Predicting Wing Drop in the Harrier II Using the Static Wind Tunnel Test and Analysis Technique CBSTAT

Abstract

A sta tic wind tunnel test and analysis technique (CBSTAT) developed during the System Development and Demonstration (SDD) Phase of the F-35 Joint Strike Fighter (JSF) Program identified a figure of merit with the potential to predict in -flight wing drop. To eva luate the effectiveness of the CBSTAT technique, it was necessary to wind tunnel test aircraf t with known in -flight wing drop . An opportunity arose to apply this technique on a Harrier II (GRMk.7/AV -8B) 1/7.5 scale model, at the ARA Transonic Wind Tunnel i n Bedford, England. Data was collected over a variety of conditions and configurations capturing known in -flight wing drops. Correlating the method’s results to flight test data verified the ability of this technique to confidently predict Harrier wing dro p. The CBSTAT results also showed good correlation to the Free to Roll Figure of Merit (FTR FOM), developed by the NASA/Navy/Air Force Abrupt Wing Stall (AWS) Program Team . Additionally, further insight was gained into the data collection and conditioning required to gain best advantage of this technique.