My "record" with a NCD 747 is full on/full off in 65mins. Start unloading through side-door while commencing loading through nose-door. For a SCD only a/c you're looking at roughly an hour for offload and another hour for onload. Can go faster, just depends on the ground crew. The aircraft can only be loaded as fast as the pallets are brought to the aircraft.
Just don't go trying to load any Q7 pallets through the nose
