Sky Wave

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

ft

I'd say the concrete blocks are more to keep the W&B in check than to avoid stressing the wing spar.

N1 Vibes

Gent's

it's routine to remove all 4 donks during major checks, say C and D checks. Don't think there is a special requirement to hang bricks on-wing then.

Brgd's

N1 Vibes

Sky Wave

Thinking logically, the weight of the aircraft is supported by the wings in flight so it really shouldn't matter if the wings are a bit light.

Cheers anyway.

I'm still wondering why they bothered with concrete blocks at Boeing when the 74's first came out. The mass & balance suggestion could be an answer but I understood they did it with all of them, surely you could have calculated the M & B and wouldn't have needed to put concrete blocks on every aircraft. Can anyone confirm if it was done for that reason?

NSEU

Perhaps an old wives tale? I was also told, many many years ago that it was to prevent stress.

N1 Vibes... Re C & D checks. I would check BMM 7-11-05 prior to removing engines whilst the aircraft is on jacks (due W&B considerations).

Rgds.
NSEU

SMOC

They probably have placed ballast in the fwd cargo which I have seen done before, I've also seen the nose wheel tied down.

Rgds SMOC