Prior to the end of October, CAA and EASA had slightly different Basic Fuel Policy requirements for calculating minimum fuel. CAA calculated extra fuel but no discretionary fuel, whereas EASA could also calculate discretionary fuel. We know this as the TTCAAFE(D) abbreviation, which is the way we remember the individual components of fuel.
But what has changed? The CAA have now aligned with EASA within Basic Fuel Policy by amending the description of Extra Fuel from “fuel at the Commanders discretion” to “fuel for foreseen circumstances” and adding Discretionary Fuel, which is “fuel at the Commanders discretion”.
Unlike contingency fuel, which is described as “fuel for unforeseen circumstances that can effect trip fuel”, extra fuel CAN be included at the planning stage if you know you are going to experience delays before departure, the use of bleed air for anti-icing during the flight or delays when arriving at the destination, etc. For real-world operations, this knowledge would be built up over time when you are with an airline and operating on the same routes on a regular basis.
But how could a question be worded to reflect the change to extra fuel for CAA exams?
An example of how a question could be worded to reflect the change might look something like this:
A multi-engine piston aircraft is flying a VFR trip over 3 hours. The destination aerodrome has 2 separate runways, the weather is forecast to be CAVOK all day and a 15 minute delay at the destination is expected. Given the following information, what is the minimum block fuel?
APU & engine start: 10lb
Taxi to the runway: 15lb
T/O & climb: 70lb
Cruise fuel burn: 3lb/nm
Cruise distance: 300nm
Descent & landing fuel: 30lb
Destination fuel flow: 160lb/hr
Taxi fuel: 25lb
Trip fuel: 1000lb
Contingency fuel: 50lb (5% of trip fuel; 5 minutes of destination fuel flow is 13.3lb)Alternate fuel: Nil
Additional fuel: 40lb (15 minutes of fuel if no destination alternate is nominated)
Final Reserve fuel: 120lb
Extra fuel: 40lb (Expect a 15 minute delay at the destination)
Discretionary fuel: Nil
Block fuel: 1275lb
The key difference in this ‘new’ question is the inclusion of ‘a 15 minute delay at the destination is expected’. This is the trigger to include extra fuel at the planning stage as a ‘foreseen circumstance’. If no delays are expected, then extra fuel is not required.