Originally Posted by
Coffin Dodger
Re: stiffeners. This is as close as I can match to the area in question from pics in my collection, no further aft view from this angle unfortunately. Alpha Alpha at East Fortune.
Coffin Dodger,
M2dude and
Brit312,
M2dude will have to confirm that the 'lateral stiffeners' he is thinking of are indeed the very roughly 2' long and 5" strips at the location of each spar just outboard of the engine, that are very clearly visible on Coffin Dodger's photo of 'AA.
If so, they are indeed shown in the structural repair manual and listed as 'doublers'. There are ten of those, from spar 62 to spar 71.
Reading "between the lines", the modification dates from about 1978, and was applied by successive service bulletins to both the BA and AF aircraft.
CJ