Duty Times: A Scientific View

Abstract

Already very early in the history of commercial aviation, it was re- cognized that serious performance degradation could occur as a resultof pilot fatigue. Pilots and airline managers had a natural interest in maximizing the utilization of aircrews. For the pilots, the more hours per day that they could work, the amount of money or the number of days off duty would be increased. For manage ment, more hours of utilization per pilot meant that fewer pilots would be required on the payroll. However, this vested economic interest was in conflict with flight safety and with the safety of the traveling pulbic in commercial air transport. As a consequence, government regulatory bodies were established to guide aviation operators in adopting ope- rational policies an practices that were directed to ensure flight safety and to minimize the risk to the traveling public. Regulations were established that limited the scheduled flight time of aircrew in any 24-hour period, in a seven-day period, per month, etc. Similarly, requirements for minimum rest times were defined in the legal provisions. A violation of these regulations could result in fines, suspension or revocation of licenses and operating rights.