摘要 :
This report discusses the electromagnetic compatibility of the Time-Reference Scanning-Beam Microwave Landing System (MLS) with other radiating systems on-board nine types of aircraft. These nine aircraft are the McDonnell Douglas...
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This report discusses the electromagnetic compatibility of the Time-Reference Scanning-Beam Microwave Landing System (MLS) with other radiating systems on-board nine types of aircraft. These nine aircraft are the McDonnell Douglas DC-10, DC-9, DC-8, Boeing 747, 737, 727, 707, Lockheed Tristar L-1011, and the North American Rockwell T-39 Sabreliner. This MLS intra-aircraft interference analysis was performed by calculating the interference power level at a receiving antenna, comparing this power with a user-specified interference threshold, and identifying the potential problems. This report considers the TRSB MLS design as it was at the time the study was completed. Since that time a number of design changes have been made and are not addressed in this report. (Author)
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摘要 :
The technical feasibility is described of substantially reducing the noise levels of existing JT8D powered aircraft by retrofitting the existing fleet with quieter refan engines and new acoustically treated nacelles. No major tech...
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The technical feasibility is described of substantially reducing the noise levels of existing JT8D powered aircraft by retrofitting the existing fleet with quieter refan engines and new acoustically treated nacelles. No major technical problems exist that preclude the development and installation of refanned engines on aircraft currently powered by the JT8D engine. The refan concept is technically feasible and provides calculated noise reductions of from 7 to 8 EPNdb for the B727-200 aircraft and from 10 to 12 EPNdb for the DC-9-32 aircraft at the FAR Part 36 measuring stations. These noise levels are lower than both the FAR Part 36 noise standards and the noise levels of the wide-body DC-10-10. Corresponding reductions in the 90 EPNdb footprint area are estimated to vary from about 70 percent for the DC-9 to about 80 percent for the B727.
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The efforts in this phase of the 'Aircraft Noise Definition' project was comprised of processing and analysis of existing acoustic and performance data and preparing acoustic and performance (based on average engine) graphical and...
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The efforts in this phase of the 'Aircraft Noise Definition' project was comprised of processing and analysis of existing acoustic and performance data and preparing acoustic and performance (based on average engine) graphical and computer presentations for two JT3D turbofan-powered DC-8s, one with short and one with long fan ducts; two DC-9s, one with JT8D-7 and one with JT8D-9 engines; and the DC-10-10 and DC-10-40 aircraft. The acoustic data included reference-day EPNL and peak A-weighted sound level curves with empirically developed curves for adjusting the noise levels to temperatures from 30F to 100F with the relative humidity held constant at 70 percent. The performance data include provisions for a temperature variation from 30F to 100F and runway altitude from sea level to 6000 feet. Data accuracy is described in terms of assignable confidence limits.
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The costs of civil air transport emergency evacuation demonstrations using human subjects have risen as seating capacities of these aircraft have increased. Repeated tests further increase the costs and also the risks of injuries ...
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The costs of civil air transport emergency evacuation demonstrations using human subjects have risen as seating capacities of these aircraft have increased. Repeated tests further increase the costs and also the risks of injuries to participants. A method to simulate such evacuations, by use of a computer model based on statistics from measured components of the escape path, has been developed. This model uses the General Purpose Simulation System (GPSS) computer programing language to represent various features of the escape process; e.g., seating and exit configurations, passenger mix, door-opening delays, time on escape slides, slide capacity, and redirection of passengers to equalize escape lines. Results of simulated evacuations from the DC-10, L-1011, and B-747 aircraft and a military aircraft are reported. These results have been compared with results of certification demonstrations from the DC-10, L-1011, and B-747. Comparisons of exit size substitutions were evaluated as a means of estimating differences in escape potential for exit design optimization. (Author)
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The results are presented of a series of low-altitude (approximately 200 feet above ground level) fight tests in which the trailing vortices of the McDonnell-Douglas DC9 airplane were investigated, using a 140-foot instrumented to...
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The results are presented of a series of low-altitude (approximately 200 feet above ground level) fight tests in which the trailing vortices of the McDonnell-Douglas DC9 airplane were investigated, using a 140-foot instrumented tower. Data presented consists of plots of vortex tangential velocity distribution, peak velocity as a function of time, airplane configuration and windspeed, vortex descent rates, and lateral transport rates. Principal findings were that: (1) Within the time period 30 - 100 seconds after vortex generation, the peak velocities within the vortices were bounded by the function V sub theta = 396exp(-.0347t), with a half-life of 20 seconds; (2) Vortex cores were uniformly small (1 - 2 feet) in both configurations tested (takeoff and landing), and little or no growth with time was found; (3) Vortex lateral transport velocities correlated well with the crosswind measured at 140 feet; and (4) The presence of a temperature inversion markedly retarded the vortex descent rates. The highest peak recorded tangential velocity was 120 - 130 feet per second, found to occur in both configurations tested.
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摘要 :
This task is concered with development and test by piloted flight simulation of airborne techniques designed to aid the pilot to detect and cope with low-level wind shear. This report documents the Phase 3 tests on a DC-10 aircraf...
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This task is concered with development and test by piloted flight simulation of airborne techniques designed to aid the pilot to detect and cope with low-level wind shear. This report documents the Phase 3 tests on a DC-10 aircraft simulator, involving a set of wind profiles significantly expanded over those used previously and an especially large group (26) of subject pilots in the major test. The operational situation simulated was a landing under Category I visibility to a 7000-ft runway with ILS guidance. There were 10 different wind profiles, with wind shear ranging from low to high severity. In an initial trial various aiding concepts were compared in individual experiments. This involved 4 versions of groundspeed displays, 2 versions of modified (acceleration-augmented) flight director steering and speed commands, and 2 go-around decision aids: a computation of longitudinal acceleration margin and an energy-rate meter. The more promising were combined in 3 systems tested in a full trial. Performance was marginal, but would have been adequate if all the go-around advisories had been honored. False-alarm and missed-alarm rates of the advisories were too high. Additional work was recommended on go-around decision aids, the importance of effective go-around decision aids being emphasized. It was noted that the go-around warning requires improved consistency in backup information; an on-off display is not adequate.
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