Reserve Fuel

[Charter Rules]

Hello everybody,

All flights require reserve fuel - both 45 minutes of reserve and then extra fuel to go to farthest alternate. However, the reserve is almost never used. So, I assume airlines can save the reserve for the next flight and the flight after that etc etc. (Correct me if I'm wrong.)

But if the aircraft is not used that much - maybe it is only used for ad-hocs - how long can the fuel be left in the aircraft, waiting to be used for the next flight? Or does the airline have to get rid of all the fuel (and hence lose a lot of money) or can they save it? If yes, for how long?

(The sample aircraft I use in my thesis is an A319.)

[BOAC]

All flights require reserve fuel - both 45 minutes of reserve and then extra fuel to go to farthest alternate. However, the reserve is almost never used. So, I assume airlines can save the reserve for the next flight and the flight after t?- Yes. 30 minutes in JAR OPSBut if the aircraft is not used that much - maybe it is only used for ad-hocs - how long can the fuel be left in the aircraft, waiting to be used for the next flight? Or does the airline have to get rid of all the fuel (and hence lose a lot of money) or can they save it? If yes, for how long?- just stays in the tanks. A water drain will be done at a specified interval.

[flydive1]

The reserve fuel is not kept hidden in a special tank, is the main tanks, every time you fuel the aircraft it get mixed with the new fuel, so you never have old fuel on board.

[JTONeil]

The alternate fuel is not necessarily the fuel to reach the furthest alternate airport, but more usually to reach the nearest alternate. In my company the company designated alternate, and thus the one used for calculating minimum fuel requirements, is the one which takes the least amount of fuel to reach.

If I think that the 'fuel alternate' is unsuitable on the day (weather, notams, volume of traffic etc) then I uplift more to cover the next nearest (and suitable) alternate.

[esreverlluf]

Food for thought - In some parts of the world fixed reserve can be as little as 30mins with no requirement to carry fuel for an alternate if destination fulfills certain weather and navaid requirements (and yes that is for RPT).

[JTONeil]

Indeed, 30 minutes is all you get here in the UK. It's thirty minutes flying at estimated landing weight at 1500 feet (I think) which equates to about 1000 kg for my aircraft type (A320).

And yes, no alternate fuel is required for airports where multiple independent runways are available and a landing can be 'assured', although 15 minutes extra fuel needs to be carried instead. I'm not entirely sure of the rules, since it's one I have never felt persuaded to follow. Fuel for an alternate is my way of thinking; if a landing can be assured (as above) I see it as an opportunity to take plog fuel and make my employer happy (which doesn't happen often enough).

jtoneil

[mach5]

Can any one explain what is meant by contigency fuel ? Does it include reserve fuel also , one of my friend said that its 5% of total fuel but not sure.

[BOAC]

Fuel for contingencies. Traditionally 5% of trip + div for jet and 10% for piston, now also sometimes calculated on a statistical basis.

[ElitePilot]

The 5% contingencies to trip fuel may be used by extra fuel burn due to not flying at the optimum altitude, flying around weather being radar vectored around traffic etc.

These figures are generally calculated before the flight by dispatchers based on weights winds temps etc etc.

[Capt Claret]

In Oz, I've always taken contingency fuel to be that extra fuel required to satisfy Depressurised or Engine Out Ops requirements.

[frontlefthamster]

JT wrote: I'm not entirely sure of the rules, since it's one I have never felt persuaded to follow

...and that, along with other responses on this thread, sum up too many pilots' approaches to fuel planning, in my opinion.

Too many people don't know the rules and their practical consequences, have never been properly trained in understanding and applying them, and on the grounds of their professional status, they carry more than they need most of the time.

Sorry JT, but before you choose to ignore rules which could allow you to operate more efficiently, your really ought to know what they are.

The fault, I think, goes all the way back to initial training, where too little attention is paid to fuel planning, partly because the fuel gauges on light aircraft are often very inaccurate. The 'system' then teaches people (or, some of them) what the rules are, but not how to interpret them.