Fighters Made in USA, for mid 1943: how would you do it?

[tomo pauk]

It's Dec 8th 1941. As a man responsible for production of fighters, you are tasked to develop a good-sized production of world-class fighters. Only US-produced ingredients allowed; you'd be able to use those Packard Merlins finally.
Please look beyond P-51/F4U combo (those are still main contenders); the production lines for P-47 are already established, and good usage/development of P-39/40 is encouraged, since your allies would've used them too. Only single engined types, for sake of simplicity - P-38 can soldier on as it did historically.

 

[tomo pauk]

I agree with most of the proposals

My 1st proposal is the venerable P-40.
The main plus is that we have it in production service, holding the line 'till better performers arrive. Some modifications are due, though.
No Merlins for P-40.
The next variant going to production (second half of 1942) will have oil cooler relocated in one wing root, akin to XP-60Q, enabling a shallower chin. 4 x HMG standard, provisions for 2 additional ones. Light alloy radiators when possible. Wings tips clipped. Possibility for stripped variant ( fuselage tank with with half of volume, cca 30 gal), reduced armor.
In the mean time Curtiss starts preparations to produce wings of P-51, in order to mate them with hull of P-40. With later single-stage V-1710s we can possibly touch 390 mph in mid 1943 service planes?
Curtiss will not build any P-47s.

(for 1944 the two-stage V-1710s, hopefully with intercooler in front of a wing)

 

[davebender]

Immediate needs.
.....P40 short range fighter.
.....P38 long range fighter.
Drop the P39 in favor of more P-40s.
Increase U.S. Merlin engine production. Let Allison know this engine will be replacing their V-1710 V12 if performance of the American designed engine doesn't improve. Commercial competition is a good thing.

The P-47 prototype is becoming very heavy and expensive. Merlin engines and Mustang airframes are readily available. Compare the performance of this combination with the XP47. The U.S. Army should set aside dislike of the USN and compare the F4U prototype also.

Assign someone competent to manage the U.S. 20mm cannon program, if that's possible.

 

[tomo pauk]

I agree about P-38.
What quantity of fighers is assigned to combat units till Bell converts to P-40 production? If we want Bell to produce something else, P-51 is better choice anyway.
Agree about Merlin production; installing them (single-stage V-1610s) into P-40 is bad thing if you can install them in P-51.
Competition is good thing. Expecting that US public and GM would've seat idly is unlikely to happen, aside the thing that we need Allisons for 3 major fighters now. P-51A (with Allison engine in production by early 1943) has performance comparable with Spit IX and contemporary German opposition; the single stage Merlin on P-51 (the one available in quantity by early '43) won't beat that.
P-47 (historically, almost to 1945) has it's drawbacks, I agree. Combat range, performance under 25K. In the availabilty of engines it has an edge vs. Merlin Mustang, and we need plenty of fighters.
F4U is good choice, I agree.
Ditto for 20mm program.

 

[Glider]

I agree about P-38.
Competition is good thing. Expecting that US public and GM would've seat idly is unlikely to happen, aside the thing that we need Allisons for 3 major fighters now. P-51A (with Allison engine in production by early 1943) has performance comparable with Spit IX and contemporary German opposition; the single stage Merlin on P-51 (the one available in quantity by early '43) won't beat that.

I was looking at a book on the 309th Fighter Squadron last week. They flew Spit IX and converted to the P51B. When this started the CO was away and the pilots checked out on the P51 and all of them wanted to kjeep the Spit IX, they appreciated the range but for a fight there was only one choice. When the CO returned he took up a P51 wrung it out and made a point of saying how much better the P51 was. The pilots thought that he must have banged his head, until it was pointed out that he was the CO and what did they expect him to say.

Which is a long way of saying that the P51A unquestionably fast at low altitude but overall the Spit IX was clearly a better aircraft.

 

[tomo pauk]

(not trying to bash Spit, nor to start P-51 vs. debate - we have plenty of threads about their merits)

Perhaps we are both wrong, I for stating P-51A as comparable performer, and you for stating Spit IX as overall better?
Spit is clearly a better climber, plus it's slightly faster at altitude. P-51A is somewhat faster at lower alt. So I'll agree that Spit was better performer.
As for being overall better, the major disparity lies in combat ferry range. P-51A has clear edge here.

Bringing us at RAF/Allied missed opportunity for troubling Luftwaffe in 1943, Spit VIII, (un)used in ETO. Ditto for P-51A - sent in India China by mid 1943.

 

[tomo pauk]

P-40s, reworked real ones:

 

[tomo pauk]

Next is P-39.
Two main shortcomings are low performance above 12-15K and combat range. Lack of fuel carried further hampers interception of planes flying at 20K and above, more so if proper early warning is lacking. So we need to have that turbo working, while relocating coolers in wings leaves space for fuel tanks.
Oil coolers go in one wing. Glycol cooler in another; wing bulge is due here because of bigger bulk.
Turbo version gets two under-wing drop tanks, since we'll need space for inter cooler just aft nose wheel well.
Armament is either 5 x .50 cals (3 in hull, 2 in wings), or cannon (20 or 37mm) plus 2 HMG in hull.
Non-turbo version is built 'till turboed one is produced in quantity. With 1325 HP @ 25K, 400 mph looks achievable in second half of 1942.
Stripped version (3 HMG, reduced armor) to catch Japanese high flyers.

Picture from a pdf about P-39, available on our site IIRC:

 

[tango35]

To have a fine fighter at the fontline, i would take the P-40; but i would also kick my scientists to develop the Lockheed L 133 !

 

[Shortround6]

I agree about P-38.
What quantity of fighers is assigned to combat units till Bell converts to P-40 production? If we want Bell to produce something else, P-51 is better choice anyway.
Agree about Merlin production; installing them (single-stage V-1610s) into P-40 is bad thing if you can install them in P-51.
Competition is good thing. Expecting that US public and GM would've seat idly is unlikely to happen, aside the thing that we need Allisons for 3 major fighters now. P-51A (with Allison engine in production by early 1943) has performance comparable with Spit IX and contemporary German opposition; the single stage Merlin on P-51 (the one available in quantity by early '43) won't beat that.
P-47 (historically, almost to 1945) has it's drawbacks, I agree. Combat range, performance under 25K. In the availabilty of engines it has an edge vs. Merlin Mustang, and we need plenty of fighters.
F4U is good choice, I agree.
Ditto for 20mm program.

People have to get over the idea that the US aircraft manufacturing was a "free" market in 1940-41. They also have to realize that production of large numbers of planes and engines took a long time to implement and production schedules could not be changed on a whim.
Allocation of machine tools and raw materials was already in place in 1940. Maybe if your companies bid is enough cheaper you can get the controlling authorities to change allocations. Trying to go out and buy the raw materials or machine tools in a "side deal" is going to get you arrested for black marketeering and your supplier charged with war profiteering.
you can't " build it and they will come".

First P-40 With a Merlin engine flew on June 30 1941. While the first production plane doesn't roll out the door until Feb 1942 all the production tooling was ordered and most built before Dec 8th 1941. Allocations of aluminium and steel had been made to Allison and Packard during those months. If there were different radiators or oil coolers needed ( and the two engines did get rid of different amounts of heat through both oil and coolant from each other) then radiator and oil cooler odres had to have been place weeks or months before production starts.
Just getting steel beams for a factory addition required Govt. approval.

If you change Bell from P-39 production to P-51 production how many hundreds of P-39s don't get built?
In the first 3 months of 1942 there were 343 P-38s built, 433 P-39s, 960 P-40s, 5 P-47s 220 P-51s and 234 F4Fs.
Now consider it could take one to three months to get a plane from the factory door to a combat theater.

also consider that there seems to be a 5 month gap Oct 42 to Feb 1943 when NO P-51s were delivered. first production P-51B comes out the door in May of 1943. There is a major shortage of two stage Merlins and airframes pile up at the factory waiting on engines.
Despite Packard building over 800 single stage engines a month since July of 1942 production of Merlins falls to 608 in April 1943 and while production skyrockets in may it is not until July that two stage production exceeds 100 engines a month and not until Jan 1944 does production of two stage engines exceeds single stage engines.

 

[tomo pauk]

People have to get over the idea that the US aircraft manufacturing was a "free" market in 1940-41. They also have to realize that production of large numbers of planes and engines took a long time to implement and production schedules could not be changed on a whim.
Allocation of machine tools and raw materials was already in place in 1940. Maybe if your companies bid is enough cheaper you can get the controlling authorities to change allocations. Trying to go out and buy the raw materials or machine tools in a "side deal" is going to get you arrested for black marketeering and your supplier charged with war profiteering.
you can't " build it and they will come".

That's fine with me

First P-40 With a Merlin engine flew on June 30 1941. While the first production plane doesn't roll out the door until Feb 1942 all the production tooling was ordered and most built before Dec 8th 1941.

Production tooling for P-40 with Allison Merlin differs about 5% or less, so no major issues here.

Allocations of aluminium and steel had been made to Allison and Packard during those months. If there were different radiators or oil coolers needed ( and the two engines did get rid of different amounts of heat through both oil and coolant from each other) then radiator and oil cooler odres had to have been place weeks or months before production starts.
Just getting steel beams for a factory addition required Govt. approval.

Both engines get produced as historicallly. If possible, in larger quantity, if not, historical quantity is fine with me.

If you change Bell from P-39 production to P-51 production how many hundreds of P-39s don't get built?
In the first 3 months of 1942 there were 343 P-38s built, 433 P-39s, 960 P-40s, 5 P-47s 220 P-51s and 234 F4Fs.
Now consider it could take one to three months to get a plane from the factory door to a combat theater.

To quote myself:
What quantity of fighers is assigned to combat units till Bell converts to P-40 production?
That applies for Bell converting to building P-51s, obviously.

also consider that there seems to be a 5 month gap Oct 42 to Feb 1943 when NO P-51s were delivered. first production P-51B comes out the door in May of 1943. There is a major shortage of two stage Merlins and airframes pile up at the factory waiting on engines.

Despite Packard building over 800 single stage engines a month since July of 1942 production of Merlins falls to 608 in April 1943 and while production skyrockets in may it is not until July that two stage production exceeds 100 engines a month and not until Jan 1944 does production of two stage engines exceeds single stage engines.

They waited for two stage Merlins.
Tough luck for Allies the P-40 ('stead of P-51s) received single stage Merlins, and that it was only 310 P-51As built. And mostly went to Asia.
P-51 is not yet covered by yours truly in this what-if...

 

[Shortround6]

I think you are missing the point, the decision to put the Merlin in the P-40 may have been made before the first production (initial British contract) ever flew. The Contract for the first 9000 Merlins from Packard called for 6000 to the British and 3000 to the Americans. Contract was signed in Sept of 1940, Just what are the Americans supposed to put those Merlins in besides P-40s in late 1940? Again you are allocating resources a year or more ahead of actual use and up to two years before combat use. Mustang prototype doesn't fly until Oct 26 1940, it crashes on 9th test flight Nov 20 1940. Next Mustang flight is May 25th 1941, just 35 days before first P-40 flight with Merlin. When do you decide the P-51 should get the Merlins and the Merlin P-40s go back to Allisons?

 

[tomo pauk]

Indeed, you are right about Merlin allocation.
The Merlins for P-51 will be then allocated on our start date, Dec 8th 1941; that leaves perhaps 500-700 Merlins for P-40 depending on how fast NAA can adapt the P-51 production line, or build new ones.

 

[tomo pauk]

200 gal for P-39.
Ammo for wing gun is aft CoG, partially canceling out expanded-ammo issues caused by hull guns. Other wing is left mostly unchanged here (edit: for sake of comparison with historic P-39 wing):

 

[Jugman]

also consider that there seems to be a 5 month gap Oct 42 to Feb 1943 when NO P-51s were delivered. first production P-51B comes out the door in May of 1943. There is a major shortage of two stage Merlins and airframes pile up at the factory waiting on engines.

The five month "gap" was do to A-36 production.

 

[Shortround6]

The five month "gap" was do to A-36 production.

Thank you for the correction.

 

[drgondog]

Shortround - you may recall the A-36 'camel's nose under the tent' was because USAAF did not have dicretionary funds for more P-51s (fighters in general) - and NAA proposed a dive bomber where there were funds to be allocated were still avaialable - and USAAF wasn't in mood to buy more A-25 (SB2C) or A-24 (SBD). The situation arose before the P-51 line had to stop and the design changes for the dive flap were incorporated as a block CID (IIRC) but I will look it up.

 

[CPWN]

Some other choices:

XP-47 with Allison engine
http://warbirdsforum.com/showthread.php?t=584

P-66 Vanguard
Vultee P-66 Vanguard - Wikipedia, the free encyclopedia

Curtiss P-60
Curtiss P-60 - Wikipedia, the free encyclopedia

 

[tomo pauk]

I'll venture to say that P-47C is better bet for our time frame than XP-47, P-66 has some tough competition in P-39/40, while P-60 was offering nothing when comapred with what was already produced.

 

[tomo pauk]

A few ideas about P-47, developed for our time frame (provided it doesn't get phased out after F4U gets introduced).
The main shortcomings noted by it's users were low rate of climb under 25K, combat range and cockpit visibility. The 'firm' solution for some performance issues can be introduction of water injection ( provided 2300 HP for historic P-47 in early 1944), along with paddle blade prop. The doc about Mr. Frank Walker states that water injection experiments were just started in early '43, so I won't add that here.
The introduction of the paddle blade prop seem like more doable affair for 'my' P-47C. The R/C of real P-47C was cca 2300 f.p.s. at SL (using 2000 HP - MIL power), declining slowly to 2000 f.p.s. @ 20K, while P-47D, paddle blade prop, 2000 HP (MIL), was capable to almost 2500 f.p.s. at SL, despite weighting 1000 lbs more. Dunno, perhaps additional 200 f.p.s. @ SL for my P-47 with new prop - keep the plane high, boys :\