Automated Collection of Fatigue Ratings at the Top of Descent: A Practical Commercial Airline Tool

Abstract

There is a need to develop an efficient and accurate way of assessing pilot fatigue in commercial airline operations. We investigated the validity of an automated system to collect pilot ratings of alertness at the top of descent, comparing the data obtained with existing results from previous studies and those predicted by the validated SAFE fatigue model. Boeing 777 pilots were prompted to enter a Samn-Perelli fatigue scale rating directly into the flight management system of the aircraft shortly prior to descent on a variety of short- and long-haul commercial flights. These data were examined to evaluate whether the patterns were in line with predicted effects of duty length, crew number, and circadian factors. We also compared the results with data from previous studies as well as SAFE model predictions for equivalent routes. The effects of duty length, time of day, and crew complement were in line with expected trends and with data from previous studies; the correlation with predictions from the SAFE model was high (r = 0.88). Fatigue ratings were greater on longer trips (except where mitigated by adding an extra pilot) and on overnight sectors (4.68 vs 3.77). The results suggest that the automated collection of subjective ratings is a valid way to collect data on fatigue in an airline setting. This method has potential benefits for the crew in assessing fatigue risk prior to approach, as part of a fatigue risk management system, with the possibility of wider safety benefits.