ALternatives for the P-38?

[tomo pauk]

People tend to have rather opposing opinions about the P-38. Ones, mostly located at the one side of the pond, adore it, while other, mostly at the other side, think of it as fighter that was either not needed, and/or as a constant source of trouble for the pilots ground crews.
So why not propose something better, or at least something more easily 'producible': a heavy fighter that USA was capable to build from 1940/41 on, using two, historically available, engines, aerodynamics of the era, while having historically available armament. As any decent heavy fighter, the combination of performance (both speed and climb), punch and range need to eclipse any single engined fighter of the era. Your fighter will be later tasked to do the reconnaissance, bombing, maybe even some night fighting. For the sake of discussion, we can also contemplate that Lockheed still builds the P-38s, your fighter being needed as the insurance, in case the P-38 encounters issues that would hamper/delay it's combat deployment use.

If the debate can stay away from the P-38 vs. P-51 match, that would be great; we have another thread covering that.

 

[Shortround6]

All you are going to do is swap perhaps a 20mm for one of more .50s for armament, nothing else was really available (except the 37mm and I don't think we want to go there).

The two radials ( R-1830 and R-1820) don't solve the early turbo problems and have more drag. Only feasible engine substitution is the Merlin XX/ V-1650-1

Without later than P-38 aerodynamics you wind up with the same mach limit and diving problem. If you plan from the start for a spacious fuselage for the radar, crew station for the night fighter you have a bigger, heavier, draggier fuselage for the single seat day fighter role, less performance.

You are going to wind up arguing about performance difference percentages in the single digits.

See XP-49 and XP-50 for alternatives and why they didn't make it.

 

[tomo pauk]

You make some points I agree with, and some that I do not. Before entering into a debate about the things I disagree, maybe you would like to propose something along the topic?

 

[ShVAK]

Truthfully there wasn't much need for a twin-engine heavy (day) fighter after BoB pulled the rug of imagined superiority out from under the Bf 110. While I think the Lightning matured into a stellar aircraft by late war marks and was clearly better in the escort fighter role than the Bf 110, it didn't really do most things better than a single-engine fighter could. The reason the P-38 survived in the USAF in the early war years was due to its range. Even an escort fighter with glaring deficiencies was better than none at all.

On that note, if the P-38 had been scrapped for mass production you might've seen developments of the P-40 design with extra tankage, the same turbo-supercharged Allison that the P-38 had or perhaps a Merlin variant, and other modifications to improve the type's range, high altitude performance and service ceiling. Barring that the USAAC doesn't really have a horse in the escort fighter race until late P-47 marks and the P-51B/C, and losses for Bomber Command would be correspondingly severe.

 

[ShVAK]

Anyway, to stay on topic:

My proposed fighter would be similar to Westland Welkin (w/ shorter thicker wing and less complex pressurization system) or Fw 187. The V-1710 w/ turbo-supercharging wasn't any bigger than a two-stage Merlin so it shouldn't take too much reimagining to make it work in the Welkin, and the Fw 187 was probably an even better candidate. Either way the fighter would have a more conventional layout than the P-38, single or two-seat variants, hardpoints for roughly 800-1000 lbs worth of bombs and external fuel stores, and the same firepower as the Lightning (maybe 2 x 20mm 2 x .50 instead if it can be done reliably).

Dive flaps would be installed to fix compressibility (assuming this is still a problem) and also to facilitate dive bombing. I would try to simplify and automate the throttle, air mixture controls etc. as that was often cited as a problem with the P-38--for a pilot with few hours of seat time, it took more than two hands to fly.

 

[tomo pauk]

Truthfully there wasn't much need for a twin-engine heavy (day) fighter after BoB pulled the rug of imagined superiority out from under the Bf 110.

The need was there. It has nothing to do with Bf-110 being (or not) superior; none of the LW planes taking part at the BoB were judged as superior (or perfect) after the battle anyway. But that's off topic.

While I think the Lightning matured into a stellar aircraft by late war marks and was clearly better in the escort fighter role than the Bf 110, it didn't really do most things better than a single-engine fighter could.

Fair points. Time to propose something better/with less shortcomings/less complicated/of better performance (pick one or more 'answers')?

The reason the P-38 survived in the USAF in the early war years was due to its range. Even an escort fighter with glaring deficiencies was better than none at all.

Would you please stipulate the planes that were over-performing the P-38, prior late 1943, from deck to 30000 ft, while being available to the USAF? Weren't the 'glaring deficiencies' more than overweighted by plane's good sides?

On that note, if the P-38 had been scrapped for mass production you might've seen developments of the P-40 design with extra tankage, the same turbo-supercharged Allison that the P-38 had or perhaps a Merlin variant, and other modifications to improve the type's range, high altitude performance and service ceiling. Barring that the USAF doesn't really have a horse in the escort fighter race until late P-47 marks and the P-51, and losses for Bomber Command would be correspondingly severe.

Glad you went on topic

 

[ShVAK]

Would you please stipulate the planes that were over-performing the P-38, prior late 1943, from deck to 30000 ft, while being available to the USAF? Weren't the 'glaring deficiencies' more than overweighted by plane's good sides?

Certainly, but your scenario assumes that the Lightning was removed from the front running due to its teething troubles. If this thread was designed to back the contention that the P-38 was a vital aircraft to the USAAC (at least until better fighters filled the void) you have no objections from me.

 

[tomo pauk]

The scenario does not flatly assume that P-38 was removed from the front, but that USAF goes for an 'insurance' against a possible P-38 major mishap (be it an overlooked construction miscalculation, or maybe difficulties in production). USN took similar path (encouraging Grumman to perfect the F4F in case F2A gets into troubles; insisting on the F6F even when the F4U looked like a world beater). Of course, we can discuss this with P-38 being available to the USAF, or not.

This part looked like a claim that P-38 had nothing to offer, but range, along with great deficiencies, in early war years?

The reason the P-38 survived in the USAF in the early war years was due to its range. Even an escort fighter with glaring deficiencies was better than none at all.

Hence I've asked what other fighters had to offer in the same era.

 

[ShVAK]

Range was the main reason the USAAC held onto the P-38, it was not the only reason.

At the time there were no real alternatives available for the ETO bomber escort profile. Both the P-40 and P-39 lacked range and performance at altitude to compete in that theater. They had to make do with what they had, and the P-38 was not a garbage aircraft, or even a mediocre aircraft. It was a good plane that performed better than anything else in the inventory circa '42. That still doesn't change that the issues of engines blowing up and compressibility dogged the P-38 until the -J and -L models, respectively.

"I'd rather have an airplane that goes like hell and has a few things wrong with it, than one that won't go like hell and has a few things wrong with it." -General Carl Spaatz

 

[tomo pauk]

"I'd rather have an airplane that goes like hell and has a few things wrong with it, than one that won't go like hell and has a few things wrong with it." -General Carl Spaatz

Nothing to add to that statement

That still doesn't change that the issues of engines blowing up and compressibility dogged the P-38 until the -J and -L models, respectively.

The engines were blowing mostly in the -Js* (and other Allison engined planes, but at far smaller rate). Unfortunately for the P-38, that ugly episode occurred in the wrong time and place, when the USAF was trying to escort the B-17s in Germany proper. When the issues were more or less solved, USAF already decided to go for Mustangs, late P-47Ds and P-47N as the long range escorts.

*several of Shortround6 posts cover the issue, in a high quality manner I'd say; you can also take a look at 'Vee's for victory' book re. V-1710s blowing up.

 

[gjs238]

The P-82/F-82 Twin Mustang seems to have been a success, if not too late for WWII.
But perhaps the concept of a "double" could have been used earlier with a design other than the P-51 as the basis.

 

[wuzak]

I have an issue with the role.

The P-38 wasn't designed or intended as a heavy fighter. Instead it was evolved as an interceptor, requiring heavy armament to shoot down enemy bombers and two engines to provide the desired performance. The result turned out to be a heavy fighter, but that was not the taregted role.

Re as escort fighters, the USAAC/F chiefs were largely from a group known as the bomber barons. They did not believe their bombers required escort - Schweinfurt in August 1943 fixed that.

Heavy fighter? What about the P-47?

 

[davebender]

P-38 specification originated during 1937. Three years before the BoB and the P-51 wasn't even a gleam in Hap Arnolds eye. No R2800 monster engines either.

I don't see many options for a long range, high altitude intercepter aircraft during the late 1930s. Twin engines are almost mandatory to provide power for carrying that much internal fuel. Turbochargers make sense for an aircraft designed for high altitude operation. They didn't work as well as planned but that happens sometimes with cutting edge technology.

No weapon choice. You get what the U.S. Army Air Corps decides to standardize on and that's the .50cal MG. Personally I would use six .50cal MGs mounted in the nose and skip the problem plagued 20mm cannon.

Something you can change is getting simple details right. For example there's no good excuse for a high altitude interceptor not to have an effective cockpit heater.

 

[wuzak]

No weapon choice. You get what the U.S. Army Air Corps decides to standardize on and that's the .50cal MG. Personally I would use six .50cal MGs mounted in the nose and skip the problem plagued 20mm cannon

My understanding is that the Hispano was less troublesome on the P-38 than in other installations.

 

[MikeGazdik]

I was going to make the point already made, that the P-38 was designed as a bomber interceptor. Only because it was so advanced for its time, was it able to be adapted to what really was needed. Otherwise, it would have been slowly pushed aside as the P-40 / P-39 was, aircraft that were designed around the same time frame. But it was not pushed aside, and it was adapted to the role that was actually needed, long range escort, long range strike.

That being said, the only aircraft that comes to mind that potentially could have replaced its role, would ultimately end up being called the F7F Tigercat. But that was many years later. Now across the pond, I don't know, but I am sure there were some designs that may have used the Merlin that could have done the same job. Maybe.

I think we may end up coming to the same conclusion that Kelly Johnson did and that is the only way to achieve the performance goals the USAAC asked for, is to put two turbo Allisons on an airplane.

 

[stona]

My proposed fighter would be similar to Westland Welkin

The first production Welkin (DX278 ) didn't fly until May 1943.

Amongst the factors for the RAF's loss of interest in the type were the "superior performance and manoeuvrability of the de Havilland Mosquito."
I'm afraid that doesn't sound like a replacement for the P-38.

I happen to think that the P-38 did a pretty good job. There was little priority placed on the development of a "heavy" twin engined day time fighter by the British. There was certainly a lack of urgency about the development of the Welkin. The Germans carried on from the Bf 110 with the Me 210/410 but it is hard to argue that these were competitive day light interceptors.

Single engined types with increased range were rightly preferred by the Allies in the escort role. With the benefit of hindsight it is easy to see that auxiliary fuel tanks should and could have been introduced earlier. This is a much cheaper way of hauling larger fuel loads and increasing range than developing another twin engined fighter. The arrival of the P-51 in Europe was the final nail in the coffin of any putative twin engined escort design.

Cheers

Steve

 

[davebender]

That's not a real big selling point considering overall reliablity of the American built 20mm cannon.

I suppose if you put four in the P-38 nose chances are at least two will function when your life depends on it.

 

[tomo pauk]

The P-82/F-82 Twin Mustang seems to have been a success, if not too late for WWII.
But perhaps the concept of a "double" could have been used earlier with a design other than the P-51 as the basis.

A double P-40? It could be built some time 1941. Plus, it's 1st of my many never-built planes that received MS Paint 'birth'
Six HMGs (USAF will insist on 37mm, maybe, so 1st it's going to be 2 cannons + 2 HMGs, with cannons later replaced either by 20mm each, or with 2 HMGs each). The new center wing gives an opportunity to make it of a more streamlined variety. Being a 2 seater, the NF variant is a must, esp. once the 9,6:1 Allisons (FTH at ~ 15000 ft) are available. Or Packard Merlin.

I have an issue with the role.

The P-38 wasn't designed or intended as a heavy fighter. Instead it was evolved as an interceptor, requiring heavy armament to shoot down enemy bombers and two engines to provide the desired performance. The result turned out to be a heavy fighter, but that was not the taregted role.

Re as escort fighters, the USAAC/F chiefs were largely from a group known as the bomber barons. They did not believe their bombers required escort - Schweinfurt in August 1943 fixed that.

Heavy fighter? What about the P-47?

Good call by you and Mike about the intended use. The P-47 would be a tad late; maybe something around the turbo R-2600? The 2 engines are stipulated in the OP, however

I was going to make the point already made, that the P-38 was designed as a bomber interceptor. Only because it was so advanced for its time, was it able to be adapted to what really was needed. Otherwise, it would have been slowly pushed aside as the P-40 / P-39 was, aircraft that were designed around the same time frame. But it was not pushed aside, and it was adapted to the role that was actually needed, long range escort, long range strike.

That being said, the only aircraft that comes to mind that potentially could have replaced its role, would ultimately end up being called the F7F Tigercat. But that was many years later. Now across the pond, I don't know, but I am sure there were some designs that may have used the Merlin that could have done the same job. Maybe.

I think we may end up coming to the same conclusion that Kelly Johnson did and that is the only way to achieve the performance goals the USAAC asked for, is to put two turbo Allisons on an airplane.

Fair points.

 

[ShVAK]

The first production Welkin (DX278 ) didn't fly until May 1943.

Amongst the factors for the RAF's loss of interest in the type were the "superior performance and manoeuvrability of the de Havilland Mosquito."
I'm afraid that doesn't sound like a replacement for the P-38.

Imagine the Welkin's Merlin power at mid-to-high altitude and larger fuel stores with a shorter, lower aspect ratio wing like the previous Whirlwind design, and a mix of .50 cal and 20mm. That's what I'm picturing as the ideal Lightning stand-in. Or something very similar to the Supermarine 327.

 

[wuzak]

Imagine the Welkin's Merlin power at mid-to-high altitude and larger fuel stores with a shorter, lower aspect ratio wing like the previous Whirlwind design, and a mix of .50 cal and 20mm. That's what I'm picturing as the ideal Lightning stand-in. Or something very similar to the Supermarine 327.

I think the Type 327 was going to be smaller - wing span 40ft vs 50-odd ft for the P-38. The Whirlwind was also smaller.