Taxonomy of Aircraft Ground Modal Behaviour: A Brief Report

Abstract

This paper summarises the work undertaken in the developmerrt of a new computer-aided facility for flight simulator modelling and validation. Flight simulators may look like the real aeroplane but they fail to fly like the real aeroplane [Booth 1993]. Simulator systems management, procedures and instruments training are effective and transferable but they do not prepare the pilot for the dangerous on or near-the-ground scenarios. There is a belief that better results can be obtained by subjectively checking each flying mode and manoeuvre individually. When one manoeuvre is adjusted to satisfaction all the others are checked and retuned. Iteratively checking each training manoeuvre or flying mode is time-consuming and error-prone. What is needed is a conclusive one shot method of simulator flying quality validation that ensures accuracy without resort to trial and error methods. The landing or on-the-ground situation is much worse. This is due to the paucity of low level data and the difficulty of accurately deriving the root equations that describe the landing and bounce transition from 'soft' aerodynamics to 'stiff' undercarriage dynamics. The computer model is written in ACSL/ FORTRAN and can provide both time histories and eigen patterns.