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Analysis
148
Aircraft Accident Report

question the decision." The study concluded that a first officer "may be concerned that a challenge to a decision may be perceived as a direct challenge to the captain's authority."

The Safety Board is concerned that the use of the nonflying pilot in a passive role, while the flying pilot is responsible for the approach procedure, programming the autopilot/FD controls, and monitoring the aircraft flightpath, places an inordinately high work load on the flying pilot and undertasks the nonflying pilot. The Board is also concerned that, when the nonflying pilot has a passive role in the approach, the flying pilot may erroneously consider the lack of input from the nonflying pilot as confirmation that approach procedures are being properly performed. The Board is aware that some international air carriers use the nonflying pilot in a more interactive role during the performance of a nonprecision approach, in which that pilot leads or prompts the flying pilot through the approach procedure by stating the next procedural change, including course, heading, altitude, time, visual contact, or MAP. The Board is also aware that some air carriers employ a "monitored approach" method, with the first officer as the flying pilot and the captain as the monitoring, nonflying pilot until just before landing.

The Safety Board notes that the monitored approach method provides for more effective monitoring by the nonflying pilot because captains are more likely to be comfortable offering corrections or challenges to first officers than the reverse situation. Thus, the Safety Board concludes that monitored approaches decrease the workload of the flying pilot and increase flight crew interaction, especially when experienced captains monitor and prompt first officers during the execution of approaches. However, the Board also notes that, when there are differences in aircraft handling skills between captains and first officers and the approach is not flown using the autopilot, a monitored approach with the captain as the nonflying pilot may not always be appropriate. Therefore, the Safety Board believes that the FAA should conduct or sponsor research to determine the most effective use of the monitored approach method and the maximum degree to which it can be safely used and then require air carriers to modify their procedures accordingly.

2.4.3 Flight Crew Fatigue Factors

Fatigue can be a factor in flight operations.[1] The Safety Board examined several fatigue-related factors, including time of day, recent sleeping patterns, and the number of hours since awakening, to determine whether fatigue was a factor in the accident captain's performance. The Board was unable to obtain information on the recent sleeping patterns of the first officer and flight engineer.

The accident occurred after midnight (about 0042) in the flight crew's home time zone (which is 1 hour behind Guam local time). Research has found that this time of day is often associated with degraded alertness and performance and a higher probability of errors and accidents.[2] The arrival time was also several hours after the captain's normal


  1. Gander, P.H., Gregory, K.B., Miller, D.L., Graeber, R.C., Connell, L.J., and Rosekind, M.R. (1998). "Flight Crew Fatigue V: Long-Haul Air Transport Operations." Aviation, Space, and Environmental Medicine, 69 (9, Section II, Supplement), pp. B37-B48. 199
  2. Akersdet,T (1998)." Shift Work and Disturbed Sleep/Wakefullness." Sleep Medicine Reviews 2,2(2), pp 117-128.