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Hewes, D. E.

Publications and source records attributed to Hewes, D. E..

At least 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1980

Electrofluidic accelerometer

Electrofluidic accelerometer senses components of linear and angular acceleration field. Typical application of such acceleration is as active controlling element in airplane autopilot. In contrast to conventional accelerometers, electrofluidic accelerometer is lightweight, small, inexpensive, rugged, and requires little power. It consists of two temperature sensors on opposite sides of heating element. Sensors detect temperature gradient created by acceleration field on fluid; when device is accelerated, gradient changes because of bouyant force on hotter (thus lighter) portion of fluid.

Hewes, D. E.↗
NASA NTRS1978

Development of a nonlinear switching function and its application to static lift characteristics of straight wings

A mathematical modeling technique was developed for the lift characteristics of straight wings throughout a very wide angle of attack range. The technique employs a mathematical switching function that facilitates the representation of the nonlinear aerodynamic characteristics in the partially and fully stalled regions and permits matching empirical data within + or - 4 percent of maximum values. Although specifically developed for use in modeling the lift characteristics, the technique appears to have other applications in both aerodynamic and nonaerodynamic fields.

Hewes, D. E.↗
NASA NTRS1975

The foot-controlled maneuvering unit: Summary report on Skylab experiment T-020

Skylab experiment T-020 was conducted to study the maneuvering capabilities of astronauts using a relatively simple experimental self-locomotive device, referred to as the foot-controlled maneuvering unit, and to evaluate the effectiveness of ground-based facilities simulating the operation of this device in weightless conditions of space. The final results as presented of this experiment which includes comparison of the tests performed during missions SL-3 and SL-4 of the Skylab with those performed on the simulators. Some of the results of this experiment and those of Skylab experiment M509, which employed an experimental hard-controlled maneuvering unit, are discussed in terms of the development of a possible future operational maneuvering system.

Hewes, D. E.↗
NASA NTRS1975

Gust alleviation system to improve ride comfort of light airplanes

System consists of movable auxiliary aerodynamic sensors mounted on fuselage and connected to trailing-edge flaps by rigid mechanical linkages. System achieves alleviation by reducing lift-curve slope of airplane to such a small value that gust-induced angles of attack will result in small changes in lift.

Stewart, E. C.↗
NASA NTRS1975

Premission and postmission simulation studies of the foot-controlled maneuvering unit for Skylab experiment T-020

A Skylab experiment was conducted to study the maneuvering capabilities of astronauts using a relatively simple self-locomotive device, referred to as the foot-controlled maneuvering unit, and to evaluate the effectiveness of ground-based facilities simulating the operation of this device in weightless conditions of space. Some of the special considerations given in the definition and development of the experiment as related to the two ground-based simulators are reviewed. These simulators were used to train the test subjects and to obtain baseline data which could be used for comparison with the in-flight tests that were performed inside the Skylab orbital workshop. The results of both premission and postmission tests are discussed, and subjective comparisons of the in-flight and ground-based test conditions are presented.

Hewes, D. E.↗
NASA NTRS1974

Skylab Experiment T020 preliminary results concerning a foot-controlled maneuvering unit

Skylab Experiment T020 was developed to study the performance capabilities of astronauts using a relatively simple device maneuvering in an actual zero gravity environment. The experimental test bed, used as the maneuvering unit, employed foot-operated controls for translation along only the vertical or head-to-foot axis and for rotation about all three axes. The control thrusters were operated by direct mechanical linkage to the foot controls, and no stabilization system was employed. The results showed that subjects could successfully perform a number of relatively simple maneuvers but had some difficulties with unplanned or unrehearsed maneuvers of a more complex nature. Precise maneuvering within the confines of the orbital workshop was limited primarily by an inadequate body-restraint harness system and by lack of translation capability along the other two axes.

Hewes, D. E.↗
NASA NTRS1974

Exploratory tests of a simple aero-mechanical ride comfort system for lightly loaded aircraft

Some exploratory wind tunnel and radio-controlled free-flight tests were made with a small high-wing airplane model (1.23m wing span) to study the concept of a simple aero mechanical system intended to alleviate gust loads and improve ride comfort of lightly loaded aircraft. The system consisted essentially of the outer portions of each wing being hinged in the chordwise direction and connected directly to the wing flaps using internal counter weights to provide neutral mass balance. When the wing experienced a change in velocity or angle of attack, the movable wing panels, acting as sensors and flap actuators, deflected in response to the changes in lift on the wing. The corresponding movements of the interconnected flaps tended to reduce the changes in the wing lift.

Hewes, D. E.↗
NASA NTRS1973

An exploratory simulation study of a head-up display for general aviation lightplanes

The concept of a simplified head-up display referred to as a landing-site indicator (LASI) for use in lightplanes is discussed. Results of a fixed-base simulation study exploring the feasibility of the LASI concept are presented in terms of measurements of pilot performance, control-activity parameters, and subjective comments of four test subjects. These subjects, all of whom had various degrees of piloting experience in this type aircraft, performed a series of simulated landings both with and without the LASI starting from different initial conditions in the final approach leg of the landing maneuver.

Harris, R. L., Sr.↗
NASA NTRS1972

Development of Skylab experiment T020 employing a foot controlled maneuvering unit

A review of the plans and preparations is presented for Skylab experiment T020, entitled Foot-Controlled Maneuvering Unit (FCMU). The FCMU is an experimental system intended to explore the use of simple astronaut maneuvering devices in the zero-gravity environment of space. This review also includes discussions of the FCMU concept and experiment hardware systems, as well as supporting experiment definition and development research studies conducted with the aid of zero-gravity simulators.

Hewes, D. E.↗