The Measurement of Pilot Workload
Bruce L. Rosenberg
Earl S. Stein
Stein, E.S. & Rosenberg, B.L. (1983). The measurement of pilot workload (DOT/FAA/CT-82/23). Washington, DC: Federal Aviation Administration Office of Systems Engineering Management.
The evaluation of pilot workload has represented a complex measurement problem since the earliest days of manned flight. Traditional approaches have included a series of techniques, many of which have not proved successful. The most popular method has employed post-flight questionnaires or interviews.
This current experiment was an attempt to measure workload during flight simulation, using two primary variables: the pilots' own evaluation sampled once per minute with a computer and the latency or delay of that response. This was supplemented by a post-flight questionnaire. Three levels of flight difficulty were established by subject matter experts. These were varied by controlling (1) initial clearance complexity, (2) level of air traffic control, (3) turbulence, and (4) in-flight emergency. "Flights" were conducted in a General Aviation Instrument trainer and 12 pilots participated.
Results demonstrated that pilots were willing and able to make in-flight workload evaluations which corresponded directly with the induced difficulty level. Response latencies increased in relationship to difficulty, but the intermediate and most difficult flights were not significantly different. Factor analyses of all measures produced two clusters for the easiest and intermediate flights (in-flight and post-flight) and four for the most difficult flight. In the latter case, in-flight and post-flight measures separated into two factors and the questionnaire split also into two segments. These separations indicated that within the current state of the art, both types of measures should continue to be collected.
Plans call for follow-on research in General Aviation Workload.
Updated: May 04, 2012 11:21 AM