In March of 2010 NASA Dryden Flight Research Center began flying its latest flight research platform. The F-18 Full-scale Advanced Systems Testbed vehicle or F-18 FAST. The concept was initially developed with the F-18 High Angle of Attack Research Vehicle or HARV. For the HARV project a new research flight control system computer was added to a standard F-18 system. This research system allows for quick development of experimental control laws while maintaining the production system as a safe fallback. By limiting the robust F-18 fighter to a restricted slow speed flight envelope special safety could be maintained. The original HARV research system was limited in compute power and memory The Advanced Aeroelastic Wing (AAW) project upgraded the research processor. The AAW project investigated the use wing warping to achieve rolling performance as a lighter-weight wing structure. The AAW program added a significant amount of load and wing deflection instrumentation to the vehicle. The same AAW aircraft was once again upgraded for the FAST project. A second research computer dubbed the Airborne Research Test System Four where yard score was added. The yard system allows for direct auto coating of control mount algorithms from an analysis friendly computer environment. This makes it much easier to analyze and modify experimental control laws. In addition to advanced controls research, the FAST system allows for stimulating system failures. These simulated failures prevent challenging problems for the advanced systems which are required to restore normal flying characteristics and allow for a safe landing. One example might be a frozen control surface. In this case the right stabilator was disabled, which results in an predictable cross couple behavior. Because pitch control authority is significantly reduced by the failure you can see the altitude loss that occurs during a roll maneuver. in the extreme case, all primary aerodynamic surfaces can be disabled and propulsion only control can be investigated. In this case the speed brake was deployed for additional control. Without the other aerodynamic
services and oscillation and disengagement occurred. but with an advanced controller good flying characteristics can be achieved using only engine propulsion. That was a good one. The FAST vehicle paves the way for many important flight research experiments. This system will be used to investigate integrated active control with structural feedback and constraints. The work will help to enable a class of futuristic lightweight vehicles that are not possible today. Using the F-18 FAST vehicle NASA Dryden Flight Research Center is continuing to push scientific advancement through flight exploration and discovery.