PATH-ATTITUDE INCONSONANCE IN HIGH SPEED FLIGHT AND RELATED PATH CONTROL ISSUES

This paper presents results of a joint research effort of NASA Dryden Flight Research Center and the Institute of Flight Mechanics and Flight Control of Technische Universitat Munchen on longitudinal flight dynamics at hypersonic speeds. At high speeds a large time lag between pitch attitude and flight path angle exists. The mechanisms which cause this path-attitude decoupling are described. It will be shown further that an limiting effect exists. An “aggressive stick” piloting technique to avoid the shortcomings of the path-attitude lag is described. This type of control is also effective to stabilize phugoid. The simulation facility of Dryden Flight Research Center which was used in the evaluation is described. Simulation results concerning the effect of path-attitude lag on “aggressive stick” technique, of time delay and scaling of vertical speed information are presented. Furthermore results of flight tests with SR-71 and Tu-144 at high supersonic speeds for similar topics are presented.

[1]  G Sachs.  Path-attitude decoupling and flying qualities implications in hypersonic flight , 1998 .

[2]  R. C. Blanchard,et al.  Shuttle high resolution accelerometer package experiment results - Atmospheric density measurements between 60 and 160 km , 1989 .

[3]  David H. Klyde,et al.  Influence of path-altitude lag in hypersonic flying qualities , 1995 .

[4]  Timothy H. Cox,et al.  Evaluation of High-Speed Civil Transport Handling Qualities Criteria With Supersonic Flight Data , 1997 .

[5]  George E. Cooper,et al.  Handling qualities and pilot evaluation , 1986 .

[6]  Duane McRuer,et al.  Design and Modeling Issues for Integrated Airframe/Propulsion Control of Hypersonic Flight Vehicles , 1991, 1991 American Control Conference.

[7]  A. Knoll,et al.  Simulations- und Flugversuche über Flugeigenschaften von Hyperschall-Flugzeugen , 1995 .

[8]  Gottfried Sachs.  Increase and Limit of T in Super- and Hypersonic Flight , 1999 .

[9]  Daniel J. Biezad,et al.  Direct-Lift Design Strategy for Longitudinal Control of Hypersonic Aircraft , 1994 .

[10]  David K. Schmidt.  Optimum Mission Performance and Multivariable Flight Guidance for Airbreathing Launch Vehicles , 1997 .

[11]  H. Grallert.  Synthesis of a FESTIP air-breathing TSTO space transportation system , 1999 .

[12]  Siva S. Banda,et al.  Resurrection in hypersonics - Why, what and when , 1999 .

[13]  John Hodgkinson,et al.  Aircraft Handling Qualities , 1999 .

[14]  R. Stich,et al.  Path-attitude decoupling problems of aerospace craft , 1999 .

[15]  Hirofumi Taniguchi,et al.  Concept study on winged vehicle , 1999 .