clearance of the lower cutter allows contact with the ground and is a deficiency. The handling qualities of the JOH-6A LCH with WSPS installed are essentially unchanged from the JOH-6A LCH without WSPS. GRA N85-10039# Army Aviation Engineering Flight Activity, Edwards AFB, Calif. AIRWORTHINESS AND FLIGHT CHARACTERISTICS (A AND FC) TEST OF THE EH - 1X/EH - 1H HELICOPTER CONFIGURATIONS Final Report, 26 Jul. - 19 Sep. 1983 G. T. Downs, J. M. Adkins, J. I. Nagata, J. L. Kimberly, and J. L. Linehan Jan. 1984 74 p (AD-A144881) Avail: NTIS HC A04/MF A01 CSCL 01/3 Level flight performance tests were conducted on five EH-1X/ EH-1H helicopter configurations to determine the change in drag characteristics with the addition of external mission equipment to the standard UH-1H helicopter configuration. Comparison of data from a baseline test configuration with previously published UH-1H and YUH-1H data indicated approximately 8.0 increase in equivalent flat plate area which was attributed to the external mission antennas, low reflective infrared/optical paint, and heat suppression kit with vertical exhaust ejector. Installation of the M-130 chaff/flare dispensers resulted in a further increase in equivalent flat plate area of 5.0 sq ft. Replacing the vertical exhaust ejector with the hot metal plus plume infrared suppressor, including the ALQ144 countermeasures jammer resulted in a reduction in equivalent flat plate area of 1.5 sq ft. Installation of the direction finding antennas resulted in no measurable increase in drag. Addition of all external mission equipment and the hot metal plus plume exhaust resulted in a total increased equivalent flat plate area of approximately 11.5 sq ft. from the standard UH-1H helicopter. N85-10041# Societe Nationale Industrielle Aerospatiale, Toulouse (France). Structural Methods Dept. AEROSPATIALE'S EXPERIMENTATIONS OF VECTORIZATION J. M. Thomas and J. C. Dunyach In AGARD The Influence of The vectorial and parallel performances of new computer architectures was tested. The experiment consisted of adapting existing structural stress routines to existing computers. The performance throughput gain expected from these computers within the context of industrial processing of large programs is estimated. The cost for adapting the programs to the computers is assessed, and basic rules which apply to the vectorization of most programs are established. E.A.K. The Influence of Large Scale Computing on Aircraft Struct. Design Aug. 1984 29 p refs (For primary document see N85-10040 01-05) Avail: NTIS HC A04/MF A01 CSCL 01C Advances in computer technology which may have an impact on computational mechanics and flight vehicle structures technology were reviewed. The characteristics of supersystems, highly parallel systems, and small systems are summarized. The interrelations of numerical algorithms and software with parallel architectures are discussed. A scenario for future hardware/software environment and engineering analysis systems is presented. Research areas with potential for improving the effectiveness of analysis methods in the new environment are identified. E.A.K. A Canadian invention, the peripheral vision horizon display (PVHD), shows promise in alleviating vertigo or disorientation in pilots flying under instrument conditions and easing the piloting task when flying in weather or other conditions requiring close attention to aircraft attitude instruments. A diversity of research and applied work was being done to investigate and validate the benefits of the PVHD during the years immediately preceding this conference. Organizers of the conference were able to assemble a group of outstanding presenters representing academic, industrial, and military. The theoretical foundation and applied use of the PVHD are discussed, and results from operational tests are presented. For individual titles, see N85-10045 through N8510059. N85-10045*# Air Force Inspection and Safety Center, Norton AFB, Calif. Life Sciences Div. PERSONAL EXPERIENCE WITH THE PVHD AND OPINION OF Grant B. McNaughton In NASA. Dryden Flight Research Center The peripheral vision horizon display (PVHD) was examined. It is contended that many aircraft accidents could have been prevented if, the PVHD had been applied, since all the incidents had common characteristics: night, weather, formation, false horizons, and situation which require head down time. It is concluded that the PVHD could be useful on any aircraft that flies in spatially disorienting/misorienting condition, such as night, weather, or formation. It is suggested that it might be particularly useful in aircraft, which by their design, are especially disorienting in such circumstances. E.A.K. N85-10046*# Maltech Research Corp., Oakville (Ontario). The development of the Malcolm Horizon, a peripheral vision horizon used in flight simulation, is discussed. A history of the horizon display is presented as well as a brief overview of vision physiology, and the role balance plays is spatial orientation. Avenues of continued research in subconscious cockpit instrumentation are examined. M.A.C. N85-10047*# Pennsylvania State Univ., University Park. Dept. of Psychology. THE TWO MODES OF VISUAL PROCESSING: IMPLICATIONS FOR SPATIAL ORIENTATION Herschel W. Leibowitz, C. L. Shupert, and Robert B. Post (California Univ., Davis) In NASA. Dryden Flight Research Center Peripheral Vision Horizon Display (PVHD) Apr. 1984 p 41-44 refs (For primary document see N85-10044 01-06) Avail: NTIS HC A07/MF A01 CSCL 01D The roles of the focal and ambient visual systems in spatial orientation are discussed. The two modes are defined and compared. The contribution of each system is illustrated through N85-10048*# Defence and Civil Inst. of Environmental Medicine, Downsview (Ontario). THEORY UNDERLYING THE PERIPHERAL VISION HORIZON DEVICE K. E. Money In NASA. Dryden Flight Research Center Peripheral Vision Horizon Display (PVHD) Apr. 1984 p 45-56 refs (For primary document see N85-10044 01-06) Avail: NTIS HC A07/MF A01 CSCL 01D Peripheral Vision Horizon Device (PVHD) theory states that the likelihood of pilot disorientation in flight is reduced by providing an artificial horizon that provides orientation information to peripheral vision. In considering the validity of the theory, three areas are explored: the use of an artificial horizon device over some other flight instrument; the use of peripheral vision over foveal vision; and the evidence that peripheral vision is well suited to the processing of orientation information. B.G. N85-10049*# California Univ., Davis. Dept. of Ophthalmology. R. B. Post and C. A. Johnson In NASA. Dryden Flight Research The Malcolm horizon utilizes a large projected light stimulus Peripheral Vision Horizon Device (PVHD) as an attitude indicator in order to achieve a more compelling sense of roll than is obtained with smaller devices. The basic principle is that the larger stimulus is more similar to visibility of a real horizon during roll, and does not require fixation and attention to the degree that smaller displays do. Successful implementation of such a device requires adjustment of the parameters of the visual stimulus so that its effects on motion perception and spatial orientation are optimized. With this purpose in mind, the effects of relevant image variables on the perception of object motion, self motion and spatial orientation are reviewed. Author N85-10050*# National Aeronautics and Space Administration. Ames Research Center, Moffett Field, Calif. THE PERIPHERAL VISUAL CUE ASSESSMENT FACILITY AT AMES RESEARCH CENTER c54 Richard F. Haines In NASA. Dryden Flight Research Center Peripheral Vision Horizon Display (PVHD) Apr. 1984 p 63-70 refs (For primary document see N85-10044 01-06) Avail: NTIS HC A07/MF A01 CSCL 05H The Peripheral Visual Cue Assessment Facility was established to study various responses to controlled dynamic stimuli that could be considered as visual analogs of some real world counterparts such as the horizon. Careful stimulus control permits specific responses to be traced to specific stimulus dynamics. The ability of the visual system to assess various kinds of stimulus motion is examined. A major emphasis is placed upon the peripheral vision field, which plays an important role in a pilot's assessment of where he is in space, where he is going, how fast he is travelling, and what angular and linear rates of movement is taking place. The facility was designed to be able to carry out carefully controlled psychophysical vision research over a wide angular range. E.R. N85-10051*# School of Aerospace Medicine, Brooks AFB, Tex. Crew Technology Div. EVALUATION OF THE MALCOLM HORIZON IN A MOVING- Kent K. Gillingham In NASA. Dryden Flight Research Center The efficacy of the Malcolm Horizon (MH) in a controlled, simulated, instrument flight environment was examined. Eight flight c52 EFFECTS OF FOVEAL INFORMATION PROCESSING The scanning behavior of pilots must be understood so that cockpit displays can be assembled which will provide the most information accurately and quickly to the pilot. The results of seven years of collecting and analyzing pilot scanning data are summarized. The data indicate that pilot scanning behavior is: (1) subsconscious; (2) situation dependent; and (3) can be disrupted if pilots are forced to make conscious decisions. Testing techniques and scanning analysis techniques have been developed that are sensitive to pilot workload. B.W. N85-10053*# Air Force Flight Test Center, Edwards AFB, Calif. PERIPHERAL VISION HORIZON DISPLAY ON THE SINGLE SEAT NIGHT ATTACK A-10 Daniel F. Nims In NASA. Dryden Flight Research Center Peripheral Vision Horizon Display (PVHD) Apr. 1984 p 89-96 (For primary document see N85-10044 01-06) Avail: NTIS HC A07/MF A01 CSCL 01D The concept of the peripheral vision horizon display (PVHD) held promise for significant reduction in workload for the single seat night attack pilot. For this reason it was incorporated in the single seat night attack (SSNA) A-10. The implementation and results of the PVHD on the SSNA A-10 are discussed as well as the SSNA program. The part the PVHD played in the test and the results and conclusions of that effort are also considered. Author N85-10054*# Air Force Test Pilot School, Edwards AFB, Calif. PERIPHERAL VISION HORIZON DISPLAY TESTING IN RF-4C AIRCRAFT Lloyd B. Hammond, Jr. In NASA. Dryden Flight Research Center Peripheral Vision Horizon Display (PVHD) Apr. 1984 p 97-102 (For primary document see N85-10044 01-06) Avail: NTIS HC A07/MF A01 CSCL 01D A test program to assess the capability of the peripheral vision horizon display (PVHD) to provide peripheral attitude cues to the pilot is described. The system was installed in the rear cockpit of a RF-4C aircraft, selected because its poor instrument crosscheck conditions. The PVHD test plan was designed to assess three primary areas: (1) ability of the system to reduce spatial disorientation; (2) ability of the system to aid the pilot in recovering from unusual attitudes; and (3) improvement in pilot performance during instrument landing system (ILS) approaches. Results of preliminary test flights are summarized. The major problem areas concern the distinction of the display itself and the capability of the display to provide pitch motion cues. M.G. N85-10055*# Calspan Corp., Buffalo, N. Y. Flight Research EXTRACTS FROM THE TEST PLAN FOR IN-FLIGHT EVALUA- Avail: NTIS HC A07/MF A01 CSCL 01D The Peripheral Vision Display (PVD) which presents the pilot with a gyro stabilized artificial horizon projected onto his instrument panel by a laser light source is outlined. During instrument flight conditions, such a display allows the pilot to gain attitude awareness by sensing the horizon line through his peripheral vision. The pilot can detect changes to aircraft attitude without continuously referring back to his flight instruments. A second generation PVD unit was installed in the USAF/Calspan NT-33A during late 1982. An NT-33A flight evaluation of the display provides a unique opportunity to utilize a Workload Assessment Device (WAD) to obtain quantitative data regarding the utility of the PVD in reducing pilot workload. The experimental design and procedures for a two phase NT33 PVD flight evaluation program is described. Author N85-10056*# National Aeronautics and Space Administration. A homemade peripheral vision horizon device (PVHD) made from an eight-ball attitude indicator, with a slit cut at the equator of the eight ball, and a light source at its center that was used on a l-37 for several years is discussed. The instrument produced a sharp white line about one-fourth of an inch that extended completely across the cockpit from about the left to the right quarterpanels. The line remained parallel to the real horizon during all maneuvers. Its brightness and vertical distance from the horizon were adjustable in flight, as was the lateral center-of-rotation in later flights. Flight demonstrations were done on visual flight rules (VFR) moonless nights and over terrain with few lights. Pilot responses were mostly favorable to enthusiastic, with no negative reactions. Problem areas noted were the upright-inverted ambiguity; one pilot recovered inverted following an unusual attitude exercise and a general deterioration in the naturalness of cuing at bank angles greater than 60 deg or pitch attitudes greater than 30 deg. R.J.F. N85-10057*# Air Force Flight Test Center, Edwards AFB, Calif. B. Lyle Schofield In NASA. Dryden Flight Research Center Three separate Air Force Flight Test Center (AFFTC) tests were conducted in 1980 and 1981 on two models of the peripheral vision horizon displays (PVHD) (Malcolm Horizon). A fixed base simulator test was conducted with twenty test pilot subjects using the Flight Simulator Demonstration Model which incorporated a Helium Neon laser as the light bar medium. Two separate flight tests were conducted by the Test Pilot School classes 80A and 80B in a Twin Otter commuter aircraft using the Stage A Model PVHD. The Xenon lighted A Model was tested in its original configuration by class 80A. Class 80B used a modified configuration which incorporated an AFFTC designed and manufactured hood. With the hood, the PVHD projected a thinner, distinct light bar. Only a few general remarks concerning the tests and unrestricted, overall conclusions reached by the author are presented. The conclusions of all three AFFTC evaluations of the PVHD concept were that it has not yet been adequately evaluated. There seems to be a significant learning curve associated with the PVHD and the project pilots for Test Pilot School Class 80B only got a good start on the learning curve. A lengthy learning curve for the PVHD should be anticipated in view of the training period required for the attitude display indicator (ADI). This does seem to point out that the PVHD, in its present form, is simply not as compelling as the natural horizon. It can also be concluded that any attempt at a valid evaluation of the PVHD concept can be done only under instrument meteorological conditions (IMC) or validly simulated IMC conditions. The knee in the learning curve, however, may be reached without full IMC, although it may take much longer to reach. R.J.F. N85-10058*# Garrett Mfg. Ltd., Rexdale (Ontario). H. M. Assenhein In NASA. Dryden Flight Research Center Peripheral Vision Horizon Display (PVHD) Apr. 1984 p 117-124 (For primary document see N85-10044 01-06) Avail: NTIS HC A07/MF A01 CSCL 01D Several areas of research relating to peripheral vision displays used by aircraft pilots are outlined: fiber optics, display color, and holography. Various capacities and specifications of gas and solid state lasers are enumerated. These lasers are potential sources of green light for the peripheral vision displays. The relative radiance required for rod and cone vision at different wavelengths is presented graphically. Calculated and measured retinal sensitivities (foveal and peripheral) are given for wavelength produced by various lasers. R.S.L. N85-10059*# Garrett Mfg. Ltd., Rexdale (Ontario). A PRODUCTION PERIPHERAL VISION DISPLAY SYSTEM A small number of peripheral vision display systems in three significantly different configurations were evaluated in various aircraft and simulator situations. The use of these development systems enabled the gathering of much subjective and quantitative data regarding this concept of flight deck instrumentation. However, much was also learned about the limitations of this equipment which needs to be addressed prior to wide spread use. A program at Garrett Manufacturing Limited in which the peripheral vision display system is redesigned and transformed into a viable production avionics system is discussed. Modular design, interchangeable units, optical attenuators, and system fault detection are considered with respect to peripheral vision display systems. R.S.F. N85-10060# Calspan Advanced Technology Center, Buffalo, N.Y. A PRELIMINARY FLIGHT EVALUATION OF THE PERIPHERAL VISION DISPLAY USING THE NT-33A AIRCRAFT Final Report, Oct. 1982- Dec. 1983 L. Knotts and V. Gawron Wright-Patterson AFB, Ohio AFWAL Mar. 1984 43 p (Contract F33615-79-C-3618) (AD-A145123; CALSPAN-6645-F-13; AFWAL-TR-84-3020) Avail: NTIS HC A03/MF A01 CSCL 01/4 The Malcolm Horizon, a Peripheral Vision Display (PVD), was installed in the NT-33A variable stability research aircraft. The display provided the evaluation pilot with a gyro stabilized horizon line of red laser light. An experiment was conducted to determine the effect of the PVD on pilot workload. Workload was inferred from performance on a secondary task, in this case, the Sternberg task generated by the Workload Assessment Device (WAD). The primary piloting task required maintenance of airspeed, altitude, and angle of bank during instrument flight conditions. Nine NT-33A flights were flown by two evaluation pilots. Presence of the PVD reduced the WAD reaction times of one of the pilots. The reaction times of the other pilot showed mixed results. In-flight data and the pilots subjective comments about the display are discussed. Author (GRA) multifunction switch. The procedures and results obtained in the course of this study were specifically directed toward the evaluation of the performance of a LED programmable pushbutton switch (PPS), developed both as an individual unit and as a component of a multifunction keyboard (MFK). While the PPS display is limited to a single 16 x 35 LED array size, the procedures employed in the evaluation are applicable to LED switch displays in general. Similarly, the procedures and results obtained using the PPS units as a four switch MFK module are illustrative of the operation of larger keyboard matrices up to a maximum of 28 switches. This study is divided into three general areas of effort. First was the establishment of requirements for the switch function and MFK architecture and capabilities. The second covers the evaluation of the PPS switch/display module. Incorporated in this work are measurements of display parameters, electrical and mechanical characteristics, and environmental testing. The third area of effort involved the incorporation of the PPS units and their associated logic and refresh control unit (LRCU) into a MFK system. GRA Stall elimination means in a jet turbofan engine includes a plurality of pairs of generally parallel case struts arranged in an annular row in an annular fan bypass duct of the engine, and a series of freely-rotatable vanes, each vane disposed between a pair of the struts and movable between open and closed positions. In its open position, air flow in the duct, while in its closed position it extends generally across the duct and blocks most reverse air flow in the duct. The vane automatically rotates to the closed position in response to the onset of an adverse pressure gradient in the duct. GRA This patent discloses a variable inlet vane assembly for use within the inlet area of a combustor, the vane assembly having a plurality of rotatable vanes situated within an annular-shaped opening in the inlet area of the combustor. Each vane is operated by the rotation of a crank assembly and actuator. The actuator meshes with the crank assembly through a sliding interface in order to accommodate axial and/or radial growth of the combustor with no loss in the precision of the control of air entering the combustor during rotation of the vanes. Such as arrangement substantially enhances the relight capability of the combustor. (NASA-TP-2372; E-2149; NAS 1.60:2372) Avail: NTIS HC A03/MF A01 CSCL 21E The efficiency and accuracy of several algorithms recently developed for the efficient numerical integration of stiff ordinary differential equations are compared. The methods examined include two general-purpose codes, EPISODE and LSODE, and three codes (CHEMEQ, CREK1D, and GCKP84) developed specifically to integrate chemical kinetic rate equations. The codes are applied to two test problems drawn from combustion kinetics. The comparisons show that LSODE is the fastest code currently available for the integration of combustion kinetic rate equations. An important finding is that an interactive solution of the algebraic energy conservation equation to compute the temperature does not result in significant errors. In addition, this method is more efficient than evaluating the temperature by integrating its time derivative. Significant reductions in computational work are realized by updating the rate constants (k at(supra N) N exp(-E/RT) only when the temperature change exceeds an amount delta T that is problem dependent. An approximate expression for the automatic evaluation of delta T is derived and is shown to result in increased efficiency. = Author N85-10066# Pratt and Whitney Aircraft, East Hartford, Conn. Engineering Div. DEVELOPMENT TRENDS AND REQUIREMENTS OF PROPULSION SYSTEM TECHNOLOGY FOR CIVIL AIRCRAFT William A. Kerr 1984 19 p Presented at German Soc. of Aeron., Hamburg, 1-3 Oct. 1984 Avail: NTIS HC A02/MF A01 The major technology features in the PW0237 engine are discussed and the certification/flight test program is summarized. M.A.C. N85-10067*# National Aeronautics and Space Administration. Lewis Research Center, Cleveland, Ohio. EFFECT OF COMBINED PRESSURE AND TEMPERATURE DISTORTION ORIENTATION ON HIGH-BYPASS-RATIO TURBOFAN ENGINE STABILITY Ronald H. Soeder and Charles M. Mehalic Washington Oct. 1984 37 p refs (NASA-TM-83771; E-2262; NAS 1.15:83771) Avail: NTIS HC A03/MF A01 CSCL 21E Total-temperature, static-pressure and total-pressure distributions were measured in the inlet duct upstream of the engine inlet and within the fan and compressor of a YTF34 turbofan engine. Free-stream and boundary layer yaw angle variations were measured between a rotable screen assembly and the engine inlet. Total pressure distortions were generated using three 180 deg extent screens and total temperature distortions were generated using a rotatable hydrogen burner. Reynolds number index upstream of the rotatable screen assembly was maintained at 0.5 (based on the undistorted sectors at station 1, the inlet flow measuring station). The engine mechanical fan speed at sea level condition was rated at 7005 rpm. The engine was tested at a corrected fan speed of 90 percent of rated condition. Yaw angle increased between the rotatable screen assembly and the engine inlet. The largest variation in free-stream and boundary layer yaw angle occurs when the combined distortions are 180 deg out-ofphase. Static-pressure distortion increased exponentially as flow approached the engine. Total-pressure distortions were attenuated between the engine inlet and the compressor exit. Totaltemperature distortion persisted through the compressor for all four combined distortions investigated. Author N85-10068*# National Aeronautics and Space Administration. Lewis Research Center, Cleveland, Ohio. CREKID: A COMPUTER CODE FOR TRANSIENT, GAS-PHASE COMBUSTION OF KINETICS David T. Pratt (Washington Univ., Seattle) and Krishnan Radhakrishnan Washington Oct. 1984 38 p refs (Grant NAG3-147) (NASA-TM-83806; E-2176; NAS 1.15:83806) Avail: NTIS HC A03/MF A01 CSCL 21B A new algorithm was developed for fast, automatic integration of chemical kinetic rate equations describing homogeneous, gas-phase combustion at constant pressure. Particular attention is paid to the distinguishing physical and computational characteristics of the induction, heat-release and equilibration regimes. The two-part predictor-corrector algorithm, based on an exponentiallyfitted trapezoidal rule, includes filtering of ill-posed initial conditions, automatic selection of Newton-Jacobi or Newton iteration for convergence to achieve maximum computational efficiency while observing a prescribed error tolerance. The new algorithm was found to compare favorably with LSODE on two representative test problems drawn from combustion kinetics. N85-10069*# B.W. National Aeronautics and Space Administration. Lewis Research Center, Cleveland, Ohio. COMPUTATIONAL THERMO-FLUID DYNAMICS CONTRIBUTIONS TO ADVANCED GAS TURBINE ENGINE DESIGN Robert W. Graham, John J. Adamczyk, and Harold E. Rohlik Washington 1984 13 p refs Proposed for presentation at the 23d Aerospace Sciences Meeting, Reno, Nev., 14-17 Jan. 1985; sponsored by AIAA (NASA-TM-86865; E-2194; NAS 1.15:86865) Avail: NTIS HC A02/MF A01 CSCL 21E The design practices for the gas turbine are traced throughout history with particular emphasis on the calculational or analytical methods. Three principal components of the gas turbine engine will be considered: namely, the compressor, the combustor and the turbine. B.W. N85-10070# Massachusetts Inst. of Tech., Cambridge. Dept. of PRELIMINARY MECHANICAL REDESIGN OF AN EXISTING (AD-A144808) Avail: NTIS HC A05/MF A01 CSCL 21/5 The low-pressure-ratio, highly-regenerative, gas-turbine engine has been proposed as an efficient alternative to other current small-scale marine propulsion systems. This thesis provides a preliminary mechanical redesign of an existing gas-turbine engine to lower the compressor pressure ratio and incorporate a regenerator. One basic design is presented with several alternative turbine modifications. The redesign includes elimination of the second stage of the original two-stage centrifugal compressor, increasing the liner flow area of the existing annular combustor, elimination of the first stage of the three-stage axial turbine, reblading the last two turbine stages, sizing an appropriate regenerator, and designing annular inlet and outlet scroils to direct gas flow to the regenerator. Due to the simplicity of the original engine and its operating environment (high-altitude turboprop), modification to a regenerative system for marine use appears feasible and attractive. |