Removing 747 Engines
Apologies if this has been covered before.
EAAC have been juggling engines on their 4 x 747-200's parked at EGHH and very often they've left aircraft without any engines on the wings at all.
I know that I've seen pictures of the early 747 role outs with concrete blocks on the wings to save stressing the wing spar whilst they were waiting for their engines.
I was wondering if EAAC's practice is detrimental to the life of the airframe or if you can remove all engines for a certain amount of time only.
Perhaps they get around it by filling the wing tanks with fuel??
Can anyone shed any light on this?
Cheers