The Pilot Who Stopped Sleeping
A commercial pilot flying a VFR sightseeing operation has had three consecutive nights of about four hours' sleep because of a new baby. He reports feeling 'fine, just a bit flat'. His roster shows four 40-minute scenic flights in the afternoon, each with a full load of passengers, in a mountainous area with frequent low-level turbulence. His last meal was a sandwich at 08:00; it is now 13:30. He has had two coffees and no water. On the pre-flight walk-around he twice has to re-check which magneto he has already tested.
1. Identify the human-performance factors at work and assess the risk.
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Three factors combine. First, sleep loss: three nights at four hours produces a cumulative sleep debt with degraded vigilance, slowed reaction and impaired judgement, particularly in the afternoon circadian low - the classic window for involuntary micro-sleeps. Second, hypoglycaemia and dehydration: no food for 5.5 hours plus caffeine without water worsens tremor, concentration and mood. Third, task load: four repetitive short sectors with passengers, turbulence and terrain demand high attention precisely when capacity is lowest. The repeated magneto check is a concrete sign of a lapse, not a harmless quirk. The risk is not 'he might feel tired'; it is that a low-workload cruise phase will tip into a micro-sleep or that a terrain or traffic conflict will be missed.
2. What should the pilot do, and what does this say about fitness-to-fly decision-making?
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He should not fly the roster. He should declare himself unfit, hand the flights to another pilot or cancel, eat and hydrate, and treat the next night's sleep as an operational requirement. Fitness to fly is a self-declaration made before every flight, not a one-off medical certificate. The trap is that he feels 'fine': subjective alertness is a poor gauge after sleep loss, and the professional standard is to judge by the objective facts (hours slept, hours since food, symptoms such as repeated checks) rather than by mood. A pilot who cannot say 'I am not fit today' is a hazard regardless of skill.