WI: Effects of an earlier development of P-51 on Allied air campaigns?

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As it says on the tin.

What would be the effects on the Allied air campaigns in WWII if there was an earlier development of North American's P-51 Series, basically the aircraft being developed around the early 1930's, the same time as the Hurricane, Spitfire and Bf 109?

What would be the effects of these aircraft being in service from 1939?
What effect would it have on the Luftwaffe or even the Japanese?
How would the BoB or even Battle of France play out if either were used by the RAF or the French?
Would they be used as part of 'Lend-Lease' to the USSR?

Much obliged!
 
What engine does it get, ie early or late merlins? What would a P51 do speed wise with a 1,030 hp Merlin II? If you give them the later Merlins, then all the RAF aircraft using them are massively improved, especially at altitude.
 

As it says on the tin.

What would be the effects on the Allied air campaigns in WWII if there was an earlier development of North American's P-51 Series, basically the aircraft being developed around the early 1930's, the same time as the Hurricane, Spitfire and Bf 109?

What would be the effects of these aircraft being in service from 1939?
What effect would it have on the Luftwaffe or even the Japanese?
How would the BoB or even Battle of France play out if either were used by the RAF or the French?
Would they be used as part of 'Lend-Lease' to the USSR?

Much obliged!
You have an aircraft developed specifically because the manufacturer didn't want to build a different aircraft under license for the RAF, not to mention the full potential of the airframe not being realized until it received a Merlin engine. And why would the USAAF invest in such an incredibly expensive project at a time when the P40 Warhawk is perfectly acceptable? It's not ASB but it is amazingly implausible.
 
A P-51 in 1939, rivet-for-rivet as the historical machine (especially if it is the P-51D as depicted) is pretty much ASB...
 
As jsb says unless you butterfly a better Allison engine or the development of the Merlin all you get are early series Mustangs until engine technology catches up. Also unless you have the British design and specification input what you get pre-war will not be a P51 as we know it.
Now even fitted with an early mark Merlin the P51 to OTL design will be a Peer level fighter, as in 1940 the 1,030hp Merlin was right up their with just about every other engine. As the speed increases the drag efficiency of the P51 becomes more important but on average the cruising speed would be about Spitfire plus ten percent.
 
Perhaps a better question would be "what if P51 droptanks were developed earlier". The greater range would have enabled greater bomber protection by fighters which may in turn have shortened the war.
 
As jsb says unless you butterfly a better Allison engine or the development of the Merlin all you get are early series Mustangs until engine technology catches up. Also unless you have the British design and specification input what you get pre-war will not be a P51 as we know it.
Now even fitted with an early mark Merlin the P51 to OTL design will be a Peer level fighter, as in 1940 the 1,030hp Merlin was right up their with just about every other engine. As the speed increases the drag efficiency of the P51 becomes more important but on average the cruising speed would be about Spitfire plus ten percent.

By 1939, Merlin III was a 1300 HP engine. Shove it in a P-51 airframe and see it going another 10-15 mph over Spitfire I.

Perhaps a better question would be "what if P51 droptanks were developed earlier". The greater range would have enabled greater bomber protection by fighters which may in turn have shortened the war.

Probably a thing of semantics, but there was no such thing as 'P51 droptanks'. P-51A and on used standard Anglo-American drop tanks (up to the weight allowed), and A-36 used those a tad before (winter of 1942/43). A P-51A, let alone the P-51 or does not have any kind of performance edge over Fw 190 at 25000 ft, either.

FWIW: going all-in with Mustang X (Merlin 60 series in the nose) with drop tanks would've netted a whole set of problems for the LW in 1943. There was probably 500+ Mustang I airframes left in the UK by late 1942. Granted, that does not solve the 1939-1942 questions.
 
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It took a while for North American to get an Allison Engine for their Mustang prototype. Had the British sent a Merlin over instead, perhaps in the interests of streamlining maintenance/hopes of future American production, the prototype flies earlier and work begins earlier on a Merlin Mustang. It wouldn't be a world-beater but it would jumpstart the development process and make a formidable fighter to boot. Perhaps in TTL, the entire P-40F debacle is avoided in favour of earlier Merlin-Mustangs...
 
It took a while for North American to get an Allison Engine for their Mustang prototype. Had the British sent a Merlin over instead, perhaps in the interests of streamlining maintenance/hopes of future American production, the prototype flies earlier and work begins earlier on a Merlin Mustang. It wouldn't be a world-beater but it would jumpstart the development process and make a formidable fighter to boot. Perhaps in TTL, the entire P-40F debacle is avoided in favour of earlier Merlin-Mustangs...

Stuffing the RR-made Merlin on the (X)P-51, as it was done on the P-40F prototype, and later going with Packard Merlin V-1650-1 would've produced an excellent fighter for 1942-43 (and for 1944 for Asia/Pacific).
(P-40F was not that much of a debacle, though, it was of comparable speed as the Spitfire V, with better range and rate of roll, but with lower rate of climb due to greater weight; unfortunately, Germans upped their game many moons before P-40F was introduced)
 
Stuffing the RR-made Merlin on the (X)P-51, as it was done on the P-40F prototype, and later going with Packard Merlin V-1650-1 would've produced an excellent fighter for 1942-43 (and for 1944 for Asia/Pacific).
(P-40F was not that much of a debacle, though, it was of comparable speed as the Spitfire V, with better range and rate of roll, but with lower rate of climb due to greater weight; unfortunately, Germans upped their game many moons before P-40F was introduced)
Re: the P-40, I'm not sure why making a fighter variant that's largely obsolete by the time it's introduced isn't "that much of a debacle", but that's splitting hairs...

The only estimates I've seen for a P-51 with a V-1650-1 come from the French FFO site. Those strike me as "good" or maybe "very good" but not "excellent." That being said, I'm willing to consider that they made a mistake or my assessment is off.
 
Re: the P-40, I'm not sure why making a fighter variant that's largely obsolete by the time it's introduced isn't "that much of a debacle", but that's splitting hairs...

P-40F was probably a result of the P-40E being lacklustre due to all bits & pieces added through P-40 -> P-40B -> P-40C - P-40D - P-40E evolution without much of engine improvement; the P-47B being a hot mess akin to the early Typhoons (not a single of 171 produced went overseas), all while not having enough of P-38s and P-47Cs/Ds for a real global war as it unfolded.

The only estimates I've seen for a P-51 with a V-1650-1 come from the French FFO site. Those strike me as "good" or maybe "very good" but not "excellent." That being said, I'm willing to consider that they made a mistake or my assessment is off.

We can take a look here, for the (British?) estimates on Mustang powered by Merlin XX (about the V-1650-1 equivalent) and Merlin 61. 1st estimate returns 400 mph at ~18000 ft, second returns 440 mph with vastly better hi-alt performance; Merlin 60 series were excellent engines due to the 2-stage superchargers and constant development of other bits & pieces.
We can also take a look here, for the test of the Mustang II (= P-51A), powered by V-1710-81 engine (a.k.a. F20R), that did 391 mph at 18000 ft. The V-1710-81 was making a bit less of power than the Merlin XX/V-1650-1 above 10000 ft, talk 900 HP vs. 1050 or thereabout at 20000 ft. The 400 mph speed figure for the Merlin XX is very realistic, of not a tad conservative IMO.
 
P-40F was probably a result of the P-40E being lacklustre due to all bits & pieces added through P-40 -> P-40B -> P-40C - P-40D - P-40E evolution without much of engine improvement; the P-47B being a hot mess akin to the early Typhoons (not a single of 171 produced went overseas), all while not having enough of P-38s and P-47Cs/Ds for a real global war as it unfolded.



We can take a look here, for the (British?) estimates on Mustang powered by Merlin XX (about the V-1650-1 equivalent) and Merlin 61. 1st estimate returns 400 mph at ~18000 ft, second returns 440 mph with vastly better hi-alt performance; Merlin 60 series were excellent engines due to the 2-stage superchargers and constant development of other bits & pieces.
We can also take a look here, for the test of the Mustang II (= P-51A), powered by V-1710-81 engine (a.k.a. F20R), that did 391 mph at 18000 ft. The V-1710-81 was making a bit less of power than the Merlin XX/V-1650-1 above 10000 ft, talk 900 HP vs. 1050 or thereabout at 20000 ft. The 400 mph speed figure for the Merlin XX is very realistic, of not a tad conservative IMO.
Thanks for the info on the Merlin Mustangs! I was not aware of those sources.
 
Just Stuffing a Merlin XX or 61 in a Mustang one only gives you a test aircraft. the RR Merlin was heavier than the Allison and IIRC the wings had to be moved forward several inches to get the aircrafts CoG back to within limits that gave a performance and handing suitable for combat.
 
Re: the P-40, I'm not sure why making a fighter variant that's largely obsolete by the time it's introduced isn't "that much of a debacle", but that's splitting hairs...

The only estimates I've seen for a P-51 with a V-1650-1 come from the French FFO site. Those strike me as "good" or maybe "very good" but not "excellent." That being said, I'm willing to consider that they made a mistake or my assessment is off.

It suffered the same problem many US weapons had early WW2, a peacetime budget during a major war that it wasn't in yet. A lot of US weapons were good, for 1939 when the war broke out. The Hawk was one of the best planes France had in 1940 , making 12.6% of the planes with about a third of the kills. Hawks in France Even the Brewster Buffalo was a good plane...... for 1939. The M2A4 was probably better than anything the Germans had short of a Panzer IV (before the Panzer III got its armor upgrade) in 1940. The problems was that the US didn't have weapons that much better it had in 1939 when 1942 came to pass and weapons tech improved fast during the war.
 
It suffered the same problem many US weapons had early WW2, a peacetime budget during a major war that it wasn't in yet. A lot of US weapons were good, for 1939 when the war broke out. The Hawk was one of the best planes France had in 1940 , making 12.6% of the planes with about a third of the kills. Hawks in France Even the Brewster Buffalo was a good plane...... for 1939. The M2A4 was probably better than anything the Germans had short of a Panzer IV (before the Panzer III got its armor upgrade) in 1940. The problems was that the US didn't have weapons that much better it had in 1939 when 1942 came to pass and weapons tech improved fast during the war.
And even if the USA considered the P-40 inadequate the P-38 Lightning was in development and the P-39 Airacobra for that matter.
 
Even one squadron with 1945 Allied pilots would probably be sufficient to remove all the Stukas and therefore prevent the crossing?
And why not, if the Germans and Americans canadvance things by a couple of years and not on the ASB forum why not the Brits and French.

Also I want Napalm
 
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