Fatigue, Cabin Heat, and Passenger Pressure at Night
A charter pilot has been on duty 12 h 30 min, with 7 h 10 min flight time in six legs. The previous night the pilot slept 4 h after an early start. The final leg is at night, VFR, 1 h 20 min, in a Cessna 210. The pilot has a headache, feels warm, and is yawning repeatedly. The cabin heat has been on for 40 min. The route has a 3,000 ft cloud base, 8 km visibility, and high terrain with MSA 9,500 ft; the planned cruise is 8,500 ft. The passenger is a company director who says, 'We need to be there tonight.' The pilot's colleague is available at base but would need 2 h to arrive. The pilot says, 'I'm tired but I can manage.' The aircraft has a functioning autopilot, but the pilot has not eaten for 6 h.
1. Identify the most likely physiological hazards in this scenario, beyond simple fatigue, and explain the evidence for each.
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Fatigue is clearly present: 12 h 30 min on duty, six legs, only 4 h sleep, and repeated yawning. However, the headache, feeling warm, and drowsiness after 40 min of cabin heat also suggest carbon monoxide exposure from a leaking heater or exhaust. CO poisoning produces headache, dizziness, warmth, and reduced judgement, and it can mimic fatigue. Hypoglycaemia and dehydration are also possible because the pilot has not eaten for 6 h, and mild hypoxia may contribute at 8,500 ft, especially if the pilot is anaemic or fatigued. The pilot should not assume the symptoms are only fatigue. Immediate actions are to shut off the cabin heat, open fresh-air vents, descend if terrain allows, use a CO detector if available, and land as soon as practicable.
2. Evaluate the pilot's decision to continue and the effect of passenger pressure. What should the pilot do?
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The pilot is displaying press-on-itis and external pressure. The passenger's statement is not an operational reason to fly, and the pilot remains responsible for the safety of the flight. The combination of fatigue, possible CO exposure, night conditions, high terrain, and a 3,000 ft cloud base makes the leg high-risk. The pilot's statement 'I'm tired but I can manage' is a self-assessment that is unreliable when judgement is already impaired. The correct decision is not to depart, or to land at the nearest suitable aerodrome if already airborne. The pilot should advise the passenger that the flight cannot continue safely, arrange the colleague or an overnight stop, and document the decision. The autopilot is not a mitigation for impaired pilot judgement.
3. If the pilot had already taken off and suspected CO poisoning, what sequence of actions would be appropriate?
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The pilot should immediately select cabin heat off, open fresh-air vents, and if possible descend to a lower altitude while remaining clear of terrain. If a CO detector is available, confirm the indication. The pilot should declare an urgency condition to ATC, request the nearest suitable aerodrome, and land as soon as possible. The pilot should not attempt to continue the planned route or troubleshoot the heater in flight. If symptoms are severe, the pilot should consider handing control to another pilot on board, but in a single-pilot aircraft the priority is to land. After landing, the pilot should seek medical advice, have the aircraft inspected, and not fly again until cleared. The passenger should also be assessed for CO exposure.