CONVERGING ON A PRECISION HOVER CONTROL STRATEGY FOR THE F-35B STOVL AIRCRAFT

Past experimental trials for precision hover tasks have shown that a translational rate command system is the optimum control strategy for precise control and low pilot workload. Research efforts on the NASA VSTOL Systems Research Aircraft (VSRA) and the UK’s Vectored-thrust Aircraft Advanced Control (VAAC) Harrier have focused on X-Y control on a single pilot inceptor. Flight trials using the VAAC in 2007 have compared a traditional X-Y rate control on a common inceptor versus a radically new flight control strategy which splits velocity control over two inceptors. The flight trial was conducted to compare pilot ratings and performance in operationally representative hovering tasks. In order to elevate pilot gains and afford compelling visual cues for precision positioning tasks while maintaining safety, visual target boards were elevated to a height of 120ft AGL. A total of 5 evaluation pilots were used to compare alternative flight control strategies in both operationally representative and academic precision hover tasks. The results of these evaluations are presented along with lessons learned in the development and pilot evaluation of radically new control strategies.