Adaptive Differential Thrust Methodology for Lateral/Directional Stability of an Aircraft with a Completely Damaged Vertical Stabilizer

TL;DR

This paper presents an adaptive differential thrust control method to restore lateral and directional stability in aircraft with a completely damaged vertical stabilizer, ensuring safe flight performance.

Contribution

It introduces a novel adaptive control approach that maps differential thrust to rudder input, enabling stability recovery without a vertical stabilizer.

Findings

Successful stabilization of damaged aircraft demonstrated

Robustness and uncertainty analyses confirm safety margins

Adaptive control maintains performance within desired limits

Abstract

This paper investigates the utilization of differential thrust to help a commercial aircraft with a damaged vertical stabilizer regain its lateral/directional stability. In the event of an aircraft losing its vertical stabilizer, the consequential loss of the lateral/directional stability and control is likely to cause a fatal crash. In this paper, an aircraft with a completely damaged vertical stabilizer is investigated, and a unique differential thrust based adaptive control approach is proposed to achieve a stable flight envelope. The propulsion dynamics of the aircraft is modeled as a system of differential equations with engine time constant and time delay terms to study the engine response time with respect to a differential thrust input. The proposed differential thrust control module is then presented to map the rudder input to differential thrust input. Model reference adaptive control based on the Lyapunov stability approach is implemented to test the ability of the damaged aircraft to track the model aircraft's (reference) response in an extreme scenario. Investigation results demonstrate successful application of such differential thrust approach to regain lateral/directional stability of a damaged aircraft with no vertical stabilizer. Finally, the conducted robustness and uncertainty analysis results conclude that the stability and performance of the damaged aircraft remain within desirable limits, and demonstrate a safe flight mission through the proposed adaptive control methodology.