Spit or P51 in mid 43

pbfoot said:

1. The Spitfire is a beautiful and amazing aircraft but it was out of it's element post D Day.

2. I propose if push come to shove they could have set up a paralell production line in the UK in less then 3 months, most of the jigs and forms could have come over on Ferry Command flights and the heavier equipment on convoy.

Click to expand...

1. I agree, but D Day was in 1944 the thread is about mid 1943. There was no shortage of combat aircraft over Normandy and I would say for the requirements of the allies after D Day the Tempest was a better plane.

2 If the British could set up a production line in 3 months why did it take NAA so long in America? Would the people working in UK be from spitfire factories which would cut spitfire production or new labour. How long did the dallas plant take to get operational?

Strapping a bomb under a single engined fighter means it requires an escort itself unless you have eliminated the opposition.


Posted by Dragondog
Well, nearly double the range, faster. Ideal sweep aircraft, armed recce, medium bomber escort to much longer range than Spit. Spit was superior in dogfight in everything except speed and dive..

That is the point I am making it was used by the British for tactical recon but as a medium bomber escort you need the medium bombers for fighter sweep I would say its lack of performance at altitude would be a problem.

The Brits never intended to build Merlin Mustangs, they 'hoped for' delivery but realistically foresaw them going straight to USAAF Strategic Bomber forces.. your statements are all true wrt to 'what did happen' but wasn't 'what if' the the basis of the thread?

I was replying to PBfoots proposition. When the Merlin was first fitted to the Mustang the requirement for long range escort was not forseen. As I said, to start producing Mustangs in the UK with either engine in 1943 the decision would have to be made in 1942. In 1942 the US had no interest in the mustang and no requirement for a long range escort. The "what if" in the thread is mid 1943 at which time the P51B/C had not arrived.

drgondog said:

Glider - 'wrinkling' is all about exceeding design limits for shear distribution in skins due to bending loads on the wing...

Click to expand...

I know but its fair to mention that the main spar of the Spitfire had some give in it being basically a strong leaf spring, it would when pushed beyond limits bend before breaking and that could well be why the planes and pilots made it home even if the skin was damaged. Some of the spits were written off after this damage but most were repaired.
The fix does seem unlikely but it did work and was often implemented.

Well, there really wasn't anything wrong, per se, about the wing design. It simply wasn't designed for the application.

All wings are like springs, some 'springier' than others. In the elastic range the spring returns to original state - when it exceeds elastic and moves to plastic (i.e. going to Ultimate Load from Limit Load) stuff has deflected too much - resulting in permanent structural damage for that group of 'items'

The concern about the Standard Wing from the beginning was about possible control reversal when ailerons were used in really high dive speeds. The design estimate for reversal was IIRC about 580mph but later tests referenced by NACA 868 showed that the P-47C-1 reversed at 565mph when at 400mph there was a 31% reduction in effectiveness in the aileron (indicating wing torsion).. but at the same time the Spit aileron effectives was reduced 65% at 400mph --------> suggesting that the '580mph reversal estimate was perhaps seriously optimistic..

The point is that the wing was less stiff than comparable designs and it was a known fact.

The Clipped wing was much stiffer - hence the dramatically improved roll rate at high speeds over the Mark V and IX..with standard tip design.

drgondog said:

The Clipped wing was much stiffer - hence the dramatically improved roll rate at high speeds over the Mark V and IX..with standard tip design.

Click to expand...

But at a price though...the attitude performance suffered and the clipped wings look horrid.
The original Shenstone wing was superior in design and outlasted the clipped one.
Cheers
John

I am pretty sure I read a test report that said that the clipping of the wing made little difference to the roll rate and the disadvantages outweighed the advantages.

Glider said:

I am pretty sure I read a test report that said that the clipping of the wing made little difference to the roll rate and the disadvantages outweighed the advantages.

Click to expand...

Look up Naca 868. There was a dramatic difference past 250mph in favor of clipped wing for all the reasons mentioned above. The Spit V wing for example started above a Mustang but as the speed increased beyond 225 mph, it quickly degraded and remained far below the Mustang at 400mph - on the other hand the clipped wing remained above the 51 until ~ 350+ mph

I believe the VIII had a strengthened wing, which it shared with the XIV. Another question as to why the IX, very much an upgraded V, continued in production for so long in preference to the definitive two stage Merlin Spitfire (ie the VIII).

drgondog said:

Look up Naca 868. There was a dramatic difference past 250mph in favor of clipped wing for all the reasons mentioned above. The Spit V wing for example started above a Mustang but as the speed increased beyond 225 mph, it quickly degraded and remained far below the Mustang at 400mph - on the other hand the clipped wing remained above the 51 until ~ 350+ mph

Click to expand...

I stand corrected, thanks

Wasn't meant as a correction - strictly conveying information..