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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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NASA NTRS2001

Recent Events in Guidance, Navigation and Control

This article summarizes recent events in Guidance, Navigation, and Control (GN&C) in space, weapons and missiles, and aircraft. The section on space includes recent developments with the following NASA spacecraft and space vehicles: Near Earth Asteroid Rendezvous, Deep Space 1, Microwave Anisotropy Probe, Earth Observer-1, Compton Gamma Ray Observatory, the International Space Station, X-38, and X-40A. The section on weapons and missiles includes recent developments with the following missiles: Joint Air-to-Surface Standoff Missile, Storm Shadow/Scalp EG precision standoff missile, Hellfire missile, AIM-120C Advanced medium-range air-to-air missile, Derby missile, Arrow 2, and the Standard Missile SM-3. The section on aircraft includes recent developments with the following aircraft: Joint Strike Fighter, X-31, V-22, Couger/SUDer Puma Mk. 2, Predator B 001, and the Unmanned Combat Air Vehicle.

Polites, Michael E.↗
NASA NTRS1994

Aircraft ground vibration testing at the NASA Dryden Flight Research Facility, 1993

The NASA Dryden Flight Research Facility performs ground vibration testing to assess the structural characteristics of new and modified research vehicles. This paper updates the research activities, techniques used, and experiences in applying this technology to aircraft since 1987. Test equipment, data analysis methods, and test procedures used for typical test programs are discussed. The data presented illustrate the use of modal test and analysis in flight research programs for a variety of aircraft. This includes a technique to acquire control surface free-play measurements on the X-31 airplane more efficiently, and to assess the effects of structural modifications on the modal characteristics of an F-18 aircraft. In addition, the status and results from current research activities are presented. These data show the effectiveness of the discrete modal filter as a preprocessor to uncouple response measurements into simple single-degree-of-freedom responses, a database for the comparison of different excitation methods on a JetStar airplane, and the effect of heating on modal frequency and damping.

Kehoe, Michael W.↗
NASA NTRS1996

Modeling of Aircraft Unsteady Aerodynamic Characteristics/Part 3 - Parameters Estimated from Flight Data: Parameters Estimated from Flight Data - Part 3

A nonlinear least squares algorithm for aircraft parameter estimation from flight data was developed. The postulated model for the analysis represented longitudinal, short period motion of an aircraft. The corresponding aerodynamic model equations included indicial functions (unsteady terms) and conventional stability and control derivatives. The indicial functions were modeled as simple exponential functions. The estimation procedure was applied in five examples. Four of the examples used simulated and flight data from small amplitude maneuvers to the F-18 HARV and X-31A aircraft. In the fifth example a rapid, large amplitude maneuver of the X-31 drop model was analyzed. From data analysis of small amplitude maneuvers ft was found that the model with conventional stability and control derivatives was adequate. Also, parameter estimation from a rapid, large amplitude maneuver did not reveal any noticeable presence of unsteady aerodynamics.

Klein, Vladislav↗
NASA NTRS2014

Flying Beyond the Stall: The X-31 and the Advent of Supermaneuverability

This is the story of a unique research airplane-unique because the airplane and the programs that supported it did things that have never been done before or since. The major purpose of this book is to tell the story of NASA's role in the X-31 program. In order to do this, though, it is necessary to put NASA's participation in perspective with the other phases of the program, namely the genesis of the concept, the design and fabrication of the aircraft, the initial flight testing done without NASA participation, the flight testing done with NASA participation, and the subsequent Navy X-31 Vectoring ESTOL (extreme short takeoff and landings) Control Operation Research (VECTOR) program.

Joyce, Douglas A.↗
NASA NTRS2003

A Collection of Nonlinear Aircraft Simulations in MATLAB

Nonlinear six degree-of-freedom simulations for a variety of aircraft were created using MATLAB. Data for aircraft geometry, aerodynamic characteristics, mass / inertia properties, and engine characteristics were obtained from open literature publications documenting wind tunnel experiments and flight tests. Each nonlinear simulation was implemented within a common framework in MATLAB, and includes an interface with another commercially-available program to read pilot inputs and produce a three-dimensional (3-D) display of the simulated airplane motion. Aircraft simulations include the General Dynamics F-16 Fighting Falcon, Convair F-106B Delta Dart, Grumman F-14 Tomcat, McDonnell Douglas F-4 Phantom, NASA Langley Free-Flying Aircraft for Sub-scale Experimental Research (FASER), NASA HL-20 Lifting Body, NASA / DARPA X-31 Enhanced Fighter Maneuverability Demonstrator, and the Vought A-7 Corsair II. All nonlinear simulations and 3-D displays run in real time in response to pilot inputs, using contemporary desktop personal computer hardware. The simulations can also be run in batch mode. Each nonlinear simulation includes the full nonlinear dynamics of the bare airframe, with a scaled direct connection from pilot inputs to control surface deflections to provide adequate pilot control. Since all the nonlinear simulations are implemented entirely in MATLAB, user-defined control laws can be added in a straightforward fashion, and the simulations are portable across various computing platforms. Routines for trim, linearization, and numerical integration are included. The general nonlinear simulation framework and the specifics for each particular aircraft are documented.

Frederico R Garza↗
NASA NTRS1994

X-31 quasi-tailless flight demonstration

The primary objective of the quasi-tailless flight demonstration is to demonstrate the feasibility of using thrust vectoring for directional control of an unstable aircraft. By using this low-cost, low-risk approach it is possible to get information about required thrust vector control power and deflection rates from an inflight experiment as well as insight in low-power thrust vectoring issues. The quasi-tailless flight demonstration series with the X-31 began in March 1994. The demonstration flight condition was Mach 1.2 at 37,500 feet. A series of basic flying quality maneuvers, doublets, bank to bank rolls, and wind-up-turns have been performed with a simulated 100% vertical tail reduction. Flight test and supporting simulation demonstrated that the quasi-tailless approach is effective in representing the reduced stability of tailless configurations. The flights also demonstrated that thrust vectoring could be effectively used to stabilize a directionally unstable configuration and provide control power for maneuver coordination.

Huber, Peter↗
NASA NTRS1993

Aircraft digital flight control technical review

The Aircraft Digital Flight Control Technical Review was initiated by two pilot induced oscillation (PIO) incidents in the spring and summer of 1992. Maj. Gen. Franklin (PEO) wondered why the Air Force development process for digital flight control systems was not preventing PIO problems. Consequently, a technical review team was formed to examine the development process and determine why PIO problems continued to occur. The team was also to identify the 'best practices' used in the various programs. The charter of the team was to focus on the PIO problem, assess the current development process, and document the 'best practices.' The team reviewed all major USAF aircraft programs with digital flight controls, specifically, the F-15E, F-16C/D, F-22, F-111, C-17, and B-2. The team interviewed contractor, System Program Office (SPO), and Combined Test Force (CTF) personnel on these programs. The team also went to NAS Patuxent River to interview USN personnel about the F/A-18 program. The team also reviewed experimental USAF and NASA systems with digital flight control systems: X-29, X-31, F-15 STOL and Maneuver Technology Demonstrator (SMTD), and the Variable In-Flight Stability Test Aircraft (VISTA). The team also discussed the problem with other experts in the field including Ralph Smith and personnel from Calspan. The major conclusions and recommendations from the review are presented.

Davenport, Otha B.↗
NASA NTRS1995

Modeling of aircraft unsteady aerodynamic characteristics. Part 2: Parameters estimated from wind tunnel data

Aerodynamic equations with unsteady effects were formulated for an aircraft in one-degree-of-freedom, small-amplitude, harmonic motion. These equations were used as a model for aerodynamic parameter estimation from wind tunnel oscillatory data. The estimation algorithm was based on nonlinear least squares and was applied in three examples to the oscillatory data in pitch and roll of 70 deg triangular wing and an X-31 model, and in-sideslip oscillatory data of the High Incidence Research Model 2 (HIRM 2). All three examples indicated that a model using a simple indicial function can explain unsteady effects observed in measured data. The accuracy of the estimated parameters and model verification were strongly influenced by the number of data points with respect to the number of unknown parameters.

Klein, Vladislav↗
NASA NTRS1992

System overview of the NASA Dryden Integrated Test Facility

The Integrated Test Facility, built at the NASA Dryden Flight Research Facility, provides new real-time test capabilities for emerging research aircraft. An overview of the test facility and the real-time systems developed to operate this unique facility is presented. The facility will reduce flight test risk by minimizing the difference between the flight and ground test environments. This ground test environment is provided by combining real-time flight simulation with the actual aircraft. A brief introduction to the facility is followed by a discussion of the generic capabilities of its real-time systems. The simulation system with flight hardware and the remotely augmented vehicle system is described. An overview of many hardware systems developed for the facility follows. The benefits of applying simulation to hardware-in-the-loop testing on the X-31 Flight Research Program are presented.

Binkley, Robert L.↗
NASA NTRS1992

Aerodynamic parameters of the X-31 drop model estimated from flight-data at high angles of attack

Lateral aerodynamic parameters of the X-31 drop model were estimated from flight data at angles of attack between 25 deg and 45 deg. Partitioned data from an ensemble of 12 maneuvers and data from 13 single maneuvers were analyzed by a stepwise regression technique to obtain an aerodynamic model structure and least squares parameter estimates. Because of data collinearity in several maneuvers, these maneuvers were reanalyzed by two biased estimation techniques, mixed estimation and fractional rank regression. The final parameter estimates in the form of stability and control derivatives were plotted against the angle of attack and compared with wind tunnel results and a limited number of estimates from full-scale aircraft data. There was no significant disagreement between parameters from the two sets of drop model data and the full-scale aircraft data. Some differences, however, existed between the dihedral, damping-in-roll, and aileron-effectiveness parameters from flight and wind tunnel data.

Klein, Vladislav↗
NASA NTRS1998

Joint Institute for Advancement of Flight Sciences

The program objectives were defined in the original proposal entitled "Program of Research in Flight Dynamics in the JIAFS at NASA Langley Research Center" which was originated March 20, 1975, and in yearly renewals of the research program dated December 1, 1979 to December 1, 1998. The program included three major topics: 1) Improvement of existing methods and development of new methods for flight and wind tunnel data analysis based on system identification methodology. 2) Application of these methods to flight and wind tunnel data obtained from advanced aircraft. 3) Modeling and control of aircraft, space structures and spacecraft. The principal investigator of the program was Dr. Vladislav Klein, Professor at The George Washington University, Washington, D.C.. Thirty-seven Graduate Research Scholar Assistants, two of them doctoral students, also participated in the program. The results of the research conducted during nineteen years of the total co-operative period were published in 23 NASA technical reports, 2 D.Sc. Dissertations, 14 M.S. Theses and 33 papers. The list of these publications is included. The results were also reported in more than 30 seminar lectures presented at various research establishments world-wide. For contributions to the research supported by the co-operative agreement, three NASA Awards were received: 1) NASA LARC Group Achievement Award, May 30, 1990, to Dr. V. Klein as a member of the X-29 Drop Model Team. 2) NASA Medal for Exceptional Engineering Achievement, March 27, 1992, to Dr. V. Klein for innovative contributions in the development of advanced techniques and computer programs in the field of system identification. 3) NASA LaRC Team Excellence Award, May 7, 1994, to Dr. V. Klein as a member of the X-31 Drop Model Team.

Source record↗
NASA NTRS2007

Six Decades of Flight Research: An Annotated Bibliography of Technical Publications of NASA Dryden Flight Research Center, 1946-2006

Titles, authors, report numbers, and abstracts are given for nearly 2900 unclassified and unrestricted technical reports and papers published from September 1946 to December 2006 by the NASA Dryden Flight Research Center and its predecessor organizations. These technical reports and papers describe and give the results of 60 years of flight research performed by the NACA and NASA, from the X-1 and other early X-airplanes, to the X-15, Space Shuttle, X-29 Forward Swept Wing, X-31, and X-43 aircraft. Some of the other research airplanes tested were the D-558, phase 1 and 2; M-2, HL-10 and X-24 lifting bodies; Digital Fly-By-Wire and Supercritical Wing F-8; XB-70; YF-12; AFTI F-111 TACT and MAW; F-15 HiDEC; F-18 High Alpha Research Vehicle, F-18 Systems Research Aircraft and the NASA Landing Systems Research aircraft. The citations of reports and papers are listed in chronological order, with author and aircraft indices. In addition, in the appendices, citations of 270 contractor reports, more than 200 UCLA Flight System Research Center reports, nearly 200 Tech Briefs, 30 Dryden Historical Publications, and over 30 videotapes are included.

Fisher, David F.↗