Queenstown departure with fuel, performance and duty pressure
A Part 135 single-pilot IFR operator plans a Piper PA-31-350 Chieftain flight from Queenstown to Christchurch with eight passengers. Departure is 1715; the pilot signed on at 0545. The aircraft's fuel endurance is 2 hours 10 minutes. The trip is 1 hour 15 minutes, the forecast alternate is Timaru at 30 minutes, and the operator's fuel policy requires 45 minutes reserve. Forecast holding at Christchurch is 20 minutes. Temperature at Queenstown is 28 degrees C, QNH 1012 hPa, elevation 1,171 ft, runway 05, light wind. The aircraft is at maximum gross weight. The pilot says the density altitude is 'about 3,000 ft' and that the Chieftain will 'probably' meet the single-engine climb gradient. Christchurch is forecast broken cloud at 1,000 ft. The pilot is keen to depart to avoid a night landing and a hotel bill.
1. Evaluate the fuel legality of the planned flight.
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The flight cannot legally depart with the stated fuel. The required fuel is not just the trip fuel. It must include the trip to the destination, the fuel to the alternate, the applicable IFR reserve and the expected holding. On the figures given: 1 hour 15 minutes trip plus 30 minutes to Timaru plus 45 minutes reserve plus 20 minutes holding equals 2 hours 50 minutes. The aircraft's endurance is only 2 hours 10 minutes. Even if the holding were ignored, the total would be 2 hours 30 minutes, which is still greater than endurance. The operator's policy may be more restrictive than the rule, but it cannot be less restrictive. The pilot cannot solve the problem by simply 'hoping' the holding does not eventuate. The flight must be replanned with less payload, a technical stop, a closer alternate or a delay until fuel and conditions allow a compliant plan.
2. What performance and duty-time concerns arise?
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At Queenstown the density altitude is significant, and the aircraft is at maximum gross weight. The pilot must use the aircraft performance charts to establish the take-off distance, obstacle clearance and single-engine climb gradient for the actual temperature, pressure and weight. 'Probably' meeting the climb gradient is not a legal or safe standard. If the net take-off flight path or obstacle clearance cannot be assured, the operator must reduce weight, wait for cooler conditions or use another runway or departure procedure. The duty picture is also poor: signing on at 0545 for a 1715 departure already gives more than 11 hours of duty before the flight begins. Any delay would worsen that. The pilot must consider the applicable flight and duty time limitations and, equally importantly, fatigue. A hotel bill is not a valid operational reason to press on.
3. What decision should be made, and what alternatives are available?
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The flight should not depart as planned. The fuel plan is unlawful, the performance case is unproven at maximum weight and high density altitude, and the duty day is already long. The operator should consider offloading passengers or baggage, reducing fuel, planning a technical stop, using a different aircraft or crew, or delaying until the next day when temperatures are lower and the crew has had rest. If Christchurch weather is marginal, the alternate and holding fuel must be realistic, not optimistic. The pilot should record the decision and the reasons, and the operator should ensure the passengers are rebooked. This is a case where commercial pressure is pushing against several independent limits; satisfying one limit by compromising another would still leave the flight non-compliant.