buffnut453
Captain
I don't have any single factory production rates for the Spitfire but I Speculate that when sgnificant changes were made to wing etc,, they were not inserted as production articles in all Spitfire plants. Those changes were instituted equally at Inglewood and Dallas and did not disrupt assembly & delivery pace.
And this gets to the heart of the problem...you're speculating. You're also making a false equivalency between US and UK production approaches. The US had 2 big factories because they weren't under risk of enemy attack. The UK had a much more distributed approach because factories had been attacked.
Bottom line, though, is that Spitfires were ordered in distinct batches, just as were P-51s and every other aircraft type. Each batch had modifications but, generally, were internally consistent. There wasn't a need for "all factories" to be on the same page because they were delivering different batches to different modification standards. Again, I think you're overstating the impact of changes on the Spitfire and underestimating the extent of changes in the P-51.
Please feel free to prove me wrong by providing data to show that Spitfire production fell off markedly as each new variant was released. Note that from 1939 to the end of the Battle of Britain, the Spitfire deliveries included MkIa, MkIb, MkII, PR Mk IV, MkVa, and MkVb. If you can show me that the front line suffered despite these many incremental changes, then please do so...otherwise, we need to get out of speculation mode.
The Mustang IA/P-51-NA lifted the Proposed aramament configuration for the Mustang I, as well as propsed armament for the A-36 in original specification. The genesis of the slanted mount that plagued the follow on P-51A/B was the 20mm mount scheme for belt fed Hispano II. Nothing changed with respect jigs and tooling for the wing - save for leading edge planform at root for P-51D - which did not require complex change for anything other than the LE structure from WS 30 to 65. The A-36 changes to install the dive brakes, which included rib and panel changes as well as slightly different gun bay/ammo feed scheme.
And how is this different from the Spitfire? The internal structure of the wing changed to accommodate different armament configurations until the evolution of the "universal" wing. Again, you're minimizing P-51 changes and overstating Spitfire design changes.
Piece of cake had the necessity dictated the need. There is no role that the Spitfire accomplished that was not 'easily' accomodated by the P-51B/D airframe.
It's funny how, when others have argued that the Spitfire could have been adapted into a decent long-range escort, the response is often "couldda, wouldda, shouldda" from the P-51 crowd. Americans keep banging on about long-range, daylight bomber escort and yet that was not a role that the RAF wanted to take on. Similarly, AFAIK, the F-6 was not used for long-range, high-altitude PR. However, you want me to accept that the P-51 could do it? Why not accept that the Spitfire's range could have been significantly extended if there was an operational need?
To get out of speculation mode, though, let's take a look at the internals of the P-51. Installing a vertical camera with a long focal-length lens aft of the cockpit was considerably complicated by the ducting and fuel tank that sat there. Pushing the camera further aft limits the length of the lens that can be fitted....and the lens size is VITAL for high-altitude PR work. It was bad enough in the high-back P-51B/C but the P-51D fuselage got really small aft of the fuel tank. The big issue was the air intake trunking that forced any vertical camera well aft of the cockpit. You literally can't fit a vertical camera further forward than the aft-most point of the pink shaded area in the diagram below:
Putting large, heavy cameras with long lenses into a single-engine airframe is never a piece of cake and the P-51 was not a good choice for the role. Sorry to say anything negative about the Mustang but I'm afraid it simply wasn't up to the job. It was fine as a tac recce asset but not for strategic reconnaissance.
Even installing 20mm in the B/D was easily accomodated without a wing change other than the gun bay interior. Those designs andassociated analysis already existed from P-509 to NA-73 to A-36. The external bomb and fuel tank loads dictated the structural examinations - not recoil.
So for the P-51 it was a "new gun bay interior" whereas for the Spitfire it was a "new wing"? How do you figure that? From a front-line perspective, it made ZERO difference. If you were on a squadron with the early P-51 wing (with 30cals) you weren't going to install cannon or even 50 cals in that wing. Same-same for the Spitfire. You talk about minor strengthening in the wing of the P-51 but was the Spitfire any different?
The debate (for me) was definition of growth potential - not growth in fact. Much can be accomplished if the airframe is sound and the changes desired can be accomplished - but at what cost to production, field service complexity and delvery schedules.
And this brings us back to my original point. You're assuming that the changes that the Spitfire underwent significantly impacted production, field servicing and delivery. Over 20,300 Spitfires were produced and it remained in service for 15 years. That's growth potential and growth in fact.
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