ICAO recently modified it's definition of Contingency fuel to take into account extended taxi time.
Contingency fuel, which shall be the amount of fuel required to compensate for unforeseen factors.
It shall be 5 per cent of the planned trip fuel or of the fuel required from the point of in flight re-planning based on the consumption rate used to plan the trip fuel but in any case shall not be lower than the amount required to fly for five minutes at holding speed at 450 m (1 500 ft) above the destination aerodrome in standard conditions;
Note.— Unforeseen factors are those which could have an influence on the fuel consumption to the destination aerodrome, such as deviations of an individual aeroplane from the expected fuel consumption data, deviations from forecast meteorological conditions, extended taxi times before take-off, and deviations from planned routings and/or cruising levels/altitudes.
Originally Posted by
Busta Level
Exactly John!
To set the scene on this *hypothetical* (!) flight, imagine it was a long-haul ETOPS flight from JFK-LHR with reduced contingency fuel as per the Flight Plan.
There has been extra fuel to allow for a 45 minute taxi out at JFK, but taxi time ends up being more like 1h45. Therefore all the contingency fuel is burnt before we are anywhere near the runway.
Now I know that JFK is a nightmare for getting back onto stand (the last time I had to go back to stand it took 3 hours...that was in the snow though) and max FDP is relatively tight on this particular flight, but my view is that burning all the contingency fuel (and some of the ALT 2 fuel!) before you even get airborne is a tad dodgy. Ok, you could argue that it's 'only a planning thing' and statistically how likely are we to need it anyway?!
What would the view of the regulators be if you had an emergency situation that then led to a fuel emergency as well? Which is not beyond the bounds of possibility in the above scenario - maybe a flap or gear issue on final approach into LHR after holding requiring a missed approach, or a diversion due to LHR closing (as has happened to me in the past)!
I'm not so much interested in the decision making process as to what anyone would do, but more interested in terms of the regulatory requirements, and the view that the subsequent enquiry board would take!
