Originally Posted by
Capt Fathom
Aren't the outboard engines higher off the ground than the inboards?
Yes, but the jet wake still contacts the ground just passed where the tail ends. On some taxiways the outboard engines hang off the paved areas so there is a lot of stuff that can be kicked up.
A few years ago we were doing some flight testing of a 747-8 at the Boise, Idaho airport (that doesn't normally see many 747s). We actually got a panic call from the tower to not use the outboard engines during taxi - apparently we were throwing up quite the cloud
