Prior 1942: ideal fighters for USAAC

[tomo pauk]

As usually, a what-if

So you are mover shaker in USAAC, and you want to have best hardware, in good numbers, for your service country. What 2 types would you choose to build, with main parts to be Made in USA? So no DB 601s, no Hispano 20mm etc.
The two types would be a kind of hi-low mix, one featuring the best combo US companies had to offer, and second featuring more 'common' parts, so your government can sell stuff abroad more easily economically.
As stated, you need a good force of fighter planes before 1942. Choice is not restricted to the types historically available, so you can mix match parts.

EDIT: Since I agree with our Shortround6 that P-38 P-40 were good choices, I'd like to alter the thread so that it covers only SINGLE engined jobs. Still 2 types (hi-tech off-the-shelf) required

 

[parsifal]

This will be an interesting discussion.....personally I'd vote for a licence built spitfire, though thats not allowed, I know

 

[Shortround6]

The answer is simple and historic. You build P-40s and P-38s. You just fund more than one P-38 so the loss of the prototype doesn't delay the program by months.
Your engine choices?
The R-2800 will not be available in any numbers until 1942 so it is out.
The R-2600 while offering good take-off power doesn't offer much at altitude for it's weight, bulk and cost.
The R-1830 is the second best bet of available engines.
The R-1820 is the 3rd choice, while the lightest it has the worst frontal area to power ratio. Not good for a fighter.
The V-1710 is first choice, while the heaviest of the 3, it's power to installed drag is by far the lowest of the group and it's raw power is comparable to the other two at 10,000-20,000ft, and that is without turbo.

Guns;
If you take out the Hispano (which was being delivered in late 41, although in a throughly fouled up version) then you are restricted to the .50 cal Browning and the 37mm for all practical purposes. The 37mm requires either a twin engine fighter or jumping though hoops like the P-39 so basically you have the .50 cal, just decide how many you want and without the R-2800 that comes down to 4 or 6 unless the fighter is a twin.

time:
To have big numbers by 1942 you have to decide and tool up in 1939 or spring of 1940. No laminar flow wings, trick radiators etc.

 

[tomo pauk]

Indeed, P-38 P-40 were good planes, so I've altered the 1st post in this thread to cover single engined planes only. Other requirements still apply.

 

[davebender]

The P-36 will remain the main USAAC fighter through 1942. Because the P-36 program has a higher priority the P&W R1830 engine program will also have a higher priority. The P-36 with 1,200+ hp engine should be adequate against Japanese aircraft. USAAC operations vs the Luftwaffe were fortunately rather small prior to 1943.

The F4U will be the USAAC fighter during 1943 to 1945. This will be produced in two variants.

F4U-1. Fighter-Bomber for low and medium altitude.
Essentially historical. However the USAAC variant will delete naval specific features such as folding wings and a tail hook.

F4U-??. Heavy Bomber Escort.
Optimized for long range and high altitude performance. Consequently it will have a bigger supercharger (possibly two speed) and greater internal fuel capacity. This aircraft will not be exposed to groundfire. If necessary some armor protection can be deleted to increase internal fuel capacity.

 

[Shortround6]

F4U is a non-starter in this discussion, literally, with just 6 R-2800 two stage engines built in 1941 there will be no production or service use of aircraft using this engine before the late spring/summer of 1942 at best. Historically took even longer.

P-36 was toast production wise. every P-36 made is a P-40 not made. The P-36 was quite bit slower than the P-40. And no, it is not because of the the lower powered R-1830s in the original P-36. It is becasue the radia engines, in cowling of the time, had 30% more drag than the Allison installation.

There is no problem with R-1830 production priority. Buick built 8,395 in 1942 and 24,624 in 1943. Chevrolet built 4,033 in 1942 and 11,842 in 1943. This in in addition to the 6,441 P&W delivered in 1941, the 10,202 in 1942 and the 11523 delivered in 1943.

 

[Glider]

I think that I would develop the P43. It lacked armour and self sealing tanks which are easily sorted but was good at altitude and would have good protection to other fighters at low level. Just replace the 2 x LMG with 2 x HMG add the armour/SS tanks and there you have it.
Its a personal view but I always thought that the P43 had a lot of potential but emphasis was understandably switched to the P47.

 

[tomo pauk]

Hmm, what about P-43 with Allison, turboed of course?

For lower end, it's a tie between F4F-3 P-66. One was vice-free ( narrow under-carriage as only fault?), other offered good performance even with single stage T-Wasp ( prone to ground looping during landing - perhaps relocation of hull MGs to wings [ 4 HMGs total, no LMGS] could've helped, since the CoG would've been lower, plus make main legs canted so wheels are little bit forward when down?).

 

[davebender]

Why? We have the benefit of hindsight and are starting in 1941 (i.e. prior to 1942).

If I wanted a water cooled V12 I would increase Merlin engine production in the USA. Any aircraft historically powered by the Allison would probably perform better powered by a supercharged Merlin engine. A twin engine fighter (if still desired) could be designed more compact and lighter in weight then the P-38 as you no longer need space for the turbo plumbing.

 

[tomo pauk]

Do you have any objections re. turboed Allison - availability, reliability, performance, in 1941?
Choice of Allison would be more in spirit of the thread anyway

 

[Shortround6]

We have been over this many times before, 1941 is way too late to make any difference in 1942. Even 1940 barely makes a difference in 1942.
Confusing/comparing the Merlin 60 series engines with their two stage superchargers which did not exist in 1941 to the american Turbo installations planned at the time is not being fair or unbiased.
Merlin XX series engines did not offer the same performance.
Merlins did not offer the same fuel economy as the Allison and so offered shorter range in the same airplane. This also has been gone over many times. Lockheed did paper studies of three different merlin setups through the years and in no case did the Merlin over any significant increase in performance and in some case caused the estimeate range or endurance to fall some where between 8-30% depending on exact versions of engines and cruise conditions.

 

[davparlr]

Good discussion topic.

I really like the P-66. It was good performer and could possibly be upgraded to the PW2800 which would have made it a very formidable fighter. Think lighter, cleaned up F4U or Fw-190 with a PW2800 engine.

The F4U is tempting. It would be a delay risk to implement but if developed as a lighter land based fighter it has great potential, quite a bit if developed from the start as land based, see P-66 above. Keeping the wing tanks would allow adequate range for escort and, while not as effective above 20k as the P-51, it would provide an adequate competitor to the German interceptors. Push the -18 engine forward and it would do very well.

P-38 was developed as a very capable all around fighter bomber but seemed to be difficult to get to that position, I am afraid it would always be behind the power curve.

My decision would be to build the P-51. By the end of 1941 it was in production (138 was produced by that time and I am sure a lot more if the AAF had been interested) and was certainly better than the P-40 with a whole lot more potential. So, build the P-51 en masse, it was relatively easy to build, and install that Packard Merlin as soon as possible. Develop the F4U for low altitude ops, the P-47 would also be acceptable.

Most of 1942 was effectively a no-show for the AAF mostly organizing so the manufacture and deployment of the advanced aircraft in the pipeline could be tolerated.

 

[Shortround6]

If you are not aware of it this document reveals a lot what might or might not have been possible for changing things around in 1941/42.

http://www.enginehistory.org/References/WWII Eng Production.pdf

Please note that many of these factories were under construction, modification and major enlargement during the war years in addition to major subcontracting, many of the factories that produced engines and aircraft by the tens of thousands in 1943-44 were bare plots of land in 1940/41.
Any time someone says "they just should have done XXXX" they never seem to suggest just which YYYY doesn't get done to compensate. Or they seem to think that a factory can be converted from one type of engine or airframe to another type in a few weeks.

 

[davparlr]

Lockheed did paper studies of three different merlin setups through the years and in no case did the Merlin over any significant increase in performance and in some case caused the estimeate range or endurance to fall some where between 8-30% depending on exact versions of engines and cruise conditions.

I don't know how this is not to be expected. I suspect that the basic output of the Allison is close to the Merlin and if you compare the hp output of turbo Allison to the Merlin in the P-51 over altitude, they appear to be equivalent. Equivalent hp, equivalent performance.

 

[Shortround6]

One thing is that for most of WW II the Allison used a 6.65 to one compression ratio vs the 6.0 compression ratio of the Merlin. This gave better fuel economy but limited the amount of boost that could be used in the Allison before detonation set in which limited power. The "hot rod" Allison's used the experimental P-51s and in the P-82 twin mustangs had their compression ratio dropped to 6 to one to allow higher boost.

 

[tyrodtom]

How about the P-39, with a 2 stage supercharger?
Was it so different that nobody trusted it enough to develope it ?

I know it had a reputation, maybe undeserved, for some odd flight charateristics, and exiting from it in an emergency was different from the method most pilots preferred.

 

[tomo pauk]

Not the sheer beauty, but rather how might looked P-43 if they've choosed V-1710 'stead of R-1830. 4 HMGs in wings for 1941, just crying for teardrop canopy:

 

[Shortround6]

The big problem with "improving" the P-39 was that it was a small airplane. To get the most benefit from a two stage supercharger an intercooler is needed (or after cooler). The P-39 simply didn't have room for one. The P-63 was two feet longer than a P-39 , partially because of the space needed by the second stage and partially because Allison's drive for the second stage took up more room than a Merlins second stage but even this later, larger plane had no intercooler. The P-39 was also handicapped, in American use anyway, by a rather unrealistic armament set up. a lot of weight in a small plane but guns that ran out of ammo at widely different times.

 

[tomo pauk]

'My' P-43 and P-66, bubble top:

 

[parsifal]

One thing to note, and almost impossible to take account of is that the original starting point for this discussion was no foreign imports...no Me 109s in stars and bars, that kind of thing. Thats fair enough, but I have read that the US aeronautical industry benefitted enormously, financially and technologically from mostly british experince, finance and expertise in the 1939-41 runup to US entry. Do we need to try and estimate that impact, and remove it from the US dvelopment program. to what extent did the US aeonautical industry benefit from Pommie input? can they claim this US product, if it was being designed by Britons, paid for by Britons and (at the time of design and initial production at least) was being prepared for British service.......