Limited flight test experience with a laser transit velocimeter

Limited flight testing of a laser transit velocimeter provided insight into the problems associated with the use of such instruments for flight research. Although the device tested was not designed for flight application, it had certain features such as fiber optics and low laser power which are attractive in the airborne environment. During these tests, operation of the velocimeter was limited by insufficient concentrations of light-scattering particles and background light interference. Normal operation was observed when these conditions were corrected by utilizing cloud particles and flying at night. A comparison between the laser flow velocity measurements and corresponding pressure measurements is presented and shows a coarse correlation. Statistical bias due to turbulence in the flow is suspected to have affected the laser measurements

Utilization of the wing-body aerodynamic analysis program

The analysis program was used to investigate several aircraft characteristics. The studies performed included vehicle stability analysis, determination of upwash angle, identification of nonpotential flow, launch dynamics, and wake vortex upset loads. The techniques and are discussed. When possible, computed results are compared with experimental data

Electrorepulsive actuator

The invention is a linear actuator that operates under the principle that like charges repel and opposite charges attract. The linear actuator consists of first and second pairs of spaced opposed conductors where one member of each pair of conductors is attached to a fixed member, and where the other member of each pair of conductors is attached to a movable member such as an elongated rod. The two pairs of spaced conductors may be provided in the form of two spacedly interwound helical vanes where the conductors are located on the opposite sides of the two helical vanes. One helical vane extends inwardly from a housing and the other helical vane extends outwardly from an elongated rod. The elongated rod may be caused to move linearly with respect to the housing by applying appropriate charges of like or opposite polarity to the electrical conductors on the helical vanes

In-flight total forces, moments and static aeroelastic characteristics of an oblique-wing research airplane

A low-speed flight investigation has provided total force and moment coefficients and aeroelastic effects for the AD-1 oblique-wing research airplane. The results were interpreted and compared with predictions that were based on wind tunnel data. An assessment has been made of the aeroelastic wing bending design criteria. Lateral-directional trim requirements caused by asymmetry were determined. At angles of attack near stall, flow visualization indicated viscous flow separation and spanwise vortex flow. These effects were also apparent in the force and moment data

Flight-deck automation: Promises and problems

The state of the art in human factors in flight-deck automation is presented. A number of critical problem areas are identified and broad design guidelines are offered. Automation-related aircraft accidents and incidents are discussed as examples of human factors problems in automated flight

Silicon-based organic light-emitting diode operating at a wavelength of 1.5 mu m

Copyright 2000 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. This article appeared in Applied Physics Letters 77, 2271 (2000) and may be found at

Ground-effect analysis of a jet transport airplane

An analysis of the ground effect of a jet transport airplane has been made. Data were obtained from recent flight tests primarily using the constant angle-of-attack approach technique. Reasonable results were obtained for ground-effect pitching moment and lift increments. These were compared with data from other sources, including computations, wind tunnel, and previous flight test. A recommended ground-effect model was developed from the results. A brief simulator study was conducted to determine the sensitivity of a particular configuration to this ground-effect model and its associated uncertainty

Space shuttle orbiter leading-edge flight performance compared to design goals

Thermo-structural performance of the Space Shuttle orbiter Columbia's leading-edge structural subsystem for the first five (5) flights is compared with the design goals. Lessons learned from thse initial flights of the first reusable manned spacecraft are discussed in order to assess design maturity, deficiencies, and modifications required to rectify the design deficiencies. Flight data and post-flight inspections support the conclusion that the leading-edge structural subsystem hardware performance was outstanding for the initial five (5) flights

Display research, collision warning systems Final report

Display research for aircraft collision warning system

A Bayesian model for visual space perception

A model for visual space perception is proposed that contains desirable features in the theories of Gibson and Brunswik. This model is a Bayesian processor of proximal stimuli which contains three important elements: an internal model of the Markov process describing the knowledge of the distal world, the a priori distribution of the state of the Markov process, and an internal model relating state to proximal stimuli. The universality of the model is discussed and it is compared with signal detection theory models. Experimental results of Kinchla are used as a special case