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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 721 records · Page 40
All sourcesNASA NTRSDOE OSTI
NASA NTRS1976

Flight test of a stall sensor and evaluation of its application to an aircraft stall deterrent system using the NASA LRC general aviation simulator

A series of flight maneuvers were developed to cover the range of flight conditions and to define the repeatability and hysteresis of the sensors. Initial flights were made with two sensors at the + or - 68 percent span and 60 percent and 70 percent chord stations. The primary effort in simulation program development was to modify the LRC General Aviation Simulator (GAS) Fortran programs to allow execution on the MSU UNIVAC 1106. A simple model of the sensor-servo stall deterrent system was developed. A one degree of freedom model of pitch dynamics of the airplane and stall deterrent system was developed to make initial estimates of the control system gains. A position error plus rate damping control algorithm was found to have acceptable characteristics.

Bennett, G.↗
NASA NTRS1976

Sources and characteristics of interior noise in general aviation aircraft

A field study was conducted to examine the interior noise characteristics of a general aviation aircraft. The goals were to identify the major noise sources and their relative contribution and to establish the noise transmission paths and their relative importance. Tests were performed on an aircraft operating under stationary conditions on the ground. Results show that the interior noise level of light aircraft is dominated by broadband, low frequencies (below 1,000 Hz). Both the propeller and the engine are dominant sources, however, the contribution from the propeller is significantly more than the engine at its fundamental blade passage frequency. The data suggest that the airborne path is more dominant than the structure-borne path in the transmission of broadband, low frequency noise which apparently results from the exhaust.

Catherines, J. J.↗
NASA NTRS1976

Review of drag cleanup tests in Langley full-scale tunnel (from 1935 to 1945) applicable to current general aviation airplanes

Results of drag cleanup tests conducted in the Langley full-scale tunnel during the period from 1935 to 1945 are summarized for potential application to current propeller-driven general aviation airplanes. Data from tests on 23 airplanes indicate that the drag increments produced by many individual configuration features - such as, power plant installation, air leakage, cockpit canopies, control surface gaps, and antenna installations - are not large; however, when the increments are summed, the resulting total drag increase is significant. On the basis of results of the investigation, it appears that considerable reduction in drag can be obtained by proper attention to details in aerodynamic design and by adherence to the guidelines discussed.

Coe, P. L., Jr.↗
NASA NTRS1976

Flight simulation study to determine MLS lateral course width requirements on final approach for general aviation

An investigation of the effects of various lateral course widths and runway lengths for manual CAT I Microwave Landing System instrument approaches was carried out with instrument rated pilots in a General Aviation simulator. Data are presented on the lateral dispersion at the touchdown zone, and the middle and outer markers, for approaches to 3,000, 8,000 (and trial 12,000 foot) runway lengths with full scale angular lateral course widths of + or - 1.19 deg, + or - 2.35 deg, and + or - 3.63 deg. The distance from touchdown where the localizer deviation went to full scale was also recorded. Pilot acceptance was measured according to the Cooper-Harper rating system.

Crumrine, R. J.↗
NASA NTRS1975

General aviation and community development; Summer Faculty Fellowship Program in Engineering Systems Design, Hampton, Va., June 2-August 15, 1975, Report

The document summarizes the results of a faculty program in engineering systems design whose primary aim was to provide a framework for communication and collaboration between academic personnel, research engineers, and scientists in government agencies and private industry. Other objectives were to provide a useful study of a broadly based societal problem, requiring the coordinated efforts of a multidisciplinary team, and to generate experience in the development of systems design and multidisciplinary activities. The success of the program is evidenced by the resulting study of general aviation and community development, characterized by thorough scrutiny of ideas, philosophies, and academic perspectives.

Sincoff, M. Z.↗
NASA NTRS1976

A visual motion simulator for general aviation compensated within the nonlinear adaptive washout for actuator lag

A description is presented of the general aviation aircraft simulator recently acquired by the Langley Research Center, summarizing the complement of instruments, radio/navigation equipment, control loading, and other features. Emphasis is placed mainly on the two-degree-of-freedom motion drives developed for this simulator and the presentation of the dynamic response of the motion system (without washout) in terms of amplitude ratio and phase lag as a function of frequency. The nonlinear adaptive washout based on continuous steepest descent optimization presents cues in pitch rate, surge, roll rate, and sway, and allows for actuator lag compensation.

Ashworth, B. R.↗
NASA NTRS1976

Omega navigation for general aviation

A 70-hour flight test evaluation of an Omega navigation system was performed using a Piper Cherokee 180, to determine the feasibility of Omega for worldwide general aviation navigation. Measurements were made of position accuracy, noise phenomena, and signal to noise ratio. It was found that Omega accuracy is essentially insensitive to local geography, but that there are isolated local interference phenomena associated with radio transmitters, although the strongest noise source observed was due to the onboard power source for the VHF comm/nav radio. An occurrence of lane jumps was observed when attempting to navigate with one weak station.

Hollister, W. M.↗
NASA NTRS1976

Summary of the general aviation manufacturers' position on aircraft piston engine emissions

The General Aviation Manufacturers recommended that the EPA rescind the aircraft piston engine emissions regulations currently on the books. The reason was the very small emission reduction potential and the very poor benefit-cost ratio involved in this form of emission reduction. The limited resources of this industry can far better be devoted to items of much greater benefit to the citizens of this country - reducing noise, improving fuel efficiency (which will incidently reduce exhaust emissions), and improving the safety, operational, and economic aspects of aircraft, all far greater contributions to our total national transportation system.

Helms, J. L.↗
NASA NTRS1976

On the applicability of integrated circuit technology to general aviation orientation estimation

The criteria of the significant value of the panel instruments used in general aviation were examined and kinematic equations were added for comparison. An instrument survey was performed to establish the present state of the art in linear and angular accelerometers, pressure transducers, and magnetometers. A very preliminary evaluation was done of the computers available for data evaluation and estimator mechanization. The mathematical model of a light twin aircraft employed in the evaluation was documented, the results of the sensor survey and the results of the design studies were presented.

Debra, D. B.↗
NASA NTRS1976

General aviation approach and landing practices

The characteristics of air traffic patterns at uncontrolled airports and techniques used by a group of general aviation pilots in landing light airplanes are documented. The results of some 1,600 radar tracks taken at four uncontrolled airports and some 600 landings made by 22 pilots in two, four place, single engine light airplanes show that the uncontrolled traffic pattern is highly variable. The altitudes, distances, and piloting procedures utilized may affect the ability for pilots to see-and-avoid in this environment. Most landing approaches were conducted at an airspeed above recommended, resulting in significant floating during flare and touchdowns that were relatively flat and often nose-low.

Parker, L. C.↗
NASA NTRS1976

General aviation crash safety program at Langley Research Center

The purpose of the crash safety program is to support development of the technology to define and demonstrate new structural concepts for improved crash safety and occupant survivability in general aviation aircraft. The program involves three basic areas of research: full-scale crash simulation testing, nonlinear structural analyses necessary to predict failure modes and collapse mechanisms of the vehicle, and evaluation of energy absorption concepts for specific component design. Both analytical and experimental methods are being used to develop expertise in these areas. Analyses include both simplified procedures for estimating energy absorption capabilities and more complex computer programs for analysis of general airframe response. Full-scale tests of typical structures as well as tests on structural components are being used to verify the analyses and to demonstrate improved design concepts.

Thomson, R. G.↗
NASA NTRS1977

Meteorological needs of the aviation community

A study was conducted to determine the important meteorological needs of the aviation community and to recommend research in those areas judged most beneficial. The study was valuable in that it provided a comprehensive list of suspected meteorological deficiencies and ideas for research programs relative to these deficiencies. The list and ideas were generated from contacts with various pilots, air traffic controllers, and meteorologists.

Luers, J. K.↗
NASA NTRS1975

Low-speed aerodynamic characteristics of a 13-percent-thick airfoil section designed for general aviation applications

Wind-tunnel tests were conducted to determine the low-speed section characteristics of a 13 percent-thick airfoil designed for general aviation applications. The results were compared with NACA 12 percent-thick sections and with the 17 percent-thick NASA airfoil. The tests were conducted ovar a Mach number range from 0.10 to 0.35. Chord Reynolds numbers varied from about 2,000,000 to 9,000,000.

Mcghee, R. J.↗
NASA NTRS1977

Exploratory investigation of the incipient spinning characteristics of a typical light general aviation airplane

The incipient spinning characteristics of general aviation airplanes were studied. Angular rates in pitch, yaw, and roll were measured through the stall during the incipient spin and throughout the recovery along with control positions, angle of attack, and angle of sideslip. The characteristic incipient spinning motion was determined from a given set of entry conditions. The sequence of recovery controls were varied at two distinct points during the incipient spin, and the effect on recovery characteristics was examined. Aerodynamic phenomena associated with flow over the aft portion of the fuselage, vertical stabilizer, and rubber are described.

Ranaudo, R. J.↗
NASA NTRS1977

A research program to reduce interior noise in general aviation airplanes

The relevance of KU-FRL test results in predicting (theoretically or semi-empirically) interior noise levels in general aviation aircraft was studied. As a result of this study, it was decided to make a few additions to the program. These additions are: (1) to use three (instead of two) noise sources in the plane wave tube to evaluate the influence of excitation spectrum on panel response, (2) to use theoretical and experimental data obtained in the course of the project to develop more efficient noise reduction materials (or procedures to apply these), or to develop guidelines for the design of such materials for procedures, and (3) to use nonstructural materials in the collection of specimens to be tested in the KU-FRL plane wave tube.

Peschier, T. D.↗