The Loss of Manual Flying Skills in Pilots of Highly Automated Airliners

Abstract

Anecdotal and subjective evidence suggests that the manual flying ability of pilots operating highly automated aircraft is declining owing to a lack of opportunity to exercise such skills in the modern air transport environment. However, there is a paucity of objective evidence to support this safety concern. Consequently, the work presented in this thesis aims to provide empirically derived data to evaluate the extent and causes of the speculated manual skills decline and guide possible intervention strategies. Initially a cognitive task analysis is undertaken to determine the cognitive demands of performing manual flight in a large jet transport aircraft. Expert pilots report employing highly refined mental models structures which enable them to predict the aircrafts performance whilst causing minimal burden to their mental capacity. The study concludes that when measuring manual flying performance careful consideration must be given to designing a task which challenges both the cognitive and physical aspects of manual flying skill. Secondly, relatively novel pilot performance measures based upon the frequency analysis of control input data are evaluated. An empirical study finds that these techniques are both reliable and sensitive to manual flying performance. Furthermore, when studying large transport aircraft, such measures of the pilots control strategy are found to contribute valuable information about performance which is missing when just traditional ‘outer-loop’ performance measures are applied. The study concludes that these measures of control strategy are valuable in evaluating manual flying performance. Finally, the manual flying skills of a sample of pilots of highly automated aircraft are evaluated on a challenging manual flying task. A significant proportion exhibit poor manual flying performance as judged by a type rating examiner. Further analysis reveals that the performance of the pilots is significantly influenced by the amount of recent manual handling experience they have accumulated, rather than their longer-term manual flying experience. Significantly, airspeed tracking ability is influenced which is cited elsewhere as a causal factor in many manual flying skill related accidents. The results support the previous anecdotal and subjective concerns relating to the loss of manual flying skills.