samsiam wroteDidn't know the 777 could reverse !!!
Well samsiam...be enlightened...all A/C can reverse and someties do. Just select the thrust levers to reverse and throttle-up!!!
However...it is also essential to select 'reverse' on the horn...so we get the beep! beep! beep! noise...:lemo:
Seriously...you are correct in that engine reverse, on most A/C, can only be selected when the wheel switches are made on the ground. The restriction to taxiing backwards is to avoid braking fiercely as the A/C can tip back....and reverse thrust can produce crap from the ground and be ingested by the engines.
I was on VC10's for many years (4 engines high in the tail, 2 with reverse) and we often used reverse to go backwards on the ground.