Fatigue and dehydration before a dusk sector
You are a newly qualified PPL, 42 years old, flying your third sector of the day from FIMP to FIMR. You slept 4 hours last night because of a family issue, drank one small bottle of water since breakfast, and skipped lunch. The cockpit is at 34°C on the ground; you have been on duty 9 hours. You feel a mild headache, dry mouth, and a little light-headed. Your two passengers are friends and one is nervous. The aircraft is serviceable, fuel is sufficient, and the weather is VFR with a 1 h 20 min leg ahead. Sunset is in 50 minutes; you have no night rating and the destination has no runway lighting. You have flown this route once before. You are tempted to go because the passengers have paid for a hotel and the aircraft is booked tomorrow.
1. Identify the human factors and classify them using IMSAFE.
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Illness: you have a headache and feel light-headed, which may be early heat exhaustion or dehydration rather than a minor annoyance. Medication: none stated, but that must be confirmed. Stress: the family issue and the passengers' expectations are both stressors. Alcohol: none stated. Fatigue: 4 hours of sleep, a third sector, and 9 hours on duty is significant fatigue. Eating: you skipped lunch and have had very little water, so dehydration and low blood sugar are likely.
The heat in the cockpit adds a further physiological load. A dry mouth, headache, and light-headedness are not normal at rest; they are warning signs. The planned dusk arrival without a night rating or runway lighting adds a separate risk. Using IMSAFE, you fail on illness, fatigue, and eating/drinking, and stress is present. This is not a borderline call.
2. What is the correct decision and what alternatives do you have?
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Do not fly. The combination of fatigue, dehydration, heat, and an impending night arrival without a night rating or lit runway is unacceptable. The fact that the passengers have paid for a hotel is a commercial pressure, not a safety argument. A nervous passenger will also increase your workload and distract you from checklists and radio calls.
Alternatives include cancelling the flight and rebooking for the next morning after rest and fluids; using another pilot who is rested and night-current if the destination can be safely approached before dark; or arranging surface transport. If the aircraft must be repositioned, do it in daylight with a rested crew. Do not compromise by taking off and deciding later; the decision is easier on the ground. Tell the passengers clearly that the flight is not safe and that you are not departing.
3. If you nevertheless took off, what performance and decision-making errors would you be more likely to make?
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Fatigue and dehydration slow reaction time, reduce attention to detail, and increase the chance of fixation. You would be more likely to skip or rush the pre-take-off checklist, miss a radio call, or accept a poor approach rather than go around. Heat and dehydration can also cause dizziness and reduce tolerance to turbulence.
At dusk, visual illusions and reduced contrast make judging height and speed harder. Without a night rating, you may misjudge the approach and land long or flat. The destination has no lighting, so a go-around would be difficult. Fatigue also encourages continuation bias: you would be more likely to press on to the destination rather than divert after a missed approach. These are exactly the errors that turn a marginal decision into an accident.