Originally Posted by
Robbo Jock
Guessing that >150lbs fills appropriate fuel lines and ongoing siphon effect then allows the remainder to be sucked out but <150lbs doesn't get those lines filled and the fuel remains as ballast? Would be interested to know what the actual mechanism is.
If memory serves me correctly it’s an old std 330/332 problem/feature. Fuel transfer to the longitudinal tanks is via gravity and you have to be doing 100kts to get the fuselage level for it all to happen as expected. I’m reasonably sure it’s mentioned in the flight manual.