Lightning wing modification program

[Max89]

I'm looking at the history for F.6 XS925, and I noticed that in Nov '84 the aircraft was sent to a "wing modification programme".

 

A few months later in Feb '85 it was upgraded by British Aerospace to extend airframe flying hours by 400 hours.

 

Does anyone know the details behind the wing modifications of Nov '84 and upgrades of Feb '85? What did they do? And were there any externally visible differences?

 

The museum accession containing more information on this aircraft is right here: https://www.rafmuseum.org.uk/documents/collections/1990-0690-A-LIGHTNING-F.6-XS925.pdf

Edited November 4, 2021 by Max89

[Julien]

There was some cracking at the wingroots on F6s, not sure if this had any external differences.

 

The life extension I believe was called Mod 9, This had extra wing reinforcement plates to the underside near the wing roots which were visible. 

 

 

[Max89]

So the "wing modification programme" was just to repair the wings? I'm assuming the wing shape and appearance would have remained mostly the same then,

 

Was anything else done for "mod 9" besides the wing reinforcement plates?

[Bozothenutter]

Something similar as on the Phantoms?

Strips of metal in strategic places?

[tweeky]

More likely to be be inside the No1 engine bay roof as that's where the wings met. What was called the centre section.