Testing will consist of one week of ground checks, followed by two weeks of extensive flight testing, with 2 deployments per day, and 2 hours of uninterrupted flight per deployment. In-flight testing will primarily focus on handling-qualities assessment for various tasks, including capture and offset-to-landing tasks, as well as analyze the robustness margins of the L1 controller in terms of gain and time-delay margins. The main objective of the study is to investigate the ability of L1 adaptive control to maintain nominal aircraft handling qualities and prevent unfavorable aircraft-pilot interactions in the presence of aircraft failures (changes in the aerodynamics, loss of control effectiveness, coupling between control channels, shifts in the center of gravity, etc).
Testing will be led by the USAF Test Pilot School (TPS), and will use Calspan’s variable stability Learjet. This aircraft implements a variable stability system (VSS) that is able to emulate changes in aircraft aerodynamics through the use of feedback loops, which are opaque to the flight control law. A total of 16 VSS configurations will be tested, with various severity levels per configuration. The tests will be performed by F-16 and B-52 pilots. Over the past several months, the ACRL has been closely collaborating with Calspan to implement the L1 control law on the aircraft computers, and with the TPS to define the flight test plan.
These flight tests are a natural continuation of the tests performed by NASA Langley on the AirSTAR dynamically scaled Generic Transport Model research aircraft during 2009-2011 and the piloted simulation evaluations conducted by TUDelft on the SIMONA motion-based research simulator in 2011.