AV-8B flight hazard awareness analysis and training using flight simulation

The V/STOL capability of the AV-8B Harrier is provided through a sophisticated combination of vectored thrust and aerodynamic technology. The proper interaction of the nozzle thrust and flap system is of extreme importance. Specific combinations of nozzle angle and flap position are employed to optimize both jet lift and aerodynamic lift. However, if the proper flap-nozzle position schedule is violated, the resulting thrust and flap impingement may cause a severe nose-down pitching moment sufficient to override the pilot control. Depending upon ground proximity, this condition creates a hazard which causes great potential for loss of aircraft and/or pilot. Flap impingement hazard was identified on the AV-8B aircraft as a potential catastrophic flight hazard. In response, a requirement was established to 1) study the severity of the flap impingement hazard on the AV-8B, 2) devise flight operational procedures which would minimize pilot exposure to the hazard potential and the resulting pilot control problems during flight, and 3) devise a training capability to familiarize pilots with flap impingement hazard characteristics and recovery procedures. This paper comprises the results of a study which utilized piloted flight simulation and fleet simulation trainers to meet these requirements.