Review and recommended experimental procedures for evaluation of Abrupt-Wing-Stall characteristics

A review of the experimental program for four different aircraft configurations conducted as part of the Abrupt Wing Stall Program has been made. Several candidate figures of merit from conventional static-tunnel tests are summarized and correlated with data obtained in unique free-to-roll tests. The conclusion from this study is that these figures of merit can by themselves give some indication as to whether an aircraft would experience uncommanded lateral activity caused by abrupt wing stall. However, no one specific figure of merit consistently flagged a warning of potential lateral activity when actual activity was seen to occur in the free-to-roll experiments. In fact, they yielded as many or more false indications of lateral activity then were seen in the free-to-roll response data. Excellent agreement between free-to-roll results and flight was obtained for those configurations where flight data were available.