Night Approach After a Short-Night Roster
You are a first officer on a turboprop on the third sector of a night duty. You slept 4.5 hours in the last 24, and the roster was changed at short notice. It is 01:40 local. On approach to runway 27 with a 15 kt crosswind and light rain, you notice the runway edge lights appear to drift and the PAPI seems to sit slightly left of where you expect. You feel a strong urge to descend early and your captain is quiet. Your heart rate is up and you have yawned three times in the last ten minutes. The airport has a 200 ft decision altitude and no autoland. You have 900 ft to go.
1. Identify the human factors at play and explain what is happening to your perception of the approach path.
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Several factors combine here. First, cumulative sleep restriction (4.5 h in 24 h) plus a circadian low at 01:40 produces a homeostatic and circadian pressure for sleep, which degrades vigilance, slows reaction time and increases the likelihood of micro-sleeps. Second, the short-notice roster change removes the anticipation that helps you prepare, adding a stress response (raised heart rate, yawning). Third, visual illusions: in rain at night, fewer visual cues and a sloping or featureless approach can make the PAPI and edge lights appear displaced; a crosswind also causes a crab angle that shifts the apparent runway centreline. The strong urge to descend early is a classic sign of fatigue-related perceptual distortion and expectation bias - you 'see' the picture you expect. The correct response is to recognise the state, call it out, increase monitoring, use instruments as the primary reference, and consider a go-around if the picture is not stable by 500 ft.
2. You are at 900 ft and the picture still looks wrong. What do you do, and why is this the safer option?
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Call 'go-around' and fly the published missed approach. At 900 ft with an unstable visual picture, fatigue, and a non-precision-style decision altitude, continuing is a high-risk decision. A go-around costs fuel and time but preserves options: you can hold, divert, or hand over to a fresher crew. Continuing risks a late correction at low height, where the energy state and crosswind make a hard landing or runway excursion more likely. The decision should be made early and communicated clearly; the captain's silence is not consent. After the go-around, declare fatigue, request a diversion or rest, and file a report. The key judgement is that the cost of a go-around is trivial compared with the cost of a destabilised approach at night in rain with a fatigued crew.