Masters Theses

Date of Award

5-1993

Degree Type

Thesis

Degree Name

Master of Science

Major

Aviation Systems

Major Professor

Ralph D. Kimberlin

Committee Members

U. Peter Solies, Frank G. Collins

Abstract

When countering next generation threats, American pilots will likely find themselves more frequently engaging in close-in combat scenarios which require superior agility at high angles-of-attack. This rapidly emerging requirement for supermaneuverability has prompted NASA to develop an F/A-18 High Alpha Research Vehicle equipped with a thrust vectoring control system. The research conducted herewith details key elements of the thrust vectoring control system; the research flight control system, the design and implementation of the thrust vectoring vane system, and the pilot-aircraft interface. The data gathered encompass NASA Langley cold-jet testing, computer simulations, over 139 test flights, pilot interviews, flight test engineer briefings, simulator flying, and concerted research of NASA and McDonnell Aircraft technical reports. This thesis culminates in a pilot oriented analysis of the thrust vectoring control system-its benefits, drawbacks, and future technological improvements. A series of recommendations are also made to improve pilot-aircraft synergy in the tactical aviation environment. The thrust vectoring control system implementation has resulted in substantial performance gains. Steady state flight at an angle-of-attack of 70 , and 360 stability axis rolls between angles-of-attack of 25° and 65° have been demonstrated. Improved pitch, roll, and yaw rates as well as diminished wing rock at angles-of-attack between 35° and 50° were also achieved. Inertial coupling feedbacks in the flight control system, however, were found to be inadequate in the longitudinal axis. Increased weight, aerodynamic drag, asymmetric vane positioning, and large axial thrust losses at maximum vectoring of the thrust vectoring control system also detracted from aircraft performance. While additional testing remains, thrust vectoring has demonstrated great utility in high performance jet aircraft. Its tactical significance will most likely effect changes in both close-in combat doctrine and aerodynamic design of future jet fighters.

Download
Files over 3MB may be slow to open. For best results, right-click and select "save as..."

Share

COinS