Diversion fuel after a hold at destination
You are the pilot-in-command of a twin-turboprop on a scheduled 2 h 40 min sector. Planned fuel at destination was 1 050 kg, comprising 620 kg trip fuel, 180 kg contingency, 150 kg alternate fuel and 100 kg final reserve. En route ATC places you in a hold for 22 minutes at 1 400 kg/h before you begin the approach. The destination weather is at minimums with a broken deck at 400 ft and visibility 2 500 m; the alternate is 35 minutes away and its forecast is marginal but above minima. Your aircraft has 1 780 kg of fuel remaining when you enter the hold. Company policy sets the minimum landing fuel at final reserve plus 10 percent of the alternate fuel.
1. Calculate the fuel state on leaving the hold and decide whether the approach at destination should be attempted.
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Hold burn = 1 400 kg/h x (22/60) h = 513 kg. Fuel on leaving hold = 1 780 - 513 = 1 267 kg.
Subtract the fuel needed to fly the approach, land and, if a go-around is required, reach the alternate: approach and missed approach allowance (say 120 kg) plus alternate fuel 150 kg plus final reserve 100 kg = 370 kg. Remaining after that = 1 267 - 370 = 897 kg, which is well above the policy minimum of 100 + (0.10 x 150) = 115 kg.
The decision is not merely arithmetic. The destination is at minimums with a broken deck, so a go-around is plausible; the alternate is marginal. Because 897 kg of surplus exists, one approach is defensible. If the approach is not stabilised by 500 ft, a go-around and diversion must be flown without a second attempt. Recompute in flight using actual burn, not the planned figure.
2. Explain how the contingency and alternate fuel were affected by the hold, and what must be reported.
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Contingency fuel is intended to cover unforeseen factors en route; a hold is a foreseeable ATC delay and is not automatically chargeable to contingency. The 513 kg burned in the hold exceeds the 180 kg contingency, so the shortfall must come from the alternate or final reserve. Final reserve must not be planned to be used; if it appears likely to be touched, a diversion or priority handling is required.
Report the fuel state to ATC if a delay is expected to erode the reserve, and record the hold time, fuel at each checkpoint and the revised landing fuel. On arrival, the commander must ensure the actual landing fuel is not below final reserve; if it is, a safety report is filed.