Hi whiggy.

This is a problem with the 757 v4.6. If I get an insufficient fuel warning, I add it until I have enough fuel for the flight, PRIOR to engine start!

I work out if I have enough fuel by checking the PERF page after the FMC setup is complete. Say, for example, I do my flight plan and check the PERF page and it is calculated that I will have 10000 kilos of fuel when I arrive at my destination (my plan is to have 3,500 kilos when I get there), I will then remove 6,500 kilos, go back to the PERF page to see what the new calculation is. It is likely to be more like 4,000 kilos, than 3,500 kilos remaining (757 is lighter, so requires less fuel burn to get me there). I do this until I am satisfied that I should have enough fuel for the flight plan plus alternate, plus contingencies, etc.. I have never had to add more fuel during a flight.

If there is not enough fuel for the flight, you should land at the nearest airport, not top up the fuel in flight.

If you MUST add fuel during the flight, assign a Keyboard Command to Fuel quantity (increase), that way you won't need to go to Aircraft > Fuel and Payload > Fuel page to add fuel.

Mark