Originally Posted by
thetimesreader84
Without wanting to drift too much, I've been given a rule of thumb that with gear stuck down, the first 2 digits of your FOB is how many minutes until tank's are dry.
eg FOB 2800kg = 28 minutes until tank's are dry.
Hopefully never have to find out if its true!
Gear stuck down is serious situation can you depend on a thumb rule? Why not just open QRH have accurate analysis? Qantas 747 400 at Hongkong asked to hold at higher than normal altitude used a thumb rule for holding speed instead of FMS speed and stalled the aircraft thrice in the hold.