Attitude Indicator Design and Reference Frame Effects on Unusual Attitude Recoveries

The objectives of this study were to examine the combination effects of the attitude directional indicator (ADI) formats and the 2 reference frames (moving horizon [MH] and moving aircraft [MA]) on unusual attitude recovery performance. Three ADI display formats were examined: (a) conventional MH; (b) perspective-view aircraft symbol (PAS), which replaced the conventional miniature aircraft symbol with a pictorial moving aircraft symbol; and (c) command, which presented the appropriate direction for recovery using the pitch or roll arrow. Twenty-two participants (10 unmanned aircraft operators, 12 nonoperators) performed a series of trials in a low-fidelity ADI simulator in which they attempted to recover from a series of unusual attitudes. The results revealed that the combination effect differed according to display format. The command display expedited initiation of the roll input regardless of reference frame. The conventional display showed better performance in the MA reference frame. The PAS display improved the total recovery time and pitch input time of nonoperator participants in the MA reference frame.