The P-38J and L in the European theater.

[taly01]

From what I've read after developing the early P-38 and proving its concept (without much promise of purchases from USAAF in 1941) the best of the Lockheed team were moved to making revenue for the company by getting ready the Ventura and Hudson for British purchases! (remember this is pre-USA entry to WW2 and lend-lease).

So P-38 development remained in limbo until Pearl harbour and then they hurriedly tried to get it ready and found it was not really combat ready yet.

 

[redcoat]

One of the reasons often put forward in threads on the P-38 and why it was replaced in the 8th Air Force by the P-51 is economic, it was cheaper to operate a single engined fighter like the P-51 than a twin engined fighter like the P-38.
Is there any historical evidence for this claim or is it merely an assumption by the posters ?

 

[drgondog]

One of the reasons often put forward in threads on the P-38 and why it was replaced in the 8th Air Force by the P-51 is economic, it was cheaper to operate a single engined fighter like the P-51 than a twin engined fighter like the P-38.
Is there any historical evidence for this claim or is it merely an assumption by the posters ?

I have researched this question thoroughly. There is no written/sourced statement in Arnold, Spaatz, Doolittle, Eaker, Anderson, Lockheed, NAA histories or correspondence files in public or USAFHRC that I have covered that mentions economics as a factor.

What is true and verified is that Kenney would have taken every P-38 made if he could have had access and the P-38 was doing very well in multi role missions all over the globe. What is also true is that when Dallas P-51C started deliveries in September, 1943, the P-51B/C production quickly outpaced the P-38 at Burbank. What is also true is that the 85 gallon fuselage tank kits to extend range of P-51B/C beyond Berlin were being installed in October, 1943 and those kits were delivered 3:1 to UK over the 55 gallon LE kits for the P-38J-10.

Nobody in 8th AF lost sight that only 2 P-51 equipped groups nearly outscored all the 8th and 9th AF P-47D groups combined (IIRC ~ 10) performing escort for Big Week campaign - and far outscored the combined five P-38 FGs from both 8th and 15th AF. Destruction of the Luftwaffe was the Prime mission of 8th AF from January through May, 1944.

 

[P-39 Expert]

I agree with Tomo, however, in point 3, I need to address this portion:

The Wfr.Gr.21 and R4M were not used as extensively as was the 30mm cannon.
It was much more typical to have the Bf109 flying top cover while the heavier armed types (Bf110, Me410, Fw190A-8, etc.) attacked the bombers. And the presence of Allied fighter escort didn't deter the Luftwaffe's attacks.
In regards to limited fuel, only the Me163 and Me262 had short fuel windows for engagement - particularly the Me163, which had roughly 7 minutes of fuel. The Me262 had roughly 80 minutes cruise or 30 minutes of combat.
The piston-engined types had a much better fuel window and often times, they were flying from very local fields that lay in the bomber's paths.

The LW 109s and 190s had very little fuel to work with. The 190 held 140 gallons internal. It burned about 160gph at climb/combat setting giving it a theoretical 52 minutes of operation. Deduct 20 minutes to climb to 26000' and deduct 20 minutes reserve for landing and there are 12 minutes of fuel left for combat. Maybe one pass at the bombers, maybe two if there was no interference from escort fighters. The 109 was even more challenged with only 88 gallons internal.

 

[tomo pauk]

They were still finite. Removing the P-38 from production may permit increased production of equally effective, less expensive aircraft. It's not guaranteed, as Lockheed, for one, may not be able to produce Mustangs or Thunderbolts.

What would be the "equally effective, less expensive aircraft", and when to do the re-tooling? The P-40 and P-39 were less effective, but certainly not equally effective when it is about air combat 400-500-700 miles away from the base, at 20000-30000 ft. The P-47 is equaly effective, but it is not less expensive (10% cheaper?). That leaves us with P-51, that AAF didn't think much of before late 1942.
The main shortcoming of the P-38 was that it was not produced in double the numbers, so all theaters can have it already by mid-1942, while easing the introduction of needed modifications.

Folks, do we forget that Lockheed never expected to build more than 100 P-38s or that the AAF never intended to buy more than 75?

AAF ordered 13 YP-38s in late April of 1939, then 60 of P-38s, then UK and France orderd hundreds by May of 1940, then in Aug 1940 AAF ordered 608 examples. For example, Lockheed dragged their feet for 10 precoius months - time between the contract for YP-38s until start of manufacturing of those. All together, they squandered the timing advanatge held vs. P-47 and P-51.

 

[tomo pauk]

From what I've read after developing the early P-38 and proving its concept (without much promise of purchases from USAAF in 1941) the best of the Lockheed team were moved to making revenue for the company by getting ready the Ventura and Hudson for British purchases! (remember this is pre-USA entry to WW2 and lend-lease).

So P-38 development remained in limbo until Pearl harbour and then they hurriedly tried to get it ready and found it was not really combat ready yet.

As above - Lockheed have had on orders more than 1100 P-38s before Autumn of 1940, and plenty of time was squandered between April of 1939 and late 1941.

The LW 109s and 190s had very little fuel to work with. The 190 held 140 gallons internal. It burned about 160gph at climb/combat setting giving it a theoretical 52 minutes of operation. Deduct 20 minutes to climb to 26000' and deduct 20 minutes reserve for landing and there are 12 minutes of fuel left for combat. Maybe one pass at the bombers, maybe two if there was no interference from escort fighters. The 109 was even more challenged with only 88 gallons internal.

Have you accunted for drop tanks fuel? Why would the German fighters always employ the Climb/Combat setting?

 

[P-39 Expert]

As above - Lockheed have had on orders more than 1100 P-38s before Autumn of 1940, and plenty of time was squandered between April of 1939 and late 1941.



Have you accunted for drop tanks fuel? Why would the German fighters always employ the Climb/Combat setting?

Most LW fighters didn't use drop tanks for interception missions.
Regarding the climb/combat setting, they were taking off and climbing or in combat the whole mission on an intercept. Probably in climb/combat setting while returning to base in case any allied fighters were around for ground attack duty. That estimate does not include any time at TO/Emergency power or any interruption by escort fighters.
They just didn't carry much fuel. A 190's engine was in the same displacement class as the Corsair and Hellcat and they carried around 250gal and the Thunderbolt carried over 300. A 190 carried 140gal.

 

[tomo pauk]

Most LW fighters didn't use drop tanks for interception missions.

Any proof?

Regarding the climb/combat setting, they were taking off and climbing or in combat the whole mission on an intercept. Probably in climb/combat setting while returning to base in case any allied fighters were around for ground attack duty. That estimate does not include any time at TO/Emergency power or any interruption by escort fighters.
They just didn't carry much fuel. A 190's engine was in the same displacement class as the Corsair and Hellcat and they carried around 250gal and the Thunderbolt carried over 300. A 190 carried 140gal.

The Climb/Combat setting was limited to 30 minutes for the BMW 801 and DB 605.
P-47 was capable for 450-600 miles radius with wing drop tanks, LW fighters didn't needed such kind of radius in 1943-45; t's R-2800 burned from 210 gph (max continuous power) to 315 gph (war emergency power) - the BMW 801 was making less power and was consuming less. 10% less displacement.

 

[Shortround6]

A Bf-109 G (DB605A) used approximately 105 US gallons per hour at the climb/30 minute rating. With the fuel injection it didn't use as much fuel per HP hour as many of the allied engines.

US radials ran really rich ( really rich) at military power as an aid to cooling, both as an anti detonation measure and as a way to cool the engine itself.

 

[GrauGeist]

There seems to be a misconception about Luftwaffe types and their range/tactics.

The Luftwaffe interceptors most certainly did use drop tanks to increase their range & loiter time and home defense increasingly became their priority from 1944 onward.

There is plenty of proof to the interceptors using droptanks, but for this conversation, I'll use a quick example.

Seen attached, is a Bf109G-6/U2 of 3./JG301 (White 16) flown by Lt. Prenzel. He was on a "Wild Sau" night mission against RAF bombers the evening of 21 July 1944 and ended up landing at RAF Manston in error.
JG301 operated as Reichsverteidigung (Defense of the Reich), who's mission was to intercept and engage Allied bombers and fighters.

In the photo, taken when Lt. Prenzel and his Bf109 were taken into custody, the droptank can be seen still in place.

 

[swampyankee]

One of the reasons often put forward in threads on the P-38 and why it was replaced in the 8th Air Force by the P-51 is economic, it was cheaper to operate a single engined fighter like the P-51 than a twin engined fighter like the P-38.
Is there any historical evidence for this claim or is it merely an assumption by the posters ?

Well, two engines of comparable complexity, so about double engine maintenance effort, a unit cost of $97,000 for the P-38, vs $52,000 for the P-51 (Price of WW2 Aircraft), so close to 80% greater unit price, about twice the fuel consumption and oil consumption, and greater training requirements, so I think the economic argument is very strong. So is the argument based on the P-38's fitness for service, which was, by many reports, poor in the ETO for the earlier versions.

 

[Shortround6]

It may be hard to separate economic cost from logistic footprint. The P-38 and P-47 both having a much larger logistic footprint even after the initial plane was paid for.
With everything the aircraft needed fighting for priority in shipping space (even the ground crews food) to get across the Atlantic the logistic footprint was probably more important that contract cost.

 

[redcoat]

Well, two engines of comparable complexity, so about double engine maintenance effort, a unit cost of $97,000 for the P-38, vs $52,000 for the P-51 (Price of WW2 Aircraft), so close to 80% greater unit price, about twice the fuel consumption and oil consumption, and greater training requirements, so I think the economic argument is very strong. So is the argument based on the P-38's fitness for service, which was, by many reports, poor in the ETO for the earlier versions.

I've never thought the economic argument was a good one because the leadership of the Eighth were not accountants, all they were concerned about was protecting their bombers, the financial cost was irrelevant to them.

 

[MIflyer]

The P-38 cost twice what a P-51 did and required more maintenance as well. That will make the decision right there.

And my friend Ward Duncan. maintenance chief for the 9th PRS in India during most of WWII, used to go on at length about pilot errors that brought down P-38's or at least caused them to limp home on one engine.

 

[pbehn]

I've never thought the economic argument was a good one because the leadership of the Eighth were not accountants, all they were concerned about was protecting their bombers, the financial cost was irrelevant to them.

If they were accountants the cost of fighters would still be immaterial. How much does a fully crewed bomber cost in men materials and training hours?

 

[BiffF15]

If they were accountants the cost of fighters would still be immaterial. How much does a fully crewed bomber cost in men materials and training hours?

Also something to consider is the decision makers wouldn't stop 38 production to introduce the K model and it offered a perf boost. While more expensive than a Mustang it would appear costs weren't a major consideration until post war.

Cheers,
Biff

 

[swampyankee]

I've never thought the economic argument was a good one because the leadership of the Eighth were not accountants, all they were concerned about was protecting their bombers, the financial cost was irrelevant to them.

They did — one hopes — know how to count. They'd notice the lower number of aircraft — ones which cost nearly double and were not more capable — and the greater number of support staff.

 

[pbehn]

Also something to consider is the decision makers wouldn't stop 38 production to introduce the K model and it offered a perf boost. While more expensive than a Mustang it would appear costs weren't a major consideration until post war.

Cheers,
Biff

While all this was going on the B-29 and other bomber projects plus the A Bombs themselves were being financed, I suspect in the scheme of things fighter costs were "small beer".

 

[redcoat]

They did — one hopes — know how to count. They'd notice the lower number of aircraft — ones which cost nearly double and were not more capable — and the greater number of support staff.

The only counting the leadership of the Eighth was concerned with was the difference between the number of bombers setting out and the number which returned.

 

[P-39 Expert]

What would be the "equally effective, less expensive aircraft", and when to do the re-tooling? The P-40 and P-39 were less effective, but certainly not equally effective when it is about air combat 400-500-700 miles away from the base, at 20000-30000 ft. The P-47 is equaly effective, but it is not less expensive (10% cheaper?). That leaves us with P-51, that AAF didn't think much of before late 1942.
The main shortcoming of the P-38 was that it was not produced in double the numbers, so all theaters can have it already by mid-1942, while easing the introduction of needed modifications.



AAF ordered 13 YP-38s in late April of 1939, then 60 of P-38s, then UK and France orderd hundreds by May of 1940, then in Aug 1940 AAF ordered 608 examples. For example, Lockheed dragged their feet for 10 precoius months - time between the contract for YP-38s until start of manufacturing of those. All together, they squandered the timing advanatge held vs. P-47 and P-51.

Hindsight is 20/20, but why didn't the initial British order for P-51s specify the Merlin XX. It did wonders for the P-40F, imagine what it would have done for the early P-51 pending the introduction of a two stage engine. At half the cost of a P-38.

I have researched this question thoroughly. There is no written/sourced statement in Arnold, Spaatz, Doolittle, Eaker, Anderson, Lockheed, NAA histories or correspondence files in public or USAFHRC that I have covered that mentions economics as a factor.

What is true and verified is that Kenney would have taken every P-38 made if he could have had access and the P-38 was doing very well in multi role missions all over the globe. What is also true is that when Dallas P-51C started deliveries in September, 1943, the P-51B/C production quickly outpaced the P-38 at Burbank. What is also true is that the 85 gallon fuselage tank kits to extend range of P-51B/C beyond Berlin were being installed in October, 1943 and those kits were delivered 3:1 to UK over the 55 gallon LE kits for the P-38J-10.

Nobody in 8th AF lost sight that only 2 P-51 equipped groups nearly outscored all the 8th and 9th AF P-47D groups combined (IIRC ~ 10) performing escort for Big Week campaign - and far outscored the combined five P-38 FGs from both 8th and 15th AF. Destruction of the Luftwaffe was the Prime mission of 8th AF from January through May, 1944.

Page 144 "Vees for Victory" Gen. Jimmy Doolittle is said to have decided to rely on the P-51 as primary long range escort fighter because the P-38's Allisons were blowing up and the fixes were taking months. That should qualify as excessive maintenance.