Motion fidelity of uncoordinated simulator roll for simulation of coordinated aircraft roll

This paper investigates how pilots' control behavior and motion perception during a simulated roll maneuver depends on the level of normal g load using a centrifuge-based simulator. Fourteen commercial pilots participated in the study, actively controlling a series of coordinated bank angle changes between -30 and +30 degrees. By changing the cabin orientation and g load, the projected g load along the pilot's longitudinal body axis, i.e. gz, was varied between 0.36, 1.0, 1.2 and 1.4g. For each gz load, the roll rate gain was systematically varied between 0.2, 0.4, 0.6, and 0.8. Pilots gave separate motion ratings for the perceived (congruent) simulator roll motion, and for the (parasitical) sideforce, or gy, caused by the roll tilt of the simulator cabin relative to the g load. The results showed that the pilot-controlled roll rate decreased linearly with increasing roll motion gain. Furthermore, subjective ratings showed that the optimal roll rate gain decreased as gz increased, while false cue ratings of the perceived sideforce increased with increasing gz. It is concluded that the optimal fidelity of simulator roll motion is a compromise between the angular component, i.e. the congruent simulator roll, and the gy component induced by the cabin tilt relative to the g load, which can be considered a false cue for coordinated flight. Finally, it is discussed that the finding of an optimal roll motion gain is below 1.0. © 2012 by the authors.