SEARCH · Engineering Papers

Results for “Test Pilots”

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.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 451 records · Page 25

All sources NASA NTRS DOE OSTI

NASA NTRS2009

The Effects of Synthetic and Enhanced Vision Technologies for Lunar Landings

Eight pilots participated as test subjects in a fixed-based simulation experiment to evaluate advanced vision display technologies such as Enhanced Vision (EV) and Synthetic Vision (SV) for providing terrain imagery on flight displays in a Lunar Lander Vehicle. Subjects were asked to fly 20 approaches to the Apollo 15 lunar landing site with four different display concepts - Baseline (symbology only with no terrain imagery), EV only (terrain imagery from Forward Looking Infra Red, or FLIR, and LIght Detection and Ranging, or LIDAR, sensors), SV only (terrain imagery from onboard database), and Fused EV and SV concepts. As expected, manual landing performance was excellent (within a meter of landing site center) and not affected by the inclusion of EV or SV terrain imagery on the Lunar Lander flight displays. Subjective ratings revealed significant situation awareness improvements with the concepts employing EV and/or SV terrain imagery compared to the Baseline condition that had no terrain imagery. In addition, display concepts employing EV imagery (compared to the SV and Baseline concepts which had none) were significantly better for pilot detection of intentional but unannounced navigation failures since this imagery provided an intuitive and obvious visual methodology to monitor the validity of the navigation solution.

Kramer, Lynda J.↗

NASA NTRS1983

Autonomous RPRV Navigation, Guidance and Control

Dryden Flight Research Center has the responsibility for flight testing of advanced remotely piloted research vehicles (RPRV) to explore highly maneuverable aircraft technology, and to test advanced structural concepts, and related aeronautical technologies which can yield important research results with significant cost benefits. The primary purpose is to provide the preliminary design of an upgraded automatic approach and landing control system and flight director display to improve landing performance and reduce pilot workload. A secondary purpose is to determine the feasibility of an onboard autonomous navigation, orbit, and landing capability for safe vehicle recovery in the event of loss of telemetry uplink communication with the vehicles. The current RPRV approach and landing method, the proposed automatic and manual approach and autoland system, and an autonomous navigation, orbit, and landing system concept which is based on existing operational technology are described.

Johnston, Donald E.↗

NASA NTRS1974

Simulation study of intracity helicopter operations under instrument conditions to category 1 minimums

A fixed-base simulator study was conducted to define pilot workload and task performance associated with instrument flight operations for an intracity helicopter passenger service. Displays considered necessary to provide a minimal capability under Instrument Flight Rules conditions were used to fly a representative commercial helicopter route structure in the New York area, with each terminal assumed to be equipped with a precision approach guidance system. A cross section of pilots participated as test subjects, and despite the high workload level, the results indicated that for the assumptions employed, minimums of 61 m (200 ft) ceiling and 805 m (0.5 mile) visibility were feasible.

Callan, W. M.↗

NASA NTRS1977

Diurnal rhythms of visual accommodation and blink responses - Implication for flight-deck visual standards

Possible 24-h variations in accommodation responses were investigated. A recently developed servo-controlled optometer and focus stimulator were used to obtain monocular accommodation response data on four college-age subjects. No 24-h rhythm in accommodation was shown. Heart rate and blink rate also were measured and periodicity analysis showed a mean 24-h rhythm for both; however, blink rate periodograms were significant for only two of the four subjects. Thus, with the qualifications that college students were tested instead of pilots and that they performed monocular laboratory tasks instead of binocular flight-deck tasks, it is concluded that 24-h rhythms in accommodation responses need not be considered in setting visual standards for flight-deck tasks.

Murphy, M. R.↗

NASA NTRS1977

Required attention for synthesized speech perception for three levels of linguistic redundancy

The study evaluates the attention required for synthesized speech perception with reference to three levels of linguistic redundancy. Twelve commercial airline pilots were individually tested for 16 cockpit warning messages eight of which consisted of two monosyllabic key words and eight of which consisted of two polysyllabic key words. Three levels of linguistic redundancy were identified: monosyllabic words, polysyllabic words, and sentences. The experiment contained a message familiarization phase and a message recognition phase. It was found that: (1) when the messages are part of a previously learned and recently heard set, and the subject is familiar with the phrasing, the attention needed to recognize the message is not a function of the level of linguistic redundancy, and (2) there is a quantitative and qualitative difference between recognition and comprehension processes; only in the case of active comprehension does additional redundancy reduce attention requirements.

Simpson, C. A.↗

NASA NTRS1978

Digital Fly-By-Wire Flight Control Validation Experience

The experience gained in digital fly-by-wire technology through a flight test program being conducted by the NASA Dryden Flight Research Center in an F-8C aircraft is described. The system requirements are outlined, along with the requirements for flight qualification. The system is described, including the hardware components, the aircraft installation, and the system operation. The flight qualification experience is emphasized. The qualification process included the theoretical validation of the basic design, laboratory testing of the hardware and software elements, systems level testing, and flight testing. The most productive testing was performed on an iron bird aircraft, which used the actual electronic and hydraulic hardware and a simulation of the F-8 characteristics to provide the flight environment. The iron bird was used for sensor and system redundancy management testing, failure modes and effects testing, and stress testing in many cases with the pilot in the loop. The flight test program confirmed the quality of the validation process by achieving 50 flights without a known undetected failure and with no false alarms.

Szalai, K. J.↗

NASA NTRS1981

A compatibility assessment method for adaptive-wall wind tunnels

A new method is described for assessing the compatibility between inner and outer flow regimes in adaptive-wall wind tunnels. The method is applicable to both two- and three-dimensional flows, and unlike other schemes, requires the measurement of only one velocity component. Moreover, a complete solution to the outer flowfield is not required with the new method. Computer simulations of two- and three-dimensional flows are presented along with data from a two-dimensional pilot wind tunnel test using the new method.

Davis, S. S.↗

NASA NTRS1985

Remotely Piloted Aircraft for Research

NASA Technical Memorandum presents overview of remotely-piloted research vehicle (RPRV) activities. Controlled from ground, vehicles allow new concepts tried without subjecting pilots to danger. Critical role of pilot in flight testing with RPRV's demonstrated repeatedly, and many system anomalies uncovered with no risk to human life.

Rezek, T. W.↗

NASA NTRS1984

Development of an advanced pitch active control system and a reduced area horizontal tail for a wide-body jet aircraft

The development of an advanced pitch active control system (PACS) and a reduced area horizontal tail for a wide-body jet transport (L-1011) with a flying horizontal stabilizer is discussed. The advanced PACS control law design objectives were to provide satisfactory handling qualities for aft c.g. flight conditions to negative static stability margins of 10 percent and to provide good maneuver control column force gradients for nonlinear stability flight conditions. Validity of the control laws were demonstrated by piloted flight simulation tests on the NASA Langley Visual Motion Simulator. Satisfactory handling qualities were actually demonstrated to a negative 20 percent static stability margin. The PACS control laws were mechanized to provide the system architecture that would be suitable for an L-1011 flight test program to a negative stability margin of 3 percent which represents the aft c.g. limits of the aircraft. Reduced area horizontal tail designs of 30 and 38 percent with respect to the L-1011 standard tail were designed, fabricated and wind tunnel tested. Drag reductions and weight savings of the 30 percent smaller tail would provide an L/D benefit of about 2% and the 38% small tail L/D benefit would be about 3 percent. However, forward c.g. limitations would have to be imposed on the aircraft because the maximum horizontal tail lift goal was not achieved and sufficient aircraft nose-up control authority was not available. This limitation would not be required for a properly designed new aircraft.

Guinn, Wiley A.↗

NASA NTRS1987

The temperature dependence of inelastic light scattering from small particles for use in combustion diagnostic instrumentation

A computer calculation of the expected angular distribution of coherent anti-Stokes Raman scattering (CARS) from micrometer size polystyrene spheres based on a Mie-type model, and a pilot experiment to test the feasibility of measuring CARS angular distributions from micrometer size polystyrene spheres by simply suspending them in water are discussed. The computer calculations predict a very interesting structure in the angular distributions that depends strongly on the size and relative refractive index of the spheres.

Cloud, Stanley D.↗

NASA NTRS1987

Automated maneuvering decisions for air-to-air combat

A game-matrix approach is used to generate intelligent maneuvering decisions for nap-of-the-earth one-on-one helicopter air combat over hilly terrain. Decisions are made in real time using the AUTOMAN program by comparing scores based upon the predicted orientation, range, velocity, and terrain clearance for various maneuver combinations of both aircraft. The program has been demonstrated at the NASA Ames Vertical Motion Simulator, providing manned helicopter simulations. Sample trajectories from a stand-alone version of the program designed for nonpiloted simulations demonstrate that the present automated maneuvering logic generates some of the tactics employed by experienced pilots in flight tests. The program also has application to fixed-wing aircraft simulations.

Austin, Fred↗

NASA NTRS1988

Large-scale experimental technology with remote sensing in land surface hydrology and meteorology

Two field experiments to study atmospheric and land surface processes and their interactions are summarized. The Hydrologic-Atmospheric Pilot Experiment, which tested techniques for measuring evaporation, soil moisture storage, and runoff at scales of about 100 km, was conducted over a 100 X 100 km area in France from mid-1985 to early 1987. The first International Satellite Land Surface Climatology Program field experiment was conducted in 1987 to develop and use relationships between current satellite measurements and hydrologic, climatic, and biophysical variables at the earth's surface and to validate these relationships with ground truth. This experiment also validated surface parameterization methods for simulation models that describe surface processes from the scale of vegetation leaves up to scales appropriate to satellite remote sensing.

Brutsaert, Wilfried↗

NASA NTRS1991

A comparison of acceleration control and pulse control in simulated spacecraft docking maneuvers

Results are reported from a study designed to compare acceleration control with pulse control in simulated spacecraft docking maneuvers. Nine commercial airline pilots served as test subjects and the simulated remote dockings of an orbital maneuvering vehicle (OMV) to a space station were initiated from 50, 100, and 150 meters along the station's minus velocity vector. The trials were grouped into blocks of 18 consisting of six repetitions of the three ranges. It was found that mission duration was lower with pulse mode, while fuel consumption was lower with acceleration mode. It is suggested that this result is most likely specific to the thruster values that are being used.

Brody, Adam R.↗

NASA NTRS1991

Mach 3.5 boundary-layer transition on a cone at angle of attack

Boundary-layer transition on a sharp 5-deg half-angle cone at incidence was investigated at Mach 3.5 in NASA's Supersonic Low-Disturbance Pilot Tunnel. The tests were conducted with low and high levels of freestream acoustic disturbance, and four angles of attack (alpha/theta-c = 0, 0.12, 0.4, and 0.8). Transition data, obtained with and without significantly reduced freestream acoustic disturbance levels, are compared with conventional ('noisy') wind-tunnel data. It was found that, under quiet flow conditions, there was no significant unit Reynolds number effect, whereas with noisy flow conditions, a significant unit Reynolds number effect was measured on and near the windward ray for alpha/theta-c values 0.4 and 0.8.

King, Rudolph A.↗

NASA NTRS1991

Effect of short-term exposure to stereoscopic three-dimensional flight displays on real-world depth perception

High-fidelity color pictorial displays that incorporate depth cues in the display elements are currently available. Depth cuing applied to advanced head-down flight display concepts potentially enhances the pilot's situational awareness and improves task performance. Depth cues provided by stereopsis exhibit constraints that must be fully understood so depth cuing enhancements can be adequately realized and exploited. A fundamental issue (the goal of this investigation) is whether the use of head-down stereoscopic displays in flight applications degrade the real-world depth perception of pilots using such displays. Stereoacuity tests are used in this study as the measure of interest. Eight pilots flew repeated simulated landing approaches using both nonstereo and stereo 3-D head-down pathway-in-the-sky displays. At this decision height of each approach (where the pilot changes to an out-the-window view to obtain real-world visual references) the pilots changed to a stereoacuity test that used real objects. Statistical analysis of stereoacuity measures (data for a control condition of no exposure to any electronic flight display compared with data for changes from nonstereo and from stereo displays) reveals no significant differences for any of the conditions. Therefore, changing from short-term exposure to a head-down stereo display has no more effect on real-world relative depth perception than does changing from a nonstereo display. However, depth perception effects based on sized and distance judgements and on long-term exposure remain issues to be investigated.

Busquets, Anthony M.↗

NASA NTRS1992

Measurement of performance using acceleration control and pulse control in simulated spacecraft docking operations

Nine commercial airline pilots served as test subjects in a study to compare acceleration control with pulse control in simulated spacecraft maneuvers. Simulated remote dockings of an orbital maneuvering vehicle (OMV) to a space station were initiated from 50, 100, and 150 meters along the station's -V-bar (minus velocity vector). All unsuccessful missions were reflown. Five way mixed analysis of variance (ANOVA) with one between factor, first mode, and four within factors (mode, bloch, range, and trial) were performed on the data. Recorded performance measures included mission duration and fuel consumption along each of the three coordinate axes. Mission duration was lower with pulse mode, while delta V (fuel consumption) was lower with acceleration mode. Subjects used more fuel to travel faster with pulse mode than with acceleration mode. Mission duration, delta V, X delta V, Y delta V., and Z delta V all increased with range. Subjects commanded the OMV to 'fly' at faster rates from further distances. These higher average velocities were paid for with increased fuel consumption. Asymmetrical transfer was found in that the mode transitions could not be predicted solely from the mission duration main effect. More testing is advised to understand the manual control aspects of spaceflight maneuvers better.

Brody, Adam R.↗

NASA NTRS1992

ISDN at NASA Lewis Research Center

An expository investigation of the potential impact of the Integrated Services Digital Network (ISDN) at NASA Lewis Research Center is described. To properly frame the subject, the paper contains a detailed survey of the components of Narrowband ISDN. The principles and objectives are presented as decreed by the Consultative Committee for International Telephone and Telegraph (CCITT). The various channel types are delineated and their associated service combinations are described. The subscriber-access network functions are explained pictorially via the ISDN reference configuration. A section on switching techniques is presented to enable the reader to understand the emergence of the concept of fast packet switching. This new technology is designed to operate over the high bandwidth, low error rate transmission media that characterizes the LeRC environment. A brief introduction to the next generation of networks is covered with sections on Broadband ISDM (B-ISDN), Asynchronous Transfer Mode (ATM), and Synchronous Optical Networks (SONET). Applications at LeRC are presented, first in terms of targets of opportunity, then in light of compatibility constraints. In-place pilot projects and testing are described that demonstrate actual usage at LeRC.

Bakes, Catherine Murphy↗

NASA NTRS1958

Centrifugal simulation of the X-15

Paper presents the results of physiological tolerance tests of the pilot to the oscillating accelerations of large amplitude and long duration which might occur as a result of aircraft heading errors during reentries from the altitude mission in the X-15 without control augmentation.

Clark, Carl↗