Approaches and Vista On Flight Control Systems Reconfiguration - Motivating Example: Aircraft Control By Means Of Engine Thrust

Abstract

In this paper, we address the problem of the reconfiguration of flight control systems after subsystem or component failures. In the first part, typical approaches to diagnosing and handling failures of aircraft components will be discussed. The focus of this discussion will be the handling of faults by analytical redundancy. In addition, the role of the crew in dealing with faults and failures will be highlighted. In current cockpit congurations, the human-machine interaction in this context is reduced to the strict minimum and could be signicantly enhanced, providing higher resilience against malfunctions and supporting the crew in staying aware of the situation and the system state. The second part of the paper focuses on a specific reconfiguration case with the aim of showing how well a severe case can be handled with the appropriate flight control software. The scenario of this motivating example is based on the loss of all hydraulic systems, which leads to the impossibility to use the control surfaces to control the aircraft. In this case, the airplane can only be controlled by means of variations of thrust. In a previous publication a propulsion-based control law was presented with flight test results. In this paper an autoland functionality implemented on top of this control law is presented and its behavior in the presence of wind shears is evaluated using Monte Carlo simulations. The fault detection is not addressed for this example, because a failure of all primary control systems is trivial to diagnose.