Use of In-Flight Simulation to Create a Flying Qualities Database

Abstract

Even with the ever expanding capabilities of ground-based simulators, there is no substitute for flight test, particularly when evaluating aircraft flying qualities. For decades now, in-flight simulators have been used for just this reason. In fact, most of the requirements found in the current version of the military fixed wing aircraft flying qualities specification were derived from data collected on just two airplanes – the variable stability NT-33A and the Total In-Flight Simulator (TIFS). TIFS is still in operation, but the NT-33A has been retired to the Air Force Museum at Wright-Patterson AFB for nearly a decade. Today, the fleet of Learjet in-flight simulators operated by Calspan Corporation is routinely used to provide access to the advantages associated with actual flight. As part of an ongoing research program for the Air Force, Systems Technology, Inc. and Calspan created a flying qualities database that is being used to develop and evaluate new system identification techniques. This paper first describes the capabilities of the Learjet in-flight simulators. Then, a description of the recent flight test program is given including; the aircraft configuration model setup process, the test techniques used in flight, the resulting flying qualities database, and example system identification results.