Verification of a Flying Wing Handling Qualities Analysis by means of In-Flight Simulation

Abstract

The assurance of appropriate handling qualities represents a critical aspect for the development of a flying wing. This paper presents an analysis and evaluation of the handling qualities of a flying wing configuration for 750 passengers. Its flying qualities are evaluated by applying analytical handing qualities criteria. These criteria are however developed for conventional airplanes and imply that the longitudinal and lateral motion of the aircraft can approximately be considered as separate motions. As the considered flying wing configuration does not fulfill the prerequisite of an approximately decoupled lateral and longitudinal motion the applicability of the analytical criteria is not guaranteed and the additional evaluation of the handling qualities by pilots is absolutely required for such an aircraft. For this purpose an in-flight simulation is carried out with the DLR research aircraft ATTAS which is able to simulate other airplane configurations during flight. It allows analyzing the flight dynamics of the flying wing under real flight conditions and an evaluation of its handling qualities by test pilots. The flight tests are performed with the original baseline-configuration of the flying wing and a modified configuration with active control which is examined to evaluate the potential of flight control augmentation to improve the handling qualities. The maneuvers of the flight tests focus on the examination of the dynamics of the flying wing during turns. Thanks to the means of in-flight simulation it is possible to evaluate the unusual coupling of the lateral and longitudinal motion of the aircraft. The analyses permit to point out some major deficiencies in the handling qualities of the considered flying wing.