As Huck says, mode H does work on the ground. Gives a MTOGW of 630.5K instead of 625.5K. The FSC will schedule fuel to the tail when the LSDU (fuel panel) is turned off based on the aux tank quantity. 100lbs to the tail for every 750lb (above 9000) in the aux tank (or divide total aux tank fuel by 8.9). Tail tank remains empty on t/o regardless if W&B is performed in mode L, due to MEL item etc or in mode H if total FOB is around 153-154K lbs or less.
Last edited by Flightmech; 8th Dec 2009 at 12:26.