Unusable Fuel

[IcePack]

Anyone know any reference to unusable fuel quantities for Airbus FBW aircraft.
Thanks

[dhardesthard]

As far as I know all indicated fuel on the gauge is useable. If it says 2000 kgs, then you can plan on being able to consume another 2000 kgs. However your company will have SOPs that say you should land with a minimum quantity showing on the gauges.

[Canuckbirdstrike]

FAR/EASA 25 standards require that fuel quantity indicating systems only display useable fuel. The general process description is that aircraft manufacturers determine the point where fuel is unusable and build this as the "zero" point on the indicators.

[IcePack]

Thanks for the ref :)

[jettison valve]

I agree with the posts above.

For info, the relevant "unusable fuel" data from the A330-200 Weight and Balance Manual ("unusable fuel is the amount of fuel remaining in the tanks and systems after a fuel run out test has been completed in accordance with the current applicable government regulations."):

- outer tanks: 5.2l each
- inner tanks: 169l each
- centre tank: 83l
- trim tank: 6l
- systems: 68l
------------------
- Total: 504 litres

I am still impressed :ok: about the low quantities, considering that the whole thing can take way beyond 130.000 litres!

Cheers, J. V.