AFRL Assists Northrop Grumman With Supersonic Tailless Air Vehicle Tests Published June 4, 2007 By Air Vehicles Directorate AFRL/VA WRIGHT-PATTERSON AIR FORCE BASE, Ohio -- AFRL provided a full-motion flight simulation environment to test candidate control systems for Northrop Grumman's Supersonic Tailless Air Vehicle (STAV) concept. The testing, conducted in the lab's Large-Amplitude Multimode Aerospace Research Simulator (LAMARS), incorporated design improvements based on new wind tunnel data and reflecting two additional controllers, ground effects, and modified landing gear. Throughout the testing, three Northrop Grumman test pilots evaluated aircraft performance during takeoff, landing, and subsonic and supersonic tracking tasks. The pilots used the Cooper-Harper rating scale, a method that assigns quantitative scores according to desired and adequate performance criteria, to evaluate aircraft handling qualities. Compared to the results of earlier tests performed in May 2006, the aircraft's tracking and landing tasks received significantly higher ratings, due primarily to the incorporated design modifications. The study allowed Northrop Grumman engineers to collect data on over 100 different parameters throughout more than 300 tests runs. They were also able to observe the effects of auto-throttle on the STAV concept. This evaluation and data collection effort will facilitate further improvements to the concept. Once Northrop Grumman has incorporated the necessary design modifications, the research team plans to return to AFRL's LAMARS facility for additional testing. The STAV concept entails an effort to reduce the weight and drag encountered in traditional supersonic aircraft designs. This reduction is achievable by eliminating the tail and replacing conventional tail control surfaces with more innovative control effectors.