The P-38J and L in the European theater. (1 Viewer)

[Peter Gunn]

The P-40Q first flew in June 1943. The limitations including very low oxygen supply (2 3/4 hrs at 20K), no external wing rack capable of carrying either drop tanks or bombs of same weight, no internal space to add extra fuel tank, limited capability to pressurize tanks without modification, 20-30mph slower than Production P-51B with much better performance using an engine that was in full production (1650-3) rather than development stage (V-1710-119) and -121).

*SNIP*

Just a few of the reasons that to me, make the Mustang, if not the very definition of a world beater, then very close to it.

I am still amazed at what a masterpiece Edgar Schmued et. al. achieved using slide rules and the old brain box.

 

[swampyankee]

CW chose not to ask USAAF to manufacture the Q. They could have replaced the N version with the Q. The engine was available for the P63 and P51j. Q had better flight performance over all coupled with higher altitude performance CW imho became a Greedy manufacture. It would have saved lives. Example, The F87 was the last straw with the now DOD. After that CW was asset stripped by greedy investors. Second most profitable Defense contractor during WW2. Today CW is a speciality DOD contacting company.

The US failed to introduce the P63 to USAAF which would have been a far better Ground attack and fighter plane than any of the current fighters. For the same reason the P51 almost got ingnored. The NIH issue came up. Like the P40 and whole new design P51 because the calaboration of two engineering groups the P63 suffered the same fate.

CW's airframe side was having problems before WWII; they had problems getting and keeping engineering talent. It got worse post-war. CW still exists, but it's very much small potatoes

 

[drgondog]

The P-40Q didn't get the green light for three reasons:

1) Multiple prototype accidents. Never a good sign.
2) P-51 was already looking good and production ready to take off
3) War Dept, Air Force and the government in general were sick of Curtiss Aircraft.

I think 3 is actually the most important reason. Curtiss was just screwing up right and left, they hadn't improved the P-40 nearly enough, the other P-40 replacements (P-46 and P-60 etc.) were failures (and looked like crap!) and numerous other aircraft they had produced turned out to be very expensive debacles. The Helldiver and the Seamew were epic fails. Experiments like the C-76 and the XP-55 failed. Their best designers had left after 1942, and even the P-40 run was having some production quality problems. The only planes they made even partly successful after the mid-war were the C-46 and the Seahawk and neither was critical to the war effort.

Curtiss as a company was just corrupt and bloated and incapable of delivering what was needed.

The P-40Q did look promising and may have been better in some respects than a P-51 but it would have meant taking a gamble on a once great company that had let them down time and time again. North American by contrast had a much better record both in terms of design and production.

S

What you say about Curtiss reputation in 1943 is factual - but the primary reasons that the P-40Q never made the cut were 1.) as tested, it had an unproven engine for high altitude operation, 2.) as tested, it was lighter than it would have been in combat operations which would diminish projected performance and 3.) MOST IMPORTANTLY - there was no key mission for which the P-40Q was required for, in which it was better at, than P-51B, P-38H/J and P-47C/D.

The same logic applied to the XP-51G which arguably had the highest (Actual) conventional s/e performance in US R&D Inventory in early 1944. It had more performance than P-51B/D, P-47M, etc - But - the Merlin 100/14 SM engine was still in development/test, the internal fuel was inadequate for projected maximum range escort, so its only true projected role would have been very fast mid range escort/air superiority and/or long range Interceptor. The P-40Q was puny in any comparison one could make except roll and turn in mid speed range.

 

[Schweik]

What you say about Curtiss reputation in 1943 is factual - but the primary reasons that the P-40Q never made the cut were 1.) as tested, it had an unproven engine for high altitude operation, 2.) as tested, it was lighter than it would have been in combat operations which would diminish projected performance and 3.) MOST IMPORTANTLY - there was no key mission for which the P-40Q was required for, in which it was better at, than P-51B, P-38H/J and P-47C/D.

The same logic applied to the XP-51G which arguably had the highest (Actual) conventional s/e performance in US R&D Inventory in early 1944. It had more performance than P-51B/D, P-47M, etc - But - the Merlin 100/14 SM engine was still in development/test, the internal fuel was inadequate for projected maximum range escort, so its only true projected role would have been very fast mid range escort/air superiority and/or long range Interceptor. The P-40Q was puny in any comparison one could make except roll and turn in mid speed range.

I'm not sure it's that cut and dry. There was no such thing as a perfect fighter, and to a large extent the others were doing missions they weren't fully suited for either - P-47 was a high altitude fighter but they were using it for CAS. P-38 too as well to some extent. Spitfire was an interceptor but they were using it for escort some times. P-51 was a long range fighter but was being used as an interceptor.

I think if the War Dept thought they were going to get a good fighter out of a P-40Q I think they probably would have gone for it. Lack of sufficient oxygen tanks or external tank fittings are not exactly insurmountable design flaws. I think the P-63 was just too short ranged to be of much of any use (except to the Russians). If they trusted Curtiss (and if the prototypes hadn't crashed) I think they may have produced it. But given the track record at Curtiss (including making bad engines) I think it may have been a bad bet. And so did they!

S

 

[Schweik]

My take on the P-38 is this.

It was a brilliant design, certainly the best twin engined day fighter design of the War. Probably the only twin-engined fighter actually viable in day time air-to-air combat after the first year or two.

But it was also a flawed design. It had a lot of design flaws which probably could have been fixed in time but which Lockheed was a little too slow to correct. These were eventually fixed but by that time, it was past the tipping point of the war and in fact we had entered the Jet Age. WW II piston-engined fighters were in a race to be useful before their entire design basis was obsolete. It's arguable when that cutoff point was, but probably some time toward the end of 1944. You might say until the end of the war but I would argue that wasn't quite the case. Certainly by the next significant War (Korea) Jets were dominant and even the best piston engined fighters were playing tertiary roles.

The P-38 was able to be useful even in it's early flawed (E,F) variants because it had a speed (and high speed climb) advantage over the enemies in the Pacific Theater and some of the pilots were able to adapt. It didn't have this advantage in Europe. The last 'L' variant was probably good enough to hold it's own in a fight, arguably - which is unusual for twin engined fighters as I said. But it still had some pretty serious flaws (not being able to dive away was a really big flaw) and by then it didn't really have a role that wasn't already done a little better by the P-51 or the Spitfire.

Any more money put into that design or it's production was no longer worth the investment since the next fighter was going to be a Jet.

S

 

[pbehn]

I'm not sure it's that cut and dry. There was no such thing as a perfect fighter, and to a large extent the others were doing missions they weren't fully suited for either - P-47 was a high altitude fighter but they were using it for CAS. P-38 too as well to some extent. Spitfire was an interceptor but they were using it for escort some times. P-51 was a long range fighter but was being used as an interceptor.

You are taking the end, or best use of these aircraft to be their original design use. The Spitfires design brief was certainly as an interceptor, the P51 certainly wasn't designed as a long range escort, it wasn't even designed for US forces.

edit The P-38 and P-47 were ordered to other specs, I believe they were also primarily interceptors with high altitude performance in their origins.

 

[Schweik]

You are taking the end, or best use of these aircraft to be their original design use. The Spitfires design brief was certainly as an interceptor, the P51 certainly wasn't designed as a long range escort, it wasn't even designed for US forces.

edit The P-38 and P-47 were ordered to other specs, I believe they were also primarily interceptors with high altitude performance in their origins.

I'm talking about the role they were developed for, not necessarily just the original design specs or prototype. There is a subtle but very real distinction, and sometime the two things were in sync, sometimes they weren't.

The P-51 became a "real" fighter in the eyes of the USAAF when the Merlin 60 allowed it to fly (fight) at high altitude. They already knew about it's range but that was also enhanced. The combination of these traits were obvious and led to it's development as a long range escort.

I think the P-38 was also developed as an escort fighter from an early date in it's production cycle. As was the Thunderbolt. The P-47 was certainly optimized for fighting at high altitude and not as maneuverable or fast down low. But the radial engine and heavy armament made it suitable in certain respects for CAS, which ultimately became it's most important role.

 

[FLYBOYJ]

I think the P-38 was also developed as an escort fighter from an early date in it's production cycle.

100% Incorrect!!! The P-38 design was based on an Army Air Corps Circular Proposal "X-608" released in 1937. This spec was written by Lts, Ben Kelsey and Gordon Saville and called for a twin-engine high-altitude "interceptor" having "the tactical mission of interception and attack of hostile aircraft at high altitude."

 

[Schweik]

100% Incorrect!!! The P-38 design was based on an Army Air Corps Circular Proposal "X-608" released in 1937. This spec was written by Lts, Ben Kelsey and Gordon Saville and called for a twin-engine high-altitude "interceptor" having "the tactical mission of interception and attack of hostile aircraft at high altitude."

Ok well, maybe this is a matter of emphasis. Did you read this part in the post you quoted?

"I'm talking about the role they were developed for, not necessarily just the original design specs or prototype."

I think once the early P-38 models started being produced, there was an immediate push to use them in the escort role, though interception was also a useful role particularly in the Pacific and particularly at longer range (such as the dramatic shoot-down Yamomoto)

Aircraft don't appear as a prototype or an initial version and just remain the same. They start getting pushed in one direction or another. Right?

S

 

[Ascent]

The Americans were wed to the idea of the unescorted bomber formation long past the point that other countries had realised the folly of it, why would they develop an aircraft as an escort when they didn't forsee a role for it?

 

[GrauGeist]

I think...

Don't.

The P-38 was born of the long-range interceptor ideology, much like Germany's Bf110 heavy fighter/interceptor (Zerstorer) or Bell's XMF-1 Airacuda.

It was designed in a time when the philosophy of the "heavy bombers will get through", the P-38 was intended to counter that.

 

[pbehn]

I'm talking about the role they were developed for, not necessarily just the original design specs or prototype. There is a subtle but very real distinction, and sometime the two things were in sync, sometimes they weren't.

The P-51 became a "real" fighter in the eyes of the USAAF when the Merlin 60 allowed it to fly (fight) at high altitude. They already knew about it's range but that was also enhanced. The combination of these traits were obvious and led to it's development as a long range escort.

I think the P-38 was also developed as an escort fighter from an early date in it's production cycle. As was the Thunderbolt. The P-47 was certainly optimized for fighting at high altitude and not as maneuverable or fast down low. But the radial engine and heavy armament made it suitable in certain respects for CAS, which ultimately became it's most important role.

When it became clear that escorts were required the US and UK used whatever they could lay their hands on and worked on increasing the range of everything.

 

[P-39 Expert]

My take on the P-38 is this.

It was a brilliant design, certainly the best twin engined day fighter design of the War. Probably the only twin-engined fighter actually viable in day time air-to-air combat after the first year or two.

But it was also a flawed design. It had a lot of design flaws which probably could have been fixed in time but which Lockheed was a little too slow to correct. These were eventually fixed but by that time, it was past the tipping point of the war and in fact we had entered the Jet Age. WW II piston-engined fighters were in a race to be useful before their entire design basis was obsolete. It's arguable when that cutoff point was, but probably some time toward the end of 1944. You might say until the end of the war but I would argue that wasn't quite the case. Certainly by the next significant War (Korea) Jets were dominant and even the best piston engined fighters were playing tertiary roles.

The P-38 was able to be useful even in it's early flawed (E,F) variants because it had a speed (and high speed climb) advantage over the enemies in the Pacific Theater and some of the pilots were able to adapt. It didn't have this advantage in Europe. The last 'L' variant was probably good enough to hold it's own in a fight, arguably - which is unusual for twin engined fighters as I said. But it still had some pretty serious flaws (not being able to dive away was a really big flaw) and by then it didn't really have a role that wasn't already done a little better by the P-51 or the Spitfire.

Any more money put into that design or it's production was no longer worth the investment since the next fighter was going to be a Jet.

S

IMO you are correct. Almost all fighters got better as they progressed through their incremental models. The P-38 was very advanced and by the time they got it working properly (L) the LW had been beaten by (mostly) other planes.

 

[FLYBOYJ]

Ok well, maybe this is a matter of emphasis. Did you read this part in the post you quoted?

"I'm talking about the role they were developed for, not necessarily just the original design specs or prototype."

I think once the early P-38 models started being produced, there was an immediate push to use them in the escort role, though interception was also a useful role particularly in the Pacific and particularly at longer range (such as the dramatic shoot-down Yamomoto)

Aircraft don't appear as a prototype or an initial version and just remain the same. They start getting pushed in one direction or another. Right?

Don't back peddle!!!! I read your quote -

"I think the P-38 was also developed as an escort fighter from an early date in it's production cycle."

Early in the P-38 production cycle they were being built by hand!!!!!

The use of the P-38 as an escort came as an OPERATIONAL requirement by Lockheed's major customer, the USAAF. A paragraph from Wiki documents how this came about quite nicely:

"The strategic bombing proponents within the USAAF, called the Bomber Mafia by their ideological opponents, had established in the early 1930s a policy against research to create long-range fighters, which they thought would not be practical; this kind of research was not to compete for bomber resources. Aircraft manufacturers understood that they would not be rewarded if they installed subsystems on their fighters to enable them to carry drop tanks to provide more fuel for extended range. Lieutenant Kelsey, acting against this policy, risked his career in late 1941 when he convinced Lockheed to incorporate such subsystems in the P-38E model, without putting his request in writing."

Aircraft don't appear as a prototype or an initial version and just remain the same. They start getting pushed in one direction or another. Right?

Not all the time!!!

 

[drgondog]

I'm not sure it's that cut and dry. There was no such thing as a perfect fighter, and to a large extent the others were doing missions they weren't fully suited for either - P-47 was a high altitude fighter but they were using it for CAS. P-38 too as well to some extent. Spitfire was an interceptor but they were using it for escort some times. P-51 was a long range fighter but was being used as an interceptor.

I think if the War Dept thought they were going to get a good fighter out of a P-40Q I think they probably would have gone for it. Lack of sufficient oxygen tanks or external tank fittings are not exactly insurmountable design flaws. I think the P-63 was just too short ranged to be of much of any use (except to the Russians). If they trusted Curtiss (and if the prototypes hadn't crashed) I think they may have produced it. But given the track record at Curtiss (including making bad engines) I think it may have been a bad bet. And so did they!

S

Schweik - I find my self arguing when I agree much of what you post, That said, as you said, the AAF was sending out CP's from 1937 through 1940 for a War Plan Requirement that contemplated Defense of the United States - not strategic warfare fought outside US and Territories. The AAF got its nose under the tent with the B-17 based on Coastal Defense capability which was a lot more agile than aircraft carriers to maneuver in position of a foreign power (i.e. Japan) known to the WPD to be capable or potentially capable of projecting power to attack the US (Japan, UK) without regard to friendly/not friendly.

The CP's for Interceptors included the 'heavy' (P-38) and 'Lite' (P-39) - bot to be equipped with turbos to support the in-line engine technology of the time And carry 37mm cannon as primary anti bomber armament.

It was well known by several chief AAC architects (notably Spaatz) that a S/E fighter could not be developed as a long range fighter (escort or otherwise) capable of supporting WP Objectives. It wasn't until Spring 1939 that multi place fighter CP-618 (leading to P-61) which focused on t/e long range fighter aircraft and single place fighter CP-616 (NAA not invited) which led to XP-46, XP-47 and DS-312A - but still pointing toward Interceptors, not general purpose fighters for all altitudes.

When Arnold appointed a Special Board (Kilner Board) to examine R&D priorities in May, the Board came back several months later with a. Better Liquid Cooled Engines, 2.) Improved fire control systems for bomber defense, and 3.) Fighter to rank with Best in the World. Arnold also appointed the Emmons Board to perform further review on Fighter requirements. Emmons Board came back with "development of an escort fighter capable of 1500 mile range" as Number 4 - Arnold moved it to number 1.) as Spaatz and Eaker submitted reports recounting RAF difficulties in prosecuting Daylight bombing against both the Bf 110 and Bf 109, Arnold REMAINED the visionary - and the first to ask "what if the bomber can not survive, unescorted, over enemy held targets".

Note: Mustang contract for NA-73 in secret discussion with BPC in direct conflict with orders from AAC Material Command that same month.

The point of the 'blah, blah, blah' above - is that over the next several months, a.) the P-39 was believed to be inferior to the existing Bf 109 and Spitfire and the shock of the A6M had not occurred, b.) the P-38 was ordered by Brits w/o turbos and in testing which led to cancellation due to poor performance and c.) the P-40 arrived in Britain and France with questionable performance comparisons to Bf 109 and Spitfire.

As you stated, Curtiss and Bell greatly overstated performance and the follow-on development fighters were also disappointing. The Close Air Support acolytes still wedded to the notion that Army Aviation should continue to increase battlefield effectiveness were feeling greatly under-appreciated by Material Command and began to place great pressure on suitable high speed/high capability (plus bomb load/maneuverability and range (for Recon)

Both the P-39 and P-40 were small airframes, no easy growth potential for internal fuel or external loads, deemed ok as interim solutions, but neither the P-63 nor P-40Q offered anything near a complete check list of CAS requirements. All this pressure, combined with knowledge of anticipated Merlin 61 capability unfolding in fall/winter 1941 growing awareness outside Material Command of Mustang capability, desire by Arnold to find a role for the Mustang in early 1942 - killed the future of P-63 and P-40Q - before they could get traction. The interceptor role of the P-63 and possibly the P-40Q was a possibility IMO) but by that time RANGE was deemed priority 1 as an outcome of Arnold Conference in February 1942.

Note that Arnold was Not aware that the P-38E had been modified to carry external ferry tanks of 165 and 330 gallons. At the time of the Fighter conference, however, he did know that the Mustang I had greater range and cruise speed with internal fuel than the P-38E with only internal fuel. It also had 1500 mi range capability with the auxiliary tank kits replacing wing guns/ammo belts.

 

[Schweik]

I think we are talking about two different things here, and this is kind of a big deal in aircraft development.

• Phase one is initial design and planning. Requirements issued by the government, companies come up with designs they think will match them.
• Phase two is the actual building and testing of the first few prototypes
• Phase three is the introduction to the field and first contact with the enemy. Many aircraft never got past this stage.
  
• Phase four is initial series production, teething, subsequent redesigns and improvements - this is when a given aircraft either becomes viable or gets cancelled. The aircraft is in production and gets used but may not yet be ideally suited for any job.
  
• Phase five is when - if the design is very successful - they start large-scale production and it gets into the field in significant numbers, and becomes one of the mainstays of the war.

I'm talking about phases three and four. You guys are talking about phases one and two.

The design theories are often way, way off, and have to be radically rethought after they contact the enemy.

For the P-38 phase four lasted a long time. Two years arguably. For the mustang it also lasted about a year (however long the Allison Engined ones were in use). Others had a shorter

S

 

[Milosh]

Some examples of Phase Three please.

 

[pbehn]

I have seen this many times on this forum, I believe it stems first from a picture of a P-51D and an evaluation of its range, speed and altitude performance and all round handling qualities. It seems rational to conclude that it was designed to do that from the outset, but the fact is it wasn't.

 

[drgondog]

["Schweik,]I think we are talking about two different things here, and this is kind of a big deal in aircraft development.

• Phase one is initial design and planning. Requirements issued by the government, companies come up with designs they think will match them.
• Phase two is the actual building and testing of the first few prototypes
• Phase 2.1 is evaluation and recommendation to the manufacturer for mandatory and desirable improvements
• Phase 2.5 is acknowledgment, discussion and Agreement to specific improvements
• Phase 2.7 is release of Y version meeting agreement (not always followed - NA-73 and P-47 are specific examples where production was authorized before testing improvements.
• Phase 2.8 is release of early production series to customer (ie BPC/RAF) to perform Operational Suitability Testing, which if accepted as is, leads to deployment to Training and operational units for training prior to combat
  
• Phase three is the introduction to the field and first contact with the enemy. Many aircraft never got past this stage.
• Phase 3.0 is recommendation for new mods, and/or decision that aircraft does not have a strong capability to accomplish projected role, but has value elsewhere (P-39, P-40 later models as P-38 and P-47 and P-51 are produced in numbers to gradually replace the operational aircraft and return the obsolete aircraft to lower threat environment (P-40K/N assigned to Air Training Command, P-39 also assigned to train units in States, P-63 deployed to ATC and Russia)
  
• Phase four is initial series production, teething, subsequent redesigns and improvements - this is when a given aircraft either becomes viable or gets cancelled. The aircraft is in production and gets used but may not yet be ideally suited for any job.
• Phase four as you presented is actually Phase 2.8 above
  
• Phase five is when - if the design is very successful - they start large-scale production and it gets into the field in significant numbers, and becomes one of the mainstays of the war.
• During WWII in US, your Phase five was eliminated before order placed for high quantity production - examples given include P-47B, P-51B which were contracted for production before first actual prototype flight.

In the above scenario, the P-40Q was not solicited by AAF - it was an investment, originally based on upgrading wing to low drag and introducing new Allison two stage supercharger to improve high altitude cability - but use an airframe for which tooling and processes (P-40K) existed and easily placed into production following acceptance testing and Agreement for serial production -

I'm talking about phases three and four. You guys are talking about phases one and two.

I'm talking about all except end of life cycle.

The design theories are often way, way off, and have to be radically rethought after they contact the enemy.

In many examples, the Specifiers were way off and the designers did a credible job of design/fab to spec. Where many designers failed in 1937-1942 was lack of awareness of drag rise at speeds above .5M and/or low drag airfoils which reduced high speed performance estimates to crap (specifically CW and Bell and even Douglas)

For the P-38 phase four lasted a long time. Two years arguably. For the mustang it also lasted about a year (however long the Allison Engined ones were in use). Others had a shorter

From Contract to 1st Operational combat sortie:
P-38 6-23-37 to 4-42
P-39 10-7-37 to 10-9-41
P-40 4-26-38 to 9-1940 (Russia)
P-47 9-6-1940 to 4-8-1943 (8th AF)
P-51 4-12-1940 to 5-10-1942 (RAF)
P-51B 8-25-1942 to 12-1-1943 (9th AF)

 

[FLYBOYJ]

I think we are talking about two different things here, and this is kind of a big deal in aircraft development.

• Phase one is initial design and planning. Requirements issued by the government, companies come up with designs they think will match them.
• Phase two is the actual building and testing of the first few prototypes
• Phase three is the introduction to the field and first contact with the enemy. Many aircraft never got past this stage.
  
• Phase four is initial series production, teething, subsequent redesigns and improvements - this is when a given aircraft either becomes viable or gets cancelled. The aircraft is in production and gets used but may not yet be ideally suited for any job.
  
• Phase five is when - if the design is very successful - they start large-scale production and it gets into the field in significant numbers, and becomes one of the mainstays of the war.

I'm talking about phases three and four. You guys are talking about phases one and two.

The design theories are often way, way off, and have to be radically rethought after they contact the enemy.

For the P-38 phase four lasted a long time. Two years arguably. For the mustang it also lasted about a year (however long the Allison Engined ones were in use). Others had a shorter

S

The P-38, because of many circumstances went from your phase 2 to phases 4&5 simultaneously!