Thesis. 1975. M.S.--Massachusetts Institute of Technology. Dept. of Electrical Engineering and Computer Science. / Bibliography: leaves 258-259. / by Christopher S. Greene. / M.S.

Thesis: Sc. D., Massachusetts Institute of Technology. Department of Aeronautical Engineering, 1916. / MIT Institue Archives Thesis Coll.: copy is the Smithsoniam Institution publication. / Publication 2414. Hodgkins fund. Originaly prepared by Hunsaker as his Eng. D. Thesis, Massachusetts Institute of Technology, Dept. of Aeronautical Engineering, 1916. According to the MIT Registrar's Office, this degree was changed to an Sc.D., 1923 June 12. Original thesis did not contain the three plates. / by Jerome C. Hunsaker ... assisted by T. H. Huff, S. B., D. W. Douglas, S. B., H. K. Chow, S. M., and V. E. Clark. / Sc. D.

Modern, high performance aircraft are required to be able to fly and be controlled over a wide variety of flight conditions. In order to predict the aircraft behavior and control requirements over the entire flight regime it is necessary to have a proper aerodynamic model. Flight conditions at high angles of attack lead to separated flows making the aerodynamic model more difficult to obtain. In this research wind tunnel experiments are performed on an F-5 air-craft model at high angles of attack, with small oscillations about the body oriented roll axis. In addition the free stream environment can be configured in one of three ways: l) straight uniform flow, 2) curved flow to simulated a horizontal turn, and 3) rolling flow to simulated a roll motion about the relative Velocity vector. / Ph. D.

The object of this thesis is to determine the directional stability of a tricycle-geared aircraft during the landing roll. The motion of the aircraft is simulated by a computer program based on the appropriate equations of motion. Empirical aircraft and tire data are utilized in order to improve the simulation process. The stability of the aircraft is obtained by analyzing the motion of the vehicle after an initial disturbance about the vertical axis of the aircraft. The influence of the aircraft's velocity and other parameters on the stability is then determined. For the single-engine Cessna, the results show that a steady-state yaw angle is obtained after an initial disturbance. The results are presented graphically to show the effect of various parameters on the aircraft's stability. / Master of Science

This thesis presents the design of various controllers for a highly maneuverable, high performance aircraft, namely the modified F-18. The aircraft was required to perform high angle-of-attack maneuvers, for which the aircraft behaves in as a highly nonlinear system. An adaptive PID controller was used to control the aircraft through these high angle-of-attack maneuvers. Several nonlinear controllers were then developed based on the adaptive PID control, and were tested for robustness. This thesis also looks at an improvement in the aircraft which may improve performance in high angle-of-attack maneuvers. The contributions of this thesis are in the areas of control, in general, and specifically in the area of aircraft control. Successful application of linear adaptive control and nonlinear control were presented. In the area of aircraft control, controllers were presented which produce good performance for high angle-of-attack maneuvers, while maintaining implementability. Also, some insight is gained into what aircraft changes could improve performance. / Graduation date: 1995