Re-dispatch and En-Route Fuel Management
A flight is re-dispatched at a point 2 h 10 min into a 6 h flight. At the re-dispatch point, the crew must have fuel to reach the re-dispatch destination plus reserves, or to reach the original destination, whichever is more demanding. Planned figures: take-off fuel 24 000 kg, fuel at re-dispatch point 15 500 kg, burn to re-dispatch destination 6200 kg, burn to original destination 9400 kg, final reserve 1400 kg, alternate fuel 1800 kg, contingency 700 kg. The re-dispatch destination has weather at planning minima; the original destination is clear.
1. Determine the minimum fuel required at the re-dispatch point for each destination and identify the governing case.
Read the worked answer
To re-dispatch destination: burn 6200 + contingency 700 + alternate 1800 + final reserve 1400 = 10 100 kg.
To original destination: burn 9400 + contingency 700 + alternate 1800 + final reserve 1400 = 13 300 kg.
The governing case is the original destination at 13 300 kg, because it is more demanding. Fuel at the re-dispatch point is 15 500 kg, so the flight is legal with 2200 kg margin. The re-dispatch destination's weather at minima does not reduce the requirement; it is the fuel to the more demanding destination that governs. A common error is to compare only burn figures and ignore that the original destination requires more fuel even though its weather is better.
2. If the fuel at the re-dispatch point falls to 12 800 kg, what options does the crew have?
Read the worked answer
At 12 800 kg the flight is 500 kg short of the 13 300 kg required for the original destination. Options: (1) re-dispatch to the closer destination, where 10 100 kg is required and 12 800 kg is ample, provided the weather at that destination meets planning minima and the crew accepts it; (2) reduce contingency only if the operator's approved procedure allows; (3) divert or land short. The crew may not simply continue to the original destination on the basis that the shortfall is small. The decision must be recorded and the more demanding destination rule respected. If the closer destination is at minima, its usability must be confirmed before it is used as the re-dispatch point.