the second heaviest fragment and a bimodality test are also consistent with a transition in the same excitation energy region. The related phase separation parameter, S{sub p}, shows a significant change of slope at the same excitation energy. In the same region a {delta}-scaling analysis for of the heaviest fragments exhibits a transition to {delta} = 1 scaling, which is predicted to characterize a disordered phase. The fragment topological structure shows that the rank-sorted fragments obey Zipf's law at the point of largest fluctuations, providing another indication of a liquid gas phase transition. The Fisher droplet model critical exponent {tau} {approx} 2.3 obtained from the charge distribution at the same excitation energy is close to the critical exponent of the liquid gas phase transition universality class. The caloric curve for this system shows a monotonic increase of temperature with excitation energy and no apparent plateau. The temperature at the point of maximal fluctuations is 8.3{+-}0.5 MeV. Taking this temperature as the critical temperature and employing the caloric curve information we have extracted the critical

  11. Proton exchange membrane fuel cells for electrical power generation on-board commercial airplanes.

    SciTech Connect

    Curgus, Dita Brigitte; Munoz-Ramos, Karina; Pratt, Joseph William; Akhil, Abbas Ali; Klebanoff, Leonard E.; Schenkman, Benjamin L.

    2011-05-01

    Deployed on a commercial airplane, proton exchange membrane fuel cells may offer emissions reductions, thermal efficiency gains, and enable locating the power near the point of use. This work seeks to understand whether on-board fuel cell systems are technically feasible, and, if so, if they offer a performance advantage for the airplane as a whole. Through hardware analysis and thermodynamic and electrical simulation, we found that while adding a fuel cell system using today's technology for the PEM fuel cell and hydrogen storage is technically feasible, it will not likely give the airplane a performance benefit. However, when we re-did the analysis using DOE-target technology for the PEM fuel cell and hydrogen storage, we found that the fuel cell system would provide a performance benefit to the airplane (i.e., it can save the airplane some fuel), depending on the way it is configured.

  12. Proton Exchange Membrane Fuel Cells for Electrical Power Generation On-Board Commercial Airplanes

    SciTech Connect

    Pratt, Joesph W.; Klebanoff, Leonard E.; Munoz-Ramos, Karina; Akhil, Abbas A.; Curgus, Dita B.; Schenkman, Benjamin L.

    2011-05-01

    Deployed on a commercial airplane, proton exchange membrane fuel cells may offer emissions reductions, thermal efficiency gains, and enable locating the power near the point of use. This work seeks to understand whether on-board fuel cell systems are technically feasible, and, if so, if they offer a performance advantage for the airplane as a whole. Through hardware analysis and thermodynamic and electrical simulation, we found that while adding a fuel cell system using today’s technology for the PEM fuel cell and hydrogen storage is technically feasible, it will not likely give the airplane a performance benefit. However, when we re-did the analysis using DOE-target technology for the PEM fuel cell and hydrogen storage, we found that the fuel cell system would provide a performance benefit to the airplane (i.e., it can save the airplane some fuel), depending on the way it is configured.

  13. Critical dynamic approach to stationary states in complex systems

    NASA Astrophysics Data System (ADS)

    Rozenfeld, A. F.; Laneri, K.; Albano, E. V.

    2007-04-01

    A dynamic scaling Ansatz for the approach to stationary states in complex systems is proposed and tested by means of extensive simulations applied to both the Bak-Sneppen (BS) model, which exhibits robust Self-Organised Critical (SOC) behaviour, and the Game of Life (GOL) of J. Conway, whose critical behaviour is under debate. Considering the dynamic scaling behaviour of the density of sites (ρ(t)), it is shown that i) by starting the dynamic measurements with configurations such that ρ(t=0) →0, one observes an initial increase of the density with exponents θ= 0.12(2) and θ= 0.11(2) for the BS and GOL models, respectively; ii) by using initial configurations with ρ(t=0) →1, the density decays with exponents δ= 0.47(2) and δ= 0.28(2) for the BS and GOL models, respectively. It is also shown that the temporal autocorrelation decays with exponents Ca = 0.35(2) (Ca = 0.35(5)) for the BS (GOL) model. By using these dynamically determined critical exponents and suitable scaling relationships, we also obtain the dynamic exponents z = 2.10(5) (z = 2.10(5)) for the BS (GOL) model. Based on this evidence we conclude that the dynamic approach to stationary states of the investigated models can be described by suitable power-law functions of time with well-defined exponents.

  14. Gamma rays at airplane altitudes

    SciTech Connect

    Iwai, J.; Koss, T.; Lord, J.; Strausz, S.; Wilkes, J.; Woosley, J. )

    1990-03-20

    An examination of the gamma ray flux above 1 TeV in the atmosphere is needed to better understand the anomalous showers from point sources. Suggestions are made for future experiments on board airplanes.

  15. The structure of airplane fabrics

    NASA Technical Reports Server (NTRS)

    Walen, E Dean

    1920-01-01

    This report prepared by the Bureau of Standards for the National Advisory Committee for Aeronautics supplies the necessary information regarding the apparatus and methods of testing and inspecting airplane fabrics.

  16. Quantum-criticality-induced strong Kerr nonlinearities in optomechanical systems

    PubMed Central

    Lü, Xin-You; Zhang, Wei-Min; Ashhab, Sahel; Wu, Ying; Nori, Franco

    2013-01-01

    We investigate a hybrid electro-optomechanical system that allows us to realize controllable strong Kerr nonlinearities even in the weak-coupling regime. We show that when the controllable electromechanical subsystem is close to its quantum critical point, strong photon-photon interactions can be generated by adjusting the intensity (or frequency) of the microwave driving field. Nonlinear optical phenomena, such as the appearance of the photon blockade and the generation of nonclassical states (e.g., Schrödinger cat states), are demonstrated in the weak-coupling regime, making the observation of strong Kerr nonlinearities feasible with currently available optomechanical technology. PMID:24126279

  17. Magnetic and superconducting quantum critical behavior of itinerant electronic systems

    NASA Astrophysics Data System (ADS)

    Sknepnek, Rastko

    Quantum phase transitions occur at zero temperature as a function of some non-thermal parameter, e.g., pressure or chemical composition. In addition to being of fundamental interest, quantum phase transitions are important because they are believed to underlie a number of interesting low temperature phenomena. Quantum phase transitions differ from the classical phase transitions in many important aspects, two of them being (i) the mode-coupling effects and (ii) the behavior in the presence of disorder. We devote two projects of this dissertation to each of the two. First, we investigate the quantum phase transition of itinerant electrons from a paramagnet to a state which displays long-period helical structures due to a Dzyaloshinskii instability of the ferromagnetic state. In particular, we study how the self generated effective long-range interaction recently identified in itinerant quantum ferromagnets is cut-off by the helical ordering. Second, we discuss a quantum phase transition between a disordered metal and an exotic (non-s-wave) superconductor. Like in the case of ferromagnetic quantum phase transition mode coupling effects lead to an effective long-range interaction between the anomalous density fluctuations. We find that the asymptotic critical region is characterized by run-away flow to large disorder. However, for weak coupling, this region is very narrow, and it is preempted by a wide crossover regime with mean-field critical behavior. Then, we present results of large-scale Monte Carlo simulations for a 3d Ising model with short range interactions and planar defects. We show that the phase transition in this system is smeared, i.e., there is no single critical temperature, but different parts of the system order at different temperatures. Our Monte-Carlo results are in good agreement with a recent theory. Finally, we present large-scale Monte-Carlo simulations of a 2d bilayer quantum Heisenberg antiferromagnet with random dimer dilution. In contrast

  18. Effects of anesthetic agents on systemic critical O2 delivery.

    PubMed

    Van der Linden, P; Gilbart, E; Engelman, E; Schmartz, D; Vincent, J L

    1991-07-01

    The present study tested the hypothesis that anesthetic agents can alter tissue O2 extraction capabilities in a dog model of progressive hemorrhage. After administration of pentobarbital sodium (25 mg/kg iv) and endotracheal intubation, the dogs were paralyzed with pancuronium bromide, ventilated with room air, and splenectomized. A total of 60 dogs were randomized in 10 groups of 6 dogs each. The first group served as control (C). A second group (P) received a continuous infusion of pentobarbital (4 mg.kg-2.h-2), which was started immediately after the bolus dose. Three groups received enflurane (E), halothane (HL), or isoflurane (I) at the end-tidal concentration of 0.7 minimum alveolar concentration (MAC). The sixth group received halothane at the end-tidal concentration of 1 MAC (HH). Two groups received intravenous alfentanil at relatively low dose (AL) or high dose (AH). The last two groups received intravenous ketamine at either relatively low dose (KL) or high dose (KH). In each group, O2 delivery (Do2) was progressively reduced by hemorrhage. At each step, systemic Do2 and O2 consumption (VO2) were measured separately and the critical point was determined from a plot of Vo2 vs. Do2. The critical O2 extraction ratio (OER) in the control group was 65.0 +/- 7.8%. OER was lower in all anesthetized groups (P, 44.3 +/- 11.8%; E, 47.0 +/- 7.7%; HL, 45.7 +/- 11.2%; I, 44.3 +/- 7.1%; HH, 33.7 +/- 6.0%; AL, 56.5 +/- 9.6%; AH, 43.5 +/- 5.9%; KH, 57.7 +/- 7.1%), except in the KL group (78.3 +/- 10.0%). The effects of halothane and alfentanil on critical OER were dose dependent (P less than 0.05), whereas critical OER was significantly lower in the KH than in the KL group. Moreover, the effects of anesthetic agents on critical Do2 appeared related to their effects on systemic vascular resistance. Anesthetic agents therefore alter O2 extraction by their peripheral vascular effects. However, ketamine, with its unique sympathetic stimulant properties, had a lesser effect

  19. Design of the ARES Mars Airplane and Mission Architecture

    NASA Technical Reports Server (NTRS)

    Braun, Robert D.; Wright, Henry S.; Croom, Mark A.; Levine, Joel S.; Spencer, David A.

    2006-01-01

    Significant technology advances have enabled planetary aircraft to be considered as viable science platforms. Such systems fill a unique planetary science measurement gap, that of regional-scale, near-surface observation, while providing a fresh perspective for potential discovery. Recent efforts have produced mature mission and flight system concepts, ready for flight project implementation. This paper summarizes the development of a Mars airplane mission architecture that balances science, implementation risk and cost. Airplane mission performance, flight system design and technology maturation are described. The design, analysis and testing completed demonstrates the readiness of this science platform for use in a Mars flight project.

  20. 14 CFR 121.354 - Terrain awareness and warning system.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... § 121.354 Terrain awareness and warning system. (a) Airplanes manufactured after March 29, 2002. No...) Airplanes manufactured on or before March 29, 2002. No person may operate a turbine-powered airplane after... Management and Budget under control number 2120-0631) (c) Airplane Flight Manual. The Airplane Flight...

  1. 14 CFR 121.354 - Terrain awareness and warning system.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... § 121.354 Terrain awareness and warning system. (a) Airplanes manufactured after March 29, 2002. No...) Airplanes manufactured on or before March 29, 2002. No person may operate a turbine-powered airplane after... Management and Budget under control number 2120-0631) (c) Airplane Flight Manual. The Airplane Flight...

  2. 14 CFR 121.354 - Terrain awareness and warning system.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... § 121.354 Terrain awareness and warning system. (a) Airplanes manufactured after March 29, 2002. No...) Airplanes manufactured on or before March 29, 2002. No person may operate a turbine-powered airplane after... Management and Budget under control number 2120-0631) (c) Airplane Flight Manual. The Airplane Flight...

  3. 14 CFR 121.354 - Terrain awareness and warning system.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... § 121.354 Terrain awareness and warning system. (a) Airplanes manufactured after March 29, 2002. No...) Airplanes manufactured on or before March 29, 2002. No person may operate a turbine-powered airplane after... Management and Budget under control number 2120-0631) (c) Airplane Flight Manual. The Airplane Flight...

  4. Advances in Thrust-Based Emergency Control of an Airplane

    NASA Technical Reports Server (NTRS)

    Creech, Gray; Burken, John J.; Burcham, Bill

    2003-01-01

    Engineers at NASA's Dryden Flight Research Center have received a patent on an emergency flight-control method implemented by a propulsion-controlled aircraft (PCA) system. Utilizing the preexisting auto-throttle and engine-pressure-ratio trim controls of the airplane, the PCA system provides pitch and roll control for landing an airplane safely without using aerodynamic control surfaces that have ceased to function because of a primary-flight-control-system failure. The installation of the PCA does not entail any changes in pre-existing engine hardware or software. [Aspects of the method and system at previous stages of development were reported in Thrust-Control System for Emergency Control of an Airplane (DRC-96-07), NASA Tech Briefs, Vol. 25, No. 3 (March 2001), page 68 and Emergency Landing Using Thrust Control and Shift of Weight (DRC-96-55), NASA Tech Briefs, Vol. 26, No. 5 (May 2002), page 58.]. Aircraft flight-control systems are designed with extensive redundancy to ensure low probabilities of failure. During recent years, however, several airplanes have exhibited major flight-control-system failures, leaving engine thrust as the last mode of flight control. In some of these emergency situations, engine thrusts were successfully modulated by the pilots to maintain flight paths or pitch angles, but in other situations, lateral control was also needed. In the majority of such control-system failures, crashes resulted and over 1,200 people died. The challenge lay in creating a means of sufficient degree of thrust-modulation control to safely fly and land a stricken airplane. A thrust-modulation control system designed for this purpose was flight-tested in a PCA an MD-11 airplane. The results of the flight test showed that without any operational control surfaces, a pilot can land a crippled airplane (U.S. Patent 5,330,131). The installation of the original PCA system entailed modifications not only of the flight-control computer (FCC) of the airplane but

  5. 78 FR 30243 - Airworthiness Directives; Eclipse Aerospace, Inc. Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-22

    ... updates to the aircraft computer system or incorporating a temporary revision to the aircraft flight... bulletins describe procedures for updating the aircraft computer system for all affected airplanes. We have... an update to the aircraft computer system (ACS) hardware with monthly data uploads to...

  6. Airplane Upset Training Evaluation Report

    NASA Technical Reports Server (NTRS)

    Gawron, Valerie J.; Jones, Patricia M. (Technical Monitor)

    2002-01-01

    Airplane upset accidents are a leading factor in hull losses and fatalities. This study compared five types of airplane-upset training. Each group was composed of eight, non-military pilots flying in their probationary year for airlines operating in the United States. The first group, 'No aero / no upset,' was made up of pilots without any airplane upset training or aerobatic flight experience; the second group, 'Aero/no upset,' of pilots without any airplane-upset training but with aerobatic experience; the third group, 'No aero/upset,' of pilots who had received airplane-upset training in both ground school and in the simulator; the fourth group, 'Aero/upset,' received the same training as Group Three but in addition had aerobatic flight experience; and the fifth group, 'In-flight' received in-flight airplane upset training using an instrumented in-flight simulator. Recovery performance indicated that clearly training works - specifically, all 40 pilots recovered from the windshear upset. However few pilots were trained or understood the use of bank to change the direction of the lift vector to recover from nose high upsets. Further, very few thought of, or used differential thrust to recover from rudder or aileron induced roll upsets. In addition, recovery from icing-induced stalls was inadequate.

  7. Airplane design for gusts

    NASA Technical Reports Server (NTRS)

    Houbolt, J. C.

    1977-01-01

    There are two basic approaches used for the structural design of aircraft due to dust encounter. One is a discrete gust approach, the other is based on power spectral techniques. Both of these approaches are explained in this report. Tacit to the above approaches is the assumption that loading on the airplane arises primarily from vertical gusts. A study of atmospheric turbulence was made not only on the vertical component, but on the longitudinal and transverse gust components as well. An analysis was made to establish the loads that develop when explicit consideration is given to both the vertical and head-wind components. The results are reported. Also included in this report are brief comments on gust effects during approach and landing.

  8. 78 FR 68986 - Special Conditions: Boeing Model 777-200, -300, and -300ER Series Airplanes; Aircraft Electronic...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-18

    ... and connectivity capabilities of the airplane's onboard network computer systems, which may allow access to or by external computer systems and networks. This onboard network system will be composed of a... airplane's onboard network system. The applicable airworthiness regulations do not contain adequate...

  9. Multiparticle Monte Carlo Code System for Shielding and Criticality Use.

    2015-06-01

    Version 00 COG is a modern, full-featured Monte Carlo radiation transport code that provides accurate answers to complex shielding, criticality, and activation problems.COG was written to be state-of-the-art and free of physics approximations and compromises found in earlier codes. COG is fully 3-D, uses point-wise cross sections and exact angular scattering, and allows a full range of biasing options to speed up solutions for deep penetration problems. Additionally, a criticality option is available for computingmore » Keff for assemblies of fissile materials. ENDL or ENDFB cross section libraries may be used. COG home page: http://cog.llnl.gov. Cross section libraries are included in the package. COG can use either the LLNL ENDL-90 cross section set or the ENDFB/VI set. Analytic surfaces are used to describe geometric boundaries. Parts (volumes) are described by a method of Constructive Solid Geometry. Surface types include surfaces of up to fourth order, and pseudo-surfaces such as boxes, finite cylinders, and figures of revolution. Repeated assemblies need be defined only once. Parts are visualized in cross-section and perspective picture views. A lattice feature simplifies the specification of regular arrays of parts. Parallel processing under MPI is supported for multi-CPU systems. Source and random-walk biasing techniques may be selected to improve solution statistics. These include source angular biasing, importance weighting, particle splitting and Russian roulette, pathlength stretching, point detectors, scattered direction biasing, and forced collisions. Criticality – For a fissioning system, COG will compute Keff by transporting batches of neutrons through the system. Activation – COG can compute gamma-ray doses due to neutron-activated materials, starting with just a neutron source. Coupled Problems – COG can solve coupled problems involving neutrons, photons, and electrons. COG 11.1 is an updated version of COG11.1 BETA 2 (RSICC C00777MNYCP02

  10. Multiparticle Monte Carlo Code System for Shielding and Criticality Use.

    SciTech Connect

    2015-06-01

    Version 00 COG is a modern, full-featured Monte Carlo radiation transport code that provides accurate answers to complex shielding, criticality, and activation problems.COG was written to be state-of-the-art and free of physics approximations and compromises found in earlier codes. COG is fully 3-D, uses point-wise cross sections and exact angular scattering, and allows a full range of biasing options to speed up solutions for deep penetration problems. Additionally, a criticality option is available for computing Keff for assemblies of fissile materials. ENDL or ENDFB cross section libraries may be used. COG home page: http://cog.llnl.gov. Cross section libraries are included in the package. COG can use either the LLNL ENDL-90 cross section set or the ENDFB/VI set. Analytic surfaces are used to describe geometric boundaries. Parts (volumes) are described by a method of Constructive Solid Geometry. Surface types include surfaces of up to fourth order, and pseudo-surfaces such as boxes, finite cylinders, and figures of revolution. Repeated assemblies need be defined only once. Parts are visualized in cross-section and perspective picture views. A lattice feature simplifies the specification of regular arrays of parts. Parallel processing under MPI is supported for multi-CPU systems. Source and random-walk biasing techniques may be selected to improve solution statistics. These include source angular biasing, importance weighting, particle splitting and Russian roulette, pathlength stretching, point detectors, scattered direction biasing, and forced collisions. Criticality – For a fissioning system, COG will compute Keff by transporting batches of neutrons through the system. Activation – COG can compute gamma-ray doses due to neutron-activated materials, starting with just a neutron source. Coupled Problems – COG can solve coupled problems involving neutrons, photons, and electrons. COG 11.1 is an updated version of COG11.1 BETA 2 (RSICC C00777MNYCP02). New

  11. Preliminary study of propulsion systems and airplane wing parameters for a US Navy subsonic V/STOL aircraft

    NASA Technical Reports Server (NTRS)

    Zola, C. L.; Fishbach, L. H.; Allen, J. L.

    1978-01-01

    Two V/STOL propulsion concepts were evaluated in a common aircraft configuration. One propulsion system consists of cross coupled turboshaft engines driving variable pitch fans. The other system is a gas coupled combination of turbojet gas generators and tip turbine fixed pitch fans. Evaluations were made of endurance at low altitude, low speed loiter with equal takeoff fuel loads. Effects of propulsion system sizing, bypass ratio, and aircraft wing planform parameters were investigated and compared. Shaft driven propulsion systems appear to result in better overall performance, although at higher installed weight, than gas systems.

  12. Critical Technologies for the Development of Future Space Elevator Systems

    NASA Technical Reports Server (NTRS)

    Smitherman, David V., Jr.

    2005-01-01

    A space elevator is a tether structure extending through geosynchronous earth orbit (GEO) to the surface of the earth. Its center of mass is in GEO such that it orbits the earth in sync with the earth s rotation. In 2004 and 2005, the NASA Marshall Space Flight Center and the Institute for Scientific Research, Inc. worked under a cooperative agreement to research the feasibility of space elevator systems, and to advance the critical technologies required for the future development of space elevators for earth to orbit transportation. The discovery of carbon nanotubes in the early 1990's was the first indication that it might be possible to develop materials strong enough to make space elevator construction feasible. This report presents an overview of some of the latest NASA sponsored research on space elevator design, and the systems and materials that will be required to make space elevator construction possible. In conclusion, the most critical technology for earth-based space elevators is the successful development of ultra high strength carbon nanotube reinforced composites for ribbon construction in the 1OOGPa range. In addition, many intermediate technology goals and demonstration missions for the space elevator can provide significant advancements to other spaceflight and terrestrial applications.

  13. FEATURES, EVENTS, AND PROCESSES: SYSTEM-LEVEL AND CRITICALITY

    SciTech Connect

    D.L. McGregor

    2000-12-20

    The primary purpose of this Analysis/Model Report (AMR) is to identify and document the screening analyses for the features, events, and processes (FEPs) that do not easily fit into the existing Process Model Report (PMR) structure. These FEPs include the 3 1 FEPs designated as System-Level Primary FEPs and the 22 FEPs designated as Criticality Primary FEPs. A list of these FEPs is provided in Section 1.1. This AMR (AN-WIS-MD-000019) documents the Screening Decision and Regulatory Basis, Screening Argument, and Total System Performance Assessment (TSPA) Disposition for each of the subject Primary FEPs. This AMR provides screening information and decisions for the TSPA-SR report and provides the same information for incorporation into a project-specific FEPs database. This AMR may also assist reviewers during the licensing-review process.

  14. 14 CFR 36.7 - Acoustical change: Transport category large airplanes and jet airplanes.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Acoustical change: Transport category large... § 36.7 Acoustical change: Transport category large airplanes and jet airplanes. (a) Applicability. This section applies to all transport category large airplanes and jet airplanes for which an acoustical...

  15. Flight critical system design guidelines and validation methods

    NASA Technical Reports Server (NTRS)

    Holt, H. M.; Lupton, A. O.; Holden, D. G.

    1984-01-01

    Efforts being expended at NASA-Langley to define a validation methodology, techniques for comparing advanced systems concepts, and design guidelines for characterizing fault tolerant digital avionics are described with an emphasis on the capabilities of AIRLAB, an environmentally controlled laboratory. AIRLAB has VAX 11/750 and 11/780 computers with an aggregate of 22 Mb memory and over 650 Mb storage, interconnected at 256 kbaud. An additional computer is programmed to emulate digital devices. Ongoing work is easily accessed at user stations by either chronological or key word indexing. The CARE III program aids in analyzing the capabilities of test systems to recover from faults. An additional code, the semi-Markov unreliability program (SURE) generates upper and lower reliability bounds. The AIRLAB facility is mainly dedicated to research on designs of digital flight-critical systems which must have acceptable reliability before incorporation into aircraft control systems. The digital systems would be too costly to submit to a full battery of flight tests and must be initially examined with the AIRLAB simulation capabilities.

  16. 76 FR 54923 - Special Conditions: Dassault Falcon Model 900 and 900EX Airplanes; Interaction of Systems and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-06

    ... behavior of such a system or associated functions, or any effect on the structural performance of the... the system that result in forced-structural vibrations (oscillatory failures) must not produce loads that could result in detrimental deformation of primary structure. b. For the continuation of...

  17. Scaling Law for Irreversible Entropy Production in Critical Systems

    NASA Astrophysics Data System (ADS)

    Hoang, Danh-Tai; Prasanna Venkatesh, B.; Han, Seungju; Jo, Junghyo; Watanabe, Gentaro; Choi, Mahn-Soo

    2016-06-01

    We examine the Jarzynski equality for a quenching process across the critical point of second-order phase transitions, where absolute irreversibility and the effect of finite-sampling of the initial equilibrium distribution arise in a single setup with equal significance. We consider the Ising model as a prototypical example for spontaneous symmetry breaking and take into account the finite sampling issue by introducing a tolerance parameter. The initially ordered spins become disordered by quenching the ferromagnetic coupling constant. For a sudden quench, the deviation from the Jarzynski equality evaluated from the ideal ensemble average could, in principle, depend on the reduced coupling constant ε0 of the initial state and the system size L. We find that, instead of depending on ε0 and L separately, this deviation exhibits a scaling behavior through a universal combination of ε0 and L for a given tolerance parameter, inherited from the critical scaling laws of second-order phase transitions. A similar scaling law can be obtained for the finite-speed quench as well within the Kibble-Zurek mechanism.

  18. Scaling Law for Irreversible Entropy Production in Critical Systems

    PubMed Central

    Hoang, Danh-Tai; Prasanna Venkatesh, B.; Han, Seungju; Jo, Junghyo; Watanabe, Gentaro; Choi, Mahn-Soo

    2016-01-01

    We examine the Jarzynski equality for a quenching process across the critical point of second-order phase transitions, where absolute irreversibility and the effect of finite-sampling of the initial equilibrium distribution arise in a single setup with equal significance. We consider the Ising model as a prototypical example for spontaneous symmetry breaking and take into account the finite sampling issue by introducing a tolerance parameter. The initially ordered spins become disordered by quenching the ferromagnetic coupling constant. For a sudden quench, the deviation from the Jarzynski equality evaluated from the ideal ensemble average could, in principle, depend on the reduced coupling constant ε0 of the initial state and the system size L. We find that, instead of depending on ε0 and L separately, this deviation exhibits a scaling behavior through a universal combination of ε0 and L for a given tolerance parameter, inherited from the critical scaling laws of second-order phase transitions. A similar scaling law can be obtained for the finite-speed quench as well within the Kibble-Zurek mechanism. PMID:27277558

  19. Repair of Critical Calvarias Defects With Systemic Epimedium sagittatum Extract.

    PubMed

    Burim, Rafael Augusto; Sendyk, Daniel Isaac; Hernandes, Leandro Santoro; de Souza, Daniel Falbo Martins; Correa, Luciana; Deboni, Maria Cristina Zindel

    2016-05-01

    It is well established in reconstructive surgery the repair of great bone defects is a difficult goal to be achieved. The aim of this study was to evaluate the influence of an extract rich in icariin on bone neoformation in critically sized defects in rat calvaria. Under continual saline irrigation, a circular bone defect was created in 40 rat calvarias with an 8-mm diameter trephine drill. Animals were randomly divided into a test group that received an Epimedium sagittatum extract (containing 5.8 mg/mL of icariin) and a control group that received an equal volume of saline solution. Substances were administered daily through a feeding tube until euthanasia. After 7, 14, 21, and 42 days, 5 animals from each group were euthanized. Calvaria defect samples were fixed in 10% formalin for 48 hours, X-rayed, and histologically processed. In the test group, there was a significant reduction in the bone defect area on X-ray images and an increase in new bone area in all of the experimental periods in the test group. At 42 days, the bone in the test group also exhibited a significant reduction in osteocyte (P = 0.002) and osteoclast density (P = 0.041). The authors conclude that administration of systemic Epimedium extracts containing high concentrations of icariin can induce bone neoformation and reduce osteocyte and osteoclast densities, thereby altering the normal deposition and remodeling patterns that are present in critically sized bone defects. PMID:26982112

  20. Scaling Law for Irreversible Entropy Production in Critical Systems.

    PubMed

    Hoang, Danh-Tai; Prasanna Venkatesh, B; Han, Seungju; Jo, Junghyo; Watanabe, Gentaro; Choi, Mahn-Soo

    2016-01-01

    We examine the Jarzynski equality for a quenching process across the critical point of second-order phase transitions, where absolute irreversibility and the effect of finite-sampling of the initial equilibrium distribution arise in a single setup with equal significance. We consider the Ising model as a prototypical example for spontaneous symmetry breaking and take into account the finite sampling issue by introducing a tolerance parameter. The initially ordered spins become disordered by quenching the ferromagnetic coupling constant. For a sudden quench, the deviation from the Jarzynski equality evaluated from the ideal ensemble average could, in principle, depend on the reduced coupling constant ε0 of the initial state and the system size L. We find that, instead of depending on ε0 and L separately, this deviation exhibits a scaling behavior through a universal combination of ε0 and L for a given tolerance parameter, inherited from the critical scaling laws of second-order phase transitions. A similar scaling law can be obtained for the finite-speed quench as well within the Kibble-Zurek mechanism. PMID:27277558

  1. Critical parameters for coarse coal underground slurry haulage systems

    SciTech Connect

    Maynard, D.P.

    1981-02-15

    This report describes the basic parameters which directly influence the behavior of a coal slurry pipeline transportation system and determine the limitations of the system performance. The purpose of this technology assessment is to provide an identification and understanding of the critical factors which must be given consideration in the design and evaluation of such a slurry haulage system intended for use in an underground coal mine. The slurry haulage system will be utilized to satisfy the transportation requirements of conveying, in a pipeline, the coal mined by a continuous mining machine to a storage location near the mine entrance or to a coal preparation plant located on the surface. Coal-water slurries, particularly those consisting of homogeneous suspensions of small particles, frequently behave as non-Newtonian, Bingham-plastic fluids. For successful operation, slurry transport systems should be designed to operate in the turbulent flow regime and at a flow rate at least 30% greater than the deposition velocity. The deposition velocity is defined as the slurry flow rate at which the solid particles tend to settle in the pipe. Due to the importance of accurately determining the deposition velocity and the uncertainties of current methods for predicting the deposition velocity of coarse particle slurries, it is recommended that experimental efforts be performed as a part of the system design. The capacity of the haulage system should be compatible with the mine's projected coal output in order to avoid operational delays and the necessity for in-mine coal storage. The slurry pumps must generate sufficient discharge pressure to overcome the resultant friction losses in horizontal and vertical pipe sections and to satisfy the slurry hoisting requirements.

  2. Verification and Validation of Flight-Critical Systems

    NASA Technical Reports Server (NTRS)

    Brat, Guillaume

    2010-01-01

    For the first time in many years, the NASA budget presented to congress calls for a focused effort on the verification and validation (V&V) of complex systems. This is mostly motivated by the results of the VVFCS (V&V of Flight-Critical Systems) study, which should materialize as a a concrete effort under the Aviation Safety program. This talk will present the results of the study, from requirements coming out of discussions with the FAA and the Joint Planning and Development Office (JPDO) to technical plan addressing the issue, and its proposed current and future V&V research agenda, which will be addressed by NASA Ames, Langley, and Dryden as well as external partners through NASA Research Announcements (NRA) calls. This agenda calls for pushing V&V earlier in the life cycle and take advantage of formal methods to increase safety and reduce cost of V&V. I will present the on-going research work (especially the four main technical areas: Safety Assurance, Distributed Systems, Authority and Autonomy, and Software-Intensive Systems), possible extensions, and how VVFCS plans on grounding the research in realistic examples, including an intended V&V test-bench based on an Integrated Modular Avionics (IMA) architecture and hosted by Dryden.

  3. 78 FR 78705 - Airworthiness Directives; Airbus Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-27

    ...We are superseding Airworthiness Directive (AD) 2010-24-07 for all Airbus Model A318 series airplanes, Model A319 series airplanes, Model A320 series airplanes, and Model A321 series airplanes. AD 2010- 24-07 required repetitive inspections of the 80VU rack lower lateral fittings for damage, repetitive inspections of the 80VU rack lower central support for cracking, and corrective action if......

  4. 77 FR 12989 - Airworthiness Directives; Airbus Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-05

    ...We are adopting a new airworthiness directive (AD) for certain Airbus Model A330-200 series airplanes; Model A330-300 series airplanes; Model A340-200 series airplanes; and Model A340-300 series airplanes. This AD was prompted by a report that three failures of the retraction bracket occurred during fatigue testing before the calculated life limit of the main landing gear (MLG). This AD......

  5. The X-15 airplane - Lessons learned

    NASA Technical Reports Server (NTRS)

    Dana, William H.

    1993-01-01

    The X-15 rocket research airplane flew to an altitude of 354,000 ft and reached Mach 6.70. In almost 200 flights, this airplane was used to gather aerodynamic-heating, structural loads, stability and control, and atmospheric-reentry data. This paper describes the origins, design, and operation of the X-15 airplane. In addition, lessons learned from the X-15 airplane that are applicable to designing and testing the National Aero-Space Plane are discussed.

  6. Critical Education for Systemic Change: A World-Systems Analysis Perspective

    ERIC Educational Resources Information Center

    Griffiths, Tom G.

    2015-01-01

    This paper both draws on, and seeks to apply, world-systems analysis to a broad, critical education project that builds mass schooling's potential contribution to the process of world-systemic change. In short, this is done by first setting out the world-systems analysis account of the current state, and period of transition, of the capitalist…

  7. 77 FR 36950 - Airworthiness Directives; Dassault Aviation Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-20

    ... of electrical power to the fly-by-wire system and subsequent loss of control of the airplane. Actions... electrical power to the fly-by-wire system. Electrical power can also be supplied by two independent... to supply electrical power automatically triggers a command to deploy the ram air turbine, which...

  8. In-flight investigation of the effects of pilot location and control system design on airplane flying qualities for approach and landing

    NASA Technical Reports Server (NTRS)

    Weingarten, N. C.; Chalk, C. R.

    1982-01-01

    The handling qualities of large airplanes in the approach and landing flight phase were studied. The primary variables were relative pilot position with respect to center of rotation, command path time delays and phase shifts, augmentation schemes and levels of augmentation. It is indicated that the approach and landing task with large airplanes is a low bandwidth task. Low equivalent short period frequencies and relatively long time delays are tolerated only when the pilot is located at considerable distance forward of the center of rotation. The control problem experienced by the pilots, when seated behind the center of rotation, tended to occur at low altitude when they were using visual cues of rate of sink and altitude. A direct lift controller improved final flight path control of the shuttle like configurations.

  9. Self-Organised Criticality in Astrophysical Accretion Systems

    NASA Astrophysics Data System (ADS)

    Dendy, R. O.; Helander, P.; Tagger, M.

    Self-organised criticality (SOC) has been proposed as a potentially powerful unifying paradigm for interpreting non-diffusive avalanche-type transport in laboratory, space and astrophysical plasmas. After reviewing the most promising astrophysical sites where SOC might be observable, we consider the theoretical arguments for supposing that SOC can occur in accretion discs. Perhaps the most rigorous evidence is provided by numerical modelling of energy dissipation due to magnetohydrodynamic turbulence in accretion discs by G. Geertsema & A. Achterberg (Astron. Astrophys. 255, 427 (1992)); we investigate how “sandpile”-type dynamics arise in this model. It is concluded that the potential sites for SOC in accretion systems are numerous and observationally accessible, and that theoretical support for the possible occurrence of SOC can be derived from first principles.

  10. A critical review of clinical trials in systemic lupus erythematosus.

    PubMed

    Mahieu, M A; Strand, V; Simon, L S; Lipsky, P E; Ramsey-Goldman, R

    2016-09-01

    One challenge in caring for patients with systemic lupus erythematosus (SLE) is a paucity of approved therapeutics for treatment of the diverse disease manifestations. In the last 60 years, only one drug, belimumab, has been approved for SLE treatment. Critical evaluation of investigator initiated and pharma-sponsored randomized controlled trials (RCTs) highlights barriers to successful drug development in SLE, including disease heterogeneity, inadequate trial size or duration, insufficient dose finding before initiation of large trials, handling of background medications, and choice of primary endpoint. Herein we examine lessons learned from landmark SLE RCTs and subsequent advances in trial design, as well as discuss efforts to address limitations in current SLE outcome measures that will improve detection of true therapeutic responses in future RCTs. PMID:27497257

  11. A comparison of flight and simulation data for three automatic landing system control laws for the Augmentor wing jet STOL research airplane

    NASA Technical Reports Server (NTRS)

    Feinreich, B.; Gevaert, G.

    1980-01-01

    Automatic flare and decrab control laws for conventional takeoff and landing aircraft were adapted to the unique requirements of the powered lift short takeoff and landing airplane. Three longitudinal autoland control laws were developed. Direct lift and direct drag control were used in the longitudinal axis. A fast time simulation was used for the control law synthesis, with emphasis on stochastic performance prediction and evaluation. Good correlation with flight test results was obtained.

  12. Design of integrated autopilot/autothrottle for NASA TSRV airplane using integral LQG methodology. [transport systems research vehicle

    NASA Technical Reports Server (NTRS)

    Kaminer, Isaac; Benson, Russell A.

    1989-01-01

    An integrated autopilot/autothrottle control system has been developed for the NASA transport system research vehicle using a two-degree-of-freedom approach. Based on this approach, the feedback regulator was designed using an integral linear quadratic regulator design technique, which offers a systematic approach to satisfy desired feedback performance requirements and guarantees stability margins in both control and sensor loops. The resulting feedback controller was discretized and implemented using a delta coordinate concept, which allows for transient free controller switching by initializing all controller states to zero and provides a simple solution for dealing with throttle limiting cases.

  13. 14 CFR 121.605 - Airplane equipment.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Airplane equipment. 121.605 Section 121.605..., FLAG, AND SUPPLEMENTAL OPERATIONS Dispatching and Flight Release Rules § 121.605 Airplane equipment. No person may dispatch or release an airplane unless it is airworthy and is equipped as prescribed in §...

  14. 14 CFR 125.93 - Airplane limitations.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Airplane limitations. 125.93 Section 125.93...: AIRPLANES HAVING A SEATING CAPACITY OF 20 OR MORE PASSENGERS OR A MAXIMUM PAYLOAD CAPACITY OF 6,000 POUNDS OR MORE; AND RULES GOVERNING PERSONS ON BOARD SUCH AIRCRAFT Airplane Requirements § 125.93...

  15. 14 CFR 121.605 - Airplane equipment.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Airplane equipment. 121.605 Section 121.605..., FLAG, AND SUPPLEMENTAL OPERATIONS Dispatching and Flight Release Rules § 121.605 Airplane equipment. No person may dispatch or release an airplane unless it is airworthy and is equipped as prescribed in §...

  16. 14 CFR 125.93 - Airplane limitations.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Airplane limitations. 125.93 Section 125.93...: AIRPLANES HAVING A SEATING CAPACITY OF 20 OR MORE PASSENGERS OR A MAXIMUM PAYLOAD CAPACITY OF 6,000 POUNDS OR MORE; AND RULES GOVERNING PERSONS ON BOARD SUCH AIRCRAFT Airplane Requirements § 125.93...

  17. 14 CFR 121.605 - Airplane equipment.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Airplane equipment. 121.605 Section 121.605..., FLAG, AND SUPPLEMENTAL OPERATIONS Dispatching and Flight Release Rules § 121.605 Airplane equipment. No person may dispatch or release an airplane unless it is airworthy and is equipped as prescribed in §...

  18. 14 CFR 125.93 - Airplane limitations.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Airplane limitations. 125.93 Section 125.93...: AIRPLANES HAVING A SEATING CAPACITY OF 20 OR MORE PASSENGERS OR A MAXIMUM PAYLOAD CAPACITY OF 6,000 POUNDS OR MORE; AND RULES GOVERNING PERSONS ON BOARD SUCH AIRCRAFT Airplane Requirements § 125.93...

  19. 14 CFR 121.605 - Airplane equipment.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Airplane equipment. 121.605 Section 121.605..., FLAG, AND SUPPLEMENTAL OPERATIONS Dispatching and Flight Release Rules § 121.605 Airplane equipment. No person may dispatch or release an airplane unless it is airworthy and is equipped as prescribed in §...

  20. 14 CFR 125.93 - Airplane limitations.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Airplane limitations. 125.93 Section 125.93...: AIRPLANES HAVING A SEATING CAPACITY OF 20 OR MORE PASSENGERS OR A MAXIMUM PAYLOAD CAPACITY OF 6,000 POUNDS OR MORE; AND RULES GOVERNING PERSONS ON BOARD SUCH AIRCRAFT Airplane Requirements § 125.93...

  1. 78 FR 68347 - Airworthiness Directives; Airbus Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-14

    ... (74 FR 7549, February 18, 2009). Airbus also stated that for Model A340-541 and A340-642 airplanes.... Airbus stated that this requirement for Model A330 MRTT airplanes is equivalent to one in the NPRM (78 FR... (f) of AD 2009-04-07, Amendment 39-15813 (74 FR 7549, February 18, 2009). For all airplanes...

  2. 78 FR 28152 - Airworthiness Directives; Airbus Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-14

    ..., Amendment 39-16526 (75 FR 75878, December 7, 2010), exempted airplanes on which Airbus Modification 34804..., Amendment 39-16526 (75 FR 75878, December 7, 2010). Except for Model A318-121 and -122 airplanes, and except...) of AD 2010-24-07, Amendment 39-16526 (75 FR 75878, December 7, 2010). Except for airplanes on...

  3. 76 FR 77934 - Airworthiness Directives; Airbus Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-15

    ... series airplanes. Since we issued AD 2005-23-02, Amendment 39-14360 (70 FR 69067, November 14, 2005), The... certain ACT equipped airplanes, produced after AD 2005-23-02, Amendment 39-14360 (70 FR 69067, November 14...-14360 (70 FR 69067, November 14, 2005). Applicability (c) This AD applies to Airbus airplanes listed...

  4. 77 FR 51717 - Airworthiness Directives; Airbus Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-27

    ... visual inspection of the forward fitting at frame (FR) 40 on both sides of the airplane for cracks, and..., Amendment 39-16229 (75 FR cycles. 11435, March 11, 2010)), whichever occurs later; except, for airplanes... inspection for cracks of the forward fitting at FR 40 without nut removal on both sides of the airplane,...

  5. 76 FR 79560 - Airworthiness Directives; Airbus Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-22

    ... ``significant rule'' under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and 3... Federal Aviation Administration 14 CFR Part 39 RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes... airplanes; Model A330-223F and -243F airplanes; and Model A340-200, -300, -500, and -600 series...

  6. 77 FR 75833 - Airworthiness Directives; Airbus Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-26

    ... fitting at frame (FR) 40 on both sides of the airplane for cracks, and repair if necessary. This new AD...-time detailed visual inspection of the forward fitting at FR 40 on both sides of the airplane, in..., Amendment 39- 16229 (75 FR 11435, March 11, 2010)), whichever occurs later; except, for airplanes that,...

  7. 77 FR 66772 - Airworthiness Directives; Airbus Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-07

    ... date of AD 96-13-11, Amendment 39-9679 (61 FR 35122, July 5, 1996)). (2) For airplanes that have..., Amendment 39-16698 (76 FR 27875, May 13, 2011). (1) For airplanes identified in paragraph (c)(1) of this AD... FR 27875, May 13, 2011). For airplanes identified in paragraph (c)(3) of this AD: Within 3...

  8. 78 FR 70003 - Airworthiness Directives; Airbus Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-22

    ... 12866; 2. Is not a ``significant rule'' under the DOT Regulatory Policies and Procedures (44 FR 11034... Directives; Airbus Airplanes AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed... series airplanes; Airbus Model A300 B4-600, B4-600R, and F4-600R series airplanes, and Model A300...

  9. 14 CFR 125.93 - Airplane limitations.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Airplane limitations. 125.93 Section 125.93...: AIRPLANES HAVING A SEATING CAPACITY OF 20 OR MORE PASSENGERS OR A MAXIMUM PAYLOAD CAPACITY OF 6,000 POUNDS OR MORE; AND RULES GOVERNING PERSONS ON BOARD SUCH AIRCRAFT Airplane Requirements § 125.93...

  10. 14 CFR 121.605 - Airplane equipment.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Airplane equipment. 121.605 Section 121.605..., FLAG, AND SUPPLEMENTAL OPERATIONS Dispatching and Flight Release Rules § 121.605 Airplane equipment. No person may dispatch or release an airplane unless it is airworthy and is equipped as prescribed in §...

  11. Process innovation in high-performance systems: From polymeric composites R&D to design and build of airplane showers

    NASA Astrophysics Data System (ADS)

    Wu, Yi-Jui

    In the aerospace industry reducing aircraft weight is key because it increases flight performance and drives down operating costs. With fierce competition in the commercial aircraft industry, companies that focused primarily on exterior aircraft performance design issues are turning more attention to the design of aircraft interior. Simultaneously, there has been an increase in the number of new amenities offered to passengers especially in first class travel and executive jets. These new amenities present novel and challenging design parameters that include integration into existing aircraft systems without sacrificing flight performance. The objective of this study was to design a re-circulating shower system for an aircraft that weighs significantly less than pre-existing shower designs. This was accomplished by integrating processes from polymeric composite materials, water filtration, and project management. Carbon/epoxy laminates exposed to hygrothermal cycling conditions were evaluated and compared to model calculations. Novel materials and a variety of fabrication processes were developed to create new types of paper for honeycomb applications. Experiments were then performed on the properties and honeycomb processability of these new papers. Standard water quality tests were performed on samples taken from the re-circulating system to see if current regulatory standards were being met. These studies were executed and integrated with tools from project management to design a better shower system for commercial aircraft applications.

  12. 77 FR 57039 - Special Conditions: Embraer S.A., Model EMB-550 Airplane; Electronic Flight Control System...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-17

    ..., 2000 (65 FR 19477-19478), as well as at http://DocketsInfo.dot.gov/ . Docket: Background documents or...; Electronic Flight Control System: Control Surface Awareness and Mode Annunciation AGENCY: Federal Aviation... feature(s) associated with the control surface awareness and mode annunciation of the electronic...

  13. Evaluating effective swath width and droplet distribution of aerial spraying systems on M-18B and Thrush 510G airplanes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aerial spraying plays an important role in promoting agricultural production and protecting the biological environment due to its flexibility, high effectiveness, and large operational area per unit of time. In order to evaluate the performance parameters of the spraying systems on two fixed wing ai...

  14. 75 FR 53855 - Airworthiness Directives; BAE Systems (Operations) Limited Model BAe 146 and Avro 146-RJ Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-02

    ... identified in this AD, contact BAE Systems (Operations) Limited, Customer Information Department, Prestwick... products. That NPRM was published in the Federal Register on May 19, 2010 (75 FR 27959). That NPRM proposed... become brittle with age. During the production life of the aeroplane type, several methods of...

  15. Critical engine system design characteristics for SSTO vehicles

    NASA Astrophysics Data System (ADS)

    Fanciullo, Thomas J.; Judd, D. C.; Obrien, C. J.

    1992-02-01

    Engine system design characteristics are summarized for typical vertical take-off and landing (VTOL) and vertical take-off and horizontal landing (VTHL) Strategic Defense Initiative Organization (SDIO) single stage to orbit (SSTO) vehicles utilizing plug nozzle configurations. Power cycle selection trades involved the unique modular platelet engine (MPE) with the use of (1) LO2 and LH2 at fixed and variable mixture ratios, (2) LO2 and propane or RP-1, and (3) dual fuels (LO2 with LH2 and C3H8). The number of thrust cells and modules were optimized. Dual chamber bell and a cluster of conventional bell nozzle configurations were examined for comparison with the plug configuration. Thrust modulation (throttling) was selected for thrust vector control. Installed thrust ratings were established to provide an additional 20 percent overthrust capability for engine out operation. Turbopumps were designed to operate at subcritical speeds to facilitate a wide range of throttling and long life. A unique dual spool arrangement with hydrostatic bearings was selected for the LH2 turbopump. Controls and health monitoring with expert systems for diagnostics are critical subsystems to ensure minimum maintenance and supportability for a less than seven day turnaround. The use of an idle mode start, in conjunction with automated health condition monitoring, allows the rocket propulsion system to operate reliably in the manner of present day aircraft propulsion.

  16. Sensor equipment of the German earth scientific airplane program

    NASA Technical Reports Server (NTRS)

    Seige, P.

    1975-01-01

    The German airplane program for earth scientific research supports the work of a vast staff of earth scientists from universities and federal agencies. Due to their fields of interest, which are in oceanography, hydrology, geology, ecology, and forestry, five test areas were selected which are spread all over Germany. The sensor package, which was designed in accordance with the requirements of this group of scientists, will be installed in a DO 28 D2 type airplane. The sensor equipment consists of a series of 70-mm cameras having different film/filter combinations, a photogrammetric camera, an infrared radiometer, an 11-channel multispectral line scanner, a LANDSAT-compatible radiometer, and a complex avionic system. Along with the airplane, a truck will be equipped with a set of radiometers and other sensor devices for extensive ground-truth measurement; this also includes a cherry picker.

  17. Solar-Powered Airplane with Cameras and WLAN

    NASA Technical Reports Server (NTRS)

    Higgins, Robert G.; Dunagan, Steve E.; Sullivan, Don; Slye, Robert; Brass, James; Leung, Joe G.; Gallmeyer, Bruce; Aoyagi, Michio; Wei, Mei Y.; Herwitz, Stanley R.; Johnson, Lee; Arvesen, John C.

    2004-01-01

    An experimental airborne remote sensing system includes a remotely controlled, lightweight, solar-powered airplane (see figure) that carries two digital-output electronic cameras and communicates with a nearby ground control and monitoring station via a wireless local-area network (WLAN). The speed of the airplane -- typically <50 km/h -- is low enough to enable loitering over farm fields, disaster scenes, or other areas of interest to collect high-resolution digital imagery that could be delivered to end users (e.g., farm managers or disaster-relief coordinators) in nearly real time.

  18. The Effect of Supercharger Capacity on Engine and Airplane Performance

    NASA Technical Reports Server (NTRS)

    Schey, O W; Gove, W D

    1930-01-01

    This report presents the results of an investigation to determine the effect of different supercharger capacities on the performance of an airplane and its engine . The tests were conducted on a DH4-M2 airplane powered with a Liberty 12 engine. In this investigation four supercharger capacities, obtained by driving a roots type supercharger at 1.615, 1.957, 2.4, and 3 time engine speed, were used to maintain sea-level pressure at the carburetor to altitudes of 7,000, 11,500, 17,000, and 22,000 feet, respectively. The performance of the airplane in climb and in level flight was determined for each of the four supercharger drive ratios and for the unsupercharged condition. The engine power was measured during these tests by means of a calibrated propeller. It was found that very little sacrifice in sea-level performance was experienced with the larger supercharger drive ratios as compared with performance obtained when using the smaller drive ratios. The results indicate that further increase in supercharger capacity over that obtained when using 3:1 drive ratio would give a slight increase in ceiling and in high-altitude performance but would considerably impair the performance for an appreciable distance below the critical altitude. As the supercharger capacity was increased, the height at which sea-level high speeds could be equaled or improved became a larger percentage of the maximum height of operation of the airplane.

  19. The critical role of locomotion mechanics in decoding sensory systems.

    PubMed

    Cowan, Noah J; Fortune, Eric S

    2007-01-31

    How do neural systems process sensory information to control locomotion? The weakly electric knifefish Eigenmannia, an ideal model for studying sensorimotor control, swims to stabilize the sensory image of a sinusoidally moving refuge. Tracking performance is best at stimulus frequencies less than approximately 1 Hz. Kinematic analysis, which is widely used in the study of neural control of movement, predicts commensurately low-pass sensory processing for control. The inclusion of Newtonian mechanics in the analysis of the behavior, however, categorically shifts the prediction: this analysis predicts that sensory processing is high pass. The counterintuitive prediction that a low-pass behavior is controlled by a high-pass neural filter nevertheless matches previously reported but poorly understood high-pass filtering seen in electrosensory afferents and downstream neurons. Furthermore, a model incorporating the high-pass controller matches animal behavior, whereas the model with the low-pass controller does not and is unstable. Because locomotor mechanics are similar in a wide array of animals, these data suggest that such high-pass sensory filters may be a general mechanism used for task-level locomotion control. Furthermore, these data highlight the critical role of mechanical analyses in addition to widely used kinematic analyses in the study of neural control systems. PMID:17267567

  20. Landing impact studies of a 0.3-scale model air cushion landing system for a Navy fighter airplane

    NASA Technical Reports Server (NTRS)

    Leland, T. J. W.; Thompson, W. C.

    1975-01-01

    An experimental study was conducted in order to determine the landing-impact behavior of a 0.3-scale, dynamically (but not physically) similar model of a high-density Navy fighter equipped with an air cushion landing system. The model was tested over a range of landing contact attitudes at high forward speeds and sink rates on a specialized test fixture at the Langley aircraft landing loads and traction facility. The investigation indicated that vertical acceleration at landing impact was highly dependent on the pitch angle at ground contact, the higher acceleration of approximately 5g occurring near zero body-pitch attitude. A limited number of low-speed taxi tests were made in order to determine model stability characteristics. The model was found to have good pitch-damping characteristics but stability in roll was marginal.

  1. Lack of Critical Slowing Down Suggests that Financial Meltdowns Are Not Critical Transitions, yet Rising Variability Could Signal Systemic Risk.

    PubMed

    Guttal, Vishwesha; Raghavendra, Srinivas; Goel, Nikunj; Hoarau, Quentin

    2016-01-01

    Complex systems inspired analysis suggests a hypothesis that financial meltdowns are abrupt critical transitions that occur when the system reaches a tipping point. Theoretical and empirical studies on climatic and ecological dynamical systems have shown that approach to tipping points is preceded by a generic phenomenon called critical slowing down, i.e. an increasingly slow response of the system to perturbations. Therefore, it has been suggested that critical slowing down may be used as an early warning signal of imminent critical transitions. Whether financial markets exhibit critical slowing down prior to meltdowns remains unclear. Here, our analysis reveals that three major US (Dow Jones Index, S&P 500 and NASDAQ) and two European markets (DAX and FTSE) did not exhibit critical slowing down prior to major financial crashes over the last century. However, all markets showed strong trends of rising variability, quantified by time series variance and spectral function at low frequencies, prior to crashes. These results suggest that financial crashes are not critical transitions that occur in the vicinity of a tipping point. Using a simple model, we argue that financial crashes are likely to be stochastic transitions which can occur even when the system is far away from the tipping point. Specifically, we show that a gradually increasing strength of stochastic perturbations may have caused to abrupt transitions in the financial markets. Broadly, our results highlight the importance of stochastically driven abrupt transitions in real world scenarios. Our study offers rising variability as a precursor of financial meltdowns albeit with a limitation that they may signal false alarms. PMID:26761792

  2. Lack of Critical Slowing Down Suggests that Financial Meltdowns Are Not Critical Transitions, yet Rising Variability Could Signal Systemic Risk

    PubMed Central

    Hoarau, Quentin

    2016-01-01

    Complex systems inspired analysis suggests a hypothesis that financial meltdowns are abrupt critical transitions that occur when the system reaches a tipping point. Theoretical and empirical studies on climatic and ecological dynamical systems have shown that approach to tipping points is preceded by a generic phenomenon called critical slowing down, i.e. an increasingly slow response of the system to perturbations. Therefore, it has been suggested that critical slowing down may be used as an early warning signal of imminent critical transitions. Whether financial markets exhibit critical slowing down prior to meltdowns remains unclear. Here, our analysis reveals that three major US (Dow Jones Index, S&P 500 and NASDAQ) and two European markets (DAX and FTSE) did not exhibit critical slowing down prior to major financial crashes over the last century. However, all markets showed strong trends of rising variability, quantified by time series variance and spectral function at low frequencies, prior to crashes. These results suggest that financial crashes are not critical transitions that occur in the vicinity of a tipping point. Using a simple model, we argue that financial crashes are likely to be stochastic transitions which can occur even when the system is far away from the tipping point. Specifically, we show that a gradually increasing strength of stochastic perturbations may have caused to abrupt transitions in the financial markets. Broadly, our results highlight the importance of stochastically driven abrupt transitions in real world scenarios. Our study offers rising variability as a precursor of financial meltdowns albeit with a limitation that they may signal false alarms. PMID:26761792

  3. Air resistance measurements on actual airplane parts

    NASA Technical Reports Server (NTRS)

    Weiselsberger, C

    1923-01-01

    For the calculation of the parasite resistance of an airplane, a knowledge of the resistance of the individual structural and accessory parts is necessary. The most reliable basis for this is given by tests with actual airplane parts at airspeeds which occur in practice. The data given here relate to the landing gear of a Siemanms-Schuckert DI airplane; the landing gear of a 'Luftfahrzeug-Gesellschaft' airplane (type Roland Dlla); landing gear of a 'Flugzeugbau Friedrichshafen' G airplane; a machine gun, and the exhaust manifold of a 269 HP engine.

  4. 78 FR 76731 - Special Conditions: Boeing Model 777-200, -300, and -300ER Series Airplanes; Rechargeable Lithium...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-19

    ... battery systems special conditions adopted for the Boeing Model 787 (72 FR 57842; October 11, 2007..., -300, and -300ER series airplanes, was published in the Federal Register on August 22, 2013 (78 FR... Series Airplanes; Rechargeable Lithium Ion Batteries and Battery Systems AGENCY: Federal...

  5. 78 FR 70848 - Special Conditions: Boeing Model 777-200, -300, and -300ER Series Airplanes; Aircraft Electronic...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-27

    ... the EFB architecture and existing airplane network systems. The applicable airworthiness regulations... interface to existing aircraft systems. The proposed network architecture is used for a diverse set of... architecture and network configuration in the Boeing Model 777- 200, -300, and -300ER series airplanes...

  6. 78 FR 5146 - Special Conditions: Embraer S.A., Model EMB-550 Airplane, Dive Speed Definition With Speed...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-24

    ... Statement can be found in the Federal Register published on April 11, 2000 (65 FR 19477 19478), as well as...., Model EMB-550 Airplane, Dive Speed Definition With Speed Protection System AGENCY: Federal Aviation... category airplanes. These design features include a high-speed protection system. The...

  7. Analysis of Multiengine Transport Airplane Fire Records

    NASA Technical Reports Server (NTRS)

    Pesman, Gerard J.

    1950-01-01

    An analysis has been made of Civil Aeronautics Administration and Civil Aeronautics Board commercial airplane fire records collected during the 10-year period ending July 1, 1948. The results of the analysis show that: 1. Gasoline was most frequently the initial combustible ignited in flight and ground fires and is considered to be the most hazardous of the combustibles carried. 2. Although electrical-ignition sources are the most frequent flight-fire ignition source by a small margin, the exhaust system is concluded to be the most hazardous ignition source because it is necessarily located near the lubricating-oil and gasoline-plumbing systems and the resulting fires are relatively severe. The electrical-ignition sources usually involve only the electrical insulation and result in small-volume fires. The exhaust system was found to be the most frequent ground-fire ignition source. 3. Engine failures were the most frequent cause of the union of combustible and ignition source that resulted in flight fires. 4. Fuel-plumbing-system failures were the most frequent cause of fires occurring during ground operation. 5. The evidence concerning crash fires was not sufficiently extensive to provide information concerning the factors that affect the start and the spread of fire. In order that future records may be more useful, all crash accidents should be studied to determine why fire does or does not occur and to establish data that relate the occurrence and the spread of fire to airplane design and operation.

  8. 76 FR 77157 - Airworthiness Directives; The Boeing Company Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-12

    .... Additionally, this proposed AD would require installing Aero-Engine database (AEDB) software in the airplane information management system (AIMS) hardware. We are proposing this AD to eliminate T/R thermal damage caused... failure. This failure could result in large pieces of the T/R or adjacent components departing...

  9. 77 FR 50054 - Airworthiness Directives; Cessna Aircraft Company Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-20

    ... receive about this proposed AD. Discussion In January 2012, we issued AD 2012-02-02 (77 FR 6003, February... 172S airplanes that have installed an engine fuel return system modification kit. AD 2012-02-02 (77 FR... Procedures (44 FR 11034, February 26, 1979), (3) Will not affect intrastate aviation in Alaska and (4)...

  10. 78 FR 58965 - Airworthiness Directives; Bombardier, Inc. Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-25

    ... Procedures (44 FR 11034, February 26, 1979); 3. Will not affect intrastate aviation in Alaska; and 4. Will... system. Certain of those reported incidents resulted in the airplane experiencing a momentary loss of electrical power and loss of flight displays. This proposed AD would require modification of the...

  11. 76 FR 69161 - Airworthiness Directives; Bombardier, Inc. Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-08

    ... and Procedures (44 FR 11034, February 26, 1979); and 3. Will not have a significant economic impact... (TR) 1-41, dated October 22, 2010, to Section 2-- Systems/Powerplant Program of Part 1 of the... compliance times in Bombardier TR 1-41, dated October 22, 2010. (1) For airplanes with 10,000 or less...

  12. 76 FR 70377 - Airworthiness Directives; The Boeing Company Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-14

    ... faults are detected Additional design features to detect any center wing tank or auxiliary fuel tank pump... design features--for 35 work-hours x $85 per 17,000 19,975 13,742,800 airplanes with center wing tank... System Design Review, Flammability Reduction and Maintenance and Inspection Requirements'' (66 FR...

  13. 77 FR 65642 - Airworthiness Directives; The Boeing Company Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-30

    ... Model 737-400 airplanes of total loss of boost pump pressure of the fuel feed system, followed by loss... (73 FR 32256). That NPRM proposed to require repetitive operational tests of the engine fuel suction.... Actions Since Previous NPRM (73 FR 32256, June 6, 2008) Was Issued Since we issued the previous NPRM...

  14. The Paper Airplane Challenge: A Market Economy Simulation. Lesson Plan.

    ERIC Educational Resources Information Center

    Owens, Kimberly

    This lesson plan features a classroom simulation that helps students understand the characteristics of a market economic system. The lesson plan states a purpose; cites student objectives; suggests a time duration; lists materials needed; and details a step-by-step teaching procedure. The "Paper Airplane Challenge" handout is attached. (BT)

  15. CHARACTERIZATION OF PRIORITY POLLUTANTS FROM AN AIRPLANE PARTS MANUFACTURING FACILITY

    EPA Science Inventory

    Wastewater from an airplane parts manufacturing plant was sampled using the U.S. EPA screening protocol for the 129 priority pollutants. The wastewater treatment facilities at this site include batch systems to destroy cyanides, remove oil, and reduce hexavalent chromium to the t...

  16. 77 FR 41934 - Airworthiness Directives; The Boeing Company Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-17

    ..., and 747SP series airplanes. That NPRM published in the Federal Register on June 6, 2008 (73 FR 32245... of the fuel system, and other related testing if necessary. Actions Since Previous NPRM (73 FR 32245, June 6, 2008) Was Issued Since we issued the previous NPRM (73 FR 32245, June 6, 2008), we...

  17. 77 FR 16193 - Airworthiness Directives; Bombardier, Inc. Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-20

    ... 12866; 2. Is not a ``significant rule'' under the DOT Regulatory Policies and Procedures (44 FR 11034... (Regional Jet Series 900) airplanes. This proposed AD was prompted by reports of failures of a hydraulic accumulator's screw-cap/end cap while on the ground that resulted in loss of use of that hydraulic system...

  18. Comparative Analysis of Interference Pathloss Coupling Patterns on B-737 VS. B757 Airplanes

    NASA Technical Reports Server (NTRS)

    Jafri, Madiha; Ely, Jay; Vahala, Linda

    2005-01-01

    Portable wireless technology provides many benefits to modern day travelers. Over the years however, numerous reports have cited portable electronic devices (PEDs) as a possible cause of electromagnetic interference (EMI) to aircraft navigation and communication radio systems. PEDs may act as transmitters, both intentional and unintentional, and their signals may be detected by the various radio receiver antennas installed on the aircraft. Measurement of the radiated field coupling between passenger cabin locations and aircraft communication and navigation receivers, via their antennas is defined herein as interference path loss (IPL). IPL data is required for assessing the threat of PEDs to aircraft radios, and is very dependent upon airplane size, the interfering transmitter position within the airplane, and the location of the particular antenna for the aircraft system of concern. NASA Langley Research Center, Eagles Wings Inc., and United Airlines personnel performed extensive IPL measurements on several Boeing 737 airplanes. In the Spring of 2004, extensive IPL measurements were also taken on several Boeing 757 airplanes under a cooperative agreement between NASA Langley Research Center and Delta Airlines. The objective of this paper is to analyze IPL measurement data, to better understand the impact on coupling levels based on the different locations of the aircraft radio antennas on B-757 and B-737 airplanes, and to provide a basis for future fuzzy logic modeling of airplane IPL. This effort will build upon previous fuzzy modeling of IPL data for B-737 airplane data.

  19. The Testing of Airplane Fabrics

    NASA Technical Reports Server (NTRS)

    Schraivogel, Karl

    1932-01-01

    This report considers the determining factors in the choice of airplane fabrics, describes the customary methods of testing and reports some of the experimental results. To sum up briefly the results obtained with the different fabrics, it may be said that increasing the strength of covering fabrics by using coarser yarns ordinarily offers no difficulty, because the weight increment from doping is relatively smaller.

  20. Paper Airplanes: A Classroom Activity

    ERIC Educational Resources Information Center

    Painter, Richard A.

    1976-01-01

    A learning experience is described for upper elementary or junior high students involving the manufacture, transportation, and marketing of a product for consumers. Steps are given and roles are assigned for students to convert raw material (paper) to a finished product (paper airplanes) and to sell it. (AV)

  1. Testing a Windmill Airplane ("autogiro")

    NASA Technical Reports Server (NTRS)

    Seiferth, R

    1927-01-01

    In order to clear up the matter ( In the Spanish report it was stated that the reference surface for the calculation of the coefficients c(sub a) and c(sub w) was the area of all four wings, instead of a single wing), the model of a windwill airplane was tested in the Gottingen wind tunnel.

  2. Glues Used in Airplane Parts

    NASA Technical Reports Server (NTRS)

    Allen, S W; Truax, T R

    1920-01-01

    This report was prepared for the National Advisory Committee for Aeronautics and presents the results of investigations conducted by the Forest Products Laboratory of the United States Forest Service on the manufacture, preparation, application, testing and physical properties of the different types of glues used in wood airplane parts.

  3. Vibration Response of Airplane Structures

    NASA Technical Reports Server (NTRS)

    Theodorsen, Theodore; Gelalles, A G

    1935-01-01

    This report presents test results of experiments on the vibration-response characteristics of airplane structures on the ground and in flight. It also gives details regarding the construction and operation of vibration instruments developed by the National Advisory Committee for Aeronautics.

  4. 78 FR 15112 - Rulemaking Advisory Committee; Transport Airplane Performance and Handling Characteristics-New Task

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-08

    ... Federal Aviation Administration Aviation Rulemaking Advisory Committee; Transport Airplane Performance and... guidance material for airplane performance and handling characteristics in new transport category airplanes...: Joe Jacobsen, Airplane & Flight Crew Interface Branch, ANM-111, Transport Airplane...

  5. Rapid Airplane Parametric Input Design (RAPID)

    NASA Technical Reports Server (NTRS)

    Smith, Robert E.

    1995-01-01

    RAPID is a methodology and software system to define a class of airplane configurations and directly evaluate surface grids, volume grids, and grid sensitivity on and about the configurations. A distinguishing characteristic which separates RAPID from other airplane surface modellers is that the output grids and grid sensitivity are directly applicable in CFD analysis. A small set of design parameters and grid control parameters govern the process which is incorporated into interactive software for 'real time' visual analysis and into batch software for the application of optimization technology. The computed surface grids and volume grids are suitable for a wide range of Computational Fluid Dynamics (CFD) simulation. The general airplane configuration has wing, fuselage, horizontal tail, and vertical tail components. The double-delta wing and tail components are manifested by solving a fourth order partial differential equation (PDE) subject to Dirichlet and Neumann boundary conditions. The design parameters are incorporated into the boundary conditions and therefore govern the shapes of the surfaces. The PDE solution yields a smooth transition between boundaries. Surface grids suitable for CFD calculation are created by establishing an H-type topology about the configuration and incorporating grid spacing functions in the PDE equation for the lifting components and the fuselage definition equations. User specified grid parameters govern the location and degree of grid concentration. A two-block volume grid about a configuration is calculated using the Control Point Form (CPF) technique. The interactive software, which runs on Silicon Graphics IRIS workstations, allows design parameters to be continuously varied and the resulting surface grid to be observed in real time. The batch software computes both the surface and volume grids and also computes the sensitivity of the output grid with respect to the input design parameters by applying the precompiler tool

  6. The airplane: A simulated commercial air transportation study

    NASA Technical Reports Server (NTRS)

    Dauteuil, Mark; Geniesse, Pete; Hunniford, Michael; Lawler, Kathleen; Quirk, Elena; Tognarelli, Michael

    1993-01-01

    The 'Airplane' is a moderate-range, 70 passenger aircraft. It is designed to serve demands for flights up to 10,000 feet and it cruises at 32 ft/s. The major drivers for the design of the Airplane are economic competitiveness, takeoff performance, and weight minimization. The Airplane is propelled by a single Astro 15 electric motor and a Zinger 12-8 propeller. The wing section is a Spica airfoil which, because of its flat bottom, provides simplicity in manufacturing and thus helps to cut costs. The wing is constructed of a single load bearing mainspar and shape-holding ribs coated with Monokote skin, lending to a light weight structural makeup. The fuselage houses the motor, flight deck and passenger compartments as well as the fuel and control actuating systems. The wing will be attached to the top of the fuselage as will the fuel and control actuator systems for easy disassembly and maintenance. The aircraft is maneuvered about its pitch axis by means of an aft elevator on the flat plate horizontal tail. The twin vertical tail surfaces are also flat plates and each features a rudder for both directional and roll control. Along with wing dihedral, the rudders will be used to roll the aircraft. The Airplane is less costly to operate at its own maximum range and capacity as well as at its maximum range and the HB-40's maximum capacity than the HB-40.

  7. 14 CFR 121.207 - Provisionally certificated airplanes: Operating limitations.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Provisionally certificated airplanes... AND OPERATIONS OPERATING REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL OPERATIONS Airplane Performance Operating Limitations § 121.207 Provisionally certificated airplanes: Operating limitations....

  8. 14 CFR 121.207 - Provisionally certificated airplanes: Operating limitations.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Provisionally certificated airplanes... AND OPERATIONS OPERATING REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL OPERATIONS Airplane Performance Operating Limitations § 121.207 Provisionally certificated airplanes: Operating limitations....

  9. 14 CFR 121.207 - Provisionally certificated airplanes: Operating limitations.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Provisionally certificated airplanes... AND OPERATIONS OPERATING REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL OPERATIONS Airplane Performance Operating Limitations § 121.207 Provisionally certificated airplanes: Operating limitations....

  10. 14 CFR 121.207 - Provisionally certificated airplanes: Operating limitations.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Provisionally certificated airplanes... AND OPERATIONS OPERATING REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL OPERATIONS Airplane Performance Operating Limitations § 121.207 Provisionally certificated airplanes: Operating limitations....

  11. 14 CFR 121.207 - Provisionally certificated airplanes: Operating limitations.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Provisionally certificated airplanes... AND OPERATIONS OPERATING REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL OPERATIONS Airplane Performance Operating Limitations § 121.207 Provisionally certificated airplanes: Operating limitations....

  12. Certification aspects of airplanes which may operate with significant natural laminar flow

    NASA Technical Reports Server (NTRS)

    Gabriel, Edward A.; Tankesley, Earsa L.

    1986-01-01

    Recent research by NASA indicates that extensive natural laminar flow (NLF) is attainable on modern high performance airplanes currently under development. Modern airframe construction methods and materials, such as milled aluminum skins, bonded aluminum skins, and composite materials, offer the potential for production of aerodynamic surfaces having waviness and roughness below the values which are critical for boundary layer transition. Areas of concern with the certification aspects of Natural Laminar Flow (NLF) are identified to stimulate thought and discussion of the possible problems. During its development, consideration has been given to the recent research information available on several small business and experimental airplanes and the certification and operating rules for general aviation airplanes. The certification considerations discussed are generally applicable to both large and small airplanes. However, from the information available at this time, researchers expect more extensive NLF on small airplanes because of their lower operating Reynolds numbers and cleaner leading edges (due to lack of leading-edge high lift devices). Further, the use of composite materials for aerodynamic surfaces, which will permit incorporation of NLF technology, is currently beginning to appear in small airplanes.

  13. BAROS METHOD CRITICAL ANALYSIS (BARIATRIC ANALYSIS AND REPORTING SYSTEM)

    PubMed Central

    NICARETA, Jean Ricardo; de FREITAS, Alexandre Coutinho Teixeira; NICARETA, Sheyla Maris; NICARETA, Cleiton; CAMPOS, Antonio Carlos Ligocki; NASSIF, Paulo Afonso Nunes; MARCHESINI, João Batista

    2015-01-01

    Introduction : Although it has received several criticisms, which is considered to be the most effective method used for global assessment of morbid obesity surgical treatment, still needs to be updated. Objective : Critical analysis of BAROS constitution and method. Method : BAROS as headings was searched in literature review using data from the main bariatric surgery journals until 2009. Results : Where found and assessed 121 papers containing criticisms on BAROS constitution and methodology. It has some failures and few researches show results on the use of this instrument, although it is still considered a standard method. Several authors that used it found imperfections in its methodology and suggested some changes addressed to improving its acceptance, showing the need of developing new methods to qualify the bariatric surgery results. Conclusion: BAROS constitution has failures and its methodology needs to be updated. PMID:26537280

  14. The Pressure Distribution over the Wings and Tail Surfaces of a PW-9 Pursuit Airplane in Flight

    NASA Technical Reports Server (NTRS)

    Rhode, Richard

    1931-01-01

    This report presents the results of an investigation to determine (1) the magnitude and distribution of aerodynamic loads over the wings and tail surfaces of a pursuit-type airplane in the maneuvers likely to impose critical loads on the various subassemblies of the airplane structure. (2) To study the phenomenon of center of pressure movement and normal force coefficient variation in accelerated flight, and (3) to measure the normal accelerations at the center of gravity, wing-tip, and tail, in order to determine the nature of the inertia forces acting simultaneously with the critical aerodynamic loads. The results obtained throw light on a number of important questions involving structural design. Some of the more interesting results are discussed in some detail, but in general the report is for the purpose of making this collection of airplane-load data obtained in flight available to those interested in airplane structures.

  15. NASA's Space Launch System Marks Critical Design Review

    NASA Technical Reports Server (NTRS)

    Singer, Chris

    2016-01-01

    With completion of its Critical Design Review (CDR) in 2015, NASA is deep into the manufacturing and testing phases of its new Space Launch System (SLS) for beyond-Earth exploration. This CDR was the first in almost 40 years for a NASA human launch vehicle and marked another successful milestone on the road to the launch of a new era of deep space exploration. The review marked the 90-percent design-complete, a final look at the design and development plan of the integrated vehicle before full-scale fabrications begins and the prelude to the next milestone, design certification. Specifically, the review looked at the first of three increasingly capable configurations planned for SLS. This "Block I" design will stand 98.2 meters (m) (322 feet) tall and provide 39.1 million Newtons (8.8 million pounds) of thrust at liftoff to lift a payload of approximately 70 metric tons (154,000 pounds). This payload is more than double that of the retired space shuttle program or other current launch vehicles. It dramatically increases the mass and volume of human and robotic exploration. Additionally, it will decrease overall mission risk, increase safety, and simplify ground and mission operations - all significant considerations for crewed missions and unique, high-value national payloads. The Block 1 SLS will launch NASA's Orion Multi-Purpose Crew Vehicle (MPCV) on an uncrewed flight beyond the moon and back and the first crewed flight around the moon. The current design has a direct evolutionary path to a vehicle with a 130t lift capability that offers even more flexibility to reduce planetary trip times, simplify payload design cycles, and provide new capabilities such as planetary sample returns. Every major element of SLS has hardware in production or testing, including flight hardware for the Exploration 1 (EM-1) test flight. In fact, the SLS MPCV-to-Stage-Adapter (MSA) flew successfully on the Exploration Flight Test (EFT) 1 launch of a Delta IV and Orion spacecraft in

  16. Self-organized criticality as a fundamental property of neural systems

    PubMed Central

    Hesse, Janina; Gross, Thilo

    2014-01-01

    The neural criticality hypothesis states that the brain may be poised in a critical state at a boundary between different types of dynamics. Theoretical and experimental studies show that critical systems often exhibit optimal computational properties, suggesting the possibility that criticality has been evolutionarily selected as a useful trait for our nervous system. Evidence for criticality has been found in cell cultures, brain slices, and anesthetized animals. Yet, inconsistent results were reported for recordings in awake animals and humans, and current results point to open questions about the exact nature and mechanism of criticality, as well as its functional role. Therefore, the criticality hypothesis has remained a controversial proposition. Here, we provide an account of the mathematical and physical foundations of criticality. In the light of this conceptual framework, we then review and discuss recent experimental studies with the aim of identifying important next steps to be taken and connections to other fields that should be explored. PMID:25294989

  17. Study of stability of large maneuvers of airplanes

    NASA Technical Reports Server (NTRS)

    Haddad, E. K.

    1974-01-01

    A predictive method of nonlinear system analysis is used to investigate airplane stability and dynamic response during rolling maneuvers. The maneuver roll-rate is not assumed to be constant, and the airplane motion is represented by a set of coupled nonlinear differential equations. The general rolling maneuver is kinematically specified by its roll-rate variation p(t). A method for relating the airplane dynamic response to p(t) is developed. The method provides analytical expressions for the motion variables in terms of the maneuver descriptor p(t). A parameterized family of rolling maneuvers is considered, for which the method is used to predict specific dynamic response information, such as the dependence of the peak angle-of-attack excursion on the maneuver parameters. The stability and motion of the airplane in response to an arbitrary actuation of aileron input is considered. Analytical expressions relating motion variables to aileron input are obtained. Explicit analytical bounds on the motion variables are derived. A stability criterion which guarantees nondivergence of motion in response to aileron actuation is presented.

  18. Parametric Optimization of Some Critical Operating System Functions--An Alternative Approach to the Study of Operating Systems Design

    ERIC Educational Resources Information Center

    Sobh, Tarek M.; Tibrewal, Abhilasha

    2006-01-01

    Operating systems theory primarily concentrates on the optimal use of computing resources. This paper presents an alternative approach to teaching and studying operating systems design and concepts by way of parametrically optimizing critical operating system functions. Detailed examples of two critical operating systems functions using the…

  19. 'Known Secure Sensor Measurements' for Critical Infrastructure Systems: Detecting Falsification of System State

    SciTech Connect

    Miles McQueen; Annarita Giani

    2011-09-01

    This paper describes a first investigation on a low cost and low false alarm, reliable mechanism for detecting manipulation of critical physical processes and falsification of system state. We call this novel mechanism Known Secure Sensor Measurements (KSSM). The method moves beyond analysis of network traffic and host based state information, in fact it uses physical measurements of the process being controlled to detect falsification of state. KSSM is intended to be incorporated into the design of new, resilient, cost effective critical infrastructure control systems. It can also be included in incremental upgrades of already in- stalled systems for enhanced resilience. KSSM is based on known secure physical measurements for assessing the likelihood of an attack and will demonstrate a practical approach to creating, transmitting, and using the known secure measurements for detection.

  20. Effect of interaction on landing-gear behavior and dynamic loads in a flexible airplane structure

    NASA Technical Reports Server (NTRS)

    Cook, Francis E; Milwitzky, Benjamin

    1956-01-01

    The effects of interaction between a landing gear and a flexible airplane structure on the behavior of the landing gear and the loads in the structure have been studied by treating the equations of motion of the airplane and the landing gear as a coupled system. The landing gear is considered to have nonlinear characteristics typical of conventional gears, namely, velocity-squared damping, polytropic air-compression springing, and exponential tire force-deflection characteristics. For the case where only two modes of the structure are considered, an equivalent three-mass system is derived for representing the airplane and landing-gear combination, which may be used to simulate the effects of structural flexibility in jig drop tests of landing gears. As examples to illustrate the effects of interaction, numerical calculations, based on the structural properties of two large airplanes having considerably different mass and flexibility characteristics, are presented.

  1. Analysis of Stresses in German Airplanes

    NASA Technical Reports Server (NTRS)

    Hoff, Wilhelm

    1923-01-01

    This report contains an account of the origin of the views and fundamental principles underlying the construction of German airplanes during the war. The report contains a detailed discussion of the aerodynamic principles and their use in determining the strength of airplanes, the analysis of the strength qualities of materials and in the construction, the calculated strength of air flows and a description of tests made in determining the strength of airplanes.

  2. 78 FR 29666 - Airworthiness Directives; Airbus Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-21

    ...We propose to adopt a new airworthiness directive (AD) for certain Airbus Model A330-200 and -300 series airplanes; Model A340-200 and -300 series airplanes; and Model A340-541 and -642 airplanes. This proposed AD was prompted by reports of wing tip brakes (WTBs) losing their braking function in service due to heavy wear on the brake discs. WTBs are designed to stop and hold the mechanical......

  3. 77 FR 65812 - Airworthiness Directives; Airbus Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-31

    ...We are adopting a new airworthiness directive (AD) for all Airbus Model A330-200 freighter series airplanes; Model A330-200 and - 300 series airplanes; and Model A340-200 and -300 series airplanes. This AD was prompted by reports of ram air turbine (RAT) pump failure. This AD requires inspecting the RAT pump anti-stall valve for correct setting, re-identifying the RAT pump, performing a......

  4. 77 FR 40830 - Airworthiness Directives; Airbus Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-11

    ...We propose to adopt a new airworthiness directive (AD) for all Airbus Model A330-200 freighter series airplanes; Model A330-200 and - 300 series airplanes; and Model A340-200 and -300 series airplanes. This proposed AD was prompted by reports of ram air turbine (RAT) pump failure. This proposed AD would require inspecting the RAT pump anti- stall valve for correct setting, re-identifying the......

  5. Crash Tests of Protective Airplane Floors

    NASA Technical Reports Server (NTRS)

    Carden, H. D.

    1986-01-01

    Energy-absorbing floors reduce structural buckling and impact forces on occupants. 56-page report discusses crash tests of energy-absorbing aircraft floors. Describes test facility and procedures; airplanes, structural modifications, and seats; crash dynamics; floor and seat behavior; and responses of anthropometric dummies seated in airplanes. Also presents plots of accelerations, photographs and diagrams of test facility, and photographs and drawings of airplanes before, during, and after testing.

  6. Serving the System: A Critical History of Distance Education.

    ERIC Educational Resources Information Center

    Sumner, Jennifer

    2000-01-01

    Examines the history of distance education in terms of its ability to foster communicative action. Discusses Habermas's Theory of Communicative Action; Critical Theory; rationality; the role of technology in distance education; correspondence study; multimedia instruction; computer-mediated distance education; and the potential for interactivity…

  7. Electromagnetic Structure of Few-Nucleon Systems: a Critical Review

    SciTech Connect

    R. Schiavilla

    2000-10-01

    Our current understanding of the structure of nuclei with up to A=8, including energy spectra, electromagnetic form factors, and capture reactions, is critically reviewed within the context of a realistic approach to nuclear dynamics based on two- and three-nucleon interactions and associated electromagnetic currents.

  8. RFID-Based Critical Path Expert System for Agility Manufacture Process Management

    NASA Astrophysics Data System (ADS)

    Cheng, Haifang; Xiang, Yuli

    This paper presents a critical path expert system for the agility manufacture process management based on radio frequency identification (RFID) technology. The paper explores that the agility manufacture processes can be visible and controllable with RFID. The critical paths or activities can be easily found out and tracked by the RFID tracing technology. And the expert system can optimize the bottle neck of the task process of the agility management with the critical path adjusting and reforming method. Finally, the paper gives a simple application example of the system to discuss how to adjust the critical paths and how to make the process more agility and flexibility with the critical path expert system. With an RFID-based critical path expert system, the agility manufacture process management will be more effective and efficient.

  9. A preliminary analysis of flight data from the AFTI/F-16 airplane

    NASA Technical Reports Server (NTRS)

    Batterson, J. G.; Klein, V.

    1984-01-01

    Flight test data from the AFTI/F-16 airplane are analyzed. Two flight control system modes (Independent Backup Unit and Standard Normal Mode) are considered. Estimated stability and control derivatives are compared with values from the wind tunnel and F-16A flight tests. Modeling difficulties are shown to arise due to the near-neutral static stability of the airplane and the number of coordinated control surface movements commanded in the Standard Normal Mode.

  10. Facilities and Methods Used in Full-scale Airplane Crash-fire Investigation

    NASA Technical Reports Server (NTRS)

    Black, Dugald O.

    1952-01-01

    The facilities and the techniques employed in the conduct of full scale airplane crash-fire studies currently being conducted at the NACA Lewis laboratory are discussed herein. This investigation is part of a comprehensive study of the airplane crash-fire problem. The crash configuration chosen, the general physical layout of the crash site, the test methods, the instrumentation, the data-recording systems, and the post-crash examination procedure are described

  11. 75 FR 11918 - Hewlett Pachard Company, Business Critical Systems, Mission Critical Business Software Division...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-12

    ... in the Federal Register on November 5, 2009 (75 FR 57341). The notice was amended on January 14th... Federal Register on February 1, 2010 (75 FR 5146). At the request of the State Agency, the Department... Business Software Division, Openvms Operating System Development Group, Including Employees Working...

  12. Increment 23/24 Critical Readiness Review Health Maintenance System

    NASA Technical Reports Server (NTRS)

    Nieschwitz, Linda

    2010-01-01

    This slide presentation reviews the Health Maintenance System. It includes information on the carbon dioxide (CO2) and moisture removal system (CMRS), the variable oxygen system,rendevous station panels, and the crew contamination protection kit (CCPK).

  13. Critical exponents of a self-propelled particles system

    NASA Astrophysics Data System (ADS)

    Cambui, Dorilson S.; de Arruda, Alberto S.; Godoy, Maurício

    2016-02-01

    The Vicsek model of self-propelled particles is an important tool in the study of the collective motion of live organisms. The model consists of particles that move with a constant velocity and adopt, in a region called the zone of repulsion, the average motion direction of their neighbors disturbed by an external noise. A second-order phase transition from a disordered state, with motion in random directions, to an ordered motion state was observed. In this work, we have estimated, using finite-size scaling arguments, the critical exponents β, γ and ν of the original Vicsek model as a function of parameters important to the model, such as the orientation radius size, density, and velocity modulus. Our results show that the critical exponents depend greatly on these parameters.

  14. Integrated Flight-propulsion Control Concepts for Supersonic Transport Airplanes

    NASA Technical Reports Server (NTRS)

    Burcham, Frank W., Jr.; Gilyard, Glenn B.; Gelhausen, Paul A.

    1990-01-01

    Integration of propulsion and flight control systems will provide significant performance improvements for supersonic transport airplanes. Increased engine thrust and reduced fuel consumption can be obtained by controlling engine stall margin as a function of flight and engine operating conditions. Improved inlet pressure recovery and decreased inlet drag can result from inlet control system integration. Using propulsion system forces and moments to augment the flight control system and airplane stability can reduce the flight control surface and tail size, weight, and drag. Special control modes may also be desirable for minimizing community noise and for emergency procedures. The overall impact of integrated controls on the takeoff gross weight for a generic high speed civil transport is presented.

  15. Supersonic airplane study and design

    NASA Technical Reports Server (NTRS)

    Cheung, Samson

    1993-01-01

    A supersonic airplane creates shocks which coalesce and form a classical N-wave on the ground, forming a double bang noise termed sonic boom. A recent supersonic commercial transport (the Concorde) has a loud sonic boom (over 100 PLdB) and low aerodynamic performance (cruise lift-drag ratio 7). To enhance the U.S. market share in supersonic transport, an airframer's market risk for a low-boom airplane has to be reduced. Computational fluid dynamics (CFD) is used to design airplanes to meet the dual constraints of low sonic boom and high aerodynamic performance. During the past year, a research effort was focused on three main topics. The first was to use the existing design tools, developed in past years, to design one of the low-boom wind-tunnel configurations (Ames Model 3) for testing at Ames Research Center in April 1993. The second was to use a Navier-Stokes code (Overflow) to support the Oblique-All-Wing (OAW) study at Ames. The third was to study an optimization technique applied on a Haack-Adams body to reduce aerodynamic drag.

  16. General Theory of the Steady Motion of an Airplane

    NASA Technical Reports Server (NTRS)

    De Bothezat, George

    1921-01-01

    The writer points out briefly the history of the method proposed for the study of steady motion of an airplane, which is different from other methods now used. M. Paul Painleve has shown how convenient the drag-lift curve was for the study of airplane steady motion. The author later added to the drift-lift curve the curve called the "speed curve" which permits a direct checking of the speed of the airplane under all flying conditions. But the speed curve was plotted in the same quadrant as the drag-lift curve. Later, with the progressive development of aeronautical science, and with the continually increasing knowledge concerning engines and propellers, the author was brought to add the three other quadrants to the original quadrant, and thus was obtained the steady motion chart which is described in detail in this report. This charts permits one to read directly for a given airplane its horizontal speed at any altitude, its rate of climb at any altitude, its apparent inclination to the horizon at any moment, its ceiling, its propeller thrust, revolutions, efficiency, and power absorbed, that is the complete set of quantities involved in the subject, and to follow the variations of all these quantities both for variable altitude and for variable throttle. The chart also permits one to follow the variation of all of the above in flight as a function of the lift coefficient and of the speed. The author also discusses the interaction of the airplane and propeller through the slipstream and the question of the properties of the engine-propeller system and its dependence upon the properties of the engine considered alone and of the propeller considered alone. There is also a discussion of a standard atmosphere.

  17. Evaluation of an aeroelastic model technique for predicting airplane buffet loads

    NASA Technical Reports Server (NTRS)

    Hanson, P. W.

    1973-01-01

    A wind-tunnel technique which makes use of a dynamically scaled aeroelastic model to predict full-scale airplane buffet loads during buffet boundary penetration is evaluated. A 1/8-scale flutter model of a fighter airplane with remotely controllable variable-sweep wings and trimming surfaces was used for the evaluation. The model was flown on a cable-mount system which permitted high lift forces comparable to those in maneuvering flight. Bending moments and accelerations due to buffet were measured on the flutter model and compared with those measured on the full-scale airplane in an independent flight buffet research study. It is concluded that the technique can provide valuable information on airplane buffet load characteristics not available from any other source except flight test.

  18. RICIS Symposium 1992: Mission and Safety Critical Systems Research and Applications

    NASA Technical Reports Server (NTRS)

    1992-01-01

    This conference deals with computer systems which control systems whose failure to operate correctly could produce the loss of life and or property, mission and safety critical systems. Topics covered are: the work of standards groups, computer systems design and architecture, software reliability, process control systems, knowledge based expert systems, and computer and telecommunication protocols.

  19. Lattice animals, fractality and criticality in hadronic and partonic systems

    NASA Astrophysics Data System (ADS)

    Moretto, L. G.; Elliot, J. B.; Lake, P. T.; Phair, L.

    2011-01-01

    The cluster description of near coexistence phases (e.g. Fisher theory) requires an evaluation of cluster surface entropy. This surface degeneracy can be estimated with lattice models where clusters appear. The maximum probability lies near the maximum cluster surface. At low temperatures, clusters are forced to be nearly spherical by the surface energy and the associated Boltzmann factor. At higher temperatures and near criticality, the fractal dimension of clusters changes so that clusters become fractal. In the MIT bag model, where there is no surface energy, bags are always fractal.

  20. Optical System Critical Design Review (CDR) Flight Software Summary

    NASA Technical Reports Server (NTRS)

    Khorrami, Mori

    2006-01-01

    The Mid Infrared Instrument (MIRI FSW presentation covers: (1) Optical System FSW only and Cooling System FSW is covered at its CDR (2) Requirements & Interfaces (3) Relationship with the ISIM FSW (4) FSW Design Drivers & Solutions.

  1. Clock performance as a critical parameter in navigation satellite systems

    NASA Technical Reports Server (NTRS)

    Anderle, R. J.

    1978-01-01

    The high performance of available oscillators has permitted the development of invaluable navigation and geodetic satellite systems. However, still higher performance oscillators would further improve the accuracy or flexibility of the systems.

  2. Research on the control of airplanes

    NASA Technical Reports Server (NTRS)

    Jones, B Melvill

    1928-01-01

    Our task is to endeavor to obtain precise experimental records of the motion of stalled airplanes, both when left to themselves and when the pilot is trying to control them. The apparatus which we use consists of a box containing tree gyroscopes which are slightly deflected against a spring control when the airplane is turning.

  3. 77 FR 73343 - Airworthiness Directives; Airbus Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-10

    ... 39-16634 (76 FR 15805, March 22, 2011)] had been accomplished on this seat, but due to seizure, the... rule'' under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); 3. Will not... F4-600R series airplanes, and Model A300 C4-605R Variant F airplanes (collectively called Model...

  4. 14 CFR 125.355 - Airplane equipment.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Airplane equipment. 125.355 Section 125.355...: AIRPLANES HAVING A SEATING CAPACITY OF 20 OR MORE PASSENGERS OR A MAXIMUM PAYLOAD CAPACITY OF 6,000 POUNDS OR MORE; AND RULES GOVERNING PERSONS ON BOARD SUCH AIRCRAFT Flight Release Rules § 125.355...

  5. 14 CFR 125.355 - Airplane equipment.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Airplane equipment. 125.355 Section 125.355...: AIRPLANES HAVING A SEATING CAPACITY OF 20 OR MORE PASSENGERS OR A MAXIMUM PAYLOAD CAPACITY OF 6,000 POUNDS OR MORE; AND RULES GOVERNING PERSONS ON BOARD SUCH AIRCRAFT Flight Release Rules § 125.355...

  6. 14 CFR 125.355 - Airplane equipment.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Airplane equipment. 125.355 Section 125.355...: AIRPLANES HAVING A SEATING CAPACITY OF 20 OR MORE PASSENGERS OR A MAXIMUM PAYLOAD CAPACITY OF 6,000 POUNDS OR MORE; AND RULES GOVERNING PERSONS ON BOARD SUCH AIRCRAFT Flight Release Rules § 125.355...

  7. 14 CFR 125.355 - Airplane equipment.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Airplane equipment. 125.355 Section 125.355...: AIRPLANES HAVING A SEATING CAPACITY OF 20 OR MORE PASSENGERS OR A MAXIMUM PAYLOAD CAPACITY OF 6,000 POUNDS OR MORE; AND RULES GOVERNING PERSONS ON BOARD SUCH AIRCRAFT Flight Release Rules § 125.355...

  8. 78 FR 40057 - Airworthiness Directives; Airbus Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-03

    ... Procedures (44 FR 11034, February 26, 1979); 3. Will not affect intrastate aviation in Alaska; and 4. Will... Federal Aviation Administration 14 CFR Part 39 RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes... A321 series airplanes. This proposed AD was prompted by reports of certain sliding windows that...

  9. 78 FR 37498 - Airworthiness Directives; Airbus Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-21

    ... Procedures (44 FR 11034, February 26, 1979); 3. Will not affect intrastate aviation in Alaska; and 4. Will... Federal Aviation Administration 14 CFR Part 39 RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes... Freighter, and -300 series airplanes. This proposed AD was prompted by a report that a certain wire...

  10. 76 FR 72350 - Airworthiness Directives; Airbus Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-23

    ..., A319, A320, and A321 airplanes. Since we issued AD 2008-08-04, Amendment 39-15456 (73 FR 19975, April..., Amendment 39-15456 (73 FR 19975, April 14, 2008), With Revised Affected Airplanes Referenced Conditions (j... proposed AD. Discussion On March 31, 2008, we issued AD 2008-08-04, Amendment 39-15456 (73 FR 19975,...

  11. 78 FR 72834 - Airworthiness Directives; SOCATA Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-04

    ... 12866, (2) Is not a ``significant rule'' under the DOT Regulatory Policies and Procedures (44 FR 11034... Directives; SOCATA Airplanes AGENCY: Federal Aviation Administration (FAA), Department of Transportation (DOT... (AD) for SOCATA Model TBM 700 airplanes. This proposed AD results from mandatory...

  12. 77 FR 69391 - Airworthiness Directives; Airbus Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-19

    ... Policies and Procedures (44 FR 11034, February 26, 1979); 3. Will not affect intrastate aviation in Alaska... Directives; Airbus Airplanes AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed... A310-204, -222, -304, -322, and -324 airplanes. This proposed AD was prompted by the manufacturer...

  13. 77 FR 60331 - Airworthiness Directives; Airbus Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-03

    ...; 2. Is not a ``significant rule'' under the DOT Regulatory Policies and Procedures (44 FR 11034... Federal Aviation Administration 14 CFR Part 39 RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes... A321 series airplanes. This proposed AD was prompted by a report of an uncommanded nose landing...

  14. 77 FR 51729 - Airworthiness Directives; Airbus Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-27

    ... rule'' under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); 3. Will not... Federal Aviation Administration 14 CFR Part 39 RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes..., A340-200 and A340-300 series airplanes. This proposed AD was prompted by a report that revealed...

  15. 77 FR 66760 - Airworthiness Directives; Airbus Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-07

    ... Policies and Procedures (44 FR 11034, February 26, 1979); 3. Will not affect intrastate aviation in Alaska... Federal Aviation Administration 14 CFR Part 39 RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes...-200, A330-300, A340-200, A340- 300, A340-500, and A340-600 series airplanes. This proposed AD...

  16. 14 CFR 125.355 - Airplane equipment.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Airplane equipment. 125.355 Section 125.355...: AIRPLANES HAVING A SEATING CAPACITY OF 20 OR MORE PASSENGERS OR A MAXIMUM PAYLOAD CAPACITY OF 6,000 POUNDS OR MORE; AND RULES GOVERNING PERSONS ON BOARD SUCH AIRCRAFT Flight Release Rules § 125.355...

  17. 77 FR 66762 - Airworthiness Directives; Airbus Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-07

    ... 12866; 2. Is not a ``significant rule'' under the DOT Regulatory Policies and Procedures (44 FR 11034... Federal Aviation Administration 14 CFR Part 39 RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes..., -304, -322, and -324 airplanes. This proposed AD was prompted by a design review of the fuel...

  18. 14 CFR 91.821 - Civil supersonic airplanes: Noise limits.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 2 2013-01-01 2013-01-01 false Civil supersonic airplanes: Noise limits... Noise Limits § 91.821 Civil supersonic airplanes: Noise limits. Except for Concorde airplanes having... airplane that does not comply with Stage 2 noise limits of part 36 in effect on October 13, 1977,...

  19. 14 CFR 125.75 - Airplane flight manual.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Airplane flight manual. 125.75 Section 125... OPERATIONS: AIRPLANES HAVING A SEATING CAPACITY OF 20 OR MORE PASSENGERS OR A MAXIMUM PAYLOAD CAPACITY OF 6... Airplane flight manual. (a) Each certificate holder shall keep a current approved Airplane Flight Manual...

  20. 14 CFR 91.853 - Final compliance: Civil subsonic airplanes.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false Final compliance: Civil subsonic airplanes... Noise Limits § 91.853 Final compliance: Civil subsonic airplanes. Except as provided in § 91.873, after... airplane subject to § 91.801(c) of this subpart, unless that airplane has been shown to comply with Stage...

  1. 14 CFR 91.853 - Final compliance: Civil subsonic airplanes.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false Final compliance: Civil subsonic airplanes... Noise Limits § 91.853 Final compliance: Civil subsonic airplanes. Except as provided in § 91.873, after... airplane subject to § 91.801(c) of this subpart, unless that airplane has been shown to comply with Stage...

  2. 14 CFR 91.853 - Final compliance: Civil subsonic airplanes.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 2 2012-01-01 2012-01-01 false Final compliance: Civil subsonic airplanes... Noise Limits § 91.853 Final compliance: Civil subsonic airplanes. Except as provided in § 91.873, after... airplane subject to § 91.801(c) of this subpart, unless that airplane has been shown to comply with Stage...

  3. 14 CFR 91.821 - Civil supersonic airplanes: Noise limits.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 2 2012-01-01 2012-01-01 false Civil supersonic airplanes: Noise limits... Noise Limits § 91.821 Civil supersonic airplanes: Noise limits. Except for Concorde airplanes having... airplane that does not comply with Stage 2 noise limits of part 36 in effect on October 13, 1977,...

  4. 14 CFR 91.821 - Civil supersonic airplanes: Noise limits.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false Civil supersonic airplanes: Noise limits... Noise Limits § 91.821 Civil supersonic airplanes: Noise limits. Except for Concorde airplanes having... airplane that does not comply with Stage 2 noise limits of part 36 in effect on October 13, 1977,...

  5. 14 CFR 21.5 - Airplane or Rotorcraft Flight Manual.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Airplane or Rotorcraft Flight Manual. 21.5... CERTIFICATION PROCEDURES FOR PRODUCTS AND PARTS General § 21.5 Airplane or Rotorcraft Flight Manual. (a) With each airplane or rotorcraft not type certificated with an Airplane or Rotorcraft Flight Manual...

  6. 14 CFR 91.821 - Civil supersonic airplanes: Noise limits.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false Civil supersonic airplanes: Noise limits... Noise Limits § 91.821 Civil supersonic airplanes: Noise limits. Except for Concorde airplanes having... airplane that does not comply with Stage 2 noise limits of part 36 in effect on October 13, 1977,...

  7. 14 CFR 125.75 - Airplane flight manual.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Airplane flight manual. 125.75 Section 125... OPERATIONS: AIRPLANES HAVING A SEATING CAPACITY OF 20 OR MORE PASSENGERS OR A MAXIMUM PAYLOAD CAPACITY OF 6... Airplane flight manual. (a) Each certificate holder shall keep a current approved Airplane Flight Manual...

  8. 14 CFR 91.853 - Final compliance: Civil subsonic airplanes.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 2 2013-01-01 2013-01-01 false Final compliance: Civil subsonic airplanes... Noise Limits § 91.853 Final compliance: Civil subsonic airplanes. Except as provided in § 91.873, after... airplane subject to § 91.801(c) of this subpart, unless that airplane has been shown to comply with Stage...

  9. 14 CFR 125.75 - Airplane flight manual.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Airplane flight manual. 125.75 Section 125... OPERATIONS: AIRPLANES HAVING A SEATING CAPACITY OF 20 OR MORE PASSENGERS OR A MAXIMUM PAYLOAD CAPACITY OF 6... Airplane flight manual. (a) Each certificate holder shall keep a current approved Airplane Flight Manual...

  10. 14 CFR 125.75 - Airplane flight manual.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Airplane flight manual. 125.75 Section 125... OPERATIONS: AIRPLANES HAVING A SEATING CAPACITY OF 20 OR MORE PASSENGERS OR A MAXIMUM PAYLOAD CAPACITY OF 6... Airplane flight manual. (a) Each certificate holder shall keep a current approved Airplane Flight Manual...

  11. 14 CFR 91.821 - Civil supersonic airplanes: Noise limits.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Civil supersonic airplanes: Noise limits... Noise Limits § 91.821 Civil supersonic airplanes: Noise limits. Except for Concorde airplanes having... airplane that does not comply with Stage 2 noise limits of part 36 in effect on October 13, 1977,...

  12. 14 CFR 91.853 - Final compliance: Civil subsonic airplanes.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Final compliance: Civil subsonic airplanes... Noise Limits § 91.853 Final compliance: Civil subsonic airplanes. Except as provided in § 91.873, after... airplane subject to § 91.801(c) of this subpart, unless that airplane has been shown to comply with Stage...

  13. 14 CFR 21.5 - Airplane or Rotorcraft Flight Manual.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Airplane or Rotorcraft Flight Manual. 21.5... CERTIFICATION PROCEDURES FOR PRODUCTS AND PARTS General § 21.5 Airplane or Rotorcraft Flight Manual. (a) With each airplane or rotorcraft that was not type certificated with an Airplane or Rotorcraft Flight...

  14. Prolonging Microgravity on Parabolic Airplane Flights

    NASA Technical Reports Server (NTRS)

    Robinson, David W.

    2003-01-01

    Three techniques have been proposed to prolong the intervals of time available for microgravity experiments aboard airplanes flown along parabolic trajectories. Typically, a pilot strives to keep an airplane on such a trajectory during a nominal time interval as long as 25 seconds, and an experimental apparatus is released to float freely in the airplane cabin to take advantage of the microgravitational environment of the trajectory for as long as possible. It is usually not possible to maintain effective microgravity during the entire nominal time interval because random aerodynamic forces and fluctuations in pilot control inputs cause the airplane to deviate slightly from a perfect parabolic trajectory, such that the freely floating apparatus bumps into the ceiling, floor, or a wall of the airplane before the completion of the parabola.

  15. Critical Path-Based Thread Placement for NUMA Systems

    SciTech Connect

    Su, Chun-Yi; Li, Dong; Nikolopoulos, Dimitrios; Grove, Matthew; Cameron, Kirk W.; de Supinski, Bronis R.

    2012-01-01

    Multicore multiprocessors use Non Uniform Memory Architecture (NUMA) to improve their scalability. However,NUMA introduces performance penalties due to remote memory accesses. Without efficiently managing data layout and thread mapping to cores, scientific applications, even if they are optimized for NUMA, may suffer performance loss. In this paper, we present an algorithm that optimizes the placement of OpenMP threads on NUMA processors. By collecting information from hardware counters and defining new metrics to capture the effects of thread placement, the algorithm reduces NUMA performance penalty by minimizing the critical path of OpenMP parallel regions and by avoiding local memory resource contention. We evaluate our algorithm with NPB benchmarks and achieve performance improvement between 8.13% and 25.68%, compared to the OS default scheduling.

  16. Adaptive critic design for computer intrusion detection system

    NASA Astrophysics Data System (ADS)

    Novokhodko, Alexander; Wunsch, Donald C., II; Dagli, Cihan H.

    2001-03-01

    This paper summarizes ongoing research. A neural network is used to detect a computer system intrusion basing on data from the system audit trail generated by Solaris Basic Security Module. The data have been provided by Lincoln Labs, MIT. The system alerts the human operator, when it encounters suspicious activity logged in the audit trail. To reduce the false alarm rate and accommodate the temporal indefiniteness of moment of attack a reinforcement learning approach is chosen to train the network.

  17. The critical path system. The road toward an efficient OR.

    PubMed

    Grudich, G

    1991-03-01

    Since January 1990, surgeons have been able to make their incision within 15 minutes of the scheduled time. Total joint procedures, craniotomies, open heart surgery, and thoracic surgeries have had incision times within 15 minutes of the critical path timetable. Daily analysis of activity is done by reviewing the time study. The monthly delay report is becoming a quality assurance monitor for the hospital. Reports are sent to nurse managers, the director of surgical services, and the vice president of nursing. Daily review of the time study points out trends that can be addressed before they become a major problem. For example, in one month a surgical group had three delays. An informal meeting was held with the SDS nurse manager and the surgeon. The SDS manager and I met with the business manager of the group and the problem was resolved. In another example, a surgeon established a trend of consistently being late for cases. After a brief hallway chat, the problem was identified and an agreement reached that his time would be moved to 8 AM induction time. The last example concerns equipment failures. In one month, we had 20 delays due to equipment failures. By the next month, we had reduced equipment failures to 10, and by the end of the following month, we had three delays due to equipment failure. This was achieved through accurate documentation of the failures and frequent follow-up calls until the equipment was repaired. Surgeons and anesthesiologists still complain about delays, but not as often. Using the critical path concept has improved our efficiency and our image. This is only one facet of achieving timeliness in the OR. The teamwork between the OR nursing staff, surgical nursing staff, anesthesia staff, and the surgeons makes this program successful. Daily maintenance of the path with timely follow-up keeps the path working. PMID:2031583

  18. 14 CFR 25.1309 - Equipment, systems, and installations.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    .... (3) The resulting effects on the airplane and occupants, considering the stage of flight and... electrical system and equipment design and installation, critical environmental conditions must be considered... shown by environmental tests, design analysis, or reference to previous comparable service experience...

  19. CRITICAL OVERVIEW OF THE PERFORMANCE OF A MULTISENSOR CAPACITANCE SYSTEM

    Technology Transfer Automated Retrieval System (TEKTRAN)

    During the last decade major advances have been made in capacitance based sensor technology that enhanced our ability to measure soil water content in the soil plant atmosphere system. Multisensor capacitance systems (MCS) took the lead in this regards. This objectives of the current work are to c...

  20. Health Systems Governance for health equity: critical reflections.

    PubMed

    Labonté, Ronald

    2010-01-01

    This article addresses several issues pertinent to health systems governance for health equity. It argues the importance of health systems using measures of positive health (well-being), discriminating in favour of historically less advantaged groups and weighing the costs of health care against investments in the social determinants of health. It cautions that the concept of governance could weaken the role of government, with disequalizing effects, while emphasizing the importance of two elements of good governance (transparency and participation) in health systems decision-making. It distinguishes between participation as volunteer labour and participation as exercising political rights, and questions the assumption that decentralization in health systems is necessarily empowering. It then identifies five health system roles to address issues of equity (educator/watchdog, resource broker, community developer, partnership developer and advocate/catalyst) and the implications of these roles for practice. Drawing on preliminary findings of a global research project on comprehensive primary health care, it discusses political aspects of progressive health system reform and the implications of equity-focused health system governance on health workers' roles, noting the importance of health workers claiming their identity as citizens. The article concludes with a commentary on the inherently political nature of health reforms based on equity; the necessary confrontation with power relations politics involves; and the health systems governance challenge of managing competing health discourses of efficiency and results-based financing, on the one hand, and equity and citizen empowerment, on the other. PMID:20963302

  1. Simulator study of vortex encounters by a twin-engine, commercial, jet transport airplane

    NASA Technical Reports Server (NTRS)

    Hastings, E. C., Jr.; Keyser, G. L., Jr.

    1982-01-01

    A simulator study of vortex encounters was conducted for a twin-engine, commercial, jet transport airplane encountering the vortex flow field of a heavy, four-engine, commercial, jet transport airplane in the final-approach configuration. The encounters were conducted with fixed controls and with a pilot using a state-of-the-art, manual-control system. Piloted encounters with the base-line vortex flow field out of ground effect (unattenuated) resulted in initial bank-angle excursions greater than 40 deg, coupled with initial sideslip-angle excursions greater than 10 deg. The severity of these initial upsets was significantly reduced when the vortex center was moved laterally or vertically away from the flight path of the encountering airplane. Smaller reductions occurred when the flow field was attenuated by the flight spoilers on the generating airplane. The largest reduction in the severity of the initial upsets, however, was from aging in ground effect. The severity of the initial upsets of the following airplane was relatively unaffected by the approach speed. Increasing the lift coefficient of the generating airplane resulted in an increase in the severity of the initial upsets.

  2. Analyzing Software Errors in Safety-Critical Embedded Systems

    NASA Technical Reports Server (NTRS)

    Lutz, Robyn R.

    1994-01-01

    This paper analyzes the root causes of safty-related software faults identified as potentially hazardous to the system are distributed somewhat differently over the set of possible error causes than non-safety-related software faults.

  3. Critical early mission design considerations for lunar data systems architecture

    NASA Technical Reports Server (NTRS)

    Hei, Donald J., Jr.; Stephens, Elaine

    1992-01-01

    This paper outlines recent early mission design activites for a lunar data systems architecture. Each major functional element is shown to be strikingly similar when viewed in a common reference system. While this similarity probably deviates with lower levels of decomposition, the sub-functions can always be arranged into similar and dissimilar categories. Similar functions can be implemented as objects - implemented once and reused several times like today's advanced integrated circuits. This approach to mission data systems, applied to other NASA programs, may result in substantial agency implementation and maintenance savings. In today's zero-sum-game budgetary environment, this approach could help to enable a lunar exploration program in the next decade. Several early mission studies leading to such an object-oriented data systems design are recommended.

  4. Critical parameters for coarse coal underground slurry haulage systems

    NASA Technical Reports Server (NTRS)

    Maynard, D. P.

    1981-01-01

    Factors are identified which must be considered in meeting the requirements of a transportation system for conveying, in a pipeline, the coal mined by a continuous mining machine to a storage location neat the mine entrance or to a coal preparation plant located near the surface. For successful operation, the slurry haulage the system should be designed to operated in the turbulent flow regime at a flow rate at least 30% greater than the deposition velocity (slurry flow rate at which the solid particles tend to settle in the pipe). The capacity of the haulage system should be compatible with the projected coal output. Partical size, solid concentration, density, and viscosity of the suspension are if importance as well as the selection of the pumps, pipes, and valves. The parameters with the greatest effect on system performance ar flow velocity, pressure coal particle size, and solids concentration.

  5. Low speed test of a high-bypass-ratio propulsion system with an asymmetric inlet designed for a tilt-nacelle V/STOL airplane

    NASA Technical Reports Server (NTRS)

    Syberg, J.

    1978-01-01

    A large scale model of a lift/cruise fan inlet designed for a tilt nacelle V/STOL airplane was tested with a high bypass ratio turbofan. Testing was conducted at low freestream velocities with inlet angles of attack ranging from 0 deg to 120 deg. The operating limits for the nacelle were found to be related to inlet boundary layer separation. Small separations originating in the inlet diffuser cause little or no performance degradation. However, at sufficiently severe freestream conditions the separation changes abruptly to a lip separation. This change is associated with a significant reduction in nacelle net thrust as well as a sharp increase in fan blade vibratory stresses. Consequently, the onset of lip separation is regarded as the nacelle operating limit. The test verified that the asymmetric inlet design will provide high performance and stable operation at the design forward speed and angle of attack conditions. At some of these, however, operation near the lower end of the design inlet airflow range is not feasible due to the occurrence of lip separation.

  6. Peak-Seeking Control For Reduced Fuel Consumption: Flight-Test Results For The Full-Scale Advanced Systems Testbed FA-18 Airplane

    NASA Technical Reports Server (NTRS)

    Brown, Nelson

    2013-01-01

    A peak-seeking control algorithm for real-time trim optimization for reduced fuel consumption has been developed by researchers at the National Aeronautics and Space Administration (NASA) Dryden Flight Research Center to address the goals of the NASA Environmentally Responsible Aviation project to reduce fuel burn and emissions. The peak-seeking control algorithm is based on a steepest-descent algorithm using a time-varying Kalman filter to estimate the gradient of a performance function of fuel flow versus control surface positions. In real-time operation, deflections of symmetric ailerons, trailing-edge flaps, and leading-edge flaps of an F/A-18 airplane are used for optimization of fuel flow. Results from six research flights are presented herein. The optimization algorithm found a trim configuration that required approximately 3 percent less fuel flow than the baseline trim at the same flight condition. This presentation also focuses on the design of the flight experiment and the practical challenges of conducting the experiment.

  7. Time-critical multirate scheduling using contemporary real-time operating system services

    NASA Technical Reports Server (NTRS)

    Eckhardt, D. E., Jr.

    1983-01-01

    Although real-time operating systems provide many of the task control services necessary to process time-critical applications (i.e., applications with fixed, invariant deadlines), it may still be necessary to provide a scheduling algorithm at a level above the operating system in order to coordinate a set of synchronized, time-critical tasks executing at different cyclic rates. The scheduling requirements for such applications and develops scheduling algorithms using services provided by contemporary real-time operating systems.

  8. Landing and Braking of Airplanes

    NASA Technical Reports Server (NTRS)

    Breguet, Louis

    1929-01-01

    In the numerical examples, we have considered an airplane landing in calm air in a fixed direction after crossing the border (with its obstacles) at a height of 30 m. Its stopping point is at a distance D from the obstacle, comprising: a distance D(sub 1) in regular gliding flight; a distance D(sub 2) in levelling off; a distance D(sub 3) in taxying on the ground. The calculations enable us to make out the following table, which gives an idea of the improvements to be expected in the use of various possible methods of braking in the air and on the ground.

  9. IMPLEMENTATION OF A HYBRID CONTROLLER FOR CRITICAL BUILDING HVAC SYSTEMS

    SciTech Connect

    Craig Rieger

    2008-11-01

    Many industrial facilities utilize pressure control gradients to prevent migration of hazardous species from containment areas to occupied zones, often using Proportional-Integral-Derivative (PID) control systems. When operators rebalance the plant, variation from the desired gradients can occur and the operating conditions can change enough that the PID parameters are no longer adequate to maintain a stable system. As the goal of the ventilation control system is to optimize the pressure gradients and associated flows for the plant, Linear Quadratic Tracking (LQT) is a method that provides a time-based approach to guiding plant interactions. However, LQT methods are susceptible to modeling and measurement errors, and therefore the additional use of soft computing methods is proposed for implementation to account for these errors and nonlinearities. The performance of the resulting hybrid controller is demonstrated through simulation and experimental testing as compared to a representative PID controller.

  10. Current and Future Critical Issues in Rocket Propulsion Systems

    NASA Technical Reports Server (NTRS)

    Navaz, Homayun K.; Dix, Jeff C.

    1998-01-01

    The objective of this research was to tackle several problems that are currently of great importance to NASA. In a liquid rocket engine several complex processes take place that are not thoroughly understood. Droplet evaporation, turbulence, finite rate chemistry, instability, and injection/atomization phenomena are some of the critical issues being encountered in a liquid rocket engine environment. Pulse Detonation Engines (PDE) performance, combustion chamber instability analysis, 60K motor flowfield pattern from hydrocarbon fuel combustion, and 3D flowfield analysis for the Combined Cycle engine were of special interest to NASA. During the summer of 1997, we made an attempt to generate computational results for all of the above problems and shed some light on understanding some of the complex physical phenomena. For this purpose, the Liquid Thrust Chamber Performance (LTCP) code, mainly designed for liquid rocket engine applications, was utilized. The following test cases were considered: (1) Characterization of a detonation wave in a Pulse Detonation Tube; (2) 60K Motor wall temperature studies; (3) Propagation of a pressure pulse in a combustion chamber (under single and two-phase flow conditions); (4) Transonic region flowfield analysis affected by viscous effects; (5) Exploring the viscous differences between a smooth and a corrugated wall; and (6) 3D thrust chamber flowfield analysis of the Combined Cycle engine. It was shown that the LTCP-2D and LTCP-3D codes are capable of solving complex and stiff conservation equations for gaseous and droplet phases in a very robust and efficient manner. These codes can be run on a workstation and personal computers (PC's).

  11. Investigation of the Forces Acting on Gliders in Automobile-pulley-winch and Airplane Towed Flight

    NASA Technical Reports Server (NTRS)

    Klemperer, W B

    1942-01-01

    The magnitude, the direction, and the fluctuation of towing forces exerted upon gliders by towing them aloft behind an automobile, by means of a winch, and by airplane were measured under a variety of conditions covering a range from gentle to severe types of operation. For these tests the towing forces did not exceed 92 percent of the gross weight of the glider. The results indicate that in pulley and winch towing the towing forces are of about the same magnitude as in automobile towing. Speed increases in the accelerated phases of the towing jerks encountered in airplane towing can readily become critical as speeds in excess of placard speeds can be attained. Passage through the slipstream of the towing airplane can be equivalent to a severe gust that, at high speed, may impose high wing loads and require large control moments.

  12. Optimization of coupled systems: A critical overview of approaches

    NASA Technical Reports Server (NTRS)

    Balling, R. J.; Sobieszczanski-Sobieski, J.

    1994-01-01

    A unified overview is given of problem formulation approaches for the optimization of multidisciplinary coupled systems. The overview includes six fundamental approaches upon which a large number of variations may be made. Consistent approach names and a compact approach notation are given. The approaches are formulated to apply to general nonhierarchic systems. The approaches are compared both from a computational viewpoint and a managerial viewpoint. Opportunities for parallelism of both computation and manpower resources are discussed. Recommendations regarding the need for future research are advanced.

  13. 2010 Critical Success Factors for the North Carolina Community College System. Twenty First Annual Report

    ERIC Educational Resources Information Center

    North Carolina Community College System (NJ1), 2010

    2010-01-01

    First mandated by the North Carolina General Assembly in 1989 (S.L. 1989; C. 752; S. 80), the Critical Success Factors report has evolved into the major accountability document for the North Carolina Community College System. This twenty first annual report on the critical success factors is the result of a process undertaken to streamline and…

  14. CSER 95-003: Exemption from Criticality Alarm System requirement for 232-Z building

    SciTech Connect

    Nirider, L.T.; Miller, E.M.

    1995-05-18

    This CSER establishes an exemption for 232-Z from the requirement for a Criticality Alarm System, because the formation of a critical configuration is not a credible event for any circumstance involving the cleaning out and removal of the Burning Hood and associated equipment.

  15. Scaling behavior of an airplane-boarding model.

    PubMed

    Brics, Martins; Kaupužs, Jevgenijs; Mahnke, Reinhard

    2013-04-01

    An airplane-boarding model, introduced earlier by Frette and Hemmer [Phys. Rev. E 85, 011130 (2012)], is studied with the aim of determining precisely its asymptotic power-law scaling behavior for a large number of passengers N. Based on Monte Carlo simulation data for very large system sizes up to N=2(16)=65536, we have analyzed numerically the scaling behavior of the mean boarding time and other related quantities. In analogy with critical phenomena, we have used appropriate scaling Ansätze, which include the leading term as some power of N (e.g., [proportionality]N(α) for ), as well as power-law corrections to scaling. Our results clearly show that α=1/2 holds with a very high numerical accuracy (α=0.5001±0.0001). This value deviates essentially from α=/~0.69, obtained earlier by Frette and Hemmer from data within the range 2≤N≤16. Our results confirm the convergence of the effective exponent α(eff)(N) to 1/2 at large N as observed by Bernstein. Our analysis explains this effect. Namely, the effective exponent α(eff)(N) varies from values about 0.7 for small system sizes to the true asymptotic value 1/2 at N→∞ almost linearly in N(-1/3) for large N. This means that the variation is caused by corrections to scaling, the leading correction-to-scaling exponent being θ≈1/3. We have estimated also other exponents: ν=1/2 for the mean number of passengers taking seats simultaneously in one time step, β=1 for the second moment of t(b), and γ≈1/3 for its variance. PMID:23679383

  16. A Multiscale Modeling System: Developments, Applications, and Critical Issues

    NASA Technical Reports Server (NTRS)

    Tao, Wei-Kuo; Lau, William; Simpson, Joanne; Chern, Jiun-Dar; Atlas, Robert; Khairoutdinov, David Randall Marat; Li, Jui-Lin; Waliser, Duane E.; Jiang, Jonathan; Hou, Arthur; Lin, Xin; Peters-Lidard, Christa

    2009-01-01

    The foremost challenge in parameterizing convective clouds and cloud systems in large-scale models are the many coupled dynamical and physical processes that interact over a wide range of scales, from microphysical scales to the synoptic and planetary scales. This makes the comprehension and representation of convective clouds and cloud systems one of the most complex scientific problems in Earth science. During the past decade, the Global Energy and Water Cycle Experiment (GEWEX) Cloud System Study (GCSS) has pioneered the use of single-column models (SCMs) and cloud-resolving models (CRMs) for the evaluation of the cloud and radiation parameterizations in general circulation models (GCMs; e.g., GEWEX Cloud System Science Team 1993). These activities have uncovered many systematic biases in the radiation, cloud and convection parameterizations of GCMs and have led to the development of new schemes (e.g., Zhang 2002; Pincus et al, 2003; Zhang and Wu 2003; Wu et al. 2003; Liang and Wu 2005; Wu and Liang 2005, and others). Comparisons between SCMs and CRMs using the same large-scale forcing derived from field campaigns have demonstrated that CRMs are superior to SCMs in the prediction of temperature and moisture tendencies (e.g., Das et al. 1999; Randall et al 2003b; Xie et al. 2005).

  17. Critical Building Blocks: Mandatory Prerequisite Registration Systems and Student Success

    ERIC Educational Resources Information Center

    Soria, Krista M.; Mumpower, Lori

    2012-01-01

    Many colleges and universities require prerequisites prior to enrollment in introductory composition courses; however, enforcement of prerequisites is not consistent across institutions. In this study, we examine the impact of an automated, mandatory prerequisite enforcement system on students and advisors at a public comprehensive university.…

  18. Factors Critical to the Adoption of Career Guidance Systems.

    ERIC Educational Resources Information Center

    Kester, Ralph J.; Howard, John, Jr.

    The study endeavors to describe, assess, and trace the progress of six high schools as the faculty and staff responded to the adoption of an innovative career guidance system. The study provides a model, a method, and some generalizations about factors influencing the process. The document is organized according to: (1) definitions of basic…

  19. National Plant Germplasm System: Critical Role of Customer Service

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The National Plant Germplasm System (NPGS) conserves plant genetic resources, not only for use by future generations, but for immediate use by scientists and educators around the world. With a great deal of interaction between genebank curators and users of plant genetic resources, customer service...

  20. Toward a Critical Theoretic Perspective in Information Systems.

    ERIC Educational Resources Information Center

    Benoit, Gerald

    2002-01-01

    Considers the logico-analytic philosophy of library and information science (LIS); discusses Jurgen Habermas' theory of communicative action; examines how LIS, particularly research into librarian-patron interaction and information system design, favors an empiricist view of language and thus may be limiting its effectiveness; and suggests the…

  1. Nutrient Use Efficiency in Bioenergy Cropping Systems: Critical Research Questions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Current U.S. plans for energy security rely on converting large areas of cropland from food to biofuel production. Additionally, lands currently considered too marginal for intensive food production may be considered suitable for biofuels production; predominant cropping systems may shift to more va...

  2. Integrated system for remotely monitoring critical physiological parameters

    NASA Astrophysics Data System (ADS)

    Alexakis, S.; Karalis, S.; Asvestas, P.

    2015-09-01

    Monitoring several human parameters (temperature, heart rate, blood pressure etc.) is an essential task in health care in hospitals as well as in home care. This paper presents the design and implementation of an integrated, embedded system that includes an electrocardiograph of nine leads and two channels, a digital thermometer for measuring the body temperature and a power supply. The system provides networking capabilities (wired or wireless) and is accessible by means of a web interface that allows the user to select the leads, as well as to review the values of heart rate (beats per minute) and body temperature. Furthermore, there is the option of saving all the data in a Micro SD memory card or in a Google Spreadsheet. The necessary analog circuits for signal conditioning (amplification and filtering) were manufactured on printed circuit boards (PCB). The system was built around Arduino Yun, which is a platform that contains a microcontroller and a microprocessor running a special LINUX distribution. Furthermore, the Arduino Yun provides the necessary network connectivity capabilities by means of the integrated Wi-Fi and Ethernet interfaces. The web interface was developed using HTML pages with JavaScript support. The system was tested on simulated data as well as real data, providing satisfactory accuracy regarding the measurement of the heart rate (±3 bpm error) and the temperature (±0.3°C error).

  3. Hospital accounting and information systems: a critical assessment.

    PubMed

    Macintosh, N B

    1991-01-01

    Public sector organisations seem to be caught up in the global wave of 'neo-Thatcherism'. As such, they are being held 'accountable' today by their respective government finance departments for the costs and benefits of the services they provide to the general public. As the public purse tightens, hospitals (and related health service units) more and more compete with other public sector organisations (old-age pensions and services, post-secondary education, day-care centres, port authorities, unemployment insurance, parks and recreation, elite sport programs, aboriginal peoples aid and development, and so on) for a diminishing piece of what seems a smaller and smaller pie. In this 'fight-for-funding', hospitals seem particularly vulnerable. Sky-rocketing costs, public resentment of doctors' high income and a deliberate restriction and limiting of medical school places, among other things, contribute to general public antagonism. The message for hospitals is that cost-effective accountability will loom large when hospitals come begging at the public trough. Even left-wing politicians today seem to be heeding the words of free-market economists like Freedman of Chicago. 'Privatisation' is the constant threat for those deemed inefficient. As a consequence, hospital administrators around the world, caught up in this trend, seem to be stampeding to 'boot-up' some kind of new accounting information system. For example, at my own university hospital (Queen's University, Kingston, Canada), the hospital administrators are in the process of introducing a version of the Johns Hopkins Hospital (Baltimore, Maryland) case-mix-loading cost-accumulation system. In other parts of the world they are known by other fancy names such as 'patient-costing', 'diagnosis-related-groups' (or DRGs). Trendy accounting systems seem to be the order of the day, a sort of panacea for the current plague of problems hospitals face. As the new systems become operational, however, traditional

  4. A Critical Element to Successful Implementation Of Future Safeguards Systems

    SciTech Connect

    Dickman, Deborah A.

    2003-12-16

    As we look to the future of nuclear materials management and safeguards systems, it is essential to place significant emphasis on creation of a strong infrastructure to support and sustain modern systems. Traditionally, safeguards infrastructure development has focused on such elements as equipment development, strengthening of the national regulatory base, creation of state-of-the-art accounting and control systems, and procedure development. Less emphasis has been placed on recognition of the 'human element' as a primary component of the necessary infrastructure and the key to successful implementation of new or existing systems. The importance of the human element can be recognized by considering the broad span of influence and control, direction, regulation and implementation of safeguards systems exhibited by a large number of professionals: diplomats, scholars, politicians, facility managers, program directors and technical specialists. These individuals provide the connectivity or 'glue' that binds together a myriad of smaller safeguards program elements and ensures a holistic approach is fostered and maintained. The education and training of our future leaders and experts must receive the highest priority. In addition, this effort must consider factors beyond development of technical capabilities. Given the rapidly evolving world climate since the end of the cold war, our safeguards leaders and experts need education and training that will provide a well-developed understanding of the broader political dimensions of current nonproliferation challenges. They need to learn how to think, rather than what to think. A sustained effort is required to highlight the importance of the human dimension of safeguards and nuclear materials management and how these systems support international nonproliferation efforts. New educational initiatives are needed to better prepare the next generation of leaders and experts. Increased regional and national cooperation in the

  5. Development of Outboard Nacelle for the XB-36 Airplane

    NASA Technical Reports Server (NTRS)

    Nuber, Robert J.

    1947-01-01

    An investigation of two 1/14 scale model configurations of an outboard nacelle for the XB-36 airplane was made in the Langley two-dimensional low-turbulence tunnels over a range of airplane lift coefficients (C (sub L) = 0.409 to C(sub L) = 0.943) for three representative flow conditions. The purpose of the investigation was to develop a low-drag wing-nacelle pusher combination which incorporated an internal air-flow system. The present investigation has led to the development of a nacelle which had external drag coefficients of similar order of magnitude to those obtained previously from tests of an inboard nacelle configuration at the corresponding operating lift coefficients and from approximately one-third to one-half of those of conventional tractor designs having the same ratio of wing thickness to nacelle diameter.

  6. Airplane stability calculations with a card programmable pocket calculator

    NASA Technical Reports Server (NTRS)

    Sherman, W. L.

    1978-01-01

    Programs are presented for calculating airplane stability characteristics with a card programmable pocket calculator. These calculations include eigenvalues of the characteristic equations of lateral and longitudinal motion as well as stability parameters such as the time to damp to one-half amplitude or the damping ratio. The effects of wind shear are included. Background information and the equations programmed are given. The programs are written for the International System of Units, the dimensional form of the stability derivatives, and stability axes. In addition to programs for stability calculations, an unusual and short program is included for the Euler transformation of coordinates used in airplane motions. The programs have been written for a Hewlett Packard HP-67 calculator. However, the use of this calculator does not constitute an endorsement of the product by the National Aeronautics and Space Administration.

  7. Systems Biology of Polycystic Kidney Disease: a Critical Review

    PubMed Central

    Menezes, Luis Fernando; Germino, Gregory G

    2015-01-01

    The proliferation and diminishing costs of ‘omics’ approaches have finally opened the doors for small and medium laboratories to enter the ‘systems biology era’. This is a welcome evolution that requires a new framework to design, interpret and validate studies. Here we highlight some of the challenges, contributions, and prospects of the“cyst-ems biology” of polycystic kidney disease. PMID:25641951

  8. Information-based fitness and the emergence of criticality in living systems.

    PubMed

    Hidalgo, Jorge; Grilli, Jacopo; Suweis, Samir; Muñoz, Miguel A; Banavar, Jayanth R; Maritan, Amos

    2014-07-15

    Empirical evidence suggesting that living systems might operate in the vicinity of critical points, at the borderline between order and disorder, has proliferated in recent years, with examples ranging from spontaneous brain activity to flock dynamics. However, a well-founded theory for understanding how and why interacting living systems could dynamically tune themselves to be poised in the vicinity of a critical point is lacking. Here we use tools from statistical mechanics and information theory to show that complex adaptive or evolutionary systems can be much more efficient in coping with diverse heterogeneous environmental conditions when operating at criticality. Analytical as well as computational evolutionary and adaptive models vividly illustrate that a community of such systems dynamically self-tunes close to a critical state as the complexity of the environment increases while they remain noncritical for simple and predictable environments. A more robust convergence to criticality emerges in coevolutionary and coadaptive setups in which individuals aim to represent other agents in the community with fidelity, thereby creating a collective critical ensemble and providing the best possible tradeoff between accuracy and flexibility. Our approach provides a parsimonious and general mechanism for the emergence of critical-like behavior in living systems needing to cope with complex environments or trying to efficiently coordinate themselves as an ensemble. PMID:24982145

  9. Information-based fitness and the emergence of criticality in living systems

    PubMed Central

    Hidalgo, Jorge; Grilli, Jacopo; Suweis, Samir; Muñoz, Miguel A.; Banavar, Jayanth R.; Maritan, Amos

    2014-01-01

    Empirical evidence suggesting that living systems might operate in the vicinity of critical points, at the borderline between order and disorder, has proliferated in recent years, with examples ranging from spontaneous brain activity to flock dynamics. However, a well-founded theory for understanding how and why interacting living systems could dynamically tune themselves to be poised in the vicinity of a critical point is lacking. Here we use tools from statistical mechanics and information theory to show that complex adaptive or evolutionary systems can be much more efficient in coping with diverse heterogeneous environmental conditions when operating at criticality. Analytical as well as computational evolutionary and adaptive models vividly illustrate that a community of such systems dynamically self-tunes close to a critical state as the complexity of the environment increases while they remain noncritical for simple and predictable environments. A more robust convergence to criticality emerges in coevolutionary and coadaptive setups in which individuals aim to represent other agents in the community with fidelity, thereby creating a collective critical ensemble and providing the best possible tradeoff between accuracy and flexibility. Our approach provides a parsimonious and general mechanism for the emergence of critical-like behavior in living systems needing to cope with complex environments or trying to efficiently coordinate themselves as an ensemble. PMID:24982145

  10. Critical diameters of detonation of explosives used in spacecraft separation systems

    NASA Astrophysics Data System (ADS)

    Kotomin, A. A.; Dushenok, S. A.; Efanov, V. V.; Trapeznikov, M. A.; Kozlov, A. S.; Gorovtsov, V. V.

    2011-12-01

    The article presents findings of systematic investigations of the detonation ability of advanced individual explosives, their mixtures, and materials used in spacecraft separation systems. A method for calculation and prediction of their critical detonation diameters is developed.

  11. A reflective lens: applying critical systems thinking and visual methods to ecohealth research.

    PubMed

    Cleland, Deborah; Wyborn, Carina

    2010-12-01

    Critical systems methodology has been advocated as an effective and ethical way to engage with the uncertainty and conflicting values common to ecohealth problems. We use two contrasting case studies, coral reef management in the Philippines and national park management in Australia, to illustrate the value of critical systems approaches in exploring how people respond to environmental threats to their physical and spiritual well-being. In both cases, we used visual methods--participatory modeling and rich picturing, respectively. The critical systems methodology, with its emphasis on reflection, guided an appraisal of the research process. A discussion of these two case studies suggests that visual methods can be usefully applied within a critical systems framework to offer new insights into ecohealth issues across a diverse range of socio-political contexts. With this article, we hope to open up a conversation with other practitioners to expand the use of visual methods in integrated research. PMID:21207106

  12. More on critical collapse of axion-dilaton system in dimension four

    SciTech Connect

    Álvarez-Gaumé, Luis; Hatefi, Ehsan E-mail: ehsan.hatefi@cern.ch

    2013-10-01

    We complete our previous study of critical gravitational collapse in the axion-dilaton system by analysing the hyperbolic and parabolic ansaetze. As could be expected, the corresponding Choptuik exponents in four-dimensions differ from the elliptic case.

  13. Network information attacks on the control systems of power facilities belonging to the critical infrastructure

    NASA Astrophysics Data System (ADS)

    Loginov, E. L.; Raikov, A. N.

    2015-04-01

    The most large-scale accidents occurred as a consequence of network information attacks on the control systems of power facilities belonging to the United States' critical infrastructure are analyzed in the context of possibilities available in modern decision support systems. Trends in the development of technologies for inflicting damage to smart grids are formulated. A volume matrix of parameters characterizing attacks on facilities is constructed. A model describing the performance of a critical infrastructure's control system after an attack is developed. The recently adopted measures and legislation acts aimed at achieving more efficient protection of critical infrastructure are considered. Approaches to cognitive modeling and networked expertise of intricate situations for supporting the decision-making process, and to setting up a system of indicators for anticipatory monitoring of critical infrastructure are proposed.

  14. Critical quasienergy states in driven many-body systems

    NASA Astrophysics Data System (ADS)

    Bastidas, V. M.; Engelhardt, G.; Pérez-Fernández, P.; Vogl, M.; Brandes, T.

    2014-12-01

    We discuss singularities in the spectrum of driven many-body spin systems. In contrast to undriven models, the driving allows us to control the geometry of the quasienergy landscape. As a consequence, one can engineer singularities in the density of quasienergy states by tuning an external control. We show that the density of levels exhibits logarithmic divergences at the saddle points, while jumps are due to local minima of the quasienergy landscape. We discuss the characteristic signatures of these divergences in observables such as the magnetization, which should be measurable with current technology.

  15. Shuttle Laser Technology Experiment Facility (LTEF)-to-airplane lasercom experiment: Airplane considerations

    NASA Technical Reports Server (NTRS)

    Kalil, Ford

    1990-01-01

    NASA is considering the use of various airplanes for a Shuttle Laser Technology Experiment Facility (LTEF)-to-Airplane laser communications experiment. As supporting documentation, pertinent technical details are included about the potential use of airplanes located at Ames Research Center and Wallops Flight Facility. The effects and application of orbital mechanics considerations are also presented, including slant range, azimuth, elevation, and time. The pros and cons of an airplane equipped with a side port with a bubble window versus a top port with a dome are discussed.

  16. Firm Size, a Self-Organized Critical Phenomenon: Evidence from the Dynamical Systems Theory

    NASA Astrophysics Data System (ADS)

    Chandra, Akhilesh

    This research draws upon a recent innovation in the dynamical systems literature called the theory of self -organized criticality (SOC) (Bak, Tang, and Wiesenfeld 1988) to develop a computational model of a firm's size by relating its internal and the external sub-systems. As a holistic paradigm, the theory of SOC implies that a firm as a composite system of many degrees of freedom naturally evolves to a critical state in which a minor event starts a chain reaction that can affect either a part or the system as a whole. Thus, the global features of a firm cannot be understood by analyzing its individual parts separately. The causal framework builds upon a constant capital resource to support a volume of production at the existing level of efficiency. The critical size is defined as the production level at which the average product of a firm's factors of production attains its maximum value. The non -linearity is inferred by a change in the nature of relations at the border of criticality, between size and the two performance variables, viz., the operating efficiency and the financial efficiency. The effect of breaching the critical size is examined on the stock price reactions. Consistent with the theory of SOC, it is hypothesized that the temporal response of a firm breaching the level of critical size should behave as a flicker noise (1/f) process. The flicker noise is characterized by correlations extended over a wide range of time scales, indicating some sort of cooperative effect among a firm's degrees of freedom. It is further hypothesized that a firm's size evolves to a spatial structure with scale-invariant, self-similar (fractal) properties. The system is said to be self-organized inasmuch as it naturally evolves to the state of criticality without any detailed specifications of the initial conditions. In this respect, the critical state is an attractor of the firm's dynamics. Another set of hypotheses examines the relations between the size and the

  17. Automatic Verification of Timing Constraints for Safety Critical Space Systems

    NASA Astrophysics Data System (ADS)

    Fernandez, Javier; Parra, Pablo; Sanchez Prieto, Sebastian; Polo, Oscar; Bernat, Guillem

    2015-09-01

    In this paper is presented an automatic process of verification. We focus in the verification of scheduling analysis parameter. This proposal is part of process based on Model Driven Engineering to automate a Verification and Validation process of the software on board of satellites. This process is implemented in a software control unit of the energy particle detector which is payload of Solar Orbiter mission. From the design model is generated a scheduling analysis model and its verification model. The verification as defined as constraints in way of Finite Timed Automatas. When the system is deployed on target the verification evidence is extracted as instrumented points. The constraints are fed with the evidence, if any of the constraints is not satisfied for the on target evidence the scheduling analysis is not valid.

  18. Critical Assessment of Information Extraction Systems in Biology

    PubMed Central

    Hirschman, Lynette; Yeh, Alexander; Valencia, Alfonso

    2003-01-01

    An increasing number of groups are now working in the area of text mining, focusing on a wide range of problems and applying both statistical and linguistic approaches. However, it is not possible to compare the different approaches, because there are no common standards or evaluation criteria; in addition, the various groups are addressing different problems, often using private datasets. As a result, it is impossible to determine how well the existing systems perform, and particularly what performance level can be expected in real applications. This is similar to the situation in text processing in the late 1980s, prior to the Message Understanding Conferences (MUCs). With the introduction of a common evaluation and standardized evaluation metrics as part of these conferences, it became possible to compare approaches, to identify those techniques that did or did not work and to make progress. This progress has resulted in a common pipeline of processes and a set of shared tools available to the general research community. The field of biology is ripe for a similar experiment. Inspired by this example, the BioLINK group (Biological Literature, Information and Knowledge [1]) is organizing a CASP-like evaluation for the text data-mining community applied to biology. The two main tasks specifically address two major bottlenecks for text mining in biology: (1) the correct detection of gene and protein names in text; and (2) the extraction of functional information related to proteins based on the GO classification system. For further information and participation details, see http://www.pdg.cnb.uam.es/BioLink/BioCreative.eval.html PMID:18629031

  19. Application of queueing models to multiprogrammed computer systems operating in a time-critical environment

    NASA Technical Reports Server (NTRS)

    Eckhardt, D. E., Jr.

    1979-01-01

    A model of a central processor (CPU) which services background applications in the presence of time critical activity is presented. The CPU is viewed as an M/M/1 queueing system subject to periodic interrupts by deterministic, time critical process. The Laplace transform of the distribution of service times for the background applications is developed. The use of state of the art queueing models for studying the background processing capability of time critical computer systems is discussed and the results of a model validation study which support this application of queueing models are presented.

  20. 76 FR 28914 - Airworthiness Directives; Airbus Model A300 B4-600, B4-600R, and F4-600R Series Airplanes, and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-19

    ... Order 12866, 2. Is not a ``significant rule'' under the DOT Regulatory Policies and Procedures (44 FR... of the rudder system design. Rudder pedal sensitivity on Model A300-600 and A310 series airplanes is greater than that of other transport category airplane designs. Such rudder control sensitivity...

  1. 77 FR 64029 - Special Conditions: Airbus Model A318, A319, A320, and A321 Series Airplanes; Design Dive Speed

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-18

    ... April 11, 2000 (65 FR 19477-19478), as well as at http: DocketsInfo.dot.gov/. Docket: Background... Series Airplanes; Design Dive Speed AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final... airplanes. These design features include a high-speed protection system. The applicable...

  2. A controls engineering approach for analyzing airplane input-output characteristics

    NASA Technical Reports Server (NTRS)

    Arbuckle, P. Douglas

    1991-01-01

    An engineering approach for analyzing airplane control and output characteristics is presented. State-space matrix equations describing the linear perturbation dynamics are transformed from physical coordinates into scaled coordinates. The scaling is accomplished by applying various transformations to the system to employ prior engineering knowledge of the airplane physics. Two different analysis techniques are then explained. Modal analysis techniques calculate the influence of each system input on each fundamental mode of motion and the distribution of each mode among the system outputs. The optimal steady state response technique computes the blending of steady state control inputs that optimize the steady state response of selected system outputs. Analysis of an example airplane model is presented to demonstrate the described engineering approach.

  3. Reconstructing the critically damaged health service system of the country.

    PubMed

    Banerji, Debabar

    2012-01-01

    India's ruling class, in association with international agencies, bureaucrats, and business interests, has formed a powerful syndicate that has been imposing its will on the country to the detriment of public health. After gaining independence, India developed a body of knowledge suited to its social, cultural, economic, and epidemiological conditions. This led to an alternative approach to public health education, practice, and research that foreshadowed the Alma Ata Declaration on Primary Health Care of 1978. In the early 1980s, global power shifts undermined national and international commitment to the Declaration. Wealthy countries' response to the declaration of self-reliance by economically disadvantaged countries was swift: an effort to suppress the Declaration's ideals in favor of an unscientific, market-driven agenda. As a result, public health practice in India virtually disappeared. Responding to growing restiveness among a population in need, political leaders have launched the foredoomed National Rural Health Mission and pursued an American brand of public health through the Public Health Foundation of India. Reconstructing the damaged public health system will require pressure on the syndicate to ensure India's public health heritage will be used to effectively transfer "People's health in people's hands" according to the guidelines set down at Alma Ata. PMID:22993963

  4. NASA-LaRc Flight-Critical Digital Systems Technology Workshop

    NASA Technical Reports Server (NTRS)

    Meissner, C. W., Jr. (Editor); Dunham, J. R. (Editor); Crim, G. (Editor)

    1989-01-01

    The outcome is documented of a Flight-Critical Digital Systems Technology Workshop held at NASA-Langley December 13 to 15 1988. The purpose of the workshop was to elicit the aerospace industry's view of the issues which must be addressed for the practical realization of flight-critical digital systems. The workshop was divided into three parts: an overview session; three half-day meetings of seven working groups addressing aeronautical and space requirements, system design for validation, failure modes, system modeling, reliable software, and flight test; and a half-day summary of the research issues presented by the working group chairmen. Issues that generated the most consensus across the workshop were: (1) the lack of effective design and validation methods with support tools to enable engineering of highly-integrated, flight-critical digital systems, and (2) the lack of high quality laboratory and field data on system failures especially due to electromagnetic environment (EME).

  5. Out of the Frying Pan into the Fire? A Critical Analysis of the Integrated Children's System

    ERIC Educational Resources Information Center

    Calder, Martin C.

    2004-01-01

    Much has been promised from the government about providing a more contemporary and streamlined system for child care at the beginning of the 21st century. In this article Calder critically evaluates the origins of the incoming Integrated Children's System and questions how welding two faulty and discredited systems from the 1990s together can…

  6. New Albatross commercial airplane "L 58"

    NASA Technical Reports Server (NTRS)

    Meyer, G

    1923-01-01

    The "L 58" is a monoplane with cantilever wings joined directly to the fuselage. It accordingly belongs to the new school of airplane construction, as founded and developed in Germany. A list of performance characteristics is included.

  7. Fire prevention on airplanes. Part I

    NASA Technical Reports Server (NTRS)

    Sabatier, J

    1929-01-01

    Various methods for preventing fires in airplanes are presented with most efforts centering around prevention of backfires, new engine and carburetor designs, as well as investigations on different types of fuels.

  8. The Kiln Drying of Wood for Airplanes

    NASA Technical Reports Server (NTRS)

    Tiemann, Harry D

    1919-01-01

    This report is descriptive of various methods used in the kiln drying of woods for airplanes and gives the results of physical tests on different types of woods after being dried by the various kiln-drying methods.

  9. Notes on New French Commercial Airplanes

    NASA Technical Reports Server (NTRS)

    1935-01-01

    This document discusses the types of commercial planes ordered by Air France. Characteristics of the Wibault 670, the Dewoitine D.620, Bloch 300, and the Potez 620 airplanes are included. Pictures and diagrams of these aircraft are also included.

  10. Development of light and small airplanes

    NASA Technical Reports Server (NTRS)

    Lachmann, G

    1926-01-01

    The author has endeavored to select only the most important lines of development and has limited the description of individual airplanes to a few typical examples. Comparisons are presented between German and foreign accomplishments.

  11. Structural integrity of future aging airplanes

    NASA Technical Reports Server (NTRS)

    Mcguire, Jack F.; Goranson, Ulf G.

    1992-01-01

    A multitude of design considerations is involved in ensuring the structural integrity of Boeing jet transports that have common design concepts validated by extensive analyses, tests, and three decades of service. As airplanes approach their design service objectives, the incidences of fatigue and corrosion may become widespread. Continuing airworthiness of the aging jet fleet requires diligent performance from the manufacturer, the airlines, and airworthiness authorities. Aging fleet support includes timely development of supplemental structural inspection documents applicable to selected older airplanes, teardown inspections of high-time airframes retired from service, fatigue testing of older airframes, and structural surveys of more than 130 airplanes operated throughout the world. Lessons learned from these activities are incorporated in service bulletin recommendations, production line modifications, and design manual updates. An overview of traditional Boeing fleet support activities and the anticipated benefits for future generations of commercial airplanes based on the continuous design improvement process are presented.

  12. Structural integrity of future aging airplanes

    NASA Astrophysics Data System (ADS)

    McGuire, Jack F.; Goranson, Ulf G.

    1992-07-01

    A multitude of design considerations is involved in ensuring the structural integrity of Boeing jet transports that have common design concepts validated by extensive analyses, tests, and three decades of service. As airplanes approach their design service objectives, the incidences of fatigue and corrosion may become widespread. Continuing airworthiness of the aging jet fleet requires diligent performance from the manufacturer, the airlines, and airworthiness authorities. Aging fleet support includes timely development of supplemental structural inspection documents applicable to selected older airplanes, teardown inspections of high-time airframes retired from service, fatigue testing of older airframes, and structural surveys of more than 130 airplanes operated throughout the world. Lessons learned from these activities are incorporated in service bulletin recommendations, production line modifications, and design manual updates. An overview of traditional Boeing fleet support activities and the anticipated benefits for future generations of commercial airplanes based on the continuous design improvement process are presented.

  13. Effects of quenched disorder on critical transitions in pattern-forming systems

    NASA Astrophysics Data System (ADS)

    Yizhaq, Hezi; Bel, Golan

    2016-02-01

    Critical transitions are of great interest to scientists in many fields. Most knowledge about these transitions comes from systems exhibiting the multistability of spatially uniform states. In spatially extended and, particularly, in pattern-forming systems, there are many possible scenarios for transitions between alternative states. Quenched disorder may affect the dynamics, bifurcation diagrams and critical transitions in nonlinear systems. However, only a few studies have explored the effects of quenched disorder on pattern-forming systems, either experimentally or by using theoretical models. Here, we use a fundamental model describing pattern formation, the Swift-Hohenberg model and a well-explored mathematical model describing the dynamics of vegetation in drylands to study the effects of quenched disorder on critical transitions in pattern-forming systems. We find that the disorder affects the patterns formed by introducing an interplay between the imposed pattern and the self-organized one. We show that, in both systems considered here, the disorder significantly increases the durability of the patterned state and makes the transition between the patterned state and the uniform state more gradual. In addition, the disorder induces hysteresis in the response of the system to changes in the bifurcation parameter well before the critical transition occurs. We also show that the cross-correlation between the disordered parameter and the dynamical variable can serve as an early indicator for an imminent critical transition.

  14. Development of a broadband telehealth system for critical care: process and lessons learned.

    PubMed

    Li, Jane; Wilson, Laurence S; Qiao, Rong-Yu; Percival, Terry; Krumm-Heller, Alex; Stapleton, Stuart; Cregan, Patrick

    2006-10-01

    A broadband telehealth system has been developed for supporting critical care services between a major referral hospital and a rural hospital by transmitting very high-quality, realtime multimedia information, including images, audio and real-time video, over an Internet Protocol (IP)-based network. The technical design team took an iterative and user-centred approach toward the system design. Usability tests with scenario analysis were incorporated into the development process to produce a system that operates seamlessly in the critical care environment. Careful analysis of the reliability of the system was incorporated into the clinical protocols for integration into existing work practices. The use of high-quality multimedia data, consideration of human factors early in the design process, and incorporation of proper development approaches were critical for the success of the system design. PMID:17042709

  15. Fittings and Other Structural Parts of Airplanes

    NASA Technical Reports Server (NTRS)

    Eydam, P

    1923-01-01

    The strength and reliability of airplanes depend greatly on the careful design and manufacture of fittings, couplings, and other highly stressed parts. The more important parts of the airplane must be occasionally tested for increased loads and in order to avoid the possibility of defects creeping in during subsequent production. Strength tests are discussed for fittings for wing spar joints, fittings for strut connections, internal bracing, control gear, and landing gear.

  16. A study of commuter airplane design optimization

    NASA Technical Reports Server (NTRS)

    Roskam, J.; Wyatt, R. D.; Griswold, D. A.; Hammer, J. L.

    1977-01-01

    Problems of commuter airplane configuration design were studied to affect a minimization of direct operating costs. Factors considered were the minimization of fuselage drag, methods of wing design, and the estimated drag of an airplane submerged in a propellor slipstream; all design criteria were studied under a set of fixed performance, mission, and stability constraints. Configuration design data were assembled for application by a computerized design methodology program similar to the NASA-Ames General Aviation Synthesis Program.

  17. 78 FR 78294 - Airworthiness Directives; Airbus Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-26

    ...We propose to adopt a new airworthiness directive (AD) for certain Airbus Model A330-200, A330-200 Freighter, and A330-300 series airplanes; and Model A340-200, A340-300, A340-500, and A340-600 series airplanes. This proposed AD was prompted by the failure of the generator control unit-constant speed motor/generator (GCU-CSM/G) during a final assembly operational test. This proposed AD would......

  18. 78 FR 64156 - Airworthiness Directives; Airbus Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-28

    ... ADs for Model A340 airplanes. AD 2003-14-11, Amendment 39-13230 (68 FR 41521, July 14, 2003). AD 2004-11-08, Amendment 39-13654 (69 FR 31874, June 8, 2004). AD 2004-13-25, Amendment 39-13707 (69 FR 41394...) through (i)(7) of this AD for Model A340 airplanes only. (1) AD 2003-14-11, Amendment 39-13230 (68...

  19. Stability analysis of closed-loop super-critical pressure systems

    NASA Astrophysics Data System (ADS)

    Smith, Walter Castro

    The current study investigates the mechanisms governing flow induced stability of super-critical pressure fluid systems. Super-critical pressure fluid systems have been investigated as a mechanism for heat extraction from power systems for over a century. There are numerous benefits to these systems, but also potential pitfalls which must be examined. While super-critical pressure systems do not undergo phase change, they may be subject to the same flow induced instabilities which affect and limit two-phase systems. The objective of the current study is to develop a modeling and analysis framework to evaluate and understand flow-induced instabilities in super-critical pressure systems. The developed framework is used to evaluate experimental systems which have been constructed and tested by other investigators. The developed model shows good comparison with both the steady state and transient results published by other researchers. The model has been used to predict instabilities in experimental systems, as well as to show how some systems are more susceptible to instability than others. Stability maps have been constructed in a similar manner to those published for single heated flow path analysis.

  20. Dynamic polarization random walk model and fishbone-like instability for self-organized critical systems

    NASA Astrophysics Data System (ADS)

    Milovanov, Alexander V.

    2011-04-01

    We study the phenomenon of self-organized criticality (SOC) as a transport problem for electrically charged particles. A model for SOC based on the idea of a dynamic polarization response with random walks of the charge carriers gives critical exponents consistent with the results of numerical simulations of the traditional 'sandpile' SOC models, and stability properties, associated with the scaling of the control parameter versus distance to criticality. Relaxations of a supercritical system to SOC are stretched-exponential similar to the typically observed properties of non-Debye relaxation in disordered amorphous dielectrics. Overdriving the system near self-organized criticality is shown to have a destabilizing effect on the SOC state. This instability of the critical state constitutes a fascinating nonlinear system in which SOC and nonlocal properties can appear on an equal footing. The instability cycle is qualitatively similar to the internal kink ('fishbone') mode in a magnetically confined toroidal plasma where beams of energetic particles are injected at high power, and has serious implications for the functioning of complex systems. Theoretical analyses, presented here, are the basis for addressing the various patterns of self-organized critical behavior in connection with the strength of the driving. The results of this work also suggest a type of mixed behavior in which the typical multi-scale features due to SOC can coexist along with the global or coherent features as a consequence of the instability present. An example of this coexistence is speculated for the solar wind-magnetosphere interaction.