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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 145 records · Page 8

Energy management - The delayed flap approach

Flight test evaluation of a Delayed Flap approach procedure intended to provide reductions in noise and fuel consumption is underway using the NASA CV-990 test aircraft. Approach is initiated at a high airspeed (240 kt) and in a drag configuration that allows for low thrust. The aircraft is flown along the conventional ILS glide slope. A Fast/Slow message display signals the pilot when to extend approach flaps, landing gear, and land flaps. Implementation of the procedure in commercial service may require the addition of a DME navigation aid co-located with the ILS glide slope transmitter. The Delayed Flap approach saves 250 lb of fuel over the Reduced Flap approach, with a 95 EPNdB noise contour only 43% as large.

Bull, J. S.↗

Individual differences in pilot performance

Selected literature on individual differences in pilot performance is reviewed in order to indicate a possible direction for research. Approaches to studying pilot decision-making processes are discussed, with emphasis given to the wrong-model approach in which accident and incident data, or 'process tracing' provide experimental computational structures. Analysis of data from a simulator experiment on V/STOL zero-visibility landing performance suggests that the order of ranking of individual pilot's effectiveness varies with particular situations defined by combinations of tracking requirements (e.g., glide slope, localizer) and glide-slope segment, or speed requirements; the data are being further analyzed.

Murphy, M. R.↗

Risk of natural environment changes after Space Shuttle deorbit decision

The purpose of the present paper is to point out the risk of change of certain natural environment events that may be of concern in Space Shuttle landing analyses and deorbit decisions. These events are: precipitation, except light rain showers; thunderstorms with ceilings below 4000 ft; runway crosswinds above 20 knots peak at 33 ft; and thunderstorms in the descending glide path. Risk calculations showed that for deorbit decisions made one hour before landing, the maximum risk of change from favorable to unfavorable natural environment conditions is approximately 12 percent, the risk existing for only a few hours in midafternoon. Thunderstorms in the glide path account for more than three fourths of the total risk.

Brown, S. C.↗

The ultralight sailplane

As presently envisioned, the ultralight sailplane is intermediate in size, cost and performance between current hang gliders and the lower end of the traditional sailplane spectrum. In the design of an ultralight sailplane, safety, low cost, and operational simplicity were emphasized at the expense of absolute performance. An overview of the design requirements for an ultralight sailplane is presented. It was concluded that by a judicious combination of the technologies of hang gliding, human powered flight, conventional soaring and motor gliding, an operationally and economically viable class of ultralight, self-launching sailplanes can be developed.

Mcmasters, J. H.↗

Heat treat fixture and method of heat treating

A heat treating fixture is disclosed in which the shape of the metal specimen is maintained by cold rolled steel support plates. Glide sheets of stainless steel, coated with boron nitride, in contact with each face of the metal specimens, allow for lateral expansion of the metal specimens without binding. Grooved support bars separate the glide sheets from the upper and lower support plates and allow flow of quenching fluid to the metal specimen.

Beuyukian, C. S.↗

Analytical study of the cruise performance of a class of remotely piloted, microwave-powered, high-altitude airplane platforms

Each cycle of the flight profile consists of climb while the vehicle is tracked and powered by a microwave beam, followed by gliding flight back to a minimum altitude. Parameter variations were used to define the effects of changes in the characteristics of the airplane aerodynamics, the power transmission systems, the propulsion system, and winds. Results show that wind effects limit the reduction of wing loading and increase the lift coefficient, two effective ways to obtain longer range and endurance for each flight cycle. Calculated climb performance showed strong sensitivity to some power and propulsion parameters. A simplified method of computing gliding endurance was developed.

Morris, C. E. K., Jr.↗

Seismic velocity, attenuation and rheology of the upper mantle

Seismic and rheological properties of the upper mantle in the vicinity of the low-velocity zone are expressed in terms of relaxation by dislocation glide. Dislocation bowing in the glide plane explains seismic velocities and attenuation. Climbing at higher stresses for longer periods of time give the observed viscosity, and explain the low velocity and high temperature attenuation found at seismic frequencies. Due to differing parameters, separate terms for thermal, seismic and rheological lithospheres are proposed. All three lithospheres, however, are related and are functions of temperature, and must be specified by parameters such as period, stress, and stress duration.

Anderson, D. L.↗

Comparative study of flare control laws

The development of a digital, three dimensional, automatic control law designed to achieve an optimal transition of a B-737 aircraft between glide slope conditions and the desired final touchdown condition is presented. The digital control law is a time invariant, state estimate feedback law, and the design is capable of using the microwave landing system. Major emphasis is placed on the reduction of aircraft noise in communities surroundings airports, the reduction of fuel consumption, the reduction of the effects of adverse weather conditions on aircraft operations, and the efficient use of airspace in congested terminal areas. Attention is also given to the development of the capability to perform automatic flares from steep glide slopes to precise touchdown locations.

Nadkarni, A. A.↗

Parametric study of microwave-powered high-altitude airplane platforms designed for linear flight

The performance of a class of remotely piloted, microwave powered, high altitude airplane platforms is studied. The first part of each cycle of the flight profile consists of climb while the vehicle is tracked and powered by a microwave beam; this is followed by gliding flight back to a minimum altitude above a microwave station and initiation of another cycle. Parametric variations were used to define the effects of changes in the characteristics of the airplane aerodynamics, the energy transmission systems, the propulsion system, and winds. Results show that wind effects limit the reduction of wing loading and the increase of lift coefficient, two effective ways to obtain longer range and endurance for each flight cycle. Calculated climb performance showed strong sensitivity to some power and propulsion parameters. A simplified method of computing gliding endurance was developed.

Morris, C. E. K., Jr.↗

Feasibility study of a procedure to detect and warn of low level wind shear

A Doppler radar system which provides an aircraft with advanced warning of longitudinal wind shear is described. This system uses a Doppler radar beamed along the glide slope linked with an on line microprocessor containing a two dimensional, three degree of freedom model of the motion of an aircraft including pilot/autopilot control. The Doppler measured longitudinal glide slope winds are entered into the aircraft motion model, and a simulated controlled aircraft trajectory is calculated. Several flight path deterioration parameters are calculated from the computed aircraft trajectory information. The aircraft trajectory program, pilot control models, and the flight path deterioration parameters are discussed. The performance of the computer model and a test pilot in a flight simulator through longitudinal and vertical wind fields characteristic of a thunderstorm wind field are compared.

Turkel, B. S.↗

A general aviation simulator evaluation of a rate-enhanced instrument landing system display

A piloted-simulation study was conducted to evaluate the effect on instrument landing system tracking performance of integrating localizer-error rate with raw localizer and glide-slope error. The display was named the pseudocommand tracking indicator (PCTI) because it provides an indication of the change of heading required to track the localizer center line. Eight instrument-rated pilots each flew five instrument approaches with the PCTI and five instrument approaches with a conventional course deviation indicator. The results show good overall pilot acceptance of the display, a significant improvement in localizer tracking error, and no significant changes in glide-slope tracking error or pilot workload.

Hinton, D. A.↗

Simulation of a cockpit-display concept for executing a wake-vortex avoidance procedure

A piloted simulation study has been undertaken to determine the feasibility and potential benefits of utilizing a forward-looking display to provide information that would enable aircraft to reduce their in-trail separation, and hence increase runway capacity, through the application of multiple glide-path approach techniques. This portion of the study was an initial exploration into a concept in which traffic information was added to a head-up display (HUD) format to allow the pilot to monitor the traffic situation and to self-space on a lead aircraft during a single glide-path approach task. The tests were conducted in a motion-base cockpit simulator configured as a current-generation transport aircraft and include the dynamic effects of the vortices generated by the lead aircraft. The information provided on the HUD included typical aircraft-guidance information and the current and past positions of the lead aircraft. Additionally, the displayed information provided self-separation cues which allowed the pilot to maintain separation on the lead aircraft. The results of this study indicate that the display concept could provide sufficient information to the pilot for traffic monitoring and self-separation.

Abbott, T. S.↗

Simulation of a cockpit display concept for increased airport capacity

A research effort has been undertaken to determine the feasibility of employing a forward-looking cockpit display to provide information that would enable aircraft to utilize reduced separation, and hence increased runway capacity, through the application of multiple-glide-path approach techniques. The current study was an initial exploration into this concept in which traffic information was added to a HUD format to allow the pilot to monitor the traffic situation and to self space on a lead aircraft during a simulated single glide-path approach. The results of this study indicate that this display concept can provide sufficient information to the pilot for traffic monitoring and self separation. Additionally, the pilots noted that an increase in situational awareness, relative to conventional instrument flight, was provided by the traffic information on the display.

Abbott, T. S.↗

Performance Measures for Aircraft Landings as a Function of Aircraft Dynamics

A theory of performance measurement for operator controlled systems is presented. The theory permits synthesis of a system performance measure which scores performance on successive data samples based on the impact of the sampled performance on the overall summary of performance. The development of measures for aircraft carrier landings for the glide path and angle of attack control channels is documented. While developing the performance measures, the measures used previously were evaluated and were found to lack the necessary discrimination capability. The previously used measure, the RMS of deviations from the glide path, can, for instance, provide identical scores for both satisfactory and unsatisfactory flight paths. Two types of performance measures developed for aircraft landings are described. Also, an argument is given for the need to test performance measures prior to their use. A suggested test of the measures is offered.

Connelly, E. M.↗

A solid-state framework for terrestrial upper mantles

A framework is proposed for understanding the upper mantle structure of the terrestrial planets which is based on solid state dislocation processes. It is proposed that the base of the lithosphere on any planet with a Mg-Fe silicate rich upper mantle is defined by the threshold temperatures of low energy dislocation glide systems in olivine and the pyroxenes. This threshold temperature is approximately 1100 to 1200 K and is directly tied to the mobility of olivine and pyroxene dislocations. Using this definition, all terrestrial planets of the Inner Solar System are expected to have mantle lithospheres. Second, the anomalous properties of the asthenosphere in the Earth are related to the rheological properties of an olivine rich differentiate approximately 220 km thick. All of these properties can be the result of the abundant low energy glide systems in olivine which are mobile at temperatures above approximately 1200 K. It is proposed that a true planetary asthenosphere must be both olivine rich and at temperatures above approximately 1200 K. This mode for the asthenosphere does not require partial melting and is therefore less sensitive to the constraints of volatile content in the upper mantle. The thickness of planetary lithospheres is estimated as is maximum thickness of the olivine rich differentiate on each planet. The cooling of the olivine rich layer on Mars (and hence disappearance of the asthenosphere) may coincide with the cessation of global tectonic activity approximately 1 Gyr ago.

Estey, L.↗

Space Shuttle night landing

The tracking and guidance requirements of the Indian National Satellite during its transition from the low-earth orbit to geosynchronous orbit dictated a night launch and subsequent night landing. The development of an Orbiter-independent external lighting system (ELS) that would work in conjunction with the Orbiter navigation, guidance, and control systems used for day approach and landing is described. The ELS includes the night landing visual aids; the heading alignment circle precision approach path indicator lights, as an aid for the outer glide slope; the runway floodlight, to accommodate for the transition area between preflare and intercepting inner glide slope (IGS) system; the ball/bar reference IGS system; and heads-up displays. The aspects of the lakebed dust problems are discussed. Diagrams illustrating the approach trajectory, final night-lighting configurations, and the approach and land symbology are included.

Brandenstein, D. C.↗

Advanced monitoring concepts

The emphasis in initial work will be on application of image processing techniques in the site monitoring of an ILS glide slope transmitting array. The glide slope requires a clear area in front of the antennas for use as a reflecting zone. Reflecting or scattering obstacles in this area can cause incorrect path formation and system outages. Direct video monitoring is impractical due to the narrow band nature of communication links from the ILS site to the regional maintenance location. Slow scan video is possible, but even this technique may require transmission of large amounts of data, tying up remote monitoring lines. The steps used to minimize data transmission are listed.

Lilley, Robert W.↗

Potential directions for a second generation Space Shuttle

This paper reports on trends and potentials for advanced rocket vehicles which may be candidates for eventual phased replacement of the Shuttle. Although such a replacement need is not foreseen until 2002 at the earliest, due to the long time to develop a new vehicle its definition has already begun. The paper discusses the role of such a "Shuttle II' in the architecture of launch vehicles likely to exist in the post-2000 era, leading to its designation as a smaller, primarily passenger-carrying vehicle to complement large, unmanned cargo launch vehicles. While a two-stage glide-back fully reusable configuration is optimum for near-term technology, a single-stage-to-orbit reusable glide-back configuration is optimum for farther-term technology advances. For advanced technology which could be available in the mid-90s, such vehicle could orbit a payload weight equal to their own dry weight - a factor of 10 better than current launch vehicles.

Bekey, I.↗