United States National Aeronautics and Space Administration Scientific and Technical Information Program

Probabilistic micromechanics and macromechanics for ceramic matrix composites by P. L. N Murthy( )

3 editions published in 1997 in English and held by 318 WorldCat member libraries worldwide

Issues in NASA program and project management by Francis T Hoban( Book )

4 editions published between 1991 and 1993 in English and held by 317 WorldCat member libraries worldwide

Supersonic flying qualities experience using the SR-71 by Timothy H Cox( )

6 editions published in 1997 in English and held by 307 WorldCat member libraries worldwide

Approximately 25 years ago NASA Dryden Flight Research Center, Edwards, California, initiated the evaluation of supersonic handling qualities issues using the XB-70 and the YF-12. Comparison of pilot comments and ratings with some of the classical handling qualities criteria for transport aircraft provided information on the usefulness of these criteria and insight into supersonic flying qualities issues. A second research study has recently been completed which again addressed supersonic flying qualities issues through evaluations of the SR-71 in flight at Mach 3. Additional insight into supersonic flying qualities issues was obtained through pilot ratings and comments. These ratings were compared with existing military specifications and proposed criteria for the High Speed Civil Transport. This paper investigates the disparity between pilot comments and the Neal/Smith criteria through a modification of the technique using vertical speed at the pilot station. The paper specifically addresses the pilot ability to control flightpath and pitch attitude in supersonic flight and pilot displays typical of supersonic maneuvering

Output data formatter for the Electronically Scanned Thinned Array Radiometer (ESTAR) instrument by William A Chren( )

5 editions published in 1993 in English and held by 305 WorldCat member libraries worldwide

In-flight flow visualization results from the X-29A aircraft at high angles of attack by John H Del Frate( )

5 editions published in 1992 in English and held by 304 WorldCat member libraries worldwide

Flow visualization techniques were used on the X-29A aircraft at high angles of attack to study the vortical flow off the forebody and the surface flow on the wing and tail. The forebody vortex system was studied because asymmetries in the vortex system were suspected of inducing uncommanded yawing moments at zero sideslip. Smoke enabled visualization of the vortex system and correlation of its orientation with flight yawing moment data. Good agreement was found between vortex system asymmetries and the occurrence of yawing moments. Surface flow on the forward-swept wing of the X-29A was studied using tufts and flow cones. As angle of attack increased, separated flow initiated at the root and spread outboard encompassing the full wing by 30º angle of attack. In general, the progression of the separated flow correlated well with subscale model lift data. Surface flow on the vertical tail was also studied using tufts and flow cones. As angle of attack increased, separated flow was observed to start at the root and spread upward. The area of separated flow on the vertical tail at angles of attack >20° correlated well with the marked decrease in aircraft directional stability

Commercial non-aerospace technology transfer program for the 2000s by Gary A. P Horsham( )

4 editions published in 1992 in English and held by 303 WorldCat member libraries worldwide

Flight test of a propulsion-based emergency control system on the MD-11 airplane with emphasis on the lateral axis by John J Burken( )

4 editions published in 1996 in English and held by 303 WorldCat member libraries worldwide

A large, civilian, multiengine transport MD-11 airplane control system was recently modified to perform as an emergency backup controller using engine thrust only. The emergency backup system, referred to as the propulsion-controlled aircraft (PCA) system, would be used if a major primary flight control system fails. To allow for longitudinal and lateral-directional control, the PCA system requires at least two engines and is implemented through software modifications. A flight-test program was conducted to evaluate the PCA system high-altitude flying characteristics and to demonstrate its capacity to perform safe landings. The cruise flight conditions, several low approaches and one landing without any aerodynamic flight control surface movement, were demonstrated. This paper presents results that show satisfactory performance of the PCA system in the longitudinal axis. Test results indicate that the lateral-directional axis of the system performed well at high altitude but was sluggish and prone to thermal upsets during landing approaches. Flight-test experiences and test techniques are also discussed with emphasis on the lateral-directional axis because of the difficulties encountered in flight test

Structural dynamic model obtained from flight use with piloted simulation and handling qualities analysis by Bruce G Powers( )

4 editions published in 1996 in English and held by 303 WorldCat member libraries worldwide

A model for Space Shuttle orbiter tire side forces based on NASA Landing Systems Research Aircraft test results by John F Carter( )

3 editions published in 1997 in English and held by 303 WorldCat member libraries worldwide

Development and flight test of an augmented thrust-only flight control system on an MD-11 transport airplane by Frank W Burcham( )

3 editions published in 1996 in English and held by 303 WorldCat member libraries worldwide

An emergency flight control system using only engine thrust, called Propulsion-Controlled Aircraft (PCA), has been developed and flight tested on an MD-11 airplane. In this thrust-only control system, pilot flightpath and track commands and aircraft feedback parameters are used to control the throttles. The PCA system was installed on the MD-11 airplane using software modifications to existing computers. Flight test results show that the PCA system can be used to fly to an airport and safely land a transport airplane with an inoperative flight control system. In up-and-away operation, the PCA system served as an acceptable autopilot capable of extended flight over a range of speeds and altitudes. The PCA approaches, go-arounds, and three landings without the use of any normal flight controls have been demonstrated, including instrument landing system-coupled hands-off landings. The PCA operation was used to recover from an upset condition. In addition, PCA was tested at altitude with all three hydraulic systems turned off. This paper reviews the principles of throttles-only flight control; describes the MD-11 airplane and systems; and discusses PCA system development, operation, flight testing, and pilot comments