Development of a Dynamically Scaled Generic Transport Model Testbed for Flight Research Experiments

This paper details the design and development of the Airborne Subscale Transport Aircraft Research (AirSTAR) test-bed at NASA Langley Research Center (LaRC). The aircraft is a 5.5% dynamically scaled, remotely piloted, twin-turbine, swept wing, Generic Transport Model (GTM) which will be used to provide an experimental flight test capability for research experiments pertaining to dynamics modeling and control beyond the normal flight envelope. The unique design challenges arising from the dimensional, weight, dynamic (inertial), and actuator scaling requirements necessitated by the research community are described along with the specific telemetry and control issues associated with a remotely piloted subscale research aircraft. Development of the necessary operational infrastructure, including operational and safety procedures, test site identification, and research pilots is also discussed. The GTM is a unique vehicle that provides significant research capacity due to its scaling, data gathering, and control characteristics. By combining data from this testbed with full-scale flight and accident data, wind tunnel data, and simulation results, NASA will advance and validate control upset prevention and recovery technologies for transport aircraft, thereby reducing vehicle loss-of-control accidents resulting from adverse and upset conditions. 1.0 Introduction The NASA Aviation Safety and Security Program (AvSSP) was established to develop technologies for improved safety and security of commercial transport aircraft. The Single Aircraft Accident Prevention (SAAP) Project of the AvSSP focuses on the development of technologies to reduce aircraft accidents resulting from loss of vehicle control (or upset) as well as failures. According to the National Transportation Safety Board's accident database, 40% of all commercial aviation fatalities from 1990 – 1996 were due to loss of control. Control Upset Prevention & Recovery (CUPR) technologies being developed under SAAP provide control under adverse flight conditions in order to accommodate failures, prevent loss of control, and recover control during loss-of-control events. Technologies being developed include enhanced models of vehicle dynamics to characterize upset conditions, failure detection and identification (FDI) algorithms, and adaptive guidance and control (G&C) laws. The upset dynamics models have been developed for integration into an enhanced aircraft simulation that is being created for improved upset recovery training, and to support the development and evaluation of the FDI and G&C algorithms. These algorithms are being developed for use onboard transport aircraft for improved situational awareness and control under adverse and upset conditions related to loss-of-control events. Validation of these technologies is therefore critical. The AirSTAR testbed is being developed to provide an in-flight validation capability for high risk flight testing of these AvSSP technologies. To accomplish this, researchers at