Night go-around: fatigue, medication and a somatogravic illusion

The chain

1. Fatigue: 20-plus hours awake, in the 0200-0600 circadian low, on the third sector with 9 hours of flight time in 24 hours. Reaction time, instrument scan and decision quality are all degraded, and the pilot is more likely to accept a poor approach rather than go around early.
2. Medication: a sedating antihistamine is disqualifying for flight, and self-medicating with an over-the-counter drug without aeromedical advice is a regulatory and safety failure. Its sedative effect adds to the fatigue.
3. Head cold and pressurisation: congestion blocks the Eustachian tubes and sinuses, producing ear pain, distraction and the risk of barotrauma during the descent - an unnecessary workload in a critical phase.
4. Black-hole approach: with no approach lights and no lit ground beyond the runway, there is no peripheral visual reference. The bright town lights to the right pull the aim point and produce the illusion that the runway lights are too high, encouraging a low approach.
5. Somatogravic illusion: on the go-around, the strong forward acceleration is misread by the vestibular system as a nose-up pitch. The correct response to the false sensation is to push forward - exactly what happened - and it drives the aircraft into a real descent, which the terrain warning then caught.

Key point

The pilot acted on a false sensation and not on the instruments. The instruments were right; the pilot's balance organs were wrong.

On the go-around

1. Recognise and name it: "somatogravic illusion - trust the instruments."
2. Fix the scan on the attitude indicator and airspeed, and set the go-around attitude and power with reference to the flight director.
3. Confirm a positive rate on the vertical speed indicator and altimeter, then call for gear up and the published missed approach.
4. Do not chase the visual picture out of the windscreen and do not fight the false sensation by feel; use the attitude indicator as the sole pitch reference until the aircraft is stable on the missed approach.
5. If disorientation persists, tell ATC and ask for radar vectors and a height check rather than continuing to fly the procedure alone.

Before the approach

• The pilot should not have been flying at all: the sedating antihistamine, the cold and the accumulated fatigue made the flight unfit to commence. The correct decision is to decline or delay the sector.
• Brief the black-hole effect: fly the VOR/DME profile to the MDA on instruments, and use the flight director and the vertical speed indicator rather than the runway picture for the glide path.
• Set a personal decision height and a callout to go around if not visual and correctly positioned by that point.
• Take the go-around decision early - before the illusion can form at low level.

Immediate decision

Do not fly another approach to the same runway. The pilot is unfit: sedated, fatigued, in the circadian low, with an active cold. Another black-hole approach with a somatogravic risk would be a repeat of the same exposure with less margin.

Options in order of preference:

1. Divert to an aerodrome with an instrument approach and full approach lighting, ideally ILS with a longer, better-lit final approach, and land there while the pilot is still capable of a simple, well-supported approach.
2. If fatigue is severe enough that even that is doubtful, land at the nearest suitable aerodrome with radar and ATC support, declare the situation and request priority.
3. On the ground, rest before any further flight; the aircraft does not move again until the pilot is fit.

Follow-up

• Report the occurrence through the operator's safety management system and to the authority as required.
• Consult an aeromedical examiner about the medication and the cold before the next flight.
• Review the rostering and the sterile-cockpit discipline that allowed a self-medicated, fatigued pilot to sign on for a third night sector. The flight should not have been accepted in the first place; the go-around was the symptom, not the cause.