Originally Posted by
Banana Joe
I've done some further research and it may be that the contingency fuel was based on city pair/aeroplane combination statistical method.
an amount of fuel based on a statistical method that ensures an appropriate statistical coverage of the deviation from the planned to the actual trip fuel. This method is used to monitor the fuel consumption on each city pair/aeroplane combination and the operator uses this data for a statistical analysis to calculate contingency fuel for that city pair/aeroplane combination
CAT.OP.MPA.150
I will of course enquire my flight ops department.
AMC1 CAT.OP.MPA.15
This is totally legal under the ICAO 9976 Flight Planning and Fuel Management Manual which EASA has adopted.
The EASA rules I think are
(c) Contingency fuel, which should be the fuel described in (1) or (2) below, whichever is higher:
(1) either:
(i) not less than 3 % of the planned trip fuel or, in the event of in-flight replanning, 3 % of the trip fuel for the remainder of the flight provided that a fuel en route alternate (fuel ERA) aerodrome is available; or
(ii) an amount of fuel sufficient for 20 min flying time based upon the planned trip fuel consumption; or
(iii) an amount of fuel based on a statistical method that ensures an appropriate statistical coverage of the deviation from the planned to the actual trip fuel; prior to implementing a statistical fuel method, a continuous 2-year operation is required during which statistical contingency fuel (SCF) data is recorded — note: in order to implement a SCF on a particular city pair/aeroplane combination, sufficient data is required to be statistically significant; this method is used to monitor the fuel consumption on each city pair/aeroplane combination, and the operator uses this data for a statistical analysis to calculate the required contingency fuel for that city pair/aeroplane combination; or
(2) an amount to fly for 5 min at holding speed at 1 500 ft (450 m) above the destination aerodrome in standard conditions.
What you would have loaded is the 5 minutes, your statistical contingency must be less than that amount. This typically occurs where the departure and arrival procedures have complicated/inefficient routing (like maintaining below 7000 ft for 70 miles, and then a zig zag STAR) which are there typically for loss of communications purposes. When radar identified significant shortcuts are normally available reducing the actual trip distance/fuel down significantly. Have a look at the planed trip distance compared to the actual distance flown on flight radar or similar. My guess is you are typically seeing a saving of around 100 nm over the city pair which is converted into contingency fuel via the statistical method.