RAF duplicate aircraft codes

[ChemicalChaos]

I stumbled across this earlier, and I was quite confused:

http://www.f4phantoms.co.uk/74-squadron-tail-lette...

It appears multiple aircraft have the same tail marking identifier, all at once in the same squadron. I wondered if the duplicated ones were replacements for writeoffs, but it appears not as they were all scrapped at the same time (post Phantom phase-out).

Can anyone please explain why they have duplicate aircraft identifiers?

[whiteonyx]

The F4-J were sadly withdrawn from service and replaced with FGR-2s,

[ChemicalChaos]

whiteonyx said:

The F4-J were sadly withdrawn from service and replaced with FGR-2s,

So the duplicated aircraft are replacements, they just presumably kept the old versions around for spares?

Also, I thought the J replaced the FGR2, as the J spec ones were the imports from the US Navy that came on strength towards the end of the RAF's Phantom service period?

[Ginetta G15 Girl]

ChemicalChaos said:

Also, I thought the J replaced the FGR2, as the J spec ones were the imports from the US Navy that came on strength towards the end of the RAF's Phantom service period?

After the Falklands war it was decided to base a Sqn of F4s Down South (initially 29 Sqn, later 23 Sqn, eventually 1435 Flt). In doing so this left a gap in the UK Air Defence system so 15 F4Js were purchased from the USA. Brought up to almost F4S standard they were termed F4J(UK).

Thus they did not replace the FG1 and FGR2 but augmented them.

Obviously the F4J(UK) were somewhat different to the FG1 and FGR2 (J79 engines for example) and also required US AEA for operation (Aircrew Equipment Assembly - ie flying kit).

Thus, as Tornado ADV came on line, it made sense (both economically and from an inter-operability point of view) to bin the F4J(UK) and replace them with surplus FGR2 until such time as they themselves could be replaced by Tornado.