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Stough, H. P.

Publications and source records attributed to Stough, H. P..

Investigation Into The Needs of Part 135 Operators to Access Airports Restricted Under FAR Part 135 Sections 135.213, 135.219 and/or 135.225

NASA and the FAA have joint interests and responsibilities for developing guidelines and standards for cockpit displays of Flight Information Services (FIS) information and for developing enhancements to the planned FAA Data Link (FISDL) services. NASA and the FAA have established responsibilities in connection with development tasks for enhancements to the FISDL project. This report is the result of NASA Task 2, "Weather Support Concept- Part 135 Operations." The objective of the task was to determine the needs of Part 135 operators as they relate to FAA Part 135 Sections 135.213, 135.219 and 135.225, which pertain to weather reporting requirements at destination airports. This report discusses the results of two questionnaires completed by volunteer Part 135 operators that questioned their operations, their needs for flying to airports without weather reporting compatibilities, and suggestions for modifying FARs 135.213, 135.219 and 135.225. The operators pointed out airports in areas of the CONUS that were needed for IFR operations but lacked weather reporting capabilities and they offered practical suggestions for changes to the FARs. Related to operators's needs, and discussed in this report, were the Fractional Ownership NPRM and the possible impact of GPS WAAS and LAAS approaches.

Eckert, Clifford A.↗

An Investigation Into Criteria Commonly Used by the FAA to Grant Relief to Part 135 Operators Under FAR Sections: 135.213, 135.219, and/or 135.225

The objective of this study was to determine the criteria commonly used by the FAA to grant waivers, exemptions, or deviations to FAR Part 135, Sections 135.213, 135.219, and 135.225 and the potential impact on Flight Information Services Data Link (FISDL) implementation. These aviation regulations address the requirements for the use of weather reports or forecasts when conducting operations under FAR Part 135. In this study a literature search was conducted to obtain historical records of requests for relief from the 3 FAR sections under consideration. The exemption request records were then analyzed in order to determine the reasons given by the FAA for either granting or denying the request. In addition, FAA personnel and Part 135 operators were interviewed to determine the procedures used for satisfying the requirements of the 3 FAR sections.

Williams, Louis J.↗

Estimating The Rate of Technology Adoption for Cockpit Weather Information Systems

In February 1997, President Clinton announced a national goal to reduce the weather related fatal accident rate for aviation by 80% in ten years. To support that goal, NASA established an Aviation Weather Information Distribution and Presentation Project to develop technologies that will provide timely and intuitive information to pilots, dispatchers, and air traffic controllers. This information should enable the detection and avoidance of atmospheric hazards and support an improvement in the fatal accident rate related to weather. A critical issue in the success of NASA's weather information program is the rate at which the market place will adopt this new weather information technology. This paper examines that question by developing estimated adoption curves for weather information systems in five critical aviation segments: commercial, commuter, business, general aviation, and rotorcraft. The paper begins with development of general product descriptions. Using this data, key adopters are surveyed and estimates of adoption rates are obtained. These estimates are regressed to develop adoption curves and equations for weather related information systems. The paper demonstrates the use of adoption rate curves in product development and research planning to improve managerial decision processes and resource allocation.

Kauffmann, Paul↗

Use of a discontinuous wing leading-edge modification to enhance spin resistance for general aviation airplanes

Spin resistance of two typical general aviation airplanes has been studied. Improvement in spin resistance due to an outboard wing leading-edge modification was evaluated through wind-tunnel and flight tests. The basic airplanes would readily enter a spin; however, with the wing modification the airplanes were highly spin resistant. Spin resistance has been related to the angle of attack of the outer wing panel and the yaw rate as a step toward development of guidelines for design of more spin resistant airplanes.

Dicarlo, D. J.↗

Wing modification for increased spin resistance

A simple wing leading-edge modification has been developed that delays outer wing panel stall, thus maintaining roll damping to higher angles of attack and delaying the onset of autorotation. The stall angle of attack of the outer wing panel has been shown to be a function of the spanwise length of the leading-edge modification. The margin of spin resistance provided by the modification is being explored through flight tests. Preliminary results have been used to evaluate spin resistance in terms of the difference in angle of attack between outer wing panel stall and the maximum attainable angle of attack.

Stough, H. P.↗

Trailing anemometer for low airspeed calibration

A propeller-type trailing airspeed anemometer system is described for low airspeed (M not exceeding 0.2) calibration which has improved accuracy and is easy to implement as compared to most methods currently in use. The trailing anemometer system consists of the trailing anemometer itself, a deployment mechanism, and an operator's control box. The trailing anemometer is a small low-drag brass body provided with tail fins for self-alignment with the airstream. The rotational speed of a small six-bladed low-inertia propeller is sensed with a miniature self-generating tachometer inside the anemometer. A very satisfactory airspeed calibration can be made with this device in which true airspeed can be measured to within 1 knot. Results from flight calibration of an aircraft and trail-back characteristics of the anemometer and cable are included. The operating speed range of the designed cable-anemometer combination is 7 to 165 knots.

Fisher, B. D.↗