Wrong assumptions

(This article first appeared as a Comment in 5 March 2013 Flight International)

If a pilot gets away with using an incorrect flying technique for long enough without a mishap, his training department assumes, wrongly, he must be using the correct technique. If that incorrect technique is then applied in a highly dynamic – but rare – manoeuvre such as a go-around, it is only a matter of time before that pilot’s luck runs out catastrophically.

There has long been an assumption in the industry that a go-around is a simple manoeuvre. So embedded was this view that several catastrophes resulting from botched go-arounds were ignored as aberrations, and it was not until a near-catastrophic go-around occurred in southern England that the airline concerned decided to test its assumptions about how pilots monitored their instruments. They set up pilot eye-tracking tests in their training simulators, and discovered many pilots did not exercise a skill that – it was assumed – was fundamental to the skillset of any pilot who had earned an instrument rating. Many pilots were found to employ a haphazard instrument scan that ignored critical primary flight information for dangerously long intervals. But because the measurement of a pilot’s instrument flying skill was previously based on whether the aircraft’s trajectory and performance remained within certain parameters, if that was achieved by luck rather than judgement, the deficiency remained undiscovered. It needed an empirical approach such as eye-tracking to discover that assumptions about skills were wrong, and accidents were waiting to happen. Since that time, the all-engines go-around manoeuvre itself has been dissected.

It can be very demanding because change happens so fast as a result of the high power/weight ratio of modern aircraft, and because many airports have tight limitations in their missed approach procedure owing to terrain or conflicting traffic patterns.

But the industry is simultaneously trying to reduce the occurrence of the most common of all aviation accidents: the runway excursion. Runway excursions frequently follow unstabilised approaches, and going around from an unstabilised approach is one of the most effective ways of reducing overruns.

Behind the discovery made by Thomson Airways with its eye-tracking technique lurks the question of whether the loss of a disciplined instrument scan is a result of modern automated flying. Whatever the cause, the solution is a disciplined scan by the pilot flying, and a trained monitoring procedure for the pilot monitoring.

Subscribe

Subscribe to our e-mail newsletter to receive updates.

Leave a Reply