Integrated Approach to Assessment of Transonic Abrupt Wing Stall for Advanced Aircraft

Abrupt wing stall at transonic flight conditions can result in uncommanded rolling motions that have historically degraded flying qualities, compromised mission performance, and reduced safety of flight for a variety of aircraft. Recently, a U.S. government research program, the Abrupt Wing Stall Program, has advanced the state of the art in detection of abrupt wing stall through computational fluid dynamics, experimental aerodynamics, and flight dynamics. It is therefore essential that these tools be combined into an integrated approach that not only provides for the identification of abrupt wing stall, but also allows for the resulting flight characteristics to be assessed and the risks to the aircraft program be mitigated. The primary means of assessing the flying qualities impacts of transonic abrupt wing stall is through the construction of an aircraft math model that can accurately characterize the dynamic response to abrupt stall. The primary means of mitigating program risks is through the inclusion of free-to-roll wind-tunnel testing in the acquisition plan. Recommendations for assessing transonic abrupt wing stall are presented for the aircraft designer and for the program manager.