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. 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... Federal Aviation Administration 14 CFR Part 35 RIN 2120-AJ88 Critical Parts for Airplane Propellers AGENCY... Administration (FAA) is amending the airworthiness standards for airplane propellers. This action would require...

  3. 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

    ... 747-8 Airplanes, Systems and Data Networks Security--Isolation or Protection From Unauthorized... airplane. This airplane will have novel or unusual design features associated with connectivity of the passenger domain computer systems to the airplane critical systems and data networks. The...

  4. 78 FR 45052 - Critical Parts for Airplane Propellers; Correction

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-26

    ... 18, 2013, the FAA published a final rule titled, ``Critical Parts for Airplane Propellers'' (78 FR... Propellers; Correction AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Correcting amendment. SUMMARY: The FAA is correcting a final rule published on January 18, 2013 (78 FR 4038). In that rule,...

  5. Airplane-Runway-Performance Monitoring System

    NASA Technical Reports Server (NTRS)

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

    1992-01-01

    Airplane-Runway-Performance Monitoring System (ARPMS) increases safety during takeoffs and landings by providing pilots with symbolic "head-up" and "head-down" information pertinent to decisions to continue or abort takeoffs or landings. Provides graphic information concerning where airplane could be stopped. Pilot monitors ground speed and predicted stopping point while looking at actual runway. High potential for incorporation into cockpit environment for entire aerospace community.

  6. 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 airplane critical systems and data networks. The applicable airworthiness regulations do not contain adequate or appropriate safety standards for these design features. These proposed special...

  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, 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.

  10. 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.

  11. 78 FR 73993 - Special Conditions: Cessna Model 680 Series Airplanes; Aircraft Electronic System Security...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-10

    ... design feature associated with the architecture and connectivity capabilities of the airplanes' computer... vulnerabilities to the airplanes' systems. The proposed network architecture includes the following connectivity... architecture is novel or unusual for executive jet airplanes by allowing connection to airplane...

  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. Autonomous Deicing System For Airplane Wing

    NASA Technical Reports Server (NTRS)

    Hickman, G. A.; Gerardi, J. J.

    1993-01-01

    Prototype autonomous deicing system for airplane includes network of electronic and electromechanical modules at various locations in wings and connected to central data-processing unit. Small, integrated solid-state device, using long coils installed under leading edge, exciting small vibrations to detect ice and larger vibrations to knock ice off. In extension of concept, outputs of vibration sensors and other sensors used to detect rivet-line fractures, fatigue cracks, and other potentially dangerous defects.

  15. Electric airplane environmental control systems energy requirements

    SciTech Connect

    Buss, L.B.

    1984-05-01

    The electric airplane environmental control system (ECS) design drivers is discussed for an electric airplane from two aspects. The first aspect considered is the type of aircraft. The three examples selected are the 150-passenger commercial airline transport, the military on-station electronic-surveillance patrol aircraft, and the air-defense interceptor fighter. These vehicle examples illustrate the effect of both mission and mission profile on the design requirements of the ECS and the differences that the requirements make on the resulting advantages and disadvantages of electrification. For the commercial transport, the selection of the air source for ventilation will be featured. For the patrol aircraft, the cooling unit will be evaluated. For the fighter, emphasis will be placed on the need for systems integration. The second and more important consideration is the definition of the environmental control system requirements for both energy supply and heat sink thermal management integration from the power plant (engine) that make an electric ECS viable for each type of vehicle.

  16. Airplane Takeoff-and-Landing Performance Monitoring System

    NASA Technical Reports Server (NTRS)

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

    1988-01-01

    Airplane Takeoff-and-Landing Performance Monitoring System (TOPMS) designed to increase safety during takeoffs and landings of aircraft. Provides pilots with graphic information crucial to decision to continue or reject takeoff. If rejected or landing in progress, provides crucial information relative to where airplane can be brought to stop.

  17. 78 FR 75453 - Special Conditions: Cessna Model 750 Series Airplanes; Aircraft Electronic System Security...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-12

    ... data network and design integration may result in security vulnerabilities from intentional or... or unusual design features associated with connectivity of the passenger service computer systems to the airplane critical systems and data networks. DATES: The effective date of these special...

  18. 76 FR 8316 - Special Conditions: Gulfstream Model GVI Airplane; Interaction of Systems and Structures

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-14

    ... stability of the airplane. These systems include the GVI's flight control systems, autopilots, stability... special condition for airplanes equipped with flight control systems, autopilots, stability augmentation... before flight. Certain elements of the control system, such as mechanical and hydraulic components,...

  19. Life-critical digital flight control systems

    NASA Technical Reports Server (NTRS)

    Mcwha, James

    1990-01-01

    Digital autopilot systems were first used on commercial airplanes in the late 1970s. The A-320 airplane was the first air transport airplane with a fly-by-wire primary flight control system. On the 767-X (777) airplane Boeing will install all fly-by-wire flight controls. Activities related to safety, industry status and program phases are discussed.

  20. 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...

  1. 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.

  2. 76 FR 77376 - Airworthiness Directives; BAE Systems (Operations) Limited Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-13

    ...-248-AD; Amendment 39-16883; AD 2011-25-07] RIN 2120-AA64 Airworthiness Directives; BAE Systems... Systems (Operations) Limited Model 4101 airplanes. This AD results from mandatory continuing airworthiness... to the specified products. That NPRM was published in the Federal Register on August 31, 2011 (76...

  3. 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.

  4. 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.

  5. 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.

  6. 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

  7. 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.

  8. 76 FR 13069 - Airworthiness Directives; BAE Systems (Operations) Limited Model ATP Airplanes; BAE Systems...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-10

    ... (Operations) Limited Model ATP Airplanes; BAE Systems (Operations) Limited Model HS 748 Airplanes AGENCY... specified products. The MCAI states: Early in the life of the ATP (circa 1989), a report was received that a... by issuing SB ATP- 27-11, describing a one-time inspection of the hinge pins, which was...

  9. 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 been undergoing ground and flight tests by Ames Research Center since late 1979, primarily as a compound aircraft. The purpose was to train pilots and to check out and develop the design flight envelope established by the Sikorsky Aircraft Company. This paper reviews the preparation and flight test of the RSRA in the airplane, or fixed-wing, configuration and discusses the results of that test.

  10. 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

    ... stability of the airplane. Such systems include flight control systems, autopilots, stability augmentation... these special conditions for airplanes equipped with flight control systems, autopilots, stability... before flight. Certain elements of the control system, such as mechanical and hydraulic components,...

  11. 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... The GVI has an electronic flight control system and no direct coupling from the cockpit controller...

  12. 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

    ... or unusual design features: Digital systems architecture ] composed of several connected networks... Gulfstream G280 airplane. This airplane will have novel or unusual design features associated with connectivity of the passenger service computer systems to the airplane critical systems and data networks....

  13. 76 FR 36865 - Special Conditions: Gulfstream Model GVI Airplane; Interaction of Systems and Structures

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-23

    ... also affect the aeroelastic stability of the airplane. These systems include the GVI's flight control... flight control systems, autopilots, stability augmentation systems, load alleviation systems, fuel... nonlinearity (rate of displacement of control surface, thresholds or any other system nonlinearities) must...

  14. 76 FR 8278 - Special Conditions: Gulfstream Model GVI Airplane; Enhanced Flight Vision System

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-14

    ... Flight Vision System AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final special conditions..., Airplane and Flight Crew Interface Branch, ANM-111, Transport Standards Staff, Transport Airplane... Design Features The enhanced flight vision system (EFVS) is a novel or unusual design feature because...

  15. 76 FR 36863 - Special Conditions: Gulfstream Model GVI Airplane; Electronic Systems Security Protection From...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-23

    ... 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 may... features: Digital systems architecture composed of several connected networks. The proposed...

  16. 76 FR 36861 - Special Conditions: Gulfstream Model GVI Airplane; Electronic Systems Security Isolation or...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-23

    ... conditions are issued for the Gulfstream GVI airplane. This airplane will have novel or unusual design... systems and data networks. The applicable airworthiness regulations do not contain adequate or appropriate safety standards for these design features. These special conditions contain the additional...

  17. 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.

  18. A Theoretical Investigation of Longitudinal Stability of Airplanes with Free Controls Including Effect of Friction in Control System

    NASA Technical Reports Server (NTRS)

    Greenberg, Harry; Sternfield, Leonard

    1944-01-01

    The relation between the elevator hinge moment parameters and the control forces for changes in forward speed and in maneuvers is shown for several values of static stability and elevator mass balance. The stability of the short period oscillations is shown as a series of boundaries giving the limits of the stable regions in terms of the elevator hinge moment parameters. The effects of static stability, elevator moment of inertia, elevator mass unbalance, and airplane density are also considered. Dynamic instability is likely to occur if there is mass unbalance of the elevator control system combined with a small restoring tendency (high aerodynamic balance). This instability can be prevented by a rearrangement of the unbalancing weights which, however, involves an increase of the amount of weight necessary. It can also be prevented by the addition of viscous friction to the elevator control system provided the airplane center of gravity is not behind a certain critical position. For high values of the density parameter, which correspond to high altitudes of flight, the addition of moderate amounts of viscous friction may be destabilizing even when the airplane is statically stable. In this case, increasing the viscous friction makes the oscillation stable again. The condition in which viscous friction causes dynamic instability of a statically stable airplane is limited to a definite range of hinge moment parameters. It is shown that, when viscous friction causes increasing oscillations, solid friction will produce steady oscillations having an amplitude proportional to the amount of friction.

  19. 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.

  20. 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,...

  1. 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.

  2. 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... architecture composed of several connected networks. The proposed architecture and network configuration may be... Conditions The proposed Model GVI architecture and network configuration may allow increased connectivity...

  3. 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.

  4. 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.

  5. 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.

  6. 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

    ... systems and networks, which may allow access to external computer systems and networks. Connectivity to... 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...

  7. 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.

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

    NASA Technical Reports Server (NTRS)

    Bradshaw, C. F.

    1980-01-01

    A tail-mounted spin-recovery parachute system has been designed and developed by the NASA Langley Research Center for use on light general aviation airplanes. The system was designed for use on typical airplane configurations, including low-wing, high-wing, single- 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 (18 lb). 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 has been used successfully in flight 17 times.

  9. 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.

  10. 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 by the NASA Langley Research Center for use on light general aviation airplanes. The system was designed for use on typical airplane configurations, including low wing, single engine, and twin-engine design. 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 (18 lb). 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.

  11. Discussion of an aeromechanical gust alleviation system to improve the ride comfort of light airplanes

    NASA Technical Reports Server (NTRS)

    Stewart, E. C.

    1975-01-01

    A discussion of an on-going NASA research project of a gust alleviation system to improve the ride comfort of a light airplane is presented. The discussion includes a description of the proposed system which uses auxiliary aerodynamic surfaces to drive the trailing-edge flaps. The results of analytical work on the effects of the system on stability and effectiveness of the system are presented. Static wind-tunnel tests of the system installed in a 1/6-scale model of a popular light airplane are also described. Problem areas which may need future investigation are discussed.

  12. 77 FR 37775 - Airworthiness Directives; BAE Systems (Operations) Limited Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-25

    ...: Todd Thompson, Aerospace Engineer, International Branch, ANM-116, Transport Airplane Directorate, FAA... Register on February 8, 2012 (77 FR 6520). That NPRM proposed to correct an unsafe condition for the... public the opportunity to participate in developing this AD. We received no comments on the NPRM (77...

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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

  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

    ... 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... be found in the Federal Register published on April 11, 2000 (65 FR 19477-19478), as well as at...

  19. 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.

  20. Critical Systems Heuristics

    NASA Astrophysics Data System (ADS)

    Ulrich, Werner; Reynolds, Martin

    Critical systems heuristics (CSH) is a framework for reflective professional practice organised around the central tool of boundary critique. This paper, written jointly by the original developer, Werner Ulrich, and Martin Reynolds, an experienced practitioner of CSH, offers a systematic introduction to the idea and use of boundary critique. Its core concepts are explained in detail and their use is illustrated by means of two case studies from the domain of environmental planning and management. A particular focus is on working constructively with tensions between opposing perspectives as they arise in many situations of professional intervention. These include tensions such as ‘situation' versus ‘system', ‘is' versus ‘ought' judgements, concerns of ‘those involved' versus ‘those affected but not involved', stakeholders' ‘stakes' versus ‘stakeholding issues', and others. Accordingly, boundary critique is presented as a participatory process of unfolding and questioning boundary judgements rather than as an expert-driven process of boundary setting. The paper concludes with a discussion of some essential skills and considerations regarding the practice of boundary critique.

  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. 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

    ... Administration 14 CFR Part 25 Special Conditions: Dassault Falcon Model 900 and 900EX Airplanes; Interaction of... have a novel or unusual design feature associated with the interaction of systems 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. The critical velocity of a body towed by a cable from an airplane

    NASA Technical Reports Server (NTRS)

    Koning, C; De Haas, T P

    1937-01-01

    It is sufficient to consider only the equations of motion of the towed body whereas those of the cable may be left out of consideration. The result obtained makes it possible to determine which factors affect the critical velocity and what modifications of the instrument are necessary for extending the upper limit of that velocity.

  5. 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.

  6. 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.

  7. 76 FR 73477 - Airworthiness Directives; BAE SYSTEMS (Operations) Limited Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-29

    ...: * * * * * * * * BAE Systems (Operations) Limited amended Chapter 05-10-15 of the AMM to introduce a new hydraulic... (75 FR 28463, May 21, 2010) and adding the following new AD: 2011-24-06 BAE SYSTEMS (Operations..., dated August 11, 2009, on June 25, 2010 (75 FR 28463, May 21, 2010). (3) For BAE Systems...

  8. 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

    ... Airplane; Electronic Flight Control System: Control Surface Awareness and Mode Annunciation AGENCY: Federal... a fly-by-wire electronic flight control system and no direct coupling from the flightdeck controller... nuisance alerting. These special conditions also address flight control system mode annunciation....

  9. 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.

  10. 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.

  11. Multiobjective insensitive design of airplane control systems with uncertain parameters

    NASA Technical Reports Server (NTRS)

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

    1981-01-01

    A multiobjective computer-aided design algorithm has been developed which minimizes the sensitivity of the design objectives to uncertainties in system parameters. The more important uncertain parameters are described by a gaussian random vector with known covariance matrix, and a vector sensitivity objective function is defined as the probabilities that the design objectives will violate specified requirements constraints. Control system parameters are found which minimize the sensitivity vector in a Pareto-optimal sense, using constrained minimization algorithms. Example results are shown for lateral stability augmentation system (SAS) design for three Shuttle flight conditions.

  12. 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...

  13. Performance Possibilities of the Turbojet System as a Power Plant for Supersonic Airplanes

    NASA Technical Reports Server (NTRS)

    Wood, George P

    1947-01-01

    The performance of hypothetical turbojet systems, without thrust augmentation, as power plants for supersonic airplanes has been calculated. The thrust, thrust power, air-fuel ratio, 1 specific fuel consumption, cross-sectional area, and thrust coefficient are shown for free-stream Mach numbers from 1.2 to 3. For comparison, the performance of ram-jet systems over the same Mach number range has also been calculated. For Mach numbers between 1.2 and 2 the calculated thrust coefficient of the turbojet system was found to be larger than the estimated drag coefficient, and the specific fuel consumption was calculated to be considerably less than the specific fuel consumption of the ram-jet system. The turbojet system therefore appears to merit consideration as a propulsion method for free-stream Mach numbers between approximately 1.2 and 2.

  14. 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.

  15. Design and development experience with a digital fly-by-wire control system in an F-8C airplane

    NASA Technical Reports Server (NTRS)

    Deets, D. A.

    1976-01-01

    To assess the feasibility of a digital fly by wire system, the mechanical flight control system of an F-8C airplane was replaced with a digital primary system and an analog backup system. The Apollo computer was used as the heart of the primary system. This paper discusses the experience gained during the design and development of the system and relates it to active control systems that are anticipated for future civil transport applications.

  16. Design and development experience with a digital fly-by-wire control system in an F-8C airplane

    NASA Technical Reports Server (NTRS)

    Deets, D. A.

    1975-01-01

    To assess the feasibility of a digital fly-by-wire system, the mechanical flight control system of an F-8C airplane was replaced with a digital system and an analog backup system. The Apollo computer was used as the heart of the primary system. This paper discusses the experience gained during the design and development of the system and relates it to active control systems that are anticipated for future civil transport applications.

  17. Airstart performance of a digital electronic engine control system in an F-15 airplane

    NASA Technical Reports Server (NTRS)

    Licata, S. J.; Burcham, F. W., Jr.

    1983-01-01

    The airstart performance of the F100 engine equipped with a digital electronic engine control (DEEC) system was evaluated in an F-15 airplane. The DEEC system incorporates closed-loop airstart logic for improved capability. Spooldown and jet fuel starter-assisted airstarts were made over a range of airspeeds and altitudes. All jet fuel starter-assisted airstarts were successful, with airstart time varying from 35 to 60 sec. All spooldown airstarts at airspeeds of 200 knots and higher were successful; airstart times ranged from 45 sec at 250 knots to 135 sec at 200 knots. The effects of altitude on airstart success and time were small. The flight results agreed closely with previous altitude facility test results. The DEEC system provided successful airstarts at airspeeds at least 50 knots lower than the standard F100 engine control system.

  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. 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... incorporate the following novel or unusual design features: Digital systems architecture composed of several connected networks. The network architecture would be used for a diverse set of functions, including:...

  20. Exploring Venus by Solar Airplane

    NASA Technical Reports Server (NTRS)

    Landis, Geoffrey A.

    2001-01-01

    A solar-powered airplane is proposed to explore the atmospheric environment of Venus. Venus has several advantages for a solar airplane. At the top of the cloud level, the solar intensity is comparable to or greater than terrestrial solar intensities. The Earthlike atmospheric pressure means that the power required for flight is lower for Venus than that of Mars, and the slow rotation of Venus allows an airplane to be designed for continuous sunlight, with no energy storage needed for night-time flight. These factors mean that Venus is perhaps the easiest planet in the solar system for flight of a long-duration solar airplane.

  1. 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.

  2. 75 FR 65051 - Consensus Standards, Standard Practice for Inspection of Airplane Electrical Wiring Systems

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-21

    ... October 13, 2010. John Colomy, Acting Manager, Small Airplane Directorate, Aircraft Certification Service... November 22, 2010. ADDRESSES: Comments may be mailed to: Federal Aviation Administration, Small Airplane Directorate, Continued Operational Safety, ACE-111, Attention: James Brady, Room 301, 901 Locust, Kansas...

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  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. 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... Model EMB-550 airplane. The Model EMB-550 airplane is the first of a new family of jet airplanes... regulations and special conditions, the Model EMB-550 airplane must comply with the fuel vent and...

  10. 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

    ...-550 airplane. The Model EMB-550 airplane is the first of a new family of jet airplanes designed for... regulations and special conditions, the Model EMB-550 airplane must comply with the fuel vent and exhaust...-135 (76 FR 74654, December 1, 2011), effective January 30, 2012. (This amendment is not in the...

  11. 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.

  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. Performance improvements of an F-15 airplane with an integrated engine-flight control system

    NASA Technical Reports Server (NTRS)

    Myers, Lawrence P.; Walsh, Kevin R.

    1988-01-01

    An integrated flight and propulsion control system has been developed and flight demonstrated on the NASA Ames-Dryden F-15 research aircraft. The highly integrated digital control (HIDEC) system provides additional engine thrust by increasing engine pressure ratio (EPR) at intermediate and afterburning power. The amount of EPR uptrim is modulated based on airplane maneuver requirements, flight conditions, and engine information. Engine thrust was increased as much as 10.5 percent at subsonic flight conditions by uptrimming EPR. The additional thrust significantly improved aircraft performance. Rate of climb was increased 14 percent at 40,000 ft and the time to climb from 10,000 to 40,000 ft was reduced 13 percent. A 14 and 24 percent increase in acceleration was obtained at intermediate and maximum power, respectively. The HIDEC logic performed fault free. No engine anomalies were encountered for EPR increases up to 12 percent and for angles of attack and sideslip of 32 and 11 degrees, respectively.

  14. Pareto-optimal multi-objective design of airplane control systems

    NASA Technical Reports Server (NTRS)

    Schy, A. A.; Johnson, K. G.; Giesy, D. P.

    1980-01-01

    A constrained minimization algorithm for the computer aided design of airplane control systems to meet many requirements over a set of flight conditions is generalized using the concept of Pareto-optimization. The new algorithm yields solutions on the boundary of the achievable domain in objective space in a single run, whereas the older method required a sequence of runs to approximate such a limiting solution. However, Pareto-optimality does not guarantee a satisfactory design, since such solutions may emphasize some objectives at the expense of others. The designer must still interact with the program to obtain a well-balanced set of objectives. Using the example of a fighter lateral stability augmentation system (SAS) design over five flight conditions, several effective techniques are developed for obtaining well-balanced Pareto-optimal solutions. For comparison, one of these techniques is also used in a recently developed algorithm of Kreisselmeier and Steinhauser, which replaces the hard constraints with soft constraints, using a special penalty function. It is shown that comparable results can be obtained.

  15. 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.

  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. 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.

  18. 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.

  19. 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.

  20. Procedures used in flight tests of an integrated propulsion control system on an F-111E airplane

    NASA Technical Reports Server (NTRS)

    Baer, J. L.; Holzman, J. K.; Burcham, F. W., Jr.

    1976-01-01

    A digital integrated propulsion control system (IPCS) was tested on an F-111E airplane. The IPCS provided full authority control of the left inlet and the TF30 afterburning engine. Supersonic test conditions were of primary interest. The operational procedures and maneuvers developed for IPCS evaluation, displays for test monitoring and data acquisition, flight safety, and problems encountered are discussed. The software refinements that made modifications to standard flight test procedures necessary are described. The flexibility of digital control and the ways software was used to overcome hardware deficiencies are discussed. Application of these procedures to a typical IPCS flight is described.

  1. 78 FR 73995 - Special Conditions: Cessna Model 680 Series Airplanes; Aircraft Electronic System Security...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-10

    ..., 2000 (65 FR 19477-19478), as well as at http://DocketsInfo.dot.gov/ . Docket: Background documents or... critical systems and data networks. The network architecture is composed of several connected networks... a change to Type Certificate No. T00012WI in the digital systems architecture in the Cessna...

  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. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  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. 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.

  11. 78 FR 68985 - 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 of the passenger service computer network systems to the airplane critical systems and data networks. This onboard network system will be composed of a network file server, a network... computer network system, and a network extension device. The network extension device will improve...

  12. 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.

  13. AIRCL: A programmed system for generating NC tapes for airplane models. User's manual

    NASA Technical Reports Server (NTRS)

    Akgerman, N.; Billhardt, C. F.

    1981-01-01

    A computer program is presented which calculates the cutter location file needed to machine models of airplane wings or wing-fuselage combinations on numerically controlled machine tools. Input to the program is a data file consisting of coordinates on the fuselage and wing. From this data file, the program calculates tool offsets, determines the intersection between wing and fuselage tool paths, and generates additional information needed to machine the fuselage and/or wing. Output from the program can be post processed for use on a variety of milling machines. Information on program structure and methodology is given as well as the user's manual for implementation of the program.

  14. 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.

  15. 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.

  16. 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.

  17. A comparison of the results of dynamic wind-tunnel tests with theoretical predictions for an aeromechanical gust-alleviation system for light airplanes

    NASA Technical Reports Server (NTRS)

    Stewart, E. C.; Redd, L. T.

    1977-01-01

    Dynamic wind tunnel tests have been conducted on a 1/6-scale model of a general aviation airplane equipped with an all-mechanical gust alleviation system which uses auxiliary aerodynamic surfaces to drive the flaps. The longitudinal short period motions were studied under simulated gust conditions in order to verify the mathematical model used in a previous study to predict the performance of the full scale system and determine the amount of normal acceleration alleviation which could be attained. The model responses were measured for different configurations with the system active and without the system active for comparison. The tests confirmed the general relationships between the experimental variables and the model responses predicted by the mathematical model, but there were significant differences in the magnitudes of the responses. The experimental results for the model were used to estimate a reduction of 30 percent in the rms normal acceleration response of a similar full scale airplane in atmospheric turbulence.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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...

  13. Plutonium Finishing Plant (PFP) Criticality Alarm System Commercial Grade Item (CGI) Critical Characteristics

    SciTech Connect

    WHITE, W.F.

    1999-09-16

    This document specifies the critical characteristics for Commercial Grade Items (CGI) procured for PFP's criticality alarm system as required by HNF-PRO-268 and HNF-PRO-1819. These are the minimum specifications that the equipment must meet in order to properly perform its safety function. There may be several manufacturers or models that meet the critical characteristics for any one item. PFP's Criticality Alarm System includes the nine criticality alarm system panels and their associated hardware. This includes all parts up to the first breaker in the electrical distribution system. Specific system boundaries and justifications are contained in HNF-SD-CP-SDD-003, ''Definition and Means of Maintaining the Criticality Detectors and Alarms Portion of the PFP Safety Envelope.'' The procurement requirements associated with the system necessitates procurement of some system equipment as Commercial Grade Items in accordance with HNF-PRO-268, ''Control of Purchased Items and Services.''

  14. 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)

  15. 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.

  16. 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.

  17. The Criticism Management System for the Cochrane Library.

    PubMed

    Ober, Melissa; Shohara, Ryo; Rennie, Drummond; Yank, Veronica; Bero, Lisa A

    2002-03-01

    In April 1997, the Cochrane Collaboration implemented the Criticism Management System for The Cochrane Library, allowing readers to electronically submit criticisms on Cochrane reviews and protocols. As a result of resource constraints and user feedback, the Criticism Management System evolved through three different versions. Major problems have included difficult access to the system, a lack of automation within the system, a low number of submissions (171 criticisms submitted per 1,388 reviews), and a low response rate to these criticisms by authors of reviews (26 criticisms have received published responses). These low figures suggest that users of The Cochrane Library are not commenting on the published reviews or not using the Criticism Management System to make their criticisms known to the authors. An easier-to-use system and better ways of encouraging feedback from readers and responses from reviewers are needed in the future.

  18. 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.

  19. 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.

  20. Critical behavior in radiation damaged systems

    NASA Astrophysics Data System (ADS)

    Arends, A. R.; Hohenemser, C.; Suter, R. M.

    1980-09-01

    Perturbed angular distribution (PAD) measurements of Bleck et al. of the critical behavior of63Ni Ni,66Cu Ni, and67Zn Ni have been reanalyzed, and shown to be insufficiently asymptotic to permit deduction of meaningful critical exponents. Via experiments on implanted111In Ni, done with and without annealing of radiation damage, and by comparison to diffused111In Ni, it is suggested that unannealed radiation damage can produce serious systematic errors in critical exponents.

  1. 76 FR 39763 - Special Conditions: Boeing Model 787-8 Airplane; Interaction of Systems and Structures...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-07

    ... condition is needed for the pitch axis because the applicant's proposed method for the pitch maneuver takes... with flight control systems, autopilots, stability augmentation systems, load alleviation systems... deceleration due to a malfunction which could result in a temporary loss of power or thrust. (2) The...

  2. 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.

  3. 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.

  4. 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.

  5. 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...

  6. 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...

  7. 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...

  8. 78 FR 32078 - Special Conditions: Gulfstream Model G280 Airplane, Enhanced Flight Vision System (EFVS) With...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-29

    ... Privacy Act Statement can be found in the Federal Register published on April 11, 2000 (65 FR 19477-19478..., Enhanced Flight Vision System (EFVS) With Head-Up Display (HUD) AGENCY: Federal Aviation Administration... Aerospace Corporation, will have an advanced, enhanced-flight-vision system (EFVS). The EFVS is a novel...

  9. 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…

  10. 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...

  11. The Criticality Hypothesis in Neural Systems

    NASA Astrophysics Data System (ADS)

    Karimipanah, Yahya

    There is mounting evidence that neural networks of the cerebral cortex exhibit scale invariant dynamics. At the larger scale, fMRI recordings have shown evidence for spatiotemporal long range correlations. On the other hand, at the smaller scales this scale invariance is marked by the power law distribution of the size and duration of spontaneous bursts of activity, which are referred as neuronal avalanches. The existence of such avalanches has been confirmed by several studies in vitro and in vivo, among different species and across multiple scales, from spatial scale of MEG and EEG down to single cell resolution. This prevalent scale free nature of cortical activity suggests the hypothesis that the cortex resides at a critical state between two phases of order (short-lasting activity) and disorder (long-lasting activity). In addition, it has been shown, both theoretically and experimentally, that being at criticality brings about certain functional advantages for information processing. However, despite the plenty of evidence and plausibility of the neural criticality hypothesis, still very little is known on how the brain may leverage such criticality to facilitate neural coding. Moreover, the emergent functions that may arise from critical dynamics is poorly understood. In the first part of this thesis, we review several pieces of evidence for the neural criticality hypothesis at different scales, as well as some of the most popular theories of self-organized criticality (SOC). Thereafter, we will focus on the most prominent evidence from small scales, namely neuronal avalanches. We will explore the effect of adaptation and how it can maintain scale free dynamics even at the presence of external stimuli. Using calcium imaging we also experimentally demonstrate the existence of scale free activity at the cellular resolution in vivo. Moreover, by exploring the subsampling issue in neural data, we will find some fundamental constraints of the conventional methods

  12. 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,...

  13. 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,...

  14. 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.

  15. 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...

  16. 78 FR 42727 - Airworthiness Directives; the Boeing Company Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-17

    ... electrical power to the IFE systems and certain circuit breakers through a utility bus switch, and doing... airplanes, doing an inspection of the electrical power control panel for a certain part number, and corrective action if necessary; and for certain other airplanes, installing a new electrical power...

  17. 78 FR 6254 - Airworthiness Directives; The Boeing Company Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-30

    ... feed manifold air pressure leak check procedure specified in airplane maintenance manual (AMM) 28- 22... 737-400 airplanes of total loss of boost pump pressure of the fuel feed system, followed by loss of... Federal Register on June 6, 2008 (73 FR 32258). That NPRM proposed to require repetitive operational...

  18. Flight experience with a digital integrated propulsion control system on an F-111E airplane

    NASA Technical Reports Server (NTRS)

    Burcham, F. W., Jr.; Batterton, P. G.

    1976-01-01

    A digital integrated propulsion control system (IPCS) installed in the left side of an F-111 E aircraft was tested in flight. The F-111 aircraft was selected for the IPCS program because it incorporated a variable geometry inlet and an afterburning turbofan engine and had two engines, one of which could remain in the normal configuration to ensure flight safety. Flight data were compared with results of tests run in an altitude test chamber. The digital system was found to be capable of duplicating the standard engine and inlet control systems. Instabilities such as inlet buzz and afterburner rumble were detected and controlled. The usefulness of an altitude chamber for developing a software and testing hardware was proven. The flexibility of IPCS was demonstrated when an autothrottle, an in-flight thrust calculation, and a coannular noise study capability were added at the end of the flight tests.

  19. 76 FR 64788 - Airworthiness Directives; BAE SYSTEMS (Operations) Limited Model 4101 Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-19

    ... information (MCAI) originated by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as: * * * BAE Systems (Operations... revision constitutes an unsafe condition. * * * * * The unsafe condition is failure of certain...

  20. 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.

  1. 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

    ...-12, amendment 39-14370 (70 FR 70483, November 22, 2005). The existing AD applies to all BAE SYSTEMS... in the Federal Register on August 26, 2008 (73 FR 50248). The original NPRM proposed to supersede the... 12866; 2. Is not a ``significant rule'' under the DOT Regulatory Policies and Procedures (44 FR...

  2. 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.

  3. Early warning signals for critical transitions in a thermoacoustic system

    PubMed Central

    Gopalakrishnan, E. A.; Sharma, Yogita; John, Tony; Dutta, Partha Sharathi; Sujith, R. I.

    2016-01-01

    Dynamical systems can undergo critical transitions where the system suddenly shifts from one stable state to another at a critical threshold called the tipping point. The decrease in recovery rate to equilibrium (critical slowing down) as the system approaches the tipping point can be used to identify the proximity to a critical transition. Several measures have been adopted to provide early indications of critical transitions that happen in a variety of complex systems. In this study, we use early warning indicators to predict subcritical Hopf bifurcation occurring in a thermoacoustic system by analyzing the observables from experiments and from a theoretical model. We find that the early warning measures perform as robust indicators in the presence and absence of external noise. Thus, we illustrate the applicability of these indicators in an engineering system depicting critical transitions. PMID:27767065

  4. 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.

  5. Design of a multilevel Active Power Filter for More Electrical Airplane variable frequency systems

    NASA Astrophysics Data System (ADS)

    Guerreiro, Joel Filipe; Pomilio, Jose Antenor; Busarello, Tiago Davi Curi

    This paper presents the design and simulation of an Aeronautical Active Power Filter (AAPF) for a Variable Speed Variable Frequency (VSVF) advanced aircraft electric power system. The purposes of the AAPF are to mitigate current harmonics, to improve the source power factor and to mitigate the effects of unbalanced loads. Regarding the fact that the Aircraft Electrical Power System (AEPS) frequency may vary between 360 Hz and 900 Hz, and the load dynamics is often modified, an enhanced filtering technique is required. The designed AAPF topology is an asymmetrical multilevel inverter (AMI), which control strategy is based on the Conservative Power Theory (CPT) and synchronized by a Kalman Filter Phase-Locked Loop (KF-PLL). The above configuration renders the AAPF very robust and effective to its purpose. Accurate simulation results on Matlab/Simulink platform verify the feasibility of the proposed AAPF and the high performance of the control strategy during steady-state and dynamic operations.

  6. 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.

  7. 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.

  8. Dynamical Critical Phenomena in Driven-Dissipative Systems

    NASA Astrophysics Data System (ADS)

    Sieberer, L. M.; Huber, S. D.; Altman, E.; Diehl, S.

    2013-05-01

    We explore the nature of the Bose condensation transition in driven open quantum systems, such as exciton-polariton condensates. Using a functional renormalization group approach formulated in the Keldysh framework, we characterize the dynamical critical behavior that governs decoherence and an effective thermalization of the low frequency dynamics. We identify a critical exponent special to the driven system, showing that it defines a new dynamical universality class. Hence critical points in driven systems lie beyond the standard classification of equilibrium dynamical phase transitions. We show how the new critical exponent can be probed in experiments with driven cold atomic systems and exciton-polariton condensates.

  9. 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.

  10. 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.

  11. Analytical investigation of the landing dynamics of a large airplane with a load-control system in the main landing gear

    NASA Technical Reports Server (NTRS)

    Mcgehee, J. R.; Carden, H. D.

    1979-01-01

    The results of an evaluation of an active load-control landing gear computer program (ACOLAG) for predicting the landing dynamics of airplanes with passive and active main gears are presented. ACOLAG was used in an analytical investigation of the landing dynamics of a large airplane with both passive and active main gears. It was concluded that the program is valid for predicting the landing dynamics of airplanes with both passive and active main gears. It was shown that the active gear reduces airframe-gear forces and airplane motions following initial impact, and has the potential for significant reductions in structural fatigue damage relative to that which occurs with the passive gear.

  12. 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.

  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. 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.

  16. SCALE system cross-section validation for criticality safety analysis

    SciTech Connect

    Hathout, A M; Westfall, R M; Dodds, Jr, H L

    1980-01-01

    The purpose of this study is to test selected data from three cross-section libraries for use in the criticality safety analysis of UO/sub 2/ fuel rod lattices. The libraries, which are distributed with the SCALE system, are used to analyze potential criticality problems which could arise in the industrial fuel cycle for PWR and BWR reactors. Fuel lattice criticality problems could occur in pool storage, dry storage with accidental moderation, shearing and dissolution of irradiated elements, and in fuel transport and storage due to inadequate packing and shipping cask design. The data were tested by using the SCALE system to analyze 25 recently performed critical experiments.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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

  5. 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

  6. 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

  7. 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

  8. 14 CFR 36.7 - Acoustical change: Transport category large airplanes and jet airplanes.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... airplanes and jet airplanes. 36.7 Section 36.7 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... § 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...

  9. 14 CFR 36.7 - Acoustical change: Transport category large airplanes and jet airplanes.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... airplanes and jet airplanes. 36.7 Section 36.7 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... § 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...

  10. Management Systems Design: A Critical Appraisal

    ERIC Educational Resources Information Center

    Schroeder, Roger G.

    1977-01-01

    Improved management systems can be developed for colleges and universities if assumptions are correct and a well-defined process is used. A life-cycle approach is suggested whose subsystems and implementation at Augsburg College, a small private liberal arts institution, are described. (LBH)

  11. 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-...

  12. 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.

  13. Automatic Stability of Airplanes

    NASA Technical Reports Server (NTRS)

    Haus, FR

    1932-01-01

    It is endeavored in this report to give a full outline of the problem of airplane stability and to classify the proposed solutions systematically. Longitudinal stability, which can be studied separately, is considered first. The combination of lateral and directional stabilities, which cannot be separated, will be dealt with later.

  14. 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.

  15. 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.

  16. Self-organized critical system with no stationary attractor state

    NASA Astrophysics Data System (ADS)

    Nørrelykke, Simon F.; Bak, Per

    2002-03-01

    A simple model economy with interacting producers and consumers is introduced. When driven by extremal dynamics, the model self-organizes not to an attractor state, but to an asymptote, on which the economy has a constant rate of deflation, is critical, and exhibits avalanches of activity with power-law distributed sizes. This example demonstrates that self-organized critical behavior occurs in a larger class of systems than so far considered: systems not driven to an attractive fixed point, but, e.g., an asymptote, may also display self-organized criticality.

  17. 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.

  18. 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.

  19. 75 FR 20518 - Special Conditions: Cirrus Design Corporation Model SF50 Airplane; Full Authority Digital Engine...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-20

    ... Airplane; Full Authority Digital Engine Control (FADEC) System AGENCY: Federal Aviation Administration (FAA... classified as catastrophic, but that the digital engine control must provide an equivalent reliability...

  20. 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…

  1. Dynamics of power systems at critical load levels

    SciTech Connect

    Rajagopalan, C.

    1989-01-01

    In this thesis, eigenvalue algorithms used in the commercial software packages (AESOPS and PEALS) to analyze low frequency oscillations in large scale power systems have been explained in terms of commonly understood iterative schemes. These algorithms have been extended to include the calculation of any desired system mode. Next, the voltage instability problem has been addressed from a dynamic viewpoint in the context of critical modes of the linearized system matrix. The eigenvalue algorithms have been used to establish a correspondence between the critical modes and certain system states. Two case studies have been performed to analyze the dynamic nature of the voltage problem. Finally, Hopf bifurcation theory has been used to analyze the nonlinear power system at critical load levels.

  2. 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

  3. 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.

  4. 77 FR 36123 - Special Conditions: Gulfstream Aerospace LP (GALP), Model Gulfstream G280 Airplane; Aircraft...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-18

    ... architecture and connectivity capabilities of the airplane's computer systems and networks, which may allow access to or by external computer systems and networks. Connectivity to, or access by, external systems and networks may result in security vulnerabilities to the airplane's systems. The...

  5. 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?

  6. 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.

  7. 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.

  8. Mechanical control of airplanes

    NASA Technical Reports Server (NTRS)

    Boykow, H

    1929-01-01

    Before undertaking a detailed description of an automatic-control mechanism, I will state briefly the fundamental conditions for such devices. These are: 1) it must be sensitive at one or more reference values; 2) it must stop the angular motions of the airplane not produced by the pilot; and 3) it must be possible to switch it off and on by a simple hand lever.

  9. Strength calculations on airplanes

    NASA Technical Reports Server (NTRS)

    Baumann, A

    1925-01-01

    Every strength calculation, including those on airplanes, must be preceded by a determination of the forces to be taken into account. In the following discussion, it will be assumed that the magnitudes of these forces are known and that it is only a question of how, on the basis of these known forces, to meet the prescribed conditions on the one hand and the practical requirements on the other.

  10. Static test of an ultralight airplane

    NASA Technical Reports Server (NTRS)

    Smith, H. W.

    1986-01-01

    This paper describes all of the work necessary to perform the static test of an ultralight airplane. A steel reaction gantry was designed first, then all of the loading whiffletrees, the hydraulic actuation system, and instrumentation systems were designed. Loads and stress analyses were performed on the airplane and the gantry and whiffletrees. Components tested to date are: tubing samples, cables, and two-by-four whiffletrees. A hydraulic system consisting of a 3000-psi hand pump, 10,000-pound actuator, pressure gage and lines, and a Barksdale valve are described. Load cell calibration and pressure indicator calibration procedures are also described. A description of the strain and deflection measurement system is included. Preliminary data obtained to date are compared to the analytical predictions.

  11. 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).

  12. 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.

  13. 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.

  14. 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.

  15. 75 FR 39472 - Airworthiness Directives; Eclipse Aerospace, Inc. Model EA500 Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-09

    ... system by the following means: the electronic flight instrument system 1.3 software update; and the... system 1.3 software update: Total cost per Labor cost Parts cost airplane 2 work-hours x $85 per hour... software update 14, 2009; or Eclipse Aviation with one of the following airplane Recommended...

  16. 76 FR 65103 - Special Conditions: Gulfstream Aerospace Corporation, Model GIV-X Airplane; Aircraft Electronic...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-20

    ... GIV-X Airplane; Aircraft Electronic System Security Protection From Unauthorized External Access... connectivity capabilities of the airplane's computer systems and networks, which may allow access by external..., including: 1. Flight-safety related control, communication, and navigation systems (aircraft control...

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. Criticality in conserved dynamical systems: Experimental observation vs. exact properties

    NASA Astrophysics Data System (ADS)

    Marković, Dimitrije; Gros, Claudius; Schuelein, André

    2013-03-01

    Conserved dynamical systems are generally considered to be critical. We study a class of critical routing models, equivalent to random maps, which can be solved rigorously in the thermodynamic limit. The information flow is conserved for these routing models and governed by cyclic attractors. We consider two classes of information flow, Markovian routing without memory and vertex routing involving a one-step routing memory. Investigating the respective cycle length distributions for complete graphs, we find log corrections to power-law scaling for the mean cycle length, as a function of the number of vertices, and a sub-polynomial growth for the overall number of cycles. When observing experimentally a real-world dynamical system one normally samples stochastically its phase space. The number and the length of the attractors are then weighted by the size of their respective basins of attraction. This situation is equivalent, for theory studies, to "on the fly" generation of the dynamical transition probabilities. For the case of vertex routing models, we find in this case power law scaling for the weighted average length of attractors, for both conserved routing models. These results show that the critical dynamical systems are generically not scale-invariant but may show power-law scaling when sampled stochastically. It is hence important to distinguish between intrinsic properties of a critical dynamical system and its behavior that one would observe when randomly probing its phase space.

  2. 77 FR 6023 - Airworthiness Directives; Airbus Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-07

    ... adequacy of existing regulations, the service history of airplanes subject to those regulations, and... Federal Aviation Administration 14 CFR Part 39 RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes... airplanes and Model A310-203, -204, - 221, and -222 airplanes. This proposed AD was prompted by a report...

  3. 14 CFR 125.93 - Airplane limitations.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...: 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 Airplane... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Airplane limitations. 125.93 Section...

  4. 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...

  5. 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...

  6. 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...

  7. '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.

  8. '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

  9. 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.

  10. 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...

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  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. Critical relaxation with overdamped quasiparticles in open quantum systems

    NASA Astrophysics Data System (ADS)

    Lang, Johannes; Piazza, Francesco

    2016-09-01

    We study the late-time relaxation following a quench in an open quantum many-body system. We consider the open Dicke model, describing the infinite-range interactions between N atoms and a single, lossy electromagnetic mode. We show that the dynamical phase transition at a critical atom-light coupling is characterized by the interplay between reservoir-driven and intrinsic relaxation processes in the absence of number conservation. Above the critical coupling, small fluctuations in the occupation of the dominant quasiparticle mode start to grow in time, while the quasiparticle lifetime remains finite due to losses. Near the critical interaction strength, we observe a crossover between exponential and power-law 1 /τ relaxation, the latter driven by collisions between quasiparticles. For a quench exactly to the critical coupling, the power-law relaxation extends to infinite times, but the finite lifetime of quasiparticles prevents aging from appearing in two-times response and correlation functions. We predict our results to be accessible to quench experiments with ultracold bosons in optical resonators.

  19. 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.

  20. 14 CFR Appendix B to Part 135 - Airplane Flight Recorder Specifications

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Airplane Flight Recorder Specifications B.... B Appendix B to Part 135—Airplane Flight Recorder Specifications Parameters Range Installed system 1 minimum accuracy (to recovered data) Sampling interval (per second) Resolution 4 read out Relative...

  1. 14 CFR Appendix E to Part 91 - Airplane Flight Recorder Specifications

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 2 2012-01-01 2012-01-01 false Airplane Flight Recorder Specifications E... (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES GENERAL OPERATING AND FLIGHT RULES Pt. 91, App. E Appendix E to Part 91—Airplane Flight Recorder Specifications Parameters Range Installed system 1...

  2. 14 CFR Appendix E to Part 91 - Airplane Flight Recorder Specifications

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false Airplane Flight Recorder Specifications E... (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES GENERAL OPERATING AND FLIGHT RULES Pt. 91, App. E Appendix E to Part 91—Airplane Flight Recorder Specifications Parameters Range Installed system 1...

  3. 14 CFR Appendix E to Part 91 - Airplane Flight Recorder Specifications

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false Airplane Flight Recorder Specifications E... (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES GENERAL OPERATING AND FLIGHT RULES Pt. 91, App. E Appendix E to Part 91—Airplane Flight Recorder Specifications Parameters Range Installed system 1...

  4. 14 CFR Appendix B to Part 135 - Airplane Flight Recorder Specifications

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Airplane Flight Recorder Specifications B.... B Appendix B to Part 135—Airplane Flight Recorder Specifications Parameters Range Installed system 1 minimum accuracy (to recovered data) Sampling interval (per second) Resolution 4 read out Relative...

  5. 14 CFR Appendix B to Part 135 - Airplane Flight Recorder Specifications

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Airplane Flight Recorder Specifications B.... B Appendix B to Part 135—Airplane Flight Recorder Specifications Parameters Range Installed system 1 minimum accuracy (to recovered data) Sampling interval (per second) Resolution 4 read out Relative...

  6. 14 CFR Appendix E to Part 91 - Airplane Flight Recorder Specifications

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 2 2013-01-01 2013-01-01 false Airplane Flight Recorder Specifications E... (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES GENERAL OPERATING AND FLIGHT RULES Pt. 91, App. E Appendix E to Part 91—Airplane Flight Recorder Specifications Parameters Range Installed system 1...

  7. 14 CFR Appendix B to Part 135 - Airplane Flight Recorder Specifications

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Airplane Flight Recorder Specifications B.... B Appendix B to Part 135—Airplane Flight Recorder Specifications Parameters Range Installed system 1 minimum accuracy (to recovered data) Sampling interval (per second) Resolution 4 read out Relative...

  8. Spin tests of a single-engine, high-wing light airplane

    NASA Technical Reports Server (NTRS)

    Stewart, E. C.; Suit, W. T.; Moul, T. M.; Brown, P. W.

    1982-01-01

    The airplane has a relatively steep spin mode (low angle of attack) with a high load factor and high velocity. The airplane recovers almost immediately after any deviation from the prospin control positions, except for one maneuver with reduced flexibility in the elevator control system.

  9. 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...

  10. 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.

  11. 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%).

  12. 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.

  13. 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.

  14. Critical properties of dissipative quantum spin systems in finite dimensions

    NASA Astrophysics Data System (ADS)

    Takada, Kabuki; Nishimori, Hidetoshi

    2016-10-01

    We study the critical properties of finite-dimensional dissipative quantum spin systems with uniform ferromagnetic interactions. Starting from the transverse field Ising model coupled to a bath of harmonic oscillators with Ohmic spectral density, we generalize its classical representation to classical spin systems with O(n) symmetry and then take the large-n limit to reduce the system to a spherical model. The exact solution to the resulting spherical model with long-range interactions along the imaginary time axis shows a phase transition with static critical exponents coinciding with those of the conventional short-range spherical model in d+2 dimensions, where d is the spatial dimensionality of the original quantum system. This implies that the dynamical exponent is z = 2. These conclusions are consistent with the results of Monte Carlo simulations and renormalization group calculations for dissipative transverse field Ising and O(n) models in one and two dimensions. The present approach therefore serves as a useful tool for analytically investigating the properties of quantum phase transitions of the dissipative transverse field Ising and other related models. Our method may also offer a platform to study more complex phase transitions in dissipative finite-dimensional quantum spin systems, which have recently received renewed interest in the context of quantum annealing in a noisy environment.

  15. 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.

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. Differential equations in airplane mechanics

    NASA Technical Reports Server (NTRS)

    Carleman, M T

    1922-01-01

    In the following report, we will first draw some conclusions of purely theoretical interest, from the general equations of motion. At the end, we will consider the motion of an airplane, with the engine dead and with the assumption that the angle of attack remains constant. Thus we arrive at a simple result, which can be rendered practically utilizable for determining the trajectory of an airplane descending at a constant steering angle.

  3. 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

  4. 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.

  5. 78 FR 44871 - Airworthiness Directives; Bombardier, Inc. Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-25

    ...., Automatic Flight Control System (AFCS), of Section 03-06, Emergency Procedures--Automatic Flight Control... (Regional Jet Series 700, 701, & 702) airplanes: Procedure 1., Automatic Flight Control System (AFCS), of Section 03-06, Emergency Procedures-- Automatic Flight Control System, of Chapter 3, Emergency......

  6. 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.

  7. 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

    ...; Electronic Flight Control System: Control Surface Awareness and Mode Annunciation AGENCY: Federal Aviation... electronic flight control system and no direct coupling from the flightdeck controller to the control surface... alerting. This special condition also addresses flight control system mode annunciation. It......

  8. 14 CFR 36.7 - Acoustical change: Transport category large airplanes and jet airplanes.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... paragraph (b) of this section: (1) Airplanes with high bypass ratio jet engines. For an airplane that has jet engines with a bypass ratio of 2 or more before a change in type design— (i) The airplane, after... do not have high bypass ratio jet engines. For an airplane that does not have jet engines with...

  9. 14 CFR 36.7 - Acoustical change: Transport category large airplanes and jet airplanes.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... paragraph (b) of this section: (1) Airplanes with high bypass ratio jet engines. For an airplane that has jet engines with a bypass ratio of 2 or more before a change in type design— (i) The airplane, after... do not have high bypass ratio jet engines. For an airplane that does not have jet engines with...

  10. 14 CFR 36.7 - Acoustical change: Transport category large airplanes and jet airplanes.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... paragraph (b) of this section: (1) Airplanes with high bypass ratio jet engines. For an airplane that has jet engines with a bypass ratio of 2 or more before a change in type design— (i) The airplane, after... do not have high bypass ratio jet engines. For an airplane that does not have jet engines with...

  11. Clinical monitoring of systemic hemodynamics in critically ill newborns.

    PubMed

    de Boode, Willem-Pieter

    2010-03-01

    Circulatory failure is a major cause of mortality and morbidity in critically ill newborn infants. Since objective measurement of systemic blood flow remains very challenging, neonatal hemodynamics is usually assessed by the interpretation of various clinical and biochemical parameters. An overview is given about the predictive value of the most used indicators of circulatory failure, which are blood pressure, heart rate, urine output, capillary refill time, serum lactate concentration, central-peripheral temperature difference, pH, standard base excess, central venous oxygen saturation and colour.

  12. Coagulation and complement system in critically ill patients.

    PubMed

    Helling, H; Stephan, B; Pindur, G

    2015-01-01

    Activation of coagulation and inflammatory response including the complement system play a major role in the pathogenesis of critical illness. However, only limited data are available addressing the relationship of both pathways and its assessment of a predictive value for the clinical outcome in intense care medicine. Therefore, parameters of the coagulation and complement system were studied in patients with septicaemia and multiple trauma regarded as being exemplary for critical illness. 34 patients (mean age: 51.38 years (±16.57), 15 females, 19 males) were investigated at day 1 of admittance to the intensive care unit (ICU). Leukocytes, complement factors C3a and C5a were significantly (p <  0.0500) higher in sepsis than in trauma, whereas platelet count and plasma fibrinogen were significantly lower in multiple trauma. Activation markers of coagulation were elevated in both groups, however, thrombin-antithrombin-complex was significantly higher in multiple trauma. DIC scores of 5 were not exceeded in any of the two groups. Analysing the influences on mortality (11/34; 32.35% ), which was not different in both groups, non-survivors were significantly older, had significantly higher multiple organ failure (MOF) scores, lactate, abnormal prothrombin times and lower C1-inhibitor activities, even more pronounced in early deaths, than survivors. In septic non-survivors protein C was significantly lower than in trauma. We conclude from these data that activation of the complement system as part of the inflammatory response is a significant mechanism in septicaemia, whereas loss and consumption of blood components including parts of the coagulation and complement system is more characteristic for multiple trauma. Protein C in case of severe reduction might be of special concern for surviving in sepsis. Activation of haemostasis was occurring in both diseases, however, overt DIC was not confirmed in this study to be a leading mechanism in critically ill patients

  13. 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

  14. 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

  15. 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.

  16. 14 CFR 25.1309 - Equipment, systems, and installations.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Equipment General § 25.1309... any foreseeable operating condition. (b) The airplane systems and associated components, considered... condition which would prevent the continued safe flight and landing of the airplane is extremely...

  17. 14 CFR 25.1309 - Equipment, systems, and installations.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Equipment General § 25.1309... any foreseeable operating condition. (b) The airplane systems and associated components, considered... condition which would prevent the continued safe flight and landing of the airplane is extremely...

  18. 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.

  19. An analysis of the stability of an airplane with free controls

    NASA Technical Reports Server (NTRS)

    Jones, Robert T; Cohen, Doris

    1941-01-01

    Report presents the results of an investigation made of the essentials to the stability of an airplane with free control surfaces. Calculations are based on typical airplane characteristics with certain factors varied to cover a range of current designs. Stability charts are included to show the limiting values of the aerodynamic hinge moments and the weight hinge moments of the control surfaces for various positions of the center of gravity of the airplane and for control systems with various moments of inertia. The effects of reducing the chord and of eliminating the floating tendency of the surface, of changing the wing loading, and of decreasing the radius of gyration of the airplane are also indicated. An investigation has also been made of the nature of the motion of the airplane with controls free and of the modes of instability that may occur.

  20. 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.

  1. 78 FR 46532 - Airworthiness Directives; the Boeing Company Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-01

    ... loss of boost pump pressure of the fuel feed system, followed by loss of fuel system suction feed... Company Model 767 airplanes. That NPRM published in the Federal Register on June 6, 2008 (73 FR 32252... Previous NPRM (73 FR 32252, June 6, 2008) Was Issued Since we issued the previous NPRM (73 FR 32252, June...

  2. 77 FR 47568 - Airworthiness Directives; Hawker Beechcraft Corporation Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-09

    ... Policies and Procedures (44 FR 11034, February 26, 1979), (3) Will not affect intrastate aviation in Alaska... for the three-light strobe system of certain Model G58 airplanes. The wire used is a smaller gauge... possible failure of the aircraft's strobe light system. The failure of the wiring for the aircraft's...

  3. 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.

  4. 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.

  5. 75 FR 58016 - Consensus Standards, Standard Practice for Design, Alteration, and Certification of Airplane...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-23

    ... TRANSPORTATION Federal Aviation Administration Consensus Standards, Standard Practice for Design, Alteration, and...-07 Standard Practice for Design, Alteration, and Certification of Airplane Electrical Wiring Systems... design, alteration, and certification of electrical wiring systems for normal, utility, acrobatic,...

  6. 14 CFR 125.355 - Airplane equipment.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...: 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 Airplane... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Airplane equipment. 125.355 Section...

  7. 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 §...

  8. 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 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES General § 23.3 Airplane...

  9. 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 §...

  10. 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...

  11. 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...

  12. 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 §...

  13. 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 §...

  14. 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...

  15. 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...

  16. 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.

  17. 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.

  18. The impact of the All Electric Airplane on production engineering

    SciTech Connect

    Cronin, M.J.

    1981-01-01

    The emergence of an All Electric Airplane in the role of an energy efficient transport is described in relation to the increasing fuel problems, which are impacting on the economic viability of the aerospace industry. The paper reviews the All Electric Airplane (which performs electrically all those functions normally powered by hydraulics, pneumatics and engine bleed air) for its impact upon the design/implementation of the aircraft systems, the advanced technology engines, the aircraft's ground-logistic support, and the producibility aspects of these advanced transport aircraft. The simplification of engine design and the prospective improvements in its specific-fuel-consumption are highlighted along with the overall simplification of the aircraft production aspects of the All Electric Airplane.

  19. 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.

  20. 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...

  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

    ... failures before flight. Certain elements of the control system, such as mechanical and hydraulic components... approximately 6,540 pounds of thrust for normal takeoff. The primary flight controls consist of hydraulically... criteria defined in Advisory Circular 25.672, Active Flight Controls, dated November 11, 1983. The...

  2. 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.

  3. 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.

  4. 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

  5. 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

  6. Plant protection system to assure criticality safety in uranium extraction

    SciTech Connect

    Wilson, R.E.

    1988-01-01

    The criticality safety of uranium reprocessing at the Idaho Chemical Processing Plant depends on the control of the uranium concentration in large vessels. Many of these controls are high-quality barriers meeting the standards of a plant protective system (PPS). The first-cycle extraction PPS has been in use since 1979; the second-cycle extraction system will be equipped with a PPS shortly and the fluorinel dissolution process has had an extensive PPS since startup in 1984. The criteria for these PPSs are based on reactor development technology standard C16-IT and standard 603 of the Institute of Electrical and Electronics Engineers. These reactor plant standards were adapted and formalized for the conditions of fuel processing. The application to the first-cycle extraction operation is described in this paper. The PPS has worked reliably and effectively since its installation. Component malfunction causes inadvertent system trips less than annually. The system provides assurance of a controlled operation with little effect on productivity. As such it relieves the burden on operational supervision. In the only know PPS challenge, the CX nitric acid concentration monitor detected the results of a nitric acid leak into the makeup tank after sampling and prevented an increase in uranium concentration in the downstream mixer settler vessel.

  7. 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.

  8. 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…

  9. 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.

  10. The frequency content of the control input and airplane response obtained during service operations of fighter airplanes

    NASA Technical Reports Server (NTRS)

    Mayer, John P; Hamer, Harold A

    1957-01-01

    The frequency content of the control input and resulting airplane motions is presented as power spectral densities for one operational flight of the fighter airplane (Republic F-84G). The frequency content, which is described by the shape of the spectrum, may be useful in providing inputs for the design of power control systems. For normal load factors, the results presented for the operational flight considered are in general agreement with the results of more complete data on three fighter airplanes (Republic F-84G, Republic F-84F, and North American F-86A) . The frequency content for the three control positions was similar and the frequency content for the three angular velocities was also similar when normalized by dividing the mean-square value.

  11. Scoring Systems in Assessing Survival of Critically Ill ICU Patients

    PubMed Central

    Sekulic, Ana D.; Trpkovic, Sladjana V.; Pavlovic, Aleksandar P.; Marinkovic, Olivera M.; Ilic, Aleksandra N.

    2015-01-01

    Background The aim of this study was to determine which of the most commonly used scoring systems for evaluation of critically ill patients in the ICU is the best and simplest to use in our hospital. Material/Methods This prospective study included 60 critically ill patients. After admittance to the ICU, APACHE II, SAPS II, and MPM II0 were calculated. During further treatment in the ICU, SOFA and MPM II were calculated at 24 h, 48 h, and 72 h and 7 days after admittance using laboratory and radiological measures. Results In comparison with survivors, non-survivors were older (p<0.01) and spent significantly more days on mechanical ventilation (p<0.01). ARDS was significantly more common in patients who survived compared to those who did not (chi-square=7.02, p<0.01), which is not the case with sepsis (chi-square=0.388, p=0.53). AUROC SAPS II was 0.690, and is only slightly higher than the other 2 AUROC incipient scoring systems, MPM II and APACHE II (0.654 and 0.623). The APACHE II has the highest specificity (81.8%) and MPM II the highest sensitivity (85.2%). MPM II7day AUROC (1.0) shows the best discrimination between patients who survived and those who did not. MPM II48 (0.836), SOFA72 (0.821) and MPM II72 (0.817) also had good discrimination scores. Conclusions APACHE II and SAPS II measured on admission to the ICU were significant predictors of complications. MPM II7day has the best discriminatory power, followed by SOFA7day and MPM II48. MPM II7day has the best calibration followed by SOFA7day and APACHE II. PMID:26336861

  12. 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.

  13. 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...

  14. 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...

  15. 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.

  16. 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.

  17. 77 FR 38224 - Airworthiness Directives; Saab AB, Saab Aerosystems Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-27

    ... operating in icing conditions, which if not corrected may result in loss of control of the airplane. DATES... corrected, could result in loss of control of the aeroplane. To address this potential unsafe condition, a... system includes stall warning curves optimized for operation in icing conditions, which are activated...

  18. 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...

  19. 77 FR 37831 - Airworthiness Directives; The Boeing Company Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-25

    ... previous NPRM (73 FR 32255, June 6, 2008) seems to be performing an engine fuel suction feed test, so... airplanes. That NPRM proposed to require repetitive operational tests of the engine fuel suction feed of the... engine fuel suction feed capability of the fuel system, which in the event of total loss of the...

  20. 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)...

  1. 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)

  2. Critical illness in systemic lupus erythematosus and the antiphospholipid syndrome

    PubMed Central

    Williams, F; Chinn, S; Hughes, G; Leach, R

    2002-01-01

    Objectives: To investigate the causes, course, and outcome of critical illness requiring emergency admission to the intensive care unit (ICU) in patients with systemic lupus erythematosus (SLE) or the antiphospholipid syndrome (APS), or both. Methods: Critically ill patients with SLE or APS, or both, admitted to a London teaching hospital ICU over a 15 year period were studied. Demographic, diagnostic, physiological, laboratory, and survival data were analysed. Kaplan-Meier survival curves were constructed by age, time from first diagnosis of SLE, and time from first ICU admission. The log rank test and a backwards stepwise Cox regression were used to identify factors associated with reduced survival. Results: Sixty one patients with SLE alone (39%) and/or APS (61%) required 76 emergency admissions to the ICU. Patients had high severity of illness scores (median APACHE II 22 (range 8–45)) and multiorgan dysfunction. The primary diagnoses for patients admitted were infection in 31/76 (41%), renal disease in 16/76 (21%), cardiovascular disease in 12/76 (16%), and coagulopathies in 11/76 (14%). The commonest secondary diagnosis was renal dysfunction (49%). Factors associated with an increased risk of death were cyclophosphamide before admission, low white cell count, and high severity of illness score. Before adjustment for these factors renal disease had a strong adverse effect on long term survival (analysis by age at diagnosis p=0.005, analysis by time since first ICU admission, p=0.07). After adjustment, infection at admission to ICU was associated with an increased ICU mortality (p=0.02) and was the cause of death in 13/17 patients who died in the ICU. Similarly, after adjustment, APS was associated with reduced ICU survival (p=0.1) and reduced long term (p=0.03) survival. Seventeen patients (28%) died in the ICU, and 31 patients (51%) had died by the last follow up. Median time from ICU admission to death was four years. Overall five year survival from the

  3. 14 CFR 125.75 - Airplane flight manual.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Airplane flight manual. 125.75 Section 125... Airplane flight manual. (a) Each certificate holder shall keep a current approved Airplane Flight Manual or... approved Airplane Flight Manual or the approved equivalent aboard each airplane it operates. A...

  4. 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

  5. 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.

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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)

  13. Safeguards Against Flutter of Airplanes

    NASA Technical Reports Server (NTRS)

    deVries, Gerhard

    1956-01-01

    This report is a complilation of practical rules, derived at the same time from theory and from experience, intended to guide the aeronautical engineer in the design of flutter-free airplanes. Rules applicable to the wing, the ailerons, flaps, tabs,tail surfaces, and fuselage are discussed.

  14. 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

  15. 75 FR 34663 - Airworthiness Directives; The Boeing Company Model 777-200, -300, and -300ER Series Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-18

    ... fasteners of the main and center fuel tanks. The original NPRM resulted from fuel system reviews conducted... proposed AD, contact Boeing Commercial Airplanes, Attention: Data & Services Management, P. O. Box 3707, MC... series airplanes. That original NPRM was published in the Federal Register on January 29, 2007 (72...

  16. 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.

  17. Diffusion and Vibrational Properties of Critically Disordered Systems.

    NASA Astrophysics Data System (ADS)

    Mukherjee, Sonali

    1995-01-01

    In this work we have studied diffusion in critically disordered system modeled by a fractal in the framework of Markov chain analysis. Within this framework the time evolution of the diffusing particle is governed by the transition probability matrix whose spectral analysis in turn leads to the the critical exponents which describe the power-law behavior of the mean-square displacement, velocity autocorrelation function, etc. of the particle diffusing in the fractal. The power-law behavior of the quantities characterizing the diffusing particle is the result of the translation of the spatial correlation of the sites of the underlying fractal substrate into temporal correlation in the trajectory of the diffusing particle. The precise extraction of the exponents demanded incorporation of numerical algorithms like Arnoldi-Saad and computational techniques like making the code compatible for parallel computations in the Markov chain analysis technique. In particular we were successful in obtaining very precise values of the walk exponent d_ w which describes the power-law behavior of the mean-square displacement of the diffusing particle and the spectral exponent d_ s which describes the number of distinct sites visited by the diffusing particle for the percolation cluster. Also the change of exponents was discernible with the change of the universality class when the site occupation probability for the percolation cluster p is increased beyond p_ c transforming the underlying substrate from a fractal to a non-fractal medium. Furthermore the increased accuracy of the exponents obtained from this method made it possible to question the validity of scaling relation between the dynamical exponents d_ w and d_ s and the static exponent d_ f given by d_ s=2d_ f/d_ w in loopless fractal structures. The outcome proved that the validity of the scaling relation is highly dependent on the intricate structure of the fractal rather than on the presence or absence of the loops

  18. 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....

  19. 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....

  20. 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....

  1. 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....

  2. [Scoring system for early detection of critical illness can fail].

    PubMed

    Kamstrup Christiansen, Lærke; Andreasen, Jo Bønding; Frederiksen, Christian Alcaraz; Juhl-Olsen, Peter; Sloth, Erik

    2013-02-18

    A 57-year old male underwent elective aortic valve replacement. The immediate post-operative course was uneventful and the patient was discharged with the lowest possible score on a newly implemented scale for early detection of critical illness. The following day he was readmitted with dyspnoea. The critical illness score was still low despite ultrasonic demonstration of a large pericardial effusion requiring drainage. We are concerned that the widely adopted critical illness scale is not sufficiently sensitive for cardiac surgery patients and advocate the use of point-of-care ultrasound.

  3. Validation of acid washes as critical control points in hazard analysis and critical control point systems.

    PubMed

    Dormedy, E S; Brashears, M M; Cutter, C N; Burson, D E

    2000-12-01

    A 2% lactic acid wash used in a large meat-processing facility was validated as an effective critical control point (CCP) in a hazard analysis and critical control point (HACCP) plan. We examined the microbial profiles of beef carcasses before the acid wash, beef carcasses immediately after the acid wash, beef carcasses 24 h after the acid wash, beef subprimal cuts from the acid-washed carcasses, and on ground beef made from acid-washed carcasses. Total mesophilic, psychrotrophic, coliforms, generic Escherichia coli, lactic acid bacteria, pseudomonads, and acid-tolerant microorganisms were enumerated on all samples. The presence of Salmonella spp. was also determined. Acid washing significantly reduced all counts except for pseudomonads that were present at very low numbers before acid washing. All other counts continued to stay significantly lower (P < 0.05) than those on pre-acid-washed carcasses throughout all processing steps. Total bacteria, coliforms, and generic E. coli enumerated on ground beef samples were more than 1 log cycle lower than those reported in the U.S. Department of Agriculture Baseline data. This study suggests that acid washes may be effective CCPs in HACCP plans and can significantly reduce the total number of microorganisms present on the carcass and during further processing. PMID:11131890

  4. 76 FR 26957 - Special Conditions: Boeing, Model 747-8 Series Airplanes; Door 1 Extendable Length Escape Slide

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-10

    ... most critical angle, escape slides usually exceed 25 knot performance at other than the critical angle... wind velocity is appropriate since the slide will be in an abnormal condition. Available data indicate... critical angle, with the airplane on all its landing gear, with the assistance of one person on the...

  5. Headache during airplane travel ("airplane headache"): first case in Greece.

    PubMed

    Kararizou, Evangelia; Anagnostou, Evangelos; Paraskevas, George P; Vassilopoulou, Sofia D; Naoumis, Dimitrios; Kararizos, Grigoris; Spengos, Konstantinos

    2011-08-01

    Headache related to airplane flights is rare. We describe a 37-year-old female patient with multiple intense, jabbing headache episodes over the last 3 years that occur exclusively during airplane flights. The pain manifests during take-off and landing, and is located always in the left retro-orbital and frontotemporal area. It is occasionally accompanied by dizziness, but no additional symptoms occur. Pain intensity diminishes and disappears after 15-20 min. Apart from occasional dizziness, no other symptoms occur. The patient has a history of tension-type headache and polycystic ovaries. Blood tests and imaging revealed no abnormalities. Here, we present the first case in Greece. We review the current literature on this rare syndrome and discuss on possible pathophysiology and the investigation of possible co-factors such as anxiety and depression.

  6. 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.

  7. 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.

  8. 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.

  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. 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

  11. 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

  12. 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

  13. 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…

  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. '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.

  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. 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.

  18. Surface critical behavior in systems with nonequilibrium phase transitions

    NASA Astrophysics Data System (ADS)

    Howard, Martin; Fröjdh, Per; Bækgaard Lauritsen, Kent

    2000-01-01

    We study the surface critical behavior of branching-annihilating random walks with an even number of offspring (BARW) and directed percolation (DP) using a variety of theoretical techniques. Above the upper critical dimensions dc, with dc=4 (DP) and dc=2 (BARW), we use mean field-theory to analyze the surface phase diagrams using the standard classification into ordinary, special, surface, and extraordinary transitions. For the case of BARW, at or below the upper critical dimension d<=dc, we use field theoretic methods to study the effects of fluctuations. As in the bulk, the field-theory suffers from technical difficulties associated with the presence of a second critical dimension. However, we are still able to analyze the phase diagrams for BARW in d=1 and 2, which turn out to be very different from their mean field analog. Furthermore, for the case of BARW only (and not for DP), we find two independent surface β1 exponents in d=1, arising from two distinct definitions of the order parameter. Using an exact duality transformation on a lattice BARW model in d=1, we uncover a relationship between these two surface β1 exponents at the ordinary and special transitions. Many of our predictions are supported using Monte Carlo simulations of two different models belonging to the BARW universality class.

  19. Surface critical behavior in systems with nonequilibrium phase transitions

    PubMed

    Howard; Frojdh; Baekgaard Lauritsen K

    2000-01-01

    We study the surface critical behavior of branching-annihilating random walks with an even number of offspring (BARW) and directed percolation (DP) using a variety of theoretical techniques. Above the upper critical dimensions d(c), with d(c)=4 (DP) and d(c)=2 (BARW), we use mean field-theory to analyze the surface phase diagrams using the standard classification into ordinary, special, surface, and extraordinary transitions. For the case of BARW, at or below the upper critical dimension dcritical dimension. However, we are still able to analyze the phase diagrams for BARW in d=1 and 2, which turn out to be very different from their mean field analog. Furthermore, for the case of BARW only (and not for DP), we find two independent surface beta(1) exponents in d=1, arising from two distinct definitions of the order parameter. Using an exact duality transformation on a lattice BARW model in d=1, we uncover a relationship between these two surface beta(1) exponents at the ordinary and special transitions. Many of our predictions are supported using Monte Carlo simulations of two different models belonging to the BARW universality class. PMID:11046253

  20. 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.

  1. 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.

  2. 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... Software Division, OpenVMS Operating System Development Group, including employees working off site in...

  3. 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).

  4. 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.

  5. Subsonic Airplane For High-Altitude Research

    NASA Technical Reports Server (NTRS)

    Chambers, Alan; Reed, R. Dale

    1993-01-01

    Report discusses engineering issues considered in design of conceptual subsonic airplane intended to cruise at altitudes of 100,000 ft or higher. Airplane would carry scientific instruments for research in chemistry and physics of atmosphere, particularly, for studies of ozone hole, greenhouse gases, and climatic effects.

  6. 77 FR 34283 - Airworthiness Directives; Airbus Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-11

    ... series airplanes. Comments We have considered the following comment received on the earlier NPRM (76 FR... Manager, Transport Airplane Directorate, Aircraft Certification Service. BILLING CODE 4910-13-P ... Federal Aviation Administration 14 CFR Part 39 RIN 2120-AA64 Airworthiness Directives; Airbus...

  7. 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.

  8. 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...

  9. 78 FR 46536 - Airworthiness Directives; Airbus Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-01

    ... 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... B4-600R series airplanes. This proposed AD was prompted by reports of cracks found in the bottom...

  10. 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...

  11. 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...

  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 23.1437 - Accessories for multiengine airplanes.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Equipment Miscellaneous Equipment § 23.1437 Accessories for multiengine airplanes. For multiengine airplanes... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Accessories for multiengine airplanes....

  14. 14 CFR 21.5 - Airplane or Rotorcraft Flight Manual.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Airplane or Rotorcraft Flight Manual. 21.5... CERTIFICATION PROCEDURES FOR PRODUCTS AND PARTS General § 21.5 Airplane or Rotorcraft Flight Manual. Link to an..., 2010. (a) With each airplane or rotorcraft that was not type certificated with an Airplane...

  15. 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...

  16. 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,...

  17. 14 CFR 21.5 - Airplane or Rotorcraft Flight Manual.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 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...

  18. 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,...

  19. 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...

  20. 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...

  1. 14 CFR 21.5 - Airplane or Rotorcraft Flight Manual.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 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...

  2. 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...

  3. 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...

  4. 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...

  5. 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,...

  6. 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...

  7. 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.

  8. 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.

  9. Optimal back-to-front airplane boarding.

    PubMed

    Bachmat, Eitan; Khachaturov, Vassilii; Kuperman, Ran

    2013-06-01

    The problem of finding an optimal back-to-front airplane boarding policy is explored, using a mathematical model that is related to the 1+1 polynuclear growth model with concave boundary conditions and to causal sets in gravity. We study all airplane configurations and boarding group sizes. Optimal boarding policies for various airplane configurations are presented. Detailed calculations are provided along with simulations that support the main conclusions of the theory. We show that the effectiveness of back-to-front policies undergoes a phase transition when passing from lightly congested airplanes to heavily congested airplanes. The phase transition also affects the nature of the optimal or near-optimal policies. Under what we consider to be realistic conditions, optimal back-to-front policies lead to a modest 8-12% improvement in boarding time over random (no policy) boarding, using two boarding groups. Having more than two groups is not effective. PMID:23848727

  10. 48 CFR 1852.246-70 - Mission Critical Space System Personnel Reliability Program.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Reliability Program. As prescribed in 1846.370(a), insert the following clause: Mission Critical Space System Personnel Reliability Program (MAR 1997) (a) In implementation of the Mission Critical Space System Personnel Reliability Program, described in 14 CFR 1214.5, the Government shall identify personnel...

  11. 48 CFR 1852.246-70 - Mission Critical Space System Personnel Reliability Program.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Reliability Program. As prescribed in 1846.370(a), insert the following clause: Mission Critical Space System Personnel Reliability Program (MAR 1997) (a) In implementation of the Mission Critical Space System Personnel Reliability Program, described in 14 CFR 1214.5, the Government shall identify personnel...

  12. 48 CFR 1852.246-70 - Mission Critical Space System Personnel Reliability Program.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Reliability Program. As prescribed in 1846.370(a), insert the following clause: Mission Critical Space System Personnel Reliability Program (MAR 1997) (a) In implementation of the Mission Critical Space System Personnel Reliability Program, described in 14 CFR 1214.5, the Government shall identify personnel...

  13. 48 CFR 1852.246-70 - Mission Critical Space System Personnel Reliability Program.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Reliability Program. As prescribed in 1846.370(a), insert the following clause: Mission Critical Space System Personnel Reliability Program (MAR 1997) (a) In implementation of the Mission Critical Space System Personnel Reliability Program, described in 14 CFR 1214.5, the Government shall identify personnel...

  14. Practical variational tomography for critical 1D systems

    NASA Astrophysics Data System (ADS)

    Lee, Jong Yeon; Landon-Cardinal, Olivier

    2015-03-01

    We further investigate a recently introduced efficient quantum state reconstruction procedure targeted to states well-approximated by the multi-scale entanglement renormalization ansatz (MERA). First, we introduce an improved optimization scheme that can be easily generalized for MERA states with larger bond dimension. Second, we provide a detailed analysis of the error propagation and quantify how it affects the distance between the experimental state and the reconstructed state. Third, we explain how to bound this distance using local data, providing an efficient scalable certification method. Fourth, we examine the performance of MERA tomography on the ground states of several 1D critical models.

  15. Relative control effectiveness technique with application to airplane control coordination

    NASA Technical Reports Server (NTRS)

    Lallman, F. J.

    1985-01-01

    A method to select optimal combinations of the control variables of a linear system is reported. The combinations are chosen so that the control channels have their principal influences on selected fundamental modes of the system. A series of algebraic maximization problems is used to maximize the effects of the control channels on selected modes while simultaneously minimizing the effects on the remaining modes. The method is applied to the lateral and directional control of a linearized airplane model having ailerons, a rudder, and differential tail surfaces. Integration of these control eliminates oscillations present in the roll rate for a step lateral-control input and improves the sideslip response with reduced rolling motions for a step directional-control input. Inclusion of thrust-vectoring engine nozzles improves the roll rate capability of the airplane.

  16. 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.

  17. 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.

  18. 76 FR 4219 - Airworthiness Directives; Airbus Model A330-200 Series Airplanes; Model A330-300 Series Airplanes...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-25

    ... Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and 3. Will not have a significant...-200 Series Airplanes; Model A330-300 Series Airplanes; Model A340-200 Series Airplanes; and Model A340-300 Series Airplanes AGENCY: Federal Aviation Administration (FAA), Department of Transportation...

  19. Flying qualities from early airplanes to the Space Shuttle

    NASA Technical Reports Server (NTRS)

    Phillips, William H.

    1988-01-01

    This paper discusses the historical development of the study of flying qualities and the evolution of flying qualities requirements. Subjects considered include the scope of flying qualities, early historical development of flying qualities, research on flying qualities requirements, human response characteristics, command control systems, gust response and its relation to flying qualities, prediction of flying qualities, discussion of the Space Shuttle and of some recent airplanes, and format of the flying qualities requirements.

  20. The FAA aging airplane program plan for transport aircraft

    NASA Technical Reports Server (NTRS)

    Curtis, Dayton; Lewis, Jess

    1992-01-01

    The Federal Aviation Administration (FAA) Aging Airplane Program is focused on five program areas: maintenance, transport airplanes, commuter airplanes, airplane engines, and research. These programs are complementary and concurrent, and have been in effect since 1988. The programs address the aging airplane challenge through different methods, including policies, procedures, and hardware development. Each program is carefully monitored and its progress tracked to ensure that the needs of the FAA, the industry, and the flying public are being met.

  1. 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.

  2. 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.

  3. 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.

  4. Critical Test Of The Directly Driven Current System Concept

    NASA Astrophysics Data System (ADS)

    Gjerloev, J. W.; Ohtani, S.; Hoffman, R.

    2009-12-01

    We present results from a study of the response of the magnetosphere-ionosphere system to southward turnings of the Interplanetary Magnetic Field. This is the period during which the M-I system is preconditioned for a subsequent substorm expansion phase onset. The loading process is manifested in the ionospheric current system and we show extensive observations challenging the “standard DP1-DP2 model”. We find significant differences in the response of the auroral electrojet system in the dark ionosphere vs. the sunlit ionosphere. This indicates a discontinuity located near or at the terminator.

  5. Do CASA systems satisfy consumers demands? A critical analysis.

    PubMed

    Feitsma, H; Broekhuijse, M L W J; Gadella, B M

    2011-09-01

    Boar studs are often offered new technologies including several CASA (computer-assisted semen analysis) systems. However, independent information to assist their purchase decisions is not available. The systems accuracy and repeatability variation because of different factors can be evaluated through duplicate testing of semen samples and comparison of the results according to WHO standards for humans. This primary analysis and a thorough economic cost benefit evaluation will help to decide whether the purchase of a CASA system will be profitable for a boar stud. Our experience of implementing several CASA systems in the cooperative Dutch Artificial Insemination (AI) centres is used as a base for this discussion.

  6. Use of a hybrid technology in a critical security system.

    SciTech Connect

    Trujillo, David J.

    2010-10-01

    Assigning an acceptable level of power reliability in a security system environment requires a methodical approach to design when considering the alternatives tied to the reliability and life of the system. The downtime for a piece of equipment, be it for failure, routine maintenance, replacement, or refurbishment or connection of new equipment is a major factor in determining the reliability of the overall system. In addition to these factors is the condition where the system is static or dynamic in its growth. Most highly reliable security power source systems are supplied by utility power with uninterruptable power source (UPS) and generator backup. The combination of UPS and generator backup with a reliable utility typically provides full compliance to security requirements. In the energy market and from government agencies, there is growing pressure to utilize alternative sources of energy other than fossil fuel to increase the number of local generating systems to reduce dependence on remote generating stations and cut down on carbon effects to the environment. There are also conditions where a security system may be limited on functionality due to lack of utility power in remote locations. One alternative energy source is a renewable energy hybrid system including a photovoltaic or solar system with battery bank and backup generator set. This is a viable source of energy in the residential and commercial markets where energy management schemes can be incorporated and systems are monitored and maintained regularly. But, the reliability of this source could be considered diminished when considering the security system environment where stringent uptime requirements are required.

  7. Use of a hybrid technology in a critical security system.

    SciTech Connect

    Scharmer, Carol; Trujillo, David J.

    2010-08-01

    Assigning an acceptable level of power reliability in a security system environment requires a methodical approach to design when considering the alternatives tied to the reliability and life of the system. The downtime for a piece of equipment, be it for failure, routine maintenance, replacement, or refurbishment or connection of new equipment is a major factor in determining the reliability of the overall system. In addition to these factors is the condition where the system is static or dynamic in its growth. Most highly reliable security power source systems are supplied by utility power with uninterruptable power source (UPS) and generator backup. The combination of UPS and generator backup with a reliable utility typically provides full compliance to security requirements. In the energy market and from government agencies, there is growing pressure to utilize alternative sources of energy other than fossil fuel to increase the number of local generating systems to reduce dependence on remote generating stations and cut down on carbon effects to the environment. There are also conditions where a security system may be limited on functionality due to lack of utility power in remote locations. One alternative energy source is a renewable energy hybrid system including a photovoltaic or solar system with battery bank and backup generator set. This is a viable source of energy in the residential and commercial markets where energy management schemes can be incorporated and systems are monitored and maintained regularly. But, the reliability of this source could be considered diminished when considering the security system environment where stringent uptime requirements are required.

  8. 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.

  9. 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

  10. 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.

  11. Critical assessment of the Boltzmann approach to active systems.

    PubMed

    Thüroff, Florian; Weber, Christoph A; Frey, Erwin

    2013-11-01

    Generic models of propelled particle systems posit that the emergence of polar order is driven by the competition between local alignment and noise. Although this notion has been confirmed employing the Boltzmann equation, the range of applicability of this equation remains elusive. We introduce a broad class of mesoscopic collision rules and analyze the prerequisites for the emergence of polar order in the framework of kinetic theory. Our findings suggest that a Boltzmann approach is appropriate for weakly aligning systems but is incompatible with experiments on cluster forming systems.

  12. 25 CFR 547.10 - What are the minimum standards for Class II gaming system critical events?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... known fault state. (v) Critical memory error Some critical memory error has occurred. When a non-correctable critical memory error has occurred, the data on the Class II gaming system component can no...

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 77 FR 15291 - Airworthiness Directives; Airbus Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-15

    ...We propose to adopt a new airworthiness directive (AD) for all Airbus Model A300 B4-603, B4-605R, and B4-622R airplanes; Model A300 C4-605R Variant F airplanes; and Model A300 F4-600R series airplanes. This proposed AD was prompted by a report that chafing was detected between the autopilot electrical wiring conduit and the wing bottom skin. This proposed AD would require modifying the wiring......

  19. 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.

  20. 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).

  1. 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.

  2. 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.

  3. 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...

  4. 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…

  5. 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).

  6. 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...

  7. 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.…

  8. 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

    ... because of those comments. We will post all comments we receive, without change, to http://www.regulations... 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...

  9. 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...

  10. 75 FR 6821 - Airworthiness Directives; The Boeing Company Model 747-400, 747-400D, and 747-400F Series Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-11

    ...), would protect the fuel densitometer for the horizontal stabilizer tank (HST) and the center wing tank...) For all airplanes: Install the HSP in the center wing tank, in accordance with the Accomplishment... system (FQIS) of the center fuel tank and, for certain airplanes, the horizontal stabilizer fuel...

  11. 75 FR 60614 - Airworthiness Directives; The Boeing Company Model 747-400, 747-400D, and 747-400F Series Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-01

    .... (1) For all airplanes: Install the HSP in the center wing tank, in accordance with the Accomplishment... the fuel quantity indicating system (FQIS) of the center fuel tank and, for certain airplanes, the... source inside the center or horizontal stabilizer fuel tanks. An ignition source, in combination...

  12. 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

  13. 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.

  14. Self-organized critical branching in systems that violate conservation laws

    NASA Astrophysics Data System (ADS)

    Juanico, D. E.; Monterola, C.; Saloma, C.

    2007-04-01

    A non-conservative critical branching model is proposed to demonstrate that self-organized criticality (SOC) can occur in mean-field sandpiles that violate a conservation law. The critical state is characterized by avalanche sizes and lifetimes that obey an inverse power-law distribution with exponents τS = 3/2 and τT = 2, respectively. Criticality is achieved when the branching process is coupled to a background activity characterized by the spontaneous switching between refractoriness and quiescence among system components. The stationary state of the system is analysed mathematically and numerically, and is shown to exhibit a transition from a subcritical phase to a critical phase. SOC in sandpile models has been widely believed to occur only when grains are conserved during avalanches. However, such a conservation law is likely to be violated by open, non-equilibrium systems such as biological networks and socially interacting systems like animal groups. The model explores the role of dynamic synapses and synaptic plasticity in maintaining criticality of cortical networks. These brain networks have been found to display neuronal avalanches that obey a power-law distribution. The non-conservative model also emulates the main features of the size distributions of free-swimming tuna schools and red deer herds. Demonstrating criticality in self-organizing systems that violate conservation laws enhances the predictive ability of the theory of SOC in the arena of biocomplexity.

  15. 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

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 77 FR 58336 - Airworthiness Directives; Airbus Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-20

    ... rule'' under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); 3. Will not... inclusive, 1071 through 1075 inclusive, 1077, 1080, and 1082. (2) Model A340-313 airplane, MSN 0955....

  1. 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.

  2. 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

  3. 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.

  4. 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

  5. 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.

  6. 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.

  7. 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.

  8. 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

  9. 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…

  10. 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).

  11. Factors of airplane engine performance

    NASA Technical Reports Server (NTRS)

    Gage, Victor R

    1921-01-01

    This report is based upon an analysis of a large number of airplane-engine tests. It contains the results of a search for fundamental relations between many variables of engine operation. The data used came from over 100 groups of tests made upon several engines, primarily for military information. The types of engines were the Liberty 12 and three models of the Hispano-Suiza. The tests were made in the altitude chamber, where conditions simulated altitudes up to about 30,000 feet, with engine speeds ranging from 1,200 to 2,200 r.p.m. The compression ratios of the different engines ranged from under 5 to over 8 to 1. The data taken on the tests were exceptionally complete, including variations of pressure and temperature, besides the brake and friction torques, rates of fuel and air consumption, the jacket and exhaust heat losses.

  12. Aerodynamic Effects of a 24-foot Multisegmented Telescoping Nose Boom on an F-15B Airplane

    NASA Technical Reports Server (NTRS)

    Cumming, Stephen B.; Smith, Mark S.; Frederick, Michael A.

    2008-01-01

    An experimental multisegmented telescoping nose boom has been installed on an F-15B airplane to be tested in a flight environment. The experimental nose boom is representative of one that could be used to tailor the sonic boom signature of an airplane such as a supersonic business jet. The nose boom consists of multiple sections and could be extended during flight to a length of 24 ft. The preliminary analyses indicate that the addition of the experimental nose boom could adversely affect vehicle flight characteristics and air data systems. Before the boom was added, a series of flights was conducted to update the aerodynamic model and characterize the air data systems of the baseline airplane. The baseline results have been used in conjunction with estimates of the nose boom's influence to prepare for a series of research flights conducted with the nose boom installed. Data from these flights indicate that the presence of the experimental boom reduced the static pitch and yaw stability of the airplane. The boom also adversely affected the static-position error of the airplane but did not significantly affect angle-of-attack or angle-of-sideslip measurements. The research flight series has been successfully completed.

  13. Modelling and simulation of fuel cell dynamics for electrical energy usage of Hercules airplanes.

    PubMed

    Radmanesh, Hamid; Heidari Yazdi, Seyed Saeid; Gharehpetian, G B; Fathi, S H

    2014-01-01

    Dynamics of proton exchange membrane fuel cells (PEMFC) with hydrogen storage system for generating part of Hercules airplanes electrical energy is presented. Feasibility of using fuel cell (FC) for this airplane is evaluated by means of simulations. Temperature change and dual layer capacity effect are considered in all simulations. Using a three-level 3-phase inverter, FC's output voltage is connected to the essential bus of the airplane. Moreover, it is possible to connect FC's output voltage to airplane DC bus alternatively. PID controller is presented to control flow of hydrogen and oxygen to FC and improve transient and steady state responses of the output voltage to load disturbances. FC's output voltage is regulated via an ultracapacitor. Simulations are carried out via MATLAB/SIMULINK and results show that the load tracking and output voltage regulation are acceptable. The proposed system utilizes an electrolyser to generate hydrogen and a tank for storage. Therefore, there is no need for batteries. Moreover, the generated oxygen could be used in other applications in airplane.

  14. Aerodynamic Effects of a 24-Foot, Multisegmented Telescoping Nose Boom on an F-15B Airplane

    NASA Technical Reports Server (NTRS)

    Cumming, Stephen B.; Smith, Mark S.; Frederick, Michael A.

    2007-01-01

    An experimental multisegmented telescoping nose boom has been installed on an F-15B airplane to be tested in a flight environment. The experimental nose boom is representative of one that could be used to tailor the sonic boom signature of an airplane such as a supersonic business jet. The nose boom consists of multiple sections and could be extended during flight to a length of 24 ft. The preliminary analyses indicated that the addition of the experimental nose boom could adversely affect vehicle flight characteristics and air data systems. Before the boom was added, a series of flights was flown to update the aerodynamic model and characterize the air data systems of the baseline airplane. The baseline results have been used in conjunction with estimates of the nose boom s influence to prepare for a series of research flights conducted with the nose boom installed. Data from these flights indicate that the presence of the experimental boom reduced the static pitch and yaw stability of the airplane. The boom also adversely affected the static-position error of the airplane but did not significantly affect angle-of-attack or angle-of-sideslip measurements. The research flight series has been successfully completed.

  15. Prediction of airplane cabin noise due to engine shock cell excitation using statistical energy analysis

    NASA Astrophysics Data System (ADS)

    Marshall, Steven E.

    As part of the effort in the 1980's to design fuel efficient propulsion systems (unducted fan engines) for large commercial airplanes, procedures were developed for predicting interior noise using statistical energy analysis (SEA). Due to stable fuel process and deregulation in the airline industry, the emphasis for propulsion systems on commercial airplanes shifted to higher thrust and lower operating costs. In order to preserve and enhance the knowledge acquired using SEA to predict cabin noise for propeller airplanes, potential noise control applications for more conventional airplane configurations were investigated. The present paper records an effort to extend the experience acquired using statistical energy analysis for unducted fan engines to noise generated by turbofan engine exhaust. The technique is applied to the generic case of a large commercial airplane with twin, wing-mounted engines. Results are presented from an evaluation of the noise source based on an uncommon set of flight test data. Model construction is decribed and prediction results compared to the flight test data. It is then demonstrated how SEA is used to prioritize the transmission paths and judge the merit of the common noise suppression techniques.

  16. Modelling and Simulation of Fuel Cell Dynamics for Electrical Energy Usage of Hercules Airplanes

    PubMed Central

    Radmanesh, Hamid; Heidari Yazdi, Seyed Saeid; Gharehpetian, G. B.; Fathi, S. H.

    2014-01-01

    Dynamics of proton exchange membrane fuel cells (PEMFC) with hydrogen storage system for generating part of Hercules airplanes electrical energy is presented. Feasibility of using fuel cell (FC) for this airplane is evaluated by means of simulations. Temperature change and dual layer capacity effect are considered in all simulations. Using a three-level 3-phase inverter, FC's output voltage is connected to the essential bus of the airplane. Moreover, it is possible to connect FC's output voltage to airplane DC bus alternatively. PID controller is presented to control flow of hydrogen and oxygen to FC and improve transient and steady state responses of the output voltage to load disturbances. FC's output voltage is regulated via an ultracapacitor. Simulations are carried out via MATLAB/SIMULINK and results show that the load tracking and output voltage regulation are acceptable. The proposed system utilizes an electrolyser to generate hydrogen and a tank for storage. Therefore, there is no need for batteries. Moreover, the generated oxygen could be used in other applications in airplane. PMID:24782664

  17. Modelling and simulation of fuel cell dynamics for electrical energy usage of Hercules airplanes.

    PubMed

    Radmanesh, Hamid; Heidari Yazdi, Seyed Saeid; Gharehpetian, G B; Fathi, S H

    2014-01-01

    Dynamics of proton exchange membrane fuel cells (PEMFC) with hydrogen storage system for generating part of Hercules airplanes electrical energy is presented. Feasibility of using fuel cell (FC) for this airplane is evaluated by means of simulations. Temperature change and dual layer capacity effect are considered in all simulations. Using a three-level 3-phase inverter, FC's output voltage is connected to the essential bus of the airplane. Moreover, it is possible to connect FC's output voltage to airplane DC bus alternatively. PID controller is presented to control flow of hydrogen and oxygen to FC and improve transient and steady state responses of the output voltage to load disturbances. FC's output voltage is regulated via an ultracapacitor. Simulations are carried out via MATLAB/SIMULINK and results show that the load tracking and output voltage regulation are acceptable. The proposed system utilizes an electrolyser to generate hydrogen and a tank for storage. Therefore, there is no need for batteries. Moreover, the generated oxygen could be used in other applications in airplane. PMID:24782664

  18. Plutonium Finishing Plant (PFP) Standby Power System Commercial Grade Item (CGI) Critical Characteristics

    SciTech Connect

    DEHKORDI, N.H.

    2000-04-12

    PFP's Standby Power System consists of the diesel generators, the generator control system, Rm 308 UPS, switchgear batteries, and the electrical equipment used to distribute this power. Due to the nature of the equipment and its use throughout general industry, the majority of the system falls within the CGI definition HNF-PRO-268, ''Control of Purchased Items and Services'' and HNF-PRO-1819, ''PHMC Engineering Requirements'' require that the critical characteristics of CGI-procured equipment be established in an engineering document prior to placing the order. HNF-5043 established these critical characteristics for the Standby Power System. This modification adds several items to the document.

  19. Patterns of measles transmission among airplane travelers.

    PubMed

    Edelson, Paul J

    2012-09-01

    With advanced air handling systems on modern aircraft and the high level of measles immunity in many countries, measles infection in air travelers may be considered a low-risk event. However, introduction of measles into countries where transmission has been controlled or eliminated can have substantial consequences both for the use of public health resources and for those still susceptible. In an effort to balance the relatively low likelihood of disease transmission among largely immune travelers and the risk to the public health of the occurrence of secondary cases resulting from importations, criteria in the United States for contact investigations for measles exposures consider contacts to be those passengers who are seated within 2 rows of the index case. However, recent work has shown that cabin air flow may not be as reliable a barrier to the spread of measles virus as previously believed. Along with these new studies, several reports have described measles developing after travel in passengers seated some distance from the index case. To understand better the potential for measles virus to spread on an airplane, reports of apparent secondary cases occurring in co-travelers of passengers with infectious cases of measles were reviewed. Medline™ was searched for articles in all languages from 1946 to week 1 of March 2012, using the search terms "measles [human] or rubeola" and ("aircraft" or "airplane" or "aeroplane" or "aviation" or "travel" or "traveler" or "traveller"); 45 citations were returned. Embase™ was searched from 1988 to week 11 2012, using the same search strategy; 95 citations were returned. Papers were included in this review if they reported secondary cases of measles occurring in persons traveling on an airplane on which a person or persons with measles also flew, and which included the seating location of both the index case(s) and the secondary case(s) on the plane. Nine reports, including 13 index cases and 23 apparent secondary cases

  20. Patterns of measles transmission among airplane travelers.

    PubMed

    Edelson, Paul J

    2012-09-01

    With advanced air handling systems on modern aircraft and the high level of measles immunity in many countries, measles infection in air travelers may be considered a low-risk event. However, introduction of measles into countries where transmission has been controlled or eliminated can have substantial consequences both for the use of public health resources and for those still susceptible. In an effort to balance the relatively low likelihood of disease transmission among largely immune travelers and the risk to the public health of the occurrence of secondary cases resulting from importations, criteria in the United States for contact investigations for measles exposures consider contacts to be those passengers who are seated within 2 rows of the index case. However, recent work has shown that cabin air flow may not be as reliable a barrier to the spread of measles virus as previously believed. Along with these new studies, several reports have described measles developing after travel in passengers seated some distance from the index case. To understand better the potential for measles virus to spread on an airplane, reports of apparent secondary cases occurring in co-travelers of passengers with infectious cases of measles were reviewed. Medline™ was searched for articles in all languages from 1946 to week 1 of March 2012, using the search terms "measles [human] or rubeola" and ("aircraft" or "airplane" or "aeroplane" or "aviation" or "travel" or "traveler" or "traveller"); 45 citations were returned. Embase™ was searched from 1988 to week 11 2012, using the same search strategy; 95 citations were returned. Papers were included in this review if they reported secondary cases of measles occurring in persons traveling on an airplane on which a person or persons with measles also flew, and which included the seating location of both the index case(s) and the secondary case(s) on the plane. Nine reports, including 13 index cases and 23 apparent secondary cases

  1. Trade Study of Multiple Thruster Options for the Mars Airplane Concept

    NASA Technical Reports Server (NTRS)

    Kuhl, Christopher A.; Gayle, Steven W.; Hunter, Craig A.; Kenney, Patrick S.; Scola, Salvatore; Paddock, David A.; Wright, Henry S.; Gasbarre, Joseph F.

    2009-01-01

    A trade study was performed at NASA Langley Research Center under the Planetary Airplane Risk Reduction (PARR) project (2004-2005) to examine the option of using multiple, smaller thrusters in place of a single large thruster on the Mars airplane concept with the goal to reduce overall cost, schedule, and technical risk. The 5-lbf (22N) thruster is a common reaction control thruster on many satellites. Thousands of these types of thrusters have been built and flown on numerous programs, including MILSTAR and Intelsat VI. This study has examined the use of three 22N thrusters for the Mars airplane propulsion system and compared the results to those of the baseline single thruster system.

  2. Graphical and Statistical Analysis of Airplane Passenger Cabin RF Coupling Paths to Avionics

    NASA Technical Reports Server (NTRS)

    Jafri, Madiha; Ely, Jay; Vahala, Linda

    2003-01-01

    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.

  3. 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.

  4. A summary of spin-recovery parachute experience on light airplanes

    NASA Technical Reports Server (NTRS)

    Stough, H. Paul, III

    1990-01-01

    From 1977 to 1989, the NASA Langley Research Center conducted stall/spin flight tests of variations of four typical light airplanes. Each was equipped with an identical tail-mounted, spin-recovery parachute system. The system was used 29 times to arrest otherwise unrecoverable spins and was used at least twice on each airplane. The 10.5 ft diameter, ring-slot, spin-recovery parachute with 20 ft attachment lines and drag coefficient of .545 provided recovery from spins at angles of attack of 32 to 79 degrees and rotation rates of 122 to 261 degrees per second in less than 3 1/2 turns.

  5. Use of virtual reality gaming systems for children who are critically ill.

    PubMed

    Salem, Yasser; Elokda, Ahmed

    2014-01-01

    Children who are critically ill are frequently viewed as "too sick" to tolerate physical activity. As a result, these children often fail to develop strength or cardiovascular endurance as compared to typically developing children. Previous reports have shown that early participation in physical activity in is safe and feasible for patients who are critically ill and may result in a shorter length of stay and improved functional outcomes. The use of the virtual reality gaming systems has become a popular form of therapy for children with disabilities and has been supported by a growing body of evidence substantiating its effectiveness with this population. The use of the virtual reality gaming systems in pediatric rehabilitation provides the children with opportunity to participate in an exercise program that is fun, enjoyable, playful, and at the same time beneficial. The integration of those systems in rehabilitation of children who are critically ill is appealing and has the potential to offer the possibility of enhancing physical activities. The lack of training studies involving children who are critically ill makes it difficult to set guidelines on the recommended physical activities and virtual reality gaming systems that is needed to confer health benefits. Several considerations should be taken into account before recommended virtual reality gaming systems as a training program for children who are critically ill. This article highlighted guidelines, limitations and challenges that need to be considered when designing exercise program using virtual reality gaming systems for critically ill children. This information is helpful given the popular use of virtual reality gaming systems in rehabilitation, particularly in children who are critically ill.

  6. Use of virtual reality gaming systems for children who are critically ill.

    PubMed

    Salem, Yasser; Elokda, Ahmed

    2014-01-01

    Children who are critically ill are frequently viewed as "too sick" to tolerate physical activity. As a result, these children often fail to develop strength or cardiovascular endurance as compared to typically developing children. Previous reports have shown that early participation in physical activity in is safe and feasible for patients who are critically ill and may result in a shorter length of stay and improved functional outcomes. The use of the virtual reality gaming systems has become a popular form of therapy for children with disabilities and has been supported by a growing body of evidence substantiating its effectiveness with this population. The use of the virtual reality gaming systems in pediatric rehabilitation provides the children with opportunity to participate in an exercise program that is fun, enjoyable, playful, and at the same time beneficial. The integration of those systems in rehabilitation of children who are critically ill is appealing and has the potential to offer the possibility of enhancing physical activities. The lack of training studies involving children who are critically ill makes it difficult to set guidelines on the recommended physical activities and virtual reality gaming systems that is needed to confer health benefits. Several considerations should be taken into account before recommended virtual reality gaming systems as a training program for children who are critically ill. This article highlighted guidelines, limitations and challenges that need to be considered when designing exercise program using virtual reality gaming systems for critically ill children. This information is helpful given the popular use of virtual reality gaming systems in rehabilitation, particularly in children who are critically ill. PMID:25260510

  7. Thermal properties of ionic systems near the liquid-liquid critical point.

    PubMed

    Méndez-Castro, Pablo; Troncoso, Jacobo; Pérez-Sánchez, Germán; Peleteiro, José; Romaní, Luis

    2011-12-01

    Isobaric heat capacity per unit volume, C(p), and excess molar enthalpy, h(E), were determined in the vicinity of the critical point for a set of binary systems formed by an ionic liquid and a molecular solvent. Moreover, and, since critical composition had to be accurately determined, liquid-liquid equilibrium curves were also obtained using a calorimetric method. The systems were selected with a view on representing, near room temperature, examples from clearly solvophobic to clearly coulombic behavior, which traditionally was related with the electric permittivity of the solvent. The chosen molecular compounds are: ethanol, 1-butanol, 1-hexanol, 1,3-dichloropropane, and diethylcarbonate, whereas ionic liquids are formed by imidazolium-based cations and tetrafluoroborate or bis-(trifluromethylsulfonyl)amide anions. The results reveal that solvophobic critical behavior-systems with molecular solvents of high dielectric permittivity-is very similar to that found for molecular binary systems. However, coulombic systems-those with low permittivity molecular solvents-show strong deviations from the results usually found for these magnitudes near the liquid-liquid phase transition. They present an extremely small critical anomaly in C(p)-several orders of magnitude lower than those typically obtained for binary mixtures-and extremely low h(E)-for one system even negative, fact not observed, up to date, for any liquid-liquid transition in the nearness of an upper critical solution temperature.

  8. Bibliography for nuclear criticality accident experience, alarm systems, and emergency management

    SciTech Connect

    Putman, V.L.

    1995-09-01

    The characteristics, detection, and emergency management of nuclear criticality accidents outside reactors has been an important component of criticality safety for as long as the need for this specialized safety discipline has been recognized. The general interest and importance of such topics receives special emphasis because of the potentially lethal, albeit highly localized, effects of criticality accidents and because of heightened public and regulatory concerns for any undesirable event in nuclear and radiological fields. This bibliography lists references which are potentially applicable to or interesting for criticality alarm, detection, and warning systems; criticality accident emergency management; and their associated programs. The lists are annotated to assist bibliography users in identifying applicable: industry and regulatory guidance and requirements, with historical development information and comments; criticality accident characteristics, consequences, experiences, and responses; hazard-, risk-, or safety-analysis criteria; CAS design and qualification criteria; CAS calibration, maintenance, repair, and testing criteria; experiences of CAS designers and maintainers; criticality accident emergency management (planning, preparedness, response, and recovery) requirements and guidance; criticality accident emergency management experience, plans, and techniques; methods and tools for analysis; and additional bibliographies.

  9. Generic Airplane Model Concept and Four Specific Models Developed for Use in Piloted Simulation Studies

    NASA Technical Reports Server (NTRS)

    Hoffler, Keith D.; Fears, Scott P.; Carzoo, Susan W.

    1997-01-01

    A generic airplane model concept was developed to allow configurations with various agility, performance, handling qualities, and pilot vehicle interface to be generated rapidly for piloted simulation studies. The simple concept allows stick shaping and various stick command types or modes to drive an airplane with both linear and nonlinear components. Output from the stick shaping goes to linear models or a series of linear models that can represent an entire flight envelope. The generic model also has provisions for control power limitations, a nonlinear feature. Therefore, departures from controlled flight are possible. Note that only loss of control is modeled, the generic airplane does not accurately model post departure phenomenon. The model concept is presented herein, along with four example airplanes. Agility was varied across the four example airplanes without altering specific excess energy or significantly altering handling qualities. A new feedback scheme to provide angle-of-attack cueing to the pilot, while using a pitch rate command system, was implemented and tested.

  10. Flight investigation of the effect of control centering springs on the apparent spiral stability of a personal-owner airplane

    NASA Technical Reports Server (NTRS)

    Campbell, John P; Hunter, Paul A; Hewes, Donald E; Whitten, James B

    1952-01-01

    Report presents the results of a flight investigation conducted on a typical high-wing personal-owner airplane to determine the effect of control centering springs on apparent spiral stability. Apparent spiral stability is the term used to describe the spiraling tendencies of an airplane in uncontrolled flight as affected both by the true spiral stability of the perfectly trimmed airplane and by out-of-trim control settings. Centering springs were used in both the aileron and rudder control systems to provide both a positive centering action and a means of trimming the airplane. The springs were preloaded so that when they were moved through neutral they produced a nonlinear force gradient sufficient to overcome the friction in the control surface at the proper setting for trim. The ailerons and rudder control surfaces did not have trim tabs that could be adjusted in flight.

  11. The critical role of the endocannabinoid system in emotional homeostasis: avoiding excess and deficiencies.

    PubMed

    Marco, E M; Viveros, M P

    2009-10-01

    The endocannabinoid system is critical in the regulation of emotion and stress responsiveness. Despite the promising therapeutic value of its pharmacological modulation, deficient and excessive endocannabinoid signalling should be avoided. This mini-review will provide an up-to-date revision on this topic, emphasizing the relevance of a normative endocannabinoid system for emotional homeostasis.

  12. 78 FR 6195 - Special Conditions: Embraer S.A., Model EMB-550 Airplanes; Flight Envelope Protection...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-30

    ... Embraer S.A. Model EMB-550 airplanes was published in the Federal Register on November 9, 2012, (77 FR... Protection: Performance Credit for Automatic Takeoff Thrust Control System (ATTCS) During Go-Around AGENCY... design feature associated with the use of an Automatic Takeoff Thrust Control System (ATTCS) during...

  13. 14 CFR 125.407 - Maintenance log: Airplanes.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Maintenance log: Airplanes. 125.407 Section... Maintenance log: Airplanes. (a) Each person who takes corrective action or defers action concerning a reported... record the action taken in the airplane maintenance log in accordance with part 43 of this chapter....

  14. 78 FR 28729 - Airworthiness Directives; The Boeing Company Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-16

    ..., 2012) Nord Wind Airlines reported the status of compliance of its airplanes with the NPRM (77 FR 65506... Airplanes AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule. SUMMARY: We are... series airplanes. That AD currently requires modifying the nacelle strut and wing structure,...

  15. 78 FR 27310 - Airworthiness Directives; the Boeing Company Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-10

    ... airplanes: AD 2007-16-12, Amendment 39-15151 (72 FR 44740, August 9, 2007), requires changes to existing... 767-200, -300, and -400ER series airplanes: AD 2008-23-15, Amendment 39-15736 (73 FR 70267, November..., -600, - 700, -700C, -800, and -900 series airplanes: AD 2009-12-06, Amendment 39-15929 (74 FR...

  16. A study of the factors affecting the range of airplanes

    NASA Technical Reports Server (NTRS)

    Biermann, David

    1937-01-01

    A study was made of the most important factors affecting the range of airplanes. Numerical examples are given showing the effects of different variables on the range of a two-engine airplane. The takeoff problems of long-range airplanes are analyzed.

  17. 14 CFR 121.570 - Airplane evacuation capability.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Airplane evacuation capability. 121.570... REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL OPERATIONS Flight Operations § 121.570 Airplane evacuation capability. (a) No person may cause an airplane carrying passengers to be moved on the surface, take off,...

  18. 14 CFR 121.303 - Airplane instruments and equipment.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Airplane instruments and equipment. 121.303... Airplane instruments and equipment. (a) Unless otherwise specified, the instrument and equipment... airspeed limitation and item of related information in the Airplane Flight Manual and pertinent...

  19. 14 CFR 125.91 - Airplane requirements: General.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... AND OPERATIONS: 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... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Airplane requirements: General....

  20. 14 CFR 121.161 - Airplane limitations: Type of route.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... OPERATING REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL OPERATIONS Aircraft Requirements § 121.161 Airplane... specifications, no certificate holder may operate a turbine-engine-powered airplane over a route that contains a... under standard conditions in still air) of 60 minutes for a two-engine airplane or 180 minutes for...

  1. 14 CFR 121.199 - Nontransport category airplanes: Takeoff limitations.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... airplane can be safely controlled in flight after an engine becomes inoperative) or 115 percent of the... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Nontransport category airplanes: Takeoff... OPERATING REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL OPERATIONS Airplane Performance...

  2. 14 CFR 121.159 - Single-engine airplanes prohibited.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Single-engine airplanes prohibited. 121.159... REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL OPERATIONS Aircraft Requirements § 121.159 Single-engine airplanes prohibited. No certificate holder may operate a single-engine airplane under this part....

  3. 14 CFR 121.159 - Single-engine airplanes prohibited.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Single-engine airplanes prohibited. 121.159... REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL OPERATIONS Aircraft Requirements § 121.159 Single-engine airplanes prohibited. No certificate holder may operate a single-engine airplane under this part....

  4. 78 FR 21074 - Airworthiness Directives; Bombardier, Inc. Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-09

    ... FR 19979, April 14, 2008). For airplanes having S/Ns 7003 through 7990 inclusive: Within 14 days... effective date of this AD. (k) New Replacement of Defective Pitch Feel Simulator Unit For airplanes having S.... Airplanes AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed rulemaking...

  5. 77 FR 54856 - Airworthiness Directives; The Boeing Company Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-06

    ... review copies of the referenced service information at the FAA, Transport Airplane Directorate, 1601 Lind... structural integrity of older transport category airplanes, the FAA concluded that the incidence of fatigue... for all airplanes in the transport fleet. Since the establishment of the SSI Supplemental...

  6. 14 CFR 121.141 - Airplane flight manual.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Airplane flight manual. 121.141 Section 121... REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL OPERATIONS Manual Requirements § 121.141 Airplane flight manual. (a) Each certificate holder shall keep a current approved airplane flight manual for each type...

  7. 14 CFR 121.570 - Airplane evacuation capability.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Airplane evacuation capability. 121.570... REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL OPERATIONS Flight Operations § 121.570 Airplane evacuation capability. (a) No person may cause an airplane carrying passengers to be moved on the surface, take off,...

  8. 14 CFR 121.159 - Single-engine airplanes prohibited.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Single-engine airplanes prohibited. 121.159 Section 121.159 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... airplanes prohibited. No certificate holder may operate a single-engine airplane under this part....

  9. 14 CFR 23.71 - Glide: Single-engine airplanes.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Glide: Single-engine airplanes. 23.71... AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Flight Performance § 23.71 Glide: Single-engine airplanes. The maximum horizontal distance traveled in still air, in nautical...

  10. 14 CFR 121.141 - 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. 121.141 Section 121... REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL OPERATIONS Manual Requirements § 121.141 Airplane flight manual. (a) Each certificate holder shall keep a current approved airplane flight manual for each type...

  11. 14 CFR 121.161 - Airplane limitations: Type of route.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Airplane limitations: Type of route. 121... OPERATING REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL OPERATIONS Aircraft Requirements § 121.161 Airplane... specifications, no certificate holder may operate a turbine-engine-powered airplane over a route that contains...

  12. 14 CFR 125.205 - Equipment requirements: Airplanes under IFR.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Equipment requirements: Airplanes under IFR... CERTIFICATION AND OPERATIONS: AIRPLANES HAVING A SEATING CAPACITY OF 20 OR MORE PASSENGERS OR A MAXIMUM PAYLOAD... Equipment Requirements § 125.205 Equipment requirements: Airplanes under IFR. No person may operate...

  13. 14 CFR 125.407 - Maintenance log: Airplanes.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Maintenance log: Airplanes. 125.407 Section... OPERATIONS: AIRPLANES HAVING A SEATING CAPACITY OF 20 OR MORE PASSENGERS OR A MAXIMUM PAYLOAD CAPACITY OF 6... Maintenance log: Airplanes. (a) Each person who takes corrective action or defers action concerning a...

  14. 14 CFR 23.1437 - Accessories for multiengine airplanes.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Accessories for multiengine airplanes. 23... TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Equipment Miscellaneous Equipment § 23.1437 Accessories for multiengine airplanes. For multiengine...

  15. 14 CFR 121.159 - Single-engine airplanes prohibited.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Single-engine airplanes prohibited. 121.159 Section 121.159 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... airplanes prohibited. No certificate holder may operate a single-engine airplane under this part....

  16. 14 CFR 121.303 - Airplane instruments and equipment.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Airplane instruments and equipment. 121.303... Airplane instruments and equipment. (a) Unless otherwise specified, the instrument and equipment... airspeed limitation and item of related information in the Airplane Flight Manual and pertinent...

  17. 14 CFR 121.199 - Nontransport category airplanes: Takeoff limitations.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Nontransport category airplanes: Takeoff... OPERATING REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL OPERATIONS Airplane Performance Operating Limitations § 121.199 Nontransport category airplanes: Takeoff limitations. (a) No person operating...

  18. 14 CFR 121.303 - Airplane instruments and equipment.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Airplane instruments and equipment. 121.303... Airplane instruments and equipment. (a) Unless otherwise specified, the instrument and equipment... airspeed limitation and item of related information in the Airplane Flight Manual and pertinent...

  19. 14 CFR 121.199 - Nontransport category airplanes: Takeoff limitations.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Nontransport category airplanes: Takeoff... OPERATING REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL OPERATIONS Airplane Performance Operating Limitations § 121.199 Nontransport category airplanes: Takeoff limitations. (a) No person operating...

  20. 14 CFR 125.91 - Airplane requirements: General.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Airplane requirements: General. 125.91... AND OPERATIONS: 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...