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 319 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 315 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 308 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

Least squares best fit method for the three parameter Weibull distribution : analysis of tensile and bend specimens with volume or surface flaw failure by Bernard Gross( )

4 editions published in 1996 in English and held by 304 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( )

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

Biomechanically induced and controller coupled oscillations experienced on the F-16XL aircraft during rolling maneuvers by J. W Smith( )

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

During rapid rolling maneuvers, the F-16 XL aircraft exhibits a 2.5 Hz lightly damped roll oscillation, perceived and described as “roll ratcheting.” This phenomenon is common with fly-by-wire control systems, particularly when primary control is derived through a pedestal-mounted sidearm controller. Analytical studies have been conducted to model the nature of the integrated control characteristics. The analytical results complement the flight observations. A three-degree-of-freedom linearized set of aerodynamic matrices was assembled to simulate the aircraft plant. The lateral-directional control system was modeled as a linear system. A combination of two second-order transfer functions was derived to couple the lateral acceleration feedthrough effect of the operator's arm and controller to the roll stick force input. From the combined systems, open-loop frequency responses and a time history were derived, describing and predicting an analogous in-flight situation. This report describes the primary control, aircraft angular rate, and position time responses of the F-16 XL-2 aircraft during subsonic and high-dynamic-pressure rolling maneuvers. The analytical description of the pilot's arm and controller can be applied to other aircraft or simulations to assess roll ratcheting susceptibility

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

4 editions published in 1993 in English and held by 303 WorldCat member libraries worldwide

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

3 editions published in 1996 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( )

2 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

A gas chromatograph/mass spectrometer system for ultralow-emission combustor exhaust studies by Chowen Chou Wey( )

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