This experiment continues earlier research (Kantowitz, Hart, & Bortolussi, 1983) conducted in a GAT-1 motion-base trainer to evaluate choice-reaction secondary tasks as measures of pilot workload. The earlier work used an asynchronous secondary task presented every 22 sec regardless of flying performance. The present experiment uses a synchronous task presented only when a critical event occurred on the flying task. Both 2- and 4-choice visual secondary tasks were investigated. Analysis of primary flying-task results showed no decrement in RMS error for altitude, indicating that the key assumption necessary for using a choice secondary task was satisfied. Reaction times showed significant differences between Easy and Hard flight scenarios as well as being able to discriminate among flight tasks.
