# With the P-38K, was the P-51 and F4U even necessary?



## Mosshorn (Jun 7, 2011)

A five (5) gun (.50 caliber) armed P-38K with drop tanks would have made a very dangerous long-range escort / patrol fighter in every theatre of operation. Why this didn't happen is beyond me. 

( The following comes from: Whatever Happened To The P-38K ? )

*The Story Of The Best Performing Variant Of The P-38 Lightning *

The Lockheed P-38K-1-LO is now nearly forgotten. No photographs of the aircraft are known to exist today. Only the original test mule was photographed. It has been relegated to that part of history where one of prototypes and special test aircraft usually go. This is rather unfortunate for this aircraft as it was the benchmark against which all other variants of the P-38 Lightning must be compared. Simply said, it was the best performing Lightning ever to take to the sky. 

Lockheed paid close attention to the performance gains achieved with the P-47 when the new "high activity" Hamilton Standard propellers where first fitted on a Republic P-47C in mid 1942 (later, in mid 1943, these propellers were retro-fitted in Britain). The new "paddle" blade prop had significantly increased the rate of climb and acceleration of the "Jug". Lockheed decided that they would install the Hamilton Standard hydraulic propellers on one of the factory test "mules". Thus, was the XP-38K born. The "mule" was an extensively modified P-38E. The original intercoolers were replaced with the newer type introduced on the J model. The initial test results were very encouraging and a P-38G service test airframe -- 422-81, AFF serial number 42-13558 -- was selected to be modified. 

The new propellers were not the only design changes made in the search for greater performance. This airframe was configured for the Allison V1710F-15 powerplants which were rated at over 1,875 bhp in War Emergency Power (as compared to 1,725 bhp for the V1710F-17 in the P-38L). This was the only P-38 so configured. The potent combination of the engine/propeller promised excellent performance. 

There were still other modifications that were necessary. The Hamilton Standard props required a spinner of greater diameter, and the thrust line was slightly higher as well. This in turn, required that new cowlings be manufactured to properly blend the spinners into the engine nacelles. These were hand made and the fit was less than perfect. The new propellers necessitated a change to the reduction gear ratio. The Curtiss Electric props had a normal ratio of 2.00 to 1. The ratio was changed to 2.36 to 1. 

Flight tests were conducted from late February through the end of April 1943. Performance was better than hoped for. Maximum speed at critical altitude (29,600 ft) was 432 mph (Military Power). At 40,000 feet, the "K" zipped along at a speed that was 40 mph faster than the current production P-38J could attain at this same height. Maximum speed in War Emergency Power, at critical altitude, was expected to exceed 450 mph. The increase in ceiling was just as remarkable. Flown to 45,000 ft on an extremely hot and humid day, Lockheed engineers predicted a "standard day" service ceiling in excess of 48,000 ft! Improvement of the cowling fit and the elimination of the heavy coat of paint would have gained even more performance. Due to the added efficiency of the new propellers, range was expected to increase by 10 to 15 %. Lockheed appeared to have a world-beater on their hands. 

The plane, now designated the P-38K-1-LO was flown to Elgin Field for evaluation by the USAAF. Flown against the P-51B and the P-47D, this Lightning proved to be vastly superior to both in every category of measured performance. What astounded the evaluation team was the incredible rate of climb demonstrated by the P-38K. From a standing start on the runway, the aircraft could take off and climb to 20,000 feet in 5 minutes flat! The "K", fully loaded, had an initial rate of climb of 4,800 fpm in Military Power. In War Emergency Power, over 5,000 fpm was predicted. 

In light of this incredible level of performance, you would certainly expect that the Government would be falling all over themselves to quickly get the P-38K into production. Yet, this was not the case. The War Production Board was unwilling to allow a short production suspension in order to get new tooling on line for the required change to the engine cowling. Even when Lockheed promised that the stoppage would only be for 2 or 3 weeks, their request was turned down. 

The true consequences of this pig-headed thinking will never be known. What would have been the impact of such a high performance fighter arriving in force to the forward combat areas in mid 1943? How many lost fighter pilots would have survived thanks to the awe inspiring performance of the P-38K? Again, we can never know these things. What we do know, is that due to bureaucratic myopia, neither the P-38K nor a Merlin powered Lightning ever really had a chance to make an impact upon the air war. For all those pilots who died at the controls of lesser aircraft, the War Production Board bears a measure of responsibility for their fate. 

RESOURCES: 
Warren M. Bodie, The Lockheed P-38 Lightning. 
Lockheed Martin Archives.


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## TheMustangRider (Jun 7, 2011)

Definitely would have been interesting to see such machine take on the Luftwaffe and the Imperial Japanese Air Force.


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## davebender (Jun 7, 2011)

> Flight tests were conducted from late February through the end of April 1943


By February 1943 the P-47 and F4U were tooled up for mass production. The P-51B was only a few months away. Converting those factories to produce P-38Ks would probably cost at least 18 months worth of lost production. The first P-38Ks might not roll off the assembly lines until late 1944.

A prototype P-38K during February 1941 would be an entirely different matter.


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## drgondog (Jun 8, 2011)

The P-38K would never have replaced either the P-47 or P-51 - Period. - And NEVER be a fleeting thought for USN who wanted a.) no part of a non-carrier qual fighter, and b.) in line liquid coolant Allison Engines

For production reasons, cost reasons and lack of sufficient incremental performance - either over the P-51B/P-47D or as compared to next Gen P-80...it Would have been an excellent upgrade of the J but there is no theory that places the K into delivery to Europe before the 'real J's and - the earlier J was still plagued with intercooler problems, no dive flap/brake, and no boosted ailerons in late 1943 through june 1944. So what do we expect the K to do during the critical Nove 1943 through May 1944 timeframe?

Dave is right about production status of the 'competitors' and the production tooling for the P-51B was complete in February 1943. What remained was more engine allocations, and de-bugging the new coolant issues with the radiator.

The 'Paddle Blade' introduction is 'fuzzy'. NONE of the production P-47C's still arriving in ETO in August-September and IIRC the 56th FG got the first paddle blade mods, along with WI in the P-47D-11 ~ Dec 1943, Jan 1944.


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## renrich (Jun 8, 2011)

You must be kidding! The P38, among other things, as a carrier fighter? Just to start with, how many P38s could a carrier carry, much less support.


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## wuzak (Jun 9, 2011)

The major problem with the P-38K for production was that the V-1710 used a different reduction gear ratio, which meant that much of the cowling had to be redesigned and retooled for manufacture. 

No chance for a P-38K prototype in 1941 because the P-38 had barely begun production, the higher grade fuels hadn't been developed yet, and the Allison V-1710 was not yet able to make the power required for the K.


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## gjs238 (Jun 9, 2011)

renrich said:


> You must be kidding! The P38, among other things, as a carrier fighter? Just to start with, how many P38s could a carrier carry, much less support.


FWIW, the Navy did pursue the F7F Tigercat.


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## tyrodtom (Jun 9, 2011)

I wonder where you could put the tailhook on a P-38 ? Folding wings ?

The F7F was designed from the beginning with carrier operations in mind , but only for the bigger Midway class carriers.

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## syscom3 (Jun 9, 2011)

It would have made it (the K model) the greatest photo-recon bird of the war. Perhaps even better than the P47 for ground support missions.


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## glennasher (Jun 10, 2011)

$$$$$$$$$$$$$$$ always a thought, and time, the P-38s were complex and slow to build, compared to the single-engine aircraft. I suspect that price paid a major part of it, though, you could buy almost 4 P-51s for the price of one P-38, and they only required one engine at a time, etc.
And then you'd still have the problem of pilots with frostbite.


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## drgondog (Jun 10, 2011)

glennasher said:


> $$$$$$$$$$$$$$$ always a thought, and time, the P-38s were complex and slow to build, compared to the single-engine aircraft. I suspect that price paid a major part of it, though, you could buy almost 4 P-51s for the price of one P-38, and they only required one engine at a time, etc.
> And then you'd still have the problem of pilots with frostbite.


 
In all fairness the P-38K would have been about 2X more expensive flyaway and nearly 2X ops - so not as bad as 4X.

The P-38 was more versatile but... you can buy a lot of 'slightly not as good' for 1/2 price which is why the P-51 survived post war in USAF inventory.


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## davebender (Jun 10, 2011)

1944 aircraft cost.
$97,147 P-38
$85,578 P-47
$51,573 P-51

The U.S. Army Air Corps purchased more P-47s then any other fighter type yet it was pretty expensive too. If the P-38K performed as advertised and was tooled up for mass production I don't think cost would have been an issue.


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## billswagger (Jun 11, 2011)

I always held it in my head that the P-38, although one of the first piston fighters to fly high altitude escort missions for the US, was the least suitable.
Much of its development was spent overcoming its complications with compressibility at high altitudes.
Most pilots, however, spoke highly of it. Mock fights between P-47s and P-38s had many pilots thanking the Japanese did not have such a plane.


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## renrich (Jun 13, 2011)

To be fair, there are a lot of conflicting statements on other aircraft also, but here are some about the P38L at the 1944 Fighter Conference: 

"Bad visibility to sides and down, would rather have F4U or F6F for the Pacific."
"I would not consider this a modern fighting aircraft. Poor coordination of control forces and effectiveness, combined with very weak directional stability make it a poor gun platform and it's maneuverabilty rating is so low as to preclude it's use in modern combat."

"Too complicated and full of gadgets-would make unserviceability rate very high."
"As a fighter bomber-good,for fighter sweep-just fair,as escort-poor."
A number of more uncomplimentary remarks but I am tired of looking and typing.


It looks to me that us armchair fighter pilots are unaware of a lot of factors which make an airplane suitable for combat. We look at Vmax, climb rate and range and get all fired up for our favorite plane and don't know what we are talking about and I include my self in that analysis. Lot more to it than meets the eye.

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## tomo pauk (Jun 13, 2011)

P-38 introduced a double number of everything for pilot to look after (excluding the radio armament) when compared with single-engined fighter, so it must've been a trouble for pilots used for F6F F4U to drive one. But, saying that it was a poor gun platform with low maneuverability (in 1944), being a poor escort, bad for Pacific - are that the words of USN aviators (bias)?


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## Lighthunmust (Jun 14, 2011)

renrich said:


> To be fair, there are a lot of conflicting statements on other aircraft also, but here are some about the P38L at the 1944 Fighter Conference:
> 
> "Bad visibility to sides and down, would rather have F4U or F6F for the Pacific."
> "I would not consider this a modern fighting aircraft. Poor coordination of control forces and effectiveness, combined with very weak directional stability make it a poor gun platform and it's maneuverabilty rating is so low as to preclude it's use in modern combat."
> ...


 
I have the book. My impression is that many of the evaluators may have been good pilots in the aircraft they had experience with but had little training in how to conduct an evaluation that would be considered preformed with good scientific method. I also think some personal and service bias skewed the evaluations. The methods used at the Conference were far removed from the more precise techniques used after the war at Wright and Edwards to test aircraft. The comment about P-38 maneuverability is very interesting considering the success of Bong and McGuirre maneuvering with Japanese single-engined fighters by manipulating control surfaces and engine controls simultaneously. Since most of the Conference pilots would not have much experience maneuvering a P-38 in the most efficient manner, the comment is not to be unexpected.

Spielberg got it wrong in "Empire of the Sun". The P-51 was a cheap Chevy, the P-38 was an expensive Cadillac. Tomo pauk is definitely right regarding the extra work load for the pilot. Also the maintenance requirements are high. What do you have when the engine on your P-51 is broken: a grounded fighter. What do you have when an engine on your P-38 is broken: a grounded fighter.

I definitely agree with you regarding our armchair warrior status as WW2 fighter pilots.


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## renrich (Jun 14, 2011)

I remember that you have the book. It has a lot of technical stuff that is hard for me to understand. I agree with your statement about the experience of the pilots at the meet. I have not gone through all the pireps on all the planes yet but I suspect that no fighter is going to come through with all flying colors. As far as the P38 is concerned, though, at least the remarks about visibility and complications would seem to have a lot of objectivity.

The thing about pilot skill and familiarity seems to me to have a huge impact on the success of a particular airplane in combat. Joe Foss was credited with 26 kills in an F4F4 under extremely tough conditions in the Solomons. No one would claim that the F4F4 was a premier fighter in WW2. An experienced and good pilot in an F4U, especially the later models could probably hold his own with any other WW2 fighter, flown well. But, a very young and inexperienced pilot was probably better off in a Hellcat. That factor was even more in evidence with the P38 with it's twin engines. A pilot with a lot of hours in a P38 and who was really skilled could make the airplane do wonders. It took a while to get that amount of skill though. I was recently flying with my brother in a Stearman. Long ago, I had a few hours solo in a 172. If my brother died while we were in the Stearman or in his Saratoga, I could probably get them down without killing myself. In a twin, probably not. Pilot skill and experience is everything.


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## Lighthunmust (Jun 14, 2011)

renrich said:


> I remember that you have the book. It has a lot of technical stuff that is hard for me to understand. I agree with your statement about the experience of the pilots at the meet. I have not gone through all the pireps on all the planes yet but I suspect that no fighter is going to come through with all flying colors. As far as the P38 is concerned, though, at least the remarks about visibility and complications would seem to have a lot of objectivity.
> 
> The thing about pilot skill and familiarity seems to me to have a huge impact on the success of a particular airplane in combat. Joe Foss was credited with 26 kills in an F4F4 under extremely tough conditions in the Solomons. No one would claim that the F4F4 was a premier fighter in WW2. An experienced and good pilot in an F4U, especially the later models could probably hold his own with any other WW2 fighter, flown well. But, a very young and inexperienced pilot was probably better off in a Hellcat. That factor was even more in evidence with the P38 with it's twin engines. A pilot with a lot of hours in a P38 and who was really skilled could make the airplane do wonders. It took a while to get that amount of skill though. I was recently flying with my brother in a Stearman. Long ago, I had a few hours solo in a 172. If my brother died while we was in the Stearman or in his Saratoga, I could probably get them down without killing myself. In a twin, probably not. Pilot skill and experience is everything.


 
I 99% agree with you. I think you'd find a way in the twin.


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## davebender (Jun 14, 2011)

IMO the P-38 was probably the best American made WWII fighter gun platform. All weapons were located in the nose and one of those weapons was a 20mm cannon.


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## tomo pauk (Jun 15, 2011)

To parapharse the title of this thread, with P-51 F4U, one does not need P-38K.


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## davebender (Jun 15, 2011)

IMO the U.S. Army didn't need half of their historical WWII aircraft models. 

We could have opted for mass production of only two fighter types as Germany did. One type powered by a V12 engine and the second type powered by an air cooled radial engine.

We could have mass produced either the B-25 or B-26 medium bomber rather then producing smaller quantities of both aircraft.

We could have mass produced either the B-17 or B-24 heavy bomber rather then producing smaller quantities of both aircraft.

The USN followed the U.S. Army example, producing both the F6F and F4U CV fighter aircraft. They could have held a flight competition with the winner getting the entire contract.

Back to this discussion...
The P-38 existed long before the P-47. The U.S. Army could have fixed P-38 flaws early on, eliminating any need for the P-47. 

The Mustang is a different story as it was originally a British aircraft. It could remain a British aircraft if the U.S. Army is happy with the P-38. But the Mustang will still be in production.


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## gjs238 (Jun 15, 2011)

But what about all the license production.
For example, ask Consolidated to build B-17's, they offer to build B-24's.
Ask North American to build P-40's, they offer to build P-51's.
Does one say, nah, we'll stick with the P-40's and B-17's?


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## davebender (Jun 15, 2011)

During WWII the U.S. Government managed the American economy just as the German Government managed the German economy. 

Order Consolidated to build B-17s. Just as RLM ordered Arado, Henschel and Heinkel to participate in the massive Ju-88 light bomber program during 1938. Otherwise Consolidated is cut off from government funding until they go bankrupt.

North American doesn't count as funding for development of the Mustang comes from Britain.


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## drgondog (Jun 15, 2011)

Minor point Dave - the US Army essentially set Lockheed bac more than a year when the destroyed the prototype - so the discovery process to figure out compressibility, intercooler issues, buffeting, etc, etc, took much longer than it should have. Additionally the tooling strictly was 'on of' for the protoype and production tooling and plant space had to be developed.


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## gjs238 (Jun 15, 2011)

davebender said:


> Order Consolidated to build B-17s. Just as RLM ordered Arado, Henschel and Heinkel to participate in the massive Ju-88 light bomber program during 1938. Otherwise Consolidated is cut off from government funding until they go bankrupt.



Yes, but would that have actually been better?
Would we want to not have B-24's?


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## davebender (Jun 15, 2011)

B-17 first flight was 28 Jul 1935.
B-24 first flight was 29 Dec 1939.
B-29 first flight was 21 Sep 1942.
IMO the B-17 could get the job done until the much larger B-29 is ready. 

It appears to me the 1941 B-17E was the last model to receive major design changes. After that it was a matter of cramming more gun turrets on the same airframe powered by the same rather small 1,200 hp engines. 

Without the huge B-24 program the B-17 might receive additional development. Start by considering a more powerful engine to increase the payload. By 1942 1,200 hp was rather small compared to engines which powered British and German bombers.


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## renrich (Jun 15, 2011)

We had this discussion a while back and I agree with TP, that the US could have gotten along very nicely with just the Corsair and Mustang. Just looking at the Corsair, if the US government had told Grumman to drop everything and help Vought develop the Corsair, the plane would have gotten through it's gestation period more quickly and if they had told Republic and perhaps Curtis to concentrate on a land based version of the Corsair, something good would have taken place. Likewise if Lockheed had focused their considerable talents on the Mustang as well as NA, no telling what would have happened. However, that would have meant that someone would have had foreknowledge that the Mustang and Corsair were going to be revolutionary and successful designs. The Navy always tried to have two different companies designing the latest, fighter, dive bomber or torpedo plane in case one was a failure The Wildcat beat out the Buffalo and Vought had a torpedo plane called the TBU which alledgedly was better than the Avenger but was behind the Avenger in development, timewise.


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## renrich (Jun 15, 2011)

Just for reference from Dean, "America's Hundred Thousand" from the Fighter Conference 1944

Best all around fighter above 25000 feet-P47D,P51D,F4U1D,F6F5, F4U4,P38L
Best all around fighter below 25000 feet-P51D,F4U1D,F6F5,F4U4
Best fighter bomber-F4U1D,P47D-30,F6F5,P51D,P38L
Best strafer-P47D-30,F4U1D,P51D,F6F5,P38L,P63A

Those guys did not seem to hold the P38L in high esteem.


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## Shortround6 (Jun 15, 2011)

davebender said:


> B-17 first flight was 28 Jul 1935.
> B-24 first flight was 29 Dec 1939.
> B-29 first flight was 21 Sep 1942.
> IMO the B-17 could get the job done until the much larger B-29 is ready.
> ...



The only more powerful engine that will really fit without major redesign is the Allison. Some later B-17s had models of the Cyclone that were rated at 1350hp for brief periods of time. For a real jump in power you need the R-2600 which means a total redesign of the airplane. 

No B-24s also means no long range range patrol planes of the battle of the Atlantic, diminished airborne logistic ability and diminished bombing capability in the far east for several years. 

You might also want to check the dates these planes went into actual squadron service. While the B-17 went into squadron service in the summer/fall of 1939 these were not combat capable aircraft. First B-17Es to reach a squadron don't do so until Nov 1941, a few B-17Es are at Pearl Harbor. USAAC had accepted it' first production B-24 back in June of 1941, the same month that the British put theirs into squadron service flying from Belfast. As if Jan 1st 1940 the USSAAC had ordered 7 YB-24s and 36 B-24As while the French had 120 on order and in 1940 the British not only took over the French order but added another 164, paid for in cash, not lend lease. 

Considering the US paid for the B-32 as a back up to the B-29 it seems depending on the B-17 alone (basically a 1935 design) until the B-29 was ready would not have been a smart thing to do without at least SOME combat experience to go on. 
The Ford plant at Willow run was under construction by April of 1941, well before combat experience was gained with either type of aircraft.


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## davebender (Jun 15, 2011)

The P-38 had probably the longest development period of any WWII fighter aircraft. By the time serious flaws were fixed there were all sorts of P-38 horror stories floating around the U.S. Army Air Corps. I think those stories influenced leadership confidence in the P-38 during 1944 even though the aircraft now functioned as well as the P-47 and P-51.


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## renrich (Jun 15, 2011)

The 1944 Fighter Conference took place in October and if one looks at the way the P38 placed in the different categories it is apparent that the pilots, not the leadership, overall were not impressed with it.


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## davparlr (Jun 15, 2011)

renrich said:


> The 1944 Fighter Conference took place in October and if one looks at the way the P38 placed in the different categories it is apparent that the pilots, not the leadership, overall were not impressed with it.


 
Some caveats are needed here, I think. First is that most of the reviewers are Navy and almost all military pilots are highly bias for one, their aircraft, and two, their service. Second, I am sure all the reviewers were single engine pilots. As such, the plane is big, complex, and they were unfamiliar with two engine idiosyncrasies like, maybe, asymmetric thrust. 

Overall, I think the P-38 had potential to be an effective fighter, it was certainly deadly in the PTO. However, I suspect it took some time for a pilot to learn how to handle the uniqueness of the aircraft. Also, two engines adds cost, reduces mission reliability and increases maintainability requirements. Faced with the simplicity, cost, ease of flying and performance of the P-51, it was difficult to justify.


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## Shortround6 (Jun 15, 2011)

Which is almost as it should be. How many fighters in 1944 conference were as old as the P-38? 

Did newer fighters have improved or modified control panel layouts?

Did newer fighters have improved control layouts (not instrument layouts) but trimmer controls, landing gear controls,etc. 

How many fighters at the conference had bubble canopy's that didn't have them 2 years earlier? 

Aside from the powered ailerons, increased power and dive flaps what improvements did the P-38 get over the last two years to make life easier for the pilot? 

And being a twin the work load was higher to begin with. 

while the fighter conference does have a lot of interesting information, not all pilots flew all the planes, Not all the pilots who flew a certain type of aircraft filled out an evaluation card, Not all evaluation cards had all questions checked or marked. 

Even if stricter procedures had been followed the P-38 might still have come out near the bottom in some categories, again hardly surprising considering the age of the design and it should not be considered a reflection of it's capabilities in 1942 or 43 when many it's competitors at the 1944 conference either didn't exist at all or or existed only on paper.


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## Shortround6 (Jun 15, 2011)

davparlr said:


> Also, two engines adds cost, reduces mission reliability and increases maintainability requirements. Faced with the simplicity, cost, ease of flying and performance of the P-51, it was difficult to justify.



On the other hand,in either the South Pacific or the Indo-China theater they were known to return home flying on one engine for 600 miles. I am not sure about mission reliability but any pilot who made it back to base flying hundreds of miles across open water or SE asia jungles probably wasn't complaining about cost or maintenance requirements 
The number of planes involved is probably too small to be statistically accurate but they did claim much fewer losses for ground strafing missions than either P-51s or P-47s if I remember right.


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## Lighthunmust (Jun 15, 2011)

Don't put all your eggs in one basket.
Don't spread yourself too thin.

Which aphorism should a country follow in the midst of national peril? Risk everything on a few choices with the consequences of those choices being disastrous or make many choices of which only a few are good but not enough because of resources spread to thin?

I think much of what happened was due to the United States having the luxury of having so much surplus of resources it could never spread itself too thin. We had a few winners and could afford the more numerous rejects. Our opponents had a few winners and could not afford the more numerous rejects because of their fewer resources.

Given the choice of starting the war with either operationally ready B-17s or B-24s, the B-24 is the obvious choice because it could do more farther and faster than the B-17. It just wasn't the better of the two to be in if under individual attack.

Without the P-38 we would have been far less successful at the beginning of the war. Without the Mustang we would have successfully made due with the P-47 and P-38, it just would have taken more time to do so. The P-51 was serendipitous and fortuitous. The P-38 was timely and vital.


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## davparlr (Jun 15, 2011)

Shortround6 said:


> On the other hand,in either the South Pacific or the Indo-China theater they were known to return home flying on one engine for 600 miles. I am not sure about mission reliability but any pilot who made it back to base flying hundreds of miles across open water or SE asia jungles probably wasn't complaining about cost or maintenance requirements



What you say is true, but I get the feeling the PTO was on the back burner for Army considerations. I think their focus on ETO success overshadowed success in the Pacific.

Mission reliability and safety of flight reliability often drive each other in opposite directions. For mission reliability, enough equipment must be available to complete the mission. For a twin engine aircraft, the probability of losing an engine, or reduced engine performance, is twice that of an single engine aircraft, therefore the probability of a mission critical failure occurring is higher for the twin engine aircraft. For safety of flight, one must have only the equipment to successfully recover the aircraft. The twin engine aircraft's probability of safely recovering with an engine failure is significantly higher than the single engine aircraft, which is roughly, zero, although reduced power may provide return capability. So, this is a case where safety of flight reliability goes up, but mission reliability goes down.


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## davebender (Jun 16, 2011)

The P-38 received a bunch of reliability and ergonomic improvements between 1941 and 1944. They add up to a much more effective combat aircraft even without considering more powerful engines and power assisted ailerons.

Improved cockpit heater.
Improved intercoolers.
Improved turbocharger controls.
More efficient radiators.
Improved electrical system.
"Combat Maneuver" setting added to the Fowler flaps.
Drop tank supply caught up with demand.
Improved radio.
Improved 20mm cannon.
Improved hard points for mounting bombs and drop tanks.
Internal fuel increased by adding tanks in wing leading edge.


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## gjs238 (Jun 16, 2011)

Or, if there had been more than one protype built.

The subsequent USAAF history might have turned out quite different.


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## davebender (Jun 16, 2011)

I'm under the impression multiple prototypes were standard practise when designing fighter aircraft. 

Why didn't they build more than one P-38 prototype?


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## Shortround6 (Jun 16, 2011)

davebender said:


> The P-38 received a bunch of reliability and ergonomic improvements between 1941 and 1944. They add up to a much more effective combat aircraft even without considering more powerful engines and power assisted ailerons.
> 
> Improved cockpit heater.
> Improved intercoolers.
> ...



All quite true but rather misses the point. 

Most of those improvements, valuable though they were, were either "invisible' to a pilot in combat or irrelevant to fighter vs fighter combat. Size and availability of drop tanks make no difference to a planes fighter vs fighter performance once they are dropped. Unless the electrical system stops working in the middle of a dog fight any "improvements" to the system are invisible to the pilot in combat and would be unrated in the fighter conference. 

and so on. 

A revamped or new layout instrument panel with easier to read instruments or closer grouping of the important ones would get a higher rating than an old awkward layout. A better layout of the hand controls that the pilot would have to reach (without take eyes from outside the cockpit) would rate higher. 
The less the pilot has to do to "fly" the plane and more time his eyes are outside the cockpit the more attention he can pay to "fighting" the plane vs 'flying' it. 
The more time a pilot has in a particular 'type' the more instinctive some of his cockpit moves get. The more standardized cockpits got the easier it was to transition from one plane to another.

In a group evaluation the planes with the most complicated cockpits are going to end up at the bottom of the list and the twins are going to have the most complicated panels.


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## Shortround6 (Jun 16, 2011)

"Why didn't they build more than one P-38 prototype?"

Congress was *CHEAP!!*


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## tomo pauk (Jun 16, 2011)

They've built the YP-38 - a second prototype. The catch is they've built it a good year after XP-38.


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## davebender (Jun 16, 2011)

North Carolina-class battleship - Wikipedia, the free encyclopedia
Congress authorized construction of two North Carolina class battleships during 1937.

http://en.wikipedia.org/wiki/South_Dakota_class_battleship_(1939)
Congress authorized construction of four North Dakota class battleships during 1938.

USN Ship Types--Iowa class (BB-61 through 66)
Congress authorized construction of two Iowa class battleships during 1940. Followed by four more during 1941.

You could purchase thousands of P-38 prototypes for the cost of a single battleship. So I don't think Congress was the problem. Most likely it was the commander of the U.S. Army Air Corps who gave the P-38 program a very low budget priority.


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## Lighthunmust (Jun 16, 2011)

Shortround6 said:


> "Why didn't they build more than one P-38 prototype?"
> 
> Congress was *CHEAP!!*


 
and nobody was shooting at us yet. I think building single prototypes was the norm not the exception. At the time the XP-38 was the most complex, innovative, and expensive fighter created. If I recall correctly other prototypes of later successful aircraft crashed but commitment to production had already been made because people were shooting at us.

No doubt by the time of the Conference the P-38's ergonomics were long in tooth. The original need to use two 1000hp engines for performance was no long necessary due to single engines making close to or more than 2000hp. Fighter pilots think more about what they need during the few minutes of fight than what they need to take with them, get them there, and get them back. The P-38 was superior to many of the other planes at the Conference with the latter mentioned items but that was not a foremost concern of the evaluators.


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## Shortround6 (Jun 16, 2011)

davebender said:


> You could purchase thousands of P-38 prototypes for the cost of a single battleship. So I don't think Congress was the problem. Most likely it was the commander of the U.S. Army Air Corps who gave the P-38 program a very low budget priority.



Yeah, just like they ordered ONE XP-39 prototype.

and ONE XP-40 Prototype.

In Feb 1937 they ordered ONE XP-37 prototype and then ordered 13 YP-37s in Dec 1937. 6 months after the XP-37 flew. 

ONE XP-41 Prototype
ONE XP-42 Prototype

Sure sounds like the P-38 had a lower priority than the other fighter programs. 

The Army Budget was not the Navy budget. For instance while the 105mm howitzer was standardized in 1928 production was not started until 1940.


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## Lighthunmust (Jun 16, 2011)

davebender said:


> North Carolina-class battleship - Wikipedia, the free encyclopedia
> Congress authorized construction of two North Carolina class battleships during 1937.
> 
> http://en.wikipedia.org/wiki/South_Dakota_class_battleship_(1939)
> ...





Yes I think you are right about USAAC Command (Bomber Mafia strikes again), but Congress considered Battleships far more important than the USAAC and their collection of "peashooters". Nobody had yet demonstrated the vulnerability of Capitol ships underway and defending themselves while subjected to aircraft attack. Billy Mitchell only proved that they could be sunk while at anchor and undefended. BTW there is not much of a wartime record for successful high altitude bomber attacks on moving defended ships. Furthermore, I don't think the commanders of the USAAC, many of whom made their careers supporting the doctrine of the bomber's virtual invulnerability to attack, would be keen to support an aircraft (Lightning) that is the origin of the term "interceptor" as applied to aircraft designed to attack in-bound bombers.


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## davebender (Jun 16, 2011)

Boeing B-17 Flying Fortress - Wikipedia, the free encyclopedia
17 Jan 1936. USAAC orders 13 YB-17s.
Scaled back from 65 YB-17s ordered during 1935 @ $99,620 each.

Consolidated B-24 Liberator - Wikipedia, the free encyclopedia
March 1939. Contract awarded to begin B-24 program.
1 prototype flying at the end of 1939. Followed by 7 more YB-24s during 1940.

There appears to be no shortage of American heavy bomber prototypes. Apparently American fighter aircraft development got crumbs for funding during the 1930s. That's not the fault of Congress.


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## Lighthunmust (Jun 16, 2011)

davebender said:


> Boeing B-17 Flying Fortress - Wikipedia, the free encyclopedia
> 17 Jan 1936. USAAC orders 13 YB-17s.
> Scaled back from 65 YB-17s ordered during 1935 @ $99,620 each.
> 
> ...



Yes, but perhaps the congressman in those districts where the much more expensive bombers were being produced had some impact. I think you are right in that the lions share of the reason falls to USAAC command.


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## Shortround6 (Jun 16, 2011)

davebender said:


> Boeing B-17 Flying Fortress - Wikipedia, the free encyclopedia
> 17 Jan 1936. USAAC orders 13 YB-17s.
> Scaled back from 65 YB-17s ordered during 1935 @ $99,620 each.
> 
> ...



The Army can only spend what they are given, and as usual, selected facts from Wiki do not tell the whole story.

The contract for the XP-38 was signed June 23 1937, The plane was completed in Dec of 1938 and made it's first flight Jan 27 1939. It crashed on Feb 11 1939. 13 YP-38s are ordered April 27 1939. 

Work on the XP-40 was started in July 1937, the plane was completed and flown for the first time in Oct 1938. In the Spring of 1939 the Army decides the P40 offers the best shot at getting modern fighters into service quickly, judging that they can be in service about ONE year sooner than the other contenders. On April 26th 1939 the Army places an order for 524 production P-40s. Not only is this the largest order for fighters since WW I it may be the largest dollar amount contract the USAAC has placed since WW I.

Back to the B-24. In Jan 1939 Consolidated pitches a concept to the Air Corp. By March 30th 1939 after mock ups and negotiations a contract is signed for ONE XB-24. On April 27th 1939 (Army is on quite buying spree on April 26th and 27th) the Army orders 7 YB-24s and on August 10th 1939 they order 38 more B-24As. Please note that none of these B-24s have turbos. 

As can be seen from the dates the B-24 program had ZERO effect on USAAC fighter or pursuit programs of the 1930s. 

A little mentioned fact of the B-24 story is that while North American is given a lot of credit for designing and building the Mustang in 120 days (and justly so) Consolidated designed and built a 4 engine bomber in about 270 days, the XB-24 flying on Dec 31st 1939.


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## Lighthunmust (Jun 16, 2011)

I think the political connections of Curtiss-Wright with USAAC and Congress may have influenced the development of the P-38. Lockheed was a political pipsqueak compared to Curtiss-Wright. The same as today, soon to be retiring officers are often thinking about getting a job with a contractor, the bigger the better.


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## davebender (Jun 16, 2011)

V-1710 V12 engine.
Designed to a 1929 USAAC specification.
Prototype first run 1930.
High altitude performance issues not fixed until 1944. Or perhaps not at all, depending on which source you want to trust.

The V-1710 engine powered only USAAC fighter aircraft. Is it a coincidence that development was so protracted?


M1 20mm cannon. 
American copy of French Hs.404 cannon. 
Program began during 1941.
Problems not fixed for at least 10 years. Consequently the .50cal MG remained the standard USAAC fighter weapon right up to the Korean War.

This weapon was intended for fighter aircraft. Is it a coincidence that development was so protracted?


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## gjs238 (Jun 16, 2011)

Yet both could have been valuable to the bomber effort.


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## Shortround6 (Jun 16, 2011)

Lighthunmust said:


> I think the political connections of Curtiss-Wright with USAAC and Congress may have influenced the development of the P-38. Lockheed was a political pipsqueak compared to Curtiss-Wright. The same as today, soon to be retiring officers are often thinking about getting a job with a contractor, the bigger the better.



I am not sure what you are getting at here. 

There may have been political connections. On the other hand some of these factories/companies were mere fractions of what they would become in just a few years.

Lockheed had about a ZERO track record with combat planes until 1939 when the British, desperate for just about anything that could fly signed the contract for the Hudson bomber. A converted airliner. Lockheed, while it had quite a reputation for fast tough airliners had probably built under 400 airplanes (maybe closer to 300) from 1930 to 1939 when the British signed up. They didn't have the factory space or trained work force to handle large orders right away. Many other companies were in the same situation.

Curtiss connections or not, was one of the largest aircraft companies in the United States and had a factory and work force that had just finished or was in the process of finishing up an order for 210 P-36 fighters which had many of the same components as the P-40 and could be built on many of the same jigs and fixtures. If the Army needed hundreds of modern fighters just as fast as it could get them then the P-40 was about the only game in town. 

with new bigger factories have to built from scratch it was going to be 1 1/2 to 2 years before large numbers of planes could be built. Who got the contracts to build what may have depended on connections. It may have depended on salesmanship, Preston Tucker got money for a fighter to be powered by a straight eight engine designed by Harry Miller, essentially money that was flushed down the porcelain facility. It may have been decided by fear of possible invasion of bombardment, an awful lot of new factories were built in Ohio, Detroit, Milwaukee, and in wheat fields in Kansas rather than close to parent factories in coastal towns/cities. 

In many cases companies wound up building planes that were almost competitors of their own. Vega, a division of Lockheed, built B-17s as did Douglas. Douglas had 8 different bomber projects sandwiched in between the Boeing B-17 and B-47.


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## gjs238 (Jun 16, 2011)

Shortround6 said:


> Preston Tucker got money for a fighter to be powered by a straight eight engine designed by Harry Miller, essentially money that was flushed down the porcelain facility.



Tucker XP-57 - Wikipedia, the free encyclopedia


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## renrich (Jun 16, 2011)

One prototype is not that unusual. There was only one XF4U that the Navy bought. The Navy sponsored a design competition in early 1938. Vought won the contract in June 1938 and the prototype was built. The prototype flew first in May, 1940 and the prototype ran out of fuel and crashed in July, 1940. It was rebuilt and in October, 1940 the Corsair set a record.


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## Lighthunmust (Jun 16, 2011)

Shortround6 said:


> I am not sure what you are getting at here.
> 
> There may have been political connections. On the other hand some of these factories/companies were mere fractions of what they would become in just a few years.
> .


 
I think you did well getting what I am getting at; that there where many factors small and large affecting the issue of procurement of aircraft, of which politics is one. Your post is an excellent summation of the procurement situation at that time. I often wonder how much politics influence decisions that should not be influenced by politics. I know it has always influenced these decisions far more than what is in the best interests of the nation as whole.


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## Shortround6 (Jun 16, 2011)

I don'y find too much fault with how a lot of programs started. Things were pretty chaotic and a lot of pre war theories were turned on their heads. There did seem to be a bit too much unwillingness to change things once they got started or to call a turkey a turkey and stop pouring good money after bad. 

There were a few programs that never should have gone as far as they did but in general they were 1940-42 programs, not 1938-40 programs. 

The P-39 and P-40 were programs that should have gone on in 1939-41 but by 1943 somebody should have taken a much harder look at them as by the beginning of 1943 they were essentially trainers or lend-lease planes for allies and not used to equip new US squadrons. Politics could have played a bigger part in keeping them going than in starting them.


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## gjs238 (Jun 16, 2011)

Shortround6 said:


> The P-39 and P-40 were programs that should have gone on in 1939-41 but by 1943 somebody should have taken a much harder look at them as by the beginning of 1943 they were essentially trainers or lend-lease planes for allies and not used to equip new US squadrons. Politics could have played a bigger part in keeping them going than in starting them.



Didn't the "Truman Committee" investigate that?


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## Shortround6 (Jun 16, 2011)

They did but then again a congressional investigation is politics.

they also had to "prove" wrong doing vs just bad or inept decisions. And if you don't give the Russian's P-40s and P-39s what do you give them and when?

It seems to come down to a matter of degree. What crosses the line from bad decision to actual negligence or ineptness to actual Malfeasance and if money was involved you have to find the money trail.


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## Lighthunmust (Jun 16, 2011)

Shortround6 said:


> I don'y find too much fault with how a lot of programs started. Things were pretty chaotic and a lot of pre war theories were turned on their heads. There did seem to be a bit too much unwillingness to change things once they got started or to call a turkey a turkey and stop pouring good money after bad.
> 
> There were a few programs that never should have gone as far as they did but in general they were 1940-42 programs, not 1938-40 programs.
> 
> The P-39 and P-40 were programs that should have gone on in 1939-41 but by 1943 somebody should have taken a much harder look at them as by the beginning of 1943 they were essentially trainers or lend-lease planes for allies and not used to equip new US squadrons. Politics could have played a bigger part in keeping them going than in starting them.


 


Shortround6 said:


> It seems to come down to a matter of degree. What crosses the line from bad decision to actual negligence or ineptness to actual Malfeasance and if money was involved you have to find the money trail.



I agree. Compared to the the American Civil War, what was happening before and during American involvement in WWII was as close as possible to a demonstration of Military/Government/Industry altruism directed toward the Nation and Allies.


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## Conslaw (Apr 24, 2013)

The B-17e in some cases had a longer range than contemporary B-24D. See http://www.wwiiaircraftperformance.org/B-24/B-17E_B-24D_Comparison.pdf.


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## MikeGazdik (Apr 25, 2013)

The whys and why-nots of the way the U.S. produced aircraft designs in spades will quickly turn political, as it is a function of capitalism. That being said, I certainly enjoy the fact that the U.S. had "too many" designs. Besides the advantages that gives to the military, it sure makes it more interesting for us some 60 years later. IF we only had 2 airplanes to argue about this would be real boring!! LOL.


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## dobbie (Apr 26, 2013)

Not only political issues, but what the military was ASKING for in the first place. The American fighter program was in some ways a lot like the procuring of tanks, which is why we ended up with the Sherman-a pretty good tank in 1942-43 with the upgrades, but failed to look down the road to what the enemy was doing with their designs. The Tiger and Panther were around in very small numbers, but the main foe was the MKIV, which the Sherman did okay against.

So it also goes with the Army Air Corps, saddled with outmoded ideas that bombers would defend themselves and always get thru. The B29 wasn't a truly effective bomber until Curtis Lemay stripped most of the guns off them and brought them down to low levels at night to burn out the enemy. 
Fighter design was mostly for a critical altitude of 15,000 feet and they were primarily to support ground troops, with a few exceptions. The AAC bought and paid for a program they designed, and they were flat wrong about the war they were about to fight. All the basic technology was there to produce higher flying and faster fighters at the beginning of America's involvement, but working out the bugs after the basic design takes time. I think overall, America did better than it had a right to expect.


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## nuuumannn (Apr 26, 2013)

Yep, Dobbie, I agree; I think it was difficult for private firms to be able to produce exactly what the military want and the political bias that was prevalent in the USA was by no means confined to there. In many countries it was a preferred way of getting decisions madeio. I read once that the biggest deals get made out of the office, like in the 19th Hole or the pub down the road from parliament. The building of many different aircraft to the same requirement was also not unique to the United States; Britain and Germany also did the same, although in some examples a new type evolved from a different requirement ended up competing with an existing fulfilled requirement, such as the Stirling, Halifax and eventually Lancaster, or even the Bf 109 and the Fw 190 - "A Second Iron in the Fire" is how the Fw 190 was described somewhere that I've read.


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## Shortround6 (Apr 26, 2013)

dobbie said:


> Fighter design was mostly for a critical altitude of 15,000 feet and they were primarily to support ground troops, with a few exceptions. The AAC bought and paid for a program they designed, and they were flat wrong about the war they were about to fight. All the basic technology was there to produce higher flying and faster fighters at the beginning of America's involvement, but working out the bugs after the basic design takes time. I think overall, America did better than it had a right to expect.



This is a persistent myth but it is still a myth. 

1. The P-38 and P-39 were being developed before the P-40. The Turbo was about 2 years from being squadron ready and the installation in the XP-39 was lousy. 
2. NOBODY in 1938/39 had an engine with a critical altitude much above 16,000ft. 
3. Both initial P-39s and P-40s had either ZERO for bomb load or the overwhelming load of SIX 20lb bombs (P-35 could carry 350lbs) and TWO .50 cal machine guns firing through the prop on the initial P-40 was a terrible strafing armament. 
4. P-40s, being a re-engined P-36 could be gotten into production and squadron service about 1 year sooner than a turbo-fighter. It was either low altitude P-40s or no fighters at all.


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## dobbie (Apr 27, 2013)

Shortround6 said:


> This is a persistent myth but it is still a myth.
> 
> 1. The P-38 and P-39 were being developed before the P-40. The Turbo was about 2 years from being squadron ready and the installation in the XP-39 was lousy.
> 2. NOBODY in 1938/39 had an engine with a critical altitude much above 16,000ft.
> ...



Call it whatever you like. 
Fighter aircraft design, particularly fighter engine design got the short end of the funding in America, and that's a cold, hard fact however you wish to color it. Homegrown effective multispeed supercharging didn't show its face until much later in the war. Wasn't like we didn't have the capability of developing it sooner-the people in charge decided we didn't need it. 
The P-40 with the single stage Merlin did a bit better than the low altitude Allisons it was saddled with-one has to wonder what might have been if the two stage Merlins or Allisons had been tried. The Army just wasn't interested in development of a high altitude fighter plane, and if it weren't for folks like Ben Kelsey who knew how to get around a few rules, we wouldn't have had either the 38 or the 39 at all.

From what I can find, Lockheed got the contract in 1937, but the prototype didn't fly until 1939, well after the P40. The P40 flew 1938 as did the P39. IIRC, the P38 being designed as an interceptor in order to get around the rules set for single engine pursuits in effect at that time-one of the requirements of the P38 was that it attain 20K in 6 minutes or less. Youre saying it did not meet that requirement when it flew? Was not aware of that fact.


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## wuzak (Apr 27, 2013)

dobbie said:


> one of the requirements of the P38 was that it attain 20K in 6 minutes or less. Youre saying it did not meet that requirement when it flew? Was not aware of that fact.



The YP-38s reached 18.000ft in 6 minutes.

It does not appear that any P-38 was capable of getting to 20,000ft in 6 minutes until the J.

P-38 Performance Tests


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## Shortround6 (Apr 27, 2013)

dobbie said:


> Call it whatever you like.
> Fighter aircraft design, particularly fighter engine design got the short end of the funding in America, and that's a cold, hard fact however you wish to color it. Homegrown effective multispeed supercharging didn't show its face until much later in the war. Wasn't like we didn't have the capability of developing it sooner-the people in charge decided we didn't need it.
> The P-40 with the single stage Merlin did a bit better than the low altitude Allisons it was saddled with-one has to wonder what might have been if the two stage Merlins or Allisons had been tried. The Army just wasn't interested in development of a high altitude fighter plane, and if it weren't for folks like Ben Kelsey who knew how to get around a few rules, we wouldn't have had either the 38 or the 39 at all.



Do you have any PROOF of any of this? 
Or do you even know what you are talking about?

" Homegrown effective multispeed supercharging didn't show its face until much later in the war. Wasn't like we didn't have the capability of developing it sooner-the people in charge decided we didn't need it."

Strange, Wright was building 2 speed supercharged engines in 1938. P&W was selling 2 speed R-1830s in 1940. First B-24s used 2 speed R-1830s with no turbos. 

multispeed is NOT the same as multi-speed stage. 

"The Army just wasn't interested in development of a high altitude fighter plane" 

And yet by 1940 they had taken delivery of around *100* fighter planes with turbo charged engines over the last *10 YEARS*. 
See the P-30A for one example. 50 built, last delivered in Aug 1936. 

They Army knew what it wanted, it also knew that what it _wanted_ could not be supplied at the current state of technology in 1938 or 39. 

You may also want to look at the YP-37. They ordered 13 service test YP-37s on December 11, 1937, first flew June of 1939. with turbo chargers in a multi stage set up, of course this indicates _NO INTEREST_ in high altitude aircraft, right? 

P W were flying a mechanical two stage R-1830 in 1939, two planes powered by that engine took part in the 1939 Army fighter trials. Results are not available but but a similar engine was not fully sorted out in the F4F two years later. 

BTW this puts P&W about 2-3 years ahead of Rolls-Royce. 

"particularly fighter engine design got the short end of the funding in America"

Prove that one, fighter engines got about ALL the developmental funding money before the war, granted there wasn't a lot of it. And a lot of what there was went into rat hole projects like the Continental (actually army) 0/V-1430 and the Lycoming O-1230.

Bombers on the other hand _made do_ with commercial engines, at least until the B-29 and the Wright R-3350. 

BTW the P-36/40 went though _7_ different engines or engine set ups, how many more do you want to try? 
It may be a record for most different engines in a single engine fighter airframe.


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## tomo pauk (Apr 27, 2013)

The Army bought P-43 (the development of the plane that didn't make it to the fighter competition where the P-40 won), ordered the XP-44, and in June 1940 ordered the P-47B - all of them were high altitude fighters.


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## dobbie (Apr 27, 2013)

The Air Corps issued its first doctrine publication in 1926, after spending almost eight years working on the problem of describing what aviation could be expected to do in war.11 The War Department, understandably dominated by ground combat arms officers, oversaw the preparation of this publication, which appeared as Training Regulation (TR) 440-15, Fundamental Principles for the Employment of the Air Service, on 26 January 1926.12 In the view of Alfred Hurley, one interpreter of the main thrust of this doc-trine: “ ‘The fundamental doctrine’ permitted the air-men was ‘to aid the ground forces to gain decisive success,’ with some recognition of the need for special missions at a great distance from the ground forces.” 13 Revised in 1935, this was the doctrine of Army Aviation from 1926 to 1940.

That doctrine is what got Foulois, Maxwell and nearly Arnold in trouble in the late 1930s for their efforts on long range high altitude bomber aircraft. I still stand by my original premise which is that until the AAF began taking huge losses in their bomber formations that the development of high altitude long range fighter aircraft was not adequately funded or pursued.


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## dobbie (Apr 27, 2013)

Shortround6 said:


> Do you have any PROOF of any of this?
> Or do you even know what you are talking about?
> 
> " Homegrown effective multispeed supercharging didn't show its face until much later in the war. Wasn't like we didn't have the capability of developing it sooner-the people in charge decided we didn't need it."
> ...


*Obviously, the P36/40 airframe was near the end of its speed range but until the XP40Q never got a successful high altitude engine*


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## dobbie (Apr 27, 2013)

tomo pauk said:


> The Army bought P-43 (the development of the plane that didn't make it to the fighter competition where the P-40 won), ordered the XP-44, and in June 1940 ordered the P-47B - all of them were high altitude fighters.



The P43 was an interesting idea, but they had a lot of issues with it which I suppose is why the design wasn't pressed further. No armor or self sealing fuel tanks, and the maneuverability wasn't what they hoped.


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## dobbie (Apr 27, 2013)

wuzak said:


> The YP-38s reached 18.000ft in 6 minutes.
> 
> It does not appear that any P-38 was capable of getting to 20,000ft in 6 minutes until the J.
> 
> P-38 Performance Tests



Thanks for the link Wuzak. Good read. I had read that the early P38s had a lot of issues with the leading edge intercoolers which seems to be borne out in the performance tests.


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## tomo pauk (Apr 27, 2013)

Hmm, I've listed 3 high-altitude fighter designs that should show the USAF was thinking about high-altitude combat, yet the P-43 is the only one worth a comment?

We can list USAF fighters and look at theis fuel systems:
-P-40: 180 USG in unprotected, non-self-sealing tanks; P-40B introduces externally-protected tanks (fuel down to 160 USG); P40C introduces self-sealing fuel tanks (fuel down to 135 USG); later models have 140-160 USG mostly
-XP-39, XP-39-B: 200 USG in unprotected tanks, YP-39, P-39C: 170 USG in unprotected tanks; P-39D: 120 USG in self-sealing tanks
-the P-38 received s-s tanks from -D model onwards. 45 examples built prior that were without s-s tanks.

P-40 got armor with the -B, the P-38 received subsequent armor upgrades in early models, P-39 received more and more armor from -C on. 

So the P-43 is as good/bad protected as other US fighters of the time, and I'm sure we can toss many a European fighter here. The USAF wanted the Republic to produce, after the P-43, 1st the (X)P-44 and P-47, and later both were canceled because the superb P-47B was recognized as such.


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## dobbie (Apr 27, 2013)

tomo pauk said:


> Hmm, I've listed 3 high-altitude fighter designs that should show the USAF was thinking about high-altitude combat, yet the P-43 is the only one worth a comment?
> 
> We can list USAF fighters and look at theis fuel systems:
> -P-40: 180 USG in unprotected, non-self-sealing tanks; P-40B introduces externally-protected tanks (fuel down to 160 USG); P40C introduces self-sealing fuel tanks (fuel down to 135 USG); later models have 140-160 USG mostly
> ...



Sorry about that Tomo-It is true that none of the early models you mentioned had self sealing fuel tanks or armor, and with both, range was necessarily sacrificed. Add to that the prohibition of external fuel tanks and the early P38 is the only one with any hope of being an escort fighter, and it had a lot of development ahead of it due to the new systems it employed-some, such as the leading edge intercoolers were never worked out but the change to the intercooler system eventually used made it a more effective fighter. The P39 never did have a true high altitude capability as a production model. Neither did the P40 at the beginning of the war. The P-43 apparently had a reputation for leaking fuel, not a great trait to have in any aircraft. Even the P-47, excellent as it was, didn't have the necessary range to escort bombers until the N model which came about near the end of the war.


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## tomo pauk (Apr 27, 2013)

No problems.


> It is true that none of the early models you mentioned had self sealing fuel tanks or armor, and with both, range was necessarily sacrificed. Add to that the prohibition of external fuel tanks



There was no prohibition of fuel tanks - when the P-39D received s-s tanks (along with reduction of internal fuel tankage), it also received the belly rack, capable to carry the fuel tanks up to 175 gals (that, ugly one, for ferry flights; the usual one was 75 gals). The P-40C received the similar alteration to the fuel system. So there was no prohibition; the P-43 with drop tank was the P-43A-1.



> the early P38 is the only one with any hope of being an escort fighter, and it had a lot of development ahead of it due to the new systems it employed-some, such as the leading edge intercoolers were never worked out but the change to the intercooler system eventually used made it a more effective fighter.



Agreed that P-38, out of all the early USAF fighters, have had the capability to perform as a viable escort fighter, but escort fighters was not something with a place in the early war USAF doctrine.



> The P39 never did have a true high altitude capability as a production model. Neither did the P40 at the beginning of the war.



Agreed pretty much, both were dogs above 15000 ft.



> The P-43 apparently had a reputation for leaking fuel, not a great trait to have in any aircraft.



+1 on that. The drive towards design production of the P-47B made the P-43 an orphan.



> Even the P-47, excellent as it was, didn't have the necessary range to escort bombers until the N model which came about near the end of the war.



The P-47 was initially provided with an external drop tank that could not be pressurized (and that for an 30000 ft fighter!), plus it was troublesome to drop once emptied; that 205 gal tank, ugly 'cow udder', was designed as a ferry tank. The 5th Air Force (Gen Kenney) quickly took the things in their hands, and soon the Ford in Brisbane, Australia, was producing the 200 gal combat drop tank. The people in ETO were not that 'hard' on the subject, 1st installing the 75 gal DT, and soon after that the 108 gal DT. The ferry flights (via Island) were conducted with 2 x 150/165 wing DTs, from P-38, in August 1943. The P-47 with 500-600 gals of fuel (= 400-500 miles of combat radius) would be such an asset in ETO in 1943, however it was not to be until 1944.


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## Marauderman26 (Apr 27, 2013)

Found this on the subject, interesting thread: The P-38K


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## dobbie (Apr 27, 2013)

I cant recall exactly where I saw it, Tomo pauk, but early on there was some sort of restriction against drop tanks on fighter aircraft which I found baffling to say the least. 

I suppose that at least some of the belief in "the bomber will always get through" might stem from the fact that the B-9 and B-10 outperformed most of the fighter aircraft in speed as well as range in their day, so the thinking was that escort fighters were unnecessary.

I think its sad that the P51, which because it was designed for the RAF and didn't have to go through the normal channels, had to be fitted with a British engine in order to become the fine escort fighter it became.

To the positive, the development of turbo supercharging helped a lot of bombers and the P-47 become a force to be reckoned with, especially at high altitude.
Might not be considered the ultimate fighter but the P-47, once they replaced the fabric control surfaces and made the ignition system reliable is my sentimental favorite.


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## Shortround6 (Apr 27, 2013)

dobbie said:


> So we are going to use B24s as fighter aircraft?



No but it shows that home grown multi-superchargers existed at the beginning of the war. 



dobbie said:


> And the P-30 is of course equal to its task at the beginning of WWII



No but it shows that the USAAC *WAS* interested in high altitude flight and spent more money and effort on it than any other 2-3 nations put together, or at least they built 2-3 times the number of "high-altitude aircraft. 



dobbie said:


> I notice the P37 wasn't built as a standard fighter due to a number of problems-cool looking aircraft though



and that is the heart of the matter isn't it. The USAAC _KNEW_ what they _WANTED_. They also _KNEW_ it wasn't available in the near future in _SERVICE_ form. SO they had a choice. Wait and build NO planes until what they wanted was ready. OR build a plane that was _LESS_ than what was really wanted so they would have SOMETHING to fly. 



dobbie said:


> Prove it, as you say


 Look early troubles with the F4F, rumbling in the intake ducts due to mismatched supercharger impellers/airflow. 



dobbie said:


> Precisely my point. There wasn't a lot of money being tossed at reliable high altitude aircraft engines



Strange point. There was *NO* reliable high altitude aircraft engine in existence in 1935-41. ANYWHERE, so where were they supposed to _toss_ the money? 
And where was the money to come from? 





dobbie said:


> Obviously, the P36/40 airframe was near the end of its speed range but until the XP40Q never got a successful high altitude engine[/B]



XP40Q was actually the 8th engine configuration. And just WHAT successful high altitude engine did you have in mind? 

There were turbo Wright R-1820s, Turbo P &W R-1830s, Turbo Allison V-1710s and two stage P W R-1830s. The trouble is the turbo and associated inter-cooler didn't fit very well. P W did fairly well With a a TWO stage R-1830 but that wasn't until the fall of 1942 in an unarmed test airframe.


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## dobbie (Apr 27, 2013)

Shortround6 said:


> No but it shows that home grown multi-superchargers existed at the beginning of the war.
> *It shows multisuperchargers on BOMBERS, not FIGHTERS and is beyond the scope of this thread*
> 
> 
> ...


*Once again, where were all the high altitude long ranged fighters? Turbosupercharging is a good system for high altitude, but you end up with something the size of the Thunderbolt in single engine form-no range, or the Lightning in twin engine form, which was not ready to take on the Luftwaffe until the later models, and is the question of the OP in case you hadn't noticed*


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## Shortround6 (Apr 27, 2013)

I was responding to your post where you said the following.

"Fighter design was mostly for a critical altitude of 15,000 feet and they were primarily to support ground troops, with a few exceptions. The AAC bought and paid for a program they designed, and they were flat wrong about the war they were about to fight. All the basic technology was there to produce higher flying and faster fighters at the beginning of America's involvement, but working out the bugs after the basic design takes time. I think overall, America did better than it had a right to expect."

Nothing there about "high altitude long ranged fighters" is there? 

Just the basic "were primarily to support ground troops, with a few exceptions" which is wrong and "All the basic technology was there to produce higher flying and faster fighters at the beginning of America's involvement" which is part right but doesn't say anything about long range does it? 

If you want a _multi-stage_ supercharger and not just a multi-speed supercharger the ONLY things you get rid of is the exhaust turbine and the exhaust plumbing. You need the second supercharger impeller and casing, a way to drive it and you need an inter cooler of some sort. 

The P-39 and P-40 were not designed to support ground troops, they were adapted to do it. 

As for "The late model Allisons with 2 stage superchargers might have been nice. Would have been nicer if Allison had been contracted to develop them earlier"

Lots of counties would have loved time machines and the ability to use 1943/44 engines in 1940/41. Allison proposed the two stage engine back in 1938 (gee, right about the time P W was starting work on their 2 stage engine), Allison didn't have the engineering staff to work on it fast enough. There may be some doubt as to whether a 1940-41 Allison would have stood up to the strain of producing the power the late model two stage engine delivered. Allison changed the size of the impeller in the aux stage, changed the drive mechanism, tried to get an intercooler and were let down by a sub contractor and a few other details that caused to project to slip, not by months but by years. 
What the USAAC wanted is one thing, what they could actually get is another.


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## tomo pauk (Apr 28, 2013)

dobbie said:


> I cant recall exactly where I saw it, Tomo pauk, but early on there was some sort of restriction against drop tanks on fighter aircraft which I found baffling to say the least.



What would be the time frame of the 'early on'? I'm afraid that supposed restrictions are product of the hanger talk.



> I suppose that at least some of the belief in "the bomber will always get through" might stem from the fact that the B-9 and B-10 outperformed most of the fighter aircraft in speed as well as range in their day, so the thinking was that escort fighters were unnecessary.



USAF bombers were also to fly higher, oce equipped with turbos, and, that failing, to fight their way in out. The 'self-defending' bombers thinking.



> I think its sad that the P51, which because it was designed for the RAF and didn't have to go through the normal channels, had to be fitted with a British engine in order to become the fine escort fighter it became.



It was not sad, just the contrary 



> To the positive, the development of turbo supercharging helped a lot of bombers and the P-47 become a force to be reckoned with, especially at high altitude.
> Might not be considered the ultimate fighter but the P-47, once they replaced the fabric control surfaces and made the ignition system reliable is my sentimental favorite.



+1 on that.



dobbie said:


> Once again, where were all the high altitude long ranged fighters? Turbosupercharging is a good system for high altitude, but you end up with something the size of the Thunderbolt in single engine form-no range, or the Lightning in twin engine form, which was not ready to take on the Luftwaffe until the later models, and is the question of the OP in case you hadn't noticed



Just to comment on the P-47 part - saying that it didn't have the range is way out of mark, the late D models were capable to fly 600 miles escort (= combat radius), the combat radius of the N was 1000 miles. We can compare other fighters of the world and quickly arrive to the conclusion that P-47 had legs. Plus, when people talk about P-47 being a big brute because of turbocharging, they tend to forget the honking big R-2800 the turbo was to cater about, and 2000-2800 HP at 25-30000 ft that no other aircraft could hope to match. 
The P-38's main problem was that it was not available in quantity (so USAF needed to prioritize), a much greater problem than this or that technical issue.


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## OldSkeptic (May 1, 2013)

Still has that miserable mach limit. In fact that maximum speed would be very close to its mach limit, coffin corner indeed.

A (very) rough calculation shows that its mach limit was about 460mph (TAS) at 30,000ft, with this being the 'lawn dart' mach limit of 0.68.

Even a very slight dive and you go out of control.

The P-51's was (tactical limit) 0.8 or about 540mph at 30,000ft and you you could push it a bit further too (albeit with things getting a bit uncomfortable).

That's one of the reasons why they went for the Mustang and swapped over from the -38 and -47, their mach limits were too low for the tactical environment.

And 48,000ft in a -38, only for the (brave) test pilots that one.


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## dobbie (May 1, 2013)

Gotta hand it to Kelly Johnson on the P38. Back when it was designed, there really wasn't a way to meet the AAC requirement on a single engine and his design team did an excellent job in working within the constraints of the RFP. For a twin engine fighter, the Lightning probably came closer to an effective fighter plane than any of the rest in that time period. True, the mach numbers were lower than the 47 or the 51, but this was at a time in aviation where a lot wasn't completely understood let alone managed. The later models overcame a lot but with the advance of technology, the Lightning needed more modifications to stay competitive with the newer aircraft.


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## Milosh (May 1, 2013)

Would a laminar type wing have helped the P-38.


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## drgondog (May 1, 2013)

OldSkeptic said:


> Still has that miserable mach limit. In fact that maximum speed would be very close to its mach limit, coffin corner indeed.
> 
> A (very) rough calculation shows that its mach limit was about 460mph (TAS) at 30,000ft, with this being the 'lawn dart' mach limit of 0.68.
> 
> ...



The number one, (and two through 21) reason was escort range combined with performance. The need for the P-51B was so great that its test phase was nowhere near a thorough cycle before the production line was spiiting them out to the docks on the east coast. Ergo, a series of field kits to replace main gear uplock kits, strengthening the eppenage, changing horizontal stabilizer incidence, replacing fabric elevators with metal ones and adding reverse rudder boost...

Also buried in the flight test data at Wright Pat and Eglin test reports was the simple fact that at 440mph, 29,000 feet @3000rpm the 1650-3 engine was driving the tip speeds on the P-51B prop into the tip shock wave region


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## OldSkeptic (May 1, 2013)

"wasn't so much 'out of control' as it was 'unable to produce enough aft stick force to overcome the pitching moment until the density of the air and subsequent airspeed reduced below Mcr. The Dive btake/flap under the wing at 30% chord, a.) delayed the time from pitch down in a dive and subsequent airspeed build up to Mcr and it affected the associated change to CMac."

They were called dive recovery flaps for a reason. Because they effected a smooth, relatively low G pullout from an out of control dive due to compressibility. Their main purpose was to recover from an out of control situation.

Without those pilots would pull back (or worse adjust trim) too much, so that when they got into the thicker air they could (and often did) overstress the airframe.
Worse you could pick up enough speed to either cause structural damage or even still be over the critical mach limit at lower altitudes, with no recovery possible (lawn dart).
The procedure was that when you were in that position was to pop the flaps, ideally before you picked up too much speed and wait. The plane would then come out of its dive, particularly as you hit lower altitudes, by itself relatively smoothly.

Yes they could be used just as you hit, or even before compressibility to delay the nose tucking down. But they only gave you another 15mph (about mach 0.7), from the pilot notes: "With these flaps extended, the nose heaviness is definitely reduced but the diving speed should never be allowed to exceed the placard by more than 15 or 20 mph".

The extra drag helped keep the speed down in a dive, so you could do steeper dives without building up so much speed: From the pilot notes again: "With the dive recovery flaps extended before entering the dive, angles of dive up to 45 degrees may be safely accomplished. Without dive recovery flaps extended the maximum angle for extending dives is 15 degrees. Diving characteristics are better with power off than power on."

Pilot notes: http://www.spruemaster.com/blog/wp-...eed P-38 Lightning Pilot Flight Operation.pdf

They were not a panacea, you could, if you were determined or stupid, still dive too fast and do a lawn dart or take the wings off. In Eric Brown's test he popped them at 0.75M and the nose came up, slowly at first then positively. But if you lost it and got into 0.8M. or worse more, there might not be enough altitude for them to take affect (by the extra drag slowing the plane) and allow a smooth pull out (from their nose up effect).


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## stug3 (May 2, 2013)

I cant see any scenario in which the P-38K does a better job than the F4U or P-51 in their respective roles, especially considering production economic factors and maintenance economic logistical factors.


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## OldSkeptic (May 2, 2013)

I agree.

"Without dive recovery flaps extended the maximum angle for extending dives is 15 degrees."

That's not a fighter its a bomber...


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## Reluctant Poster (Sep 18, 2013)

The P-38K is the unicorn of World War II fighter aircraft. No one has ever seen one yet everyone has heard of it. Like the unicorn it has taken on magical qualities; it’s faster than a P-47M, can climb higher than a T-152H, climbs faster than a Spitfire XIV, flies farther than a P-51B and according to Warren Bodie “it was superior-outstandingly superior-to the best fighter models in contention.” Blanket statements like that should always raise a red flag.

It all sounds too good to be true; and in fact it is too good to be true. Some laws of physics are being violated here. The truth is somewhat less spectacular. The Lockheed test results are posted on Mike William’s site (of course, where else). The document in the following link compares the performance of the P-38J to the P-38K. Note that these are not USAAF test results, but are a reprise of Lockheed’s tests:

http://www.wwiiaircraftperformance.org/p-38/P-38J_performance_11march44.pdf

As you would expect from similar tests on the P-47 the paddle blade propeller does not have much impact on level speed, but does have a significant impact on rate of climb and it does extend the performance envelop above critical altitude, with a consequent increase in service ceiling. A perusal shows that claims of speeds of 450 mph are pure fantasy as are ceilings above 48,000 ft.

Considering that combat above 30.000 ft was rare the improved altitude performance probably isn’t worth the production penalty, but the rate of climb would seem worthwhile. However the idea that the P-38K outclassed the P51B does not hold up, it’s still slower at all altitudes.

Incidentally this document also makes the case against water injection for the P-38, in that the substantial increase in weight that can only be compensated for by a reduction in fuel load and hence range.

The comparison test of paddle blade vs. needle blade for the P-47 is also on William’s website:

http://www.wwiiaircraftperformance.org/p-47/P-47D_43-75035_Eng-47-1714-A.pdf

davpalr posted



> Some caveats are needed here, I think. First is that most of the reviewers are Navy and almost all military pilots are highly bias for one


Actually most of the pilots were contractors (manufacturers) test pilots. The P-38L was flown by 1 army, 9 navy, 5 British and 13 contractor’s pilots. The Brits and the contractors were ALL test pilots.


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## FLYBOYJ (Sep 18, 2013)

Reluctant Poster said:


> The P-38K is the unicorn of World War II fighter aircraft. No one has ever seen one yet everyone has heard of it.



Lockheed P-38K Lightning






I worked Lockheed Burbank for almost 12 years, I know people who were on this program.


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## tomo pauk (Sep 19, 2013)

Reluctant Poster said:


> The P-38K is the unicorn of World War II fighter aircraft. No one has ever seen one yet everyone has heard of it. Like the unicorn it has taken on magical qualities; it’s faster than a P-47M, can climb higher than a T-152H, climbs faster than a Spitfire XIV, flies farther than a P-51B and according to Warren Bodie “it was superior-outstandingly superior-to the best fighter models in contention.” Blanket statements like that should always raise a red flag.



The truth was probably between this, and W.Bodie's praise-without-boundaries story. Nobody stated that P-38K would've been faster than P-47M (~470 mph); it should be able to climb higher than P-38J/L (if the engine is making 3200 rpm, and ADI works as advertised). Bodie clearly overstates the speed on WEP, as seen from the report you've kindly provided the link, as he does for the RoC. Without leading edge tanks, the radius/range would've suffered. 
However, P-38 was the best,or one of the best climbers USAF had. 



> It all sounds too good to be true; and in fact it is too good to be true. Some laws of physics are being violated here. The truth is somewhat less spectacular. The Lockheed test results are posted on Mike William’s site (of course, where else). The document in the following link compares the performance of the P-38J to the P-38K. Note that these are not USAAF test results, but are a reprise of Lockheed’s tests:
> 
> http://www.wwiiaircraftperformance.org/p-38/P-38J_performance_11march44.pdf



Thanks for the link. Both P-38s were flown without leading edge tanks, and we are left in dark why the P-38K was not faster under ~30000 ft on WEP - it did have 2x1725 HP, vs 2x1600, in the same time featuring a better prop.



> As you would expect from similar tests on the P-47 the paddle blade propeller does not have much impact on level speed, but does have a significant impact on rate of climb and it does extend the performance envelop above critical altitude, with a consequent increase in service ceiling. A perusal shows that claims of speeds of 450 mph are pure fantasy as are ceilings above 48,000 ft.



While P-47D made a good use of paddle blade prop, along with ADI system (allowing greater boost), it's engine remained with same RPM all the way, hence the performance above ~30000 ft remained about the same. The performance was improved under full throttle height, since there the supercharger system was able to provide greater manifold pressure.
The Allison F-29 engines were allowed to make 3200 rpm, vs. 3000 rpm for the engines found in the serial P-38s - more RPM means full throttle height is at higher altitude. Higher altitude (thinner air) combined with more power means higher speed.
But, the P-38 making 430-440 mph between 30-35000 ft (almost Mach .65 there) would encounter another hurdle, and that would be the compressibility - P-38's dive limit was at Mach .65.



> Considering that combat above 30.000 ft was rare the improved altitude performance probably isn’t worth the production penalty, but the rate of climb would seem worthwhile. However the idea that the P-38K outclassed the P51B does not hold up, it’s still slower at all altitudes.



Agreed, once the Merlin Mustang arrived, P-38 was unable to offer anything more, while costing much more both to purchase and operate.



> Incidentally this document also makes the case against water injection for the P-38, in that the substantial increase in weight that can only be compensated for by a reduction in fuel load and hence range.



The weight of 30 gals of ADI liquid (water-methanol) in the P-47 was 124 lbs. Lockheed assumed that ADI system would've weighted 600 lbs, 400 lbs being the ADI liquid - seems they intended to replace the LE fuel tank with ADI tank - 400 lbs is almost 100 gals of water-methanol?



> The comparison test of paddle blade vs. needle blade for the P-47 is also on William’s website:
> 
> http://www.wwiiaircraftperformance.org/p-47/P-47D_43-75035_Eng-47-1714-A.pdf



Thanks.


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## FLYBOYJ (Sep 19, 2013)

tomo pauk said:


> Agreed, once the Merlin Mustang arrived, P-38 was unable to offer anything more, while costing much more both to purchase and operate.


Except the safety factor of the extra engine....


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## swampyankee (Sep 19, 2013)

davebender said:


> During WWII the U.S. Government managed the American economy just as the German Government managed the German economy.
> 
> Order Consolidated to build B-17s. Just as RLM ordered Arado, Henschel and Heinkel to participate in the massive Ju-88 light bomber program during 1938. Otherwise Consolidated is cut off from government funding until they go bankrupt.
> 
> North American doesn't count as funding for development of the Mustang comes from Britain.



Actually, it managed it much better. 

I'm sure there was quite a bit of inefficiency in the US allocation of resources to weapons production, but business leaders were quite used to large centrally planned organizations (what do you think large corporations are?) and were also willing to accept that "most productive" is not the same as "least wasteful" or "most efficient." The US was also more efficient in utilizing its ample labor resources (and if they were short, it would have been easy to recruit -- not enslave -- workers from Mexico, Central and South America, and the Caribbean), had ample material resources, probably had better understanding of industrial engineering and mass production technology, and started with a much larger economy. Redundant weapons systems may have been inefficient (they also had somewhat different capabilities, e.g., the Hellcat was, in many ways, a better aircraft than the Corsair, and the B-24 was, in some ways, better than the B-17).


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## drgondog (Sep 20, 2013)

IIRC there is one other factor to consider Merlin Vs Allison, other than a couple of hundred extra pounds. Namely specific fuel consumption is better in the Allison. If strictly true in the configuration then the combat radius of the P-38K should be less than the J and perhaps the same as the H. In the ETO this would not be a good thing.


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## davebender (Sep 20, 2013)

That would sound better if P-38 engines didn't have such a poor reliability record over Europe. I would rather have one reliable Merlin or DB601 engine then two unreliable Allison engines.


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## FLYBOYJ (Sep 20, 2013)

davebender said:


> That would sound better if P-38 engines didn't have such a poor reliability record over Europe. I would rather have one reliable Merlin or DB601 engine then two unreliable Allison engines.


Tell that to the P-38 drivers who survived the war because of that sooo unreliable extra engine.

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## Coyote (Sep 20, 2013)

Didn't read the entire thread, so forgive me if this has been said already: In no way would the P-38K replace either one. Later modells of the '51 and '4u flew in Korea while the P-38s were being scrapped in Arizona. P-38 was a great fighter, but it had its place.


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## Shortround6 (Sep 20, 2013)

Are these the same Allisons that had a rather good record in south east asia _once_ they fixed the turbo controls? 

The tech reps in the CBI theater had figured out a "fix" for the turbo controls and a tech rep with 300 locally built kits was sent to the SWPA to modify their engines. Once modified a number of engines went to 300 hours without any major problems. the originating squadron went over 5 months _without a single_ non-combat related engine failure. Sure sounds like an unreliable engine to me..........

The basic engine was very good, the turbo controls had some problems and flying them_ against_ the recommendations of both Allison and Lockheed and then calling the engine unreliable is hardly unbiased. fly the Merlin or DB 601 for hundreds of hours in violation of the manufacturers operating instructions and see how reliable they are.

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## vinnye (Sep 20, 2013)

Once the fix was in the Allison was fine.
I like the P38, it was a goo looking bird that had range and firepower to burn. Always nice to have that spare engine when you are flying a lon, long way on your missions!
I would still have the P51 and F4U to compliment the P38.
The F4U for carrier use if nothing else!


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## swampyankee (Sep 20, 2013)

Milosh said:


> Would a laminar type wing have helped the P-38.



That's not an easy question to answer. First, laminar flow airfoils of that era, like NACA's 6 series airfoils, could not maintain laminar flow in service (indeed, even today it's considered normal practice to use the lift and drag characteristics with a tripped boundary layer, _i.e._, one that is turbulent), so there is not likely to be much drag reduction. However, because some of the 6 series airfoils were designed to have maximum flow velocity (maximum Cp​) fairly far aft, they had higher critical Mach numbers than other airfoils.

So, the answer to the question is "maybe yes, maybe no." I'd vote for probably no.


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## wuzak (Sep 20, 2013)

Milosh said:


> Would a laminar type wing have helped the P-38.





swampyankee said:


> First, laminar flow airfoils of that era, like NACA's 6 series airfoils, could not maintain laminar flow in service (indeed, even today it's considered normal practice to use the lift and drag characteristics with a tripped boundary layer, _i.e._, one that is turbulent), so there is not likely to be much drag reduction.



I would think that there was a lot of scope in the P-38's wings for drag reduction. They were quite thick and had a low critical mach number.




swampyankee said:


> However, because some of the 6 series airfoils were designed to have maximum flow velocity (maximum Cp​) fairly far aft, they had higher critical Mach numbers than other airfoils.



Tell that to RJ Mitchell, whose Spitfire wing had a higher critical mach number than the Mustang's laminar flow wing.




swampyankee said:


> So, the answer to the question is "maybe yes, maybe no." I'd vote for probably no.



You would end up trading top speed (improved with laminar flow wing) for climb rate.


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## davebender (Sep 20, 2013)

Unfortunately P-38 engines required 5 years to fix (1939 to 1944). By then the war was almost over.

Spitfire first flew during 1936. Britain would have been up a creek without a paddle if engine technical problems required 5 years to fix. So would Germany if Me-109 engine required 5 years to fix. Even the problem plagued BMW801 engine was fixed in less then 5 years.


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## swampyankee (Sep 20, 2013)

davparlr said:


> Some caveats are needed here, I think. First is that most of the reviewers are Navy and almost all military pilots are highly bias for one, their aircraft, and two, their service. Second, I am sure all the reviewers were single engine pilots. As such, the plane is big, complex, and they were unfamiliar with two engine idiosyncrasies like, maybe, asymmetric thrust.
> 
> Overall, I think the P-38 had potential to be an effective fighter, it was certainly deadly in the PTO. However, I suspect it took some time for a pilot to learn how to handle the uniqueness of the aircraft. Also, two engines adds cost, reduces mission reliability and increases maintainability requirements. Faced with the simplicity, cost, ease of flying and performance of the P-51, it was difficult to justify.



I'm trying to remember something I read a long time ago, but it comes down to the USAAF not providing adequate twin-engine flight training to its P-38 pilots, especially in type, before putting them on operations. One of the dangers of twin-engined aircraft is that the few seconds after engine failure are very busy, with a lot of choices. Make the wrong choices, and you crash and die. In a single-engined aircraft you don't have many choices, and you just want to make the crash as comfortable as possible. You can still crash and die, but in the quiet after the only engine fails, it's much easier to concentrate. As a potentially interesting factoid, the insurance rates for light twins are (or at least were in the 1980s) higher than they are for comparable single-engined aircraft. 

I think the other problem was that early models of the P-38, before hydraulically boosted ailerons were added, did not have rapid roll response, which made them feel unmaneuverable. Reportedly, P-38 pilots got an improved view of their aircraft after Tony LeVier gave some demonstrations.


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## Aozora (Sep 20, 2013)

According to Der Gabelschwanz Teufel - Assessing the Lockheed P-38 Lightning there was a combination of problems:



> Even with the arrival of the P-38J, engines and turbochargers continued to fail. The new intercooler/oil cooler design was actually too efficient and the enlarged radiators became a new problem. Fuel too, was a source of trouble, it is believed by many knowledgeable people that the majority of fuel used in Britain was improperly blended, the anti-knock lead compounds coming out of solution (separating) in the Allison's induction system at extreme low temperatures. This could lead to detonation and rapid engine failure, especially at the higher power settings demanded for combat.
> 
> Many of the P-38's assigned to escort missions were forced to abort and return to base. Most of the aborts were related to engines coming apart in flight. The intercoolers that chilled the fuel/air mixture too much. Radiators that could lower engine temps below normal operating minimums. Oil coolers that could congeal the oil to sludge. These problems could have been fixed at the squadron level. Yet, they were not. It took the P-38J-25-LO and L model to eliminate these headaches. Add sub-standard fuel, green pilots, poor tactics and the 8th had a serious problem in the making.



Re: the pilot training - there were some small but vital flight techniques that were needed to operate the turbo-chargers properly; much the same fundamentals still apply: - Flight Training



> If you fly a turbocharged engine, you need to know how the system works and be aware of several important operating techniques. Because oil pressure closes the wastegate, you must allow time for the engine and oil to warm up completely before taking off. If the oil pressure is low or the oil is cold and sluggish, the wastegate may be slow to close, which means the engine won't develop its full, rated power during takeoff and climb.
> 
> Also, engine oil lubricates the turbocharger, which can spin at more than 30,000 rpm at takeoff power During normal operation, several gallons of oil flow through the turbocharger's bearings every minute. Cold oil doesn't flow properly. If you apply high power settings before the oil warms to the proper temperature, the oil may not lubricate the turbocharger sufficiently.
> 
> Power should be applied smoothly and relatively slowly. If the throttle is shoved rapidly to the firewall on takeoff, the turbocharger controlling mechanisms may not have time to function properly, causing the engine to surge and possibly overboost.


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## Shortround6 (Sep 20, 2013)

davebender said:


> Unfortunately P-38 engines required 5 years to fix (1939 to 1944). By then the war was almost over..



Ah, no. The early P-38 engines weren't too bad. The crises was with the P-38J model. The early models with the leading edge inter-coolers could not _over cool_ the intake mixture while cruising like the "J" could. The crises started in the fall/winter of 1943/44 with the introduction of the "J" model. It was made worse by a change in the fuel specification that allowed different blends of compounds to stretch the available fuel supply to provide more 100/130 fuel. The change was implemented in the winter/spring of 1943, Allison was working on a new intake manifold to help solve this problem during the summer/fall of 1943. The manifold was standardized in Nov 1943 but many P-38s had been shipped to England before that. 

Kind of hard to "fix" a problem in 1939-42 for a fuel that doesn't exist yet. 

One reason the the MTO had a lot fewer problems was that the first P-38Js went to England, the MTO and Pacific got the Fs, Gs and Hs. By the time the MTO got P-38Js the problem had already been fixed. 

SO the P-38 didn't have severe problems for 5 years, It had severe problems for around 6 months. 

Because turbo installations are more complicated they need more maintenance and/or more careful maintenance. Turbo control linkages were often improperly set. If the turbo controls are mis-rigged is that a design fault or a maintenance/erection fault?


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## tomo pauk (Sep 21, 2013)

I was afraid that Greg will see the claim about the unreliable V-1710; fortunately, SR6 was close to the keyboard


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## davebender (Sep 21, 2013)

Biggest problem when discussing P-38 reliability is that sources disagree. Some claim problems were fixed by 1943. Other sources claim problems were never completely fixed.

However it's a fact that U.S. 8th Air Force chose to replace P-38s with P-47s and P-51s when enough of those fighter types became available. Production cost can't be the issue as P-47 costs almost as much as a P-38. P-47 was also a fuel hog. P-47 and P-51 both had weapon packages inferior to P-38. So I've got to assume people operating P-38s at high altitude lacked confidence in the aircraft even during 1944. I have not personally flown the aircraft and can only defer to those that did historically under combat conditions.


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## JtD (Sep 21, 2013)

Two engines is two times the risk for a single engine failure. Additionally, the P-38 compressibility problem made it an imperfect high altitude fighter.

On the other hand, if an engine gets shot up in a twin you still have one to bring you home, compressibility was nearly irrelevant down low and the P-38 could carry a more than impressive array of ground attack weapons, equivalent to unit cost. It's only logical that the P-38 was phased out of high altitude escort duty and used for other tasks.


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## tomo pauk (Sep 21, 2013)

Some of the issues that reduced the need for the P-38 were due to it's construction, some were due to it's engines experiencing issues in the crucial time and place (exacerbated by out-of-book use), some were due to it's performance. Pointing out at the engines as main culprit, even indirectly, is definitely not a painting a whole picture. While the P-38 did have had central battery, it was maybe a single thing that it had over P-51. Climb and turn abilities were also good on P-38, but that was not on the top of the list of USAF needs in 1943-45.

-construction: 2 engined airplane will need more pilot training, it will not roll as good as the S/E plane (especially at lower speeds), it was much more expensive than P-51 to produce and operate. The wing was not that thin (16% TtC ratio at root), nor it was last word in aerodynamics for late ww2. Big plane is easier to spot than a smaller one - enemy pilot will act 1st. As-is, the P-38 offered many blind spots, too. It took Lockheed too much of time to fix cabin heating and to introduce the generator on second engine (AAF 'gulity' for this?), too. Here the P-51 was holding most of the cards, even the P-47 did.
-engines: covered by SR6
-performance: both P-51 and P-47 were faster, both in level flight and in dive. Even once the dive flaps were introduced on the P-38 (by then the P-47 got them, too).

Then we have the nuber of the planes built in last 2 years of ww2 - Allies having far more planes than trained pilots? Further, from June/July/Aug of 1943, USA was producing 3 P-47s/-51s for each P-38 produced. 
With all this said, no wonder USAF decided it they will be better served with P-47/-51 only.


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## drgondog (Sep 21, 2013)

davebender said:


> Biggest problem when discussing P-38 reliability is that sources disagree. Some claim problems were fixed by 1943. Other sources claim problems were never completely fixed.
> 
> However it's a fact that U.S. 8th Air Force chose to replace P-38s with P-47s and P-51s when enough of those fighter types became available. Production cost can't be the issue as P-47 costs almost as much as a P-38. P-47 was also a fuel hog. P-47 and P-51 both had weapon packages inferior to P-38. So I've got to assume people operating P-38s at high altitude lacked confidence in the aircraft even during 1944. I have not personally flown the aircraft and can only defer to those that did historically under combat conditions.



Well, not so simple. The P-38 was in high demand in the PTO/MTO and had the P-51 not been available in theatre, the 8th AF would have continued with it. While the airframe cast was not too much above the P-47, the training, the operating costs were at least twice as much as a p47 and close to 2.5x over a Mustang.

I know a lot of pilots that flew both and liked both the P-51 and P-38. Robin Olds comes to mind in the forefront.


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## davebender (Sep 21, 2013)

Many pilots disliked the P-47 (i.e. most numerous American fighter aircraft). Especially if they had experience flying other fighter types. So I'm not surprised some expressed a strong preference for the P-38 even if it had technical glitches.


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## Aozora (Sep 21, 2013)

davebender said:


> Many pilots disliked the P-47 (i.e. most numerous American fighter aircraft). Especially if they had experience flying other fighter types. So I'm not surprised some expressed a strong preference for the P-38 even if it had technical glitches.



It's a given that pilots will often/usually express a strong preference for one aircraft type over another, so of course there were pilots who disliked the P-47, particularly those who had flown the Spitfire. It could equally be said that many pilots preferred the P-47 over every other fighter, including the P-38.


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## davebender (Sep 22, 2013)

2,309kg empty weight. Spitfire Vb (most common variant).
4,536kg empty weight. P-47D.

Easy to see why. Double the empty weight and comparison gets worse with loaded weight. Like telling a Formula One driver that next week he will be driving a beer truck.


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## Jugman (Sep 22, 2013)

tomo pauk said:


> Thanks for the link. Both P-38s were flown without leading edge tanks, and we are left in dark why the P-38K was not faster under ~30000 ft on WEP - it did have 2x1725 HP, vs 2x1600, in the same time featuring a better prop.



Read the first sentence of the second paragraph. Speed at 1725 hp would have been about 2% better at all altitudes.



tomo pauk said:


> The weight of 30 gals of ADI liquid (water-methanol) in the P-47 was 124 lbs. Lockheed assumed that ADI system would've weighted 600 lbs, 400 lbs being the ADI liquid - seems they intended to replace the LE fuel tank with ADI tank - 400 lbs is almost 100 gals of water-methanol?



The weight of 30 US gallons ADI was about 224-248 lbs. (50-50 to 95-5 water-alcohol) Total system weight for the P-47 was less than 300 lbs. The P-38 system seems to be a 24x2 gallon system. This system was not where the leading edge tanks were but most likely located in the wheel wells and/or outboard of the nacelles behind the main spar. The fixed weight of the systems seems very high for the capacity.


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## tomo pauk (Sep 22, 2013)

Jugman said:


> Read the first sentence of the second paragraph. Speed at 1725 hp would have been about 2% better at all altitudes.



Many thanks for pointing me at power setting used. 
If I'm reading the report right, the RoC (all altitudes) and speed (at lest from 35000 up?) was only because a better prop was installed?



> The weight of 30 US gallons ADI was about 224-248 lbs. (50-50 to 95-5 water-alcohol) Total system weight for the P-47 was less than 300 lbs.



Thanks again. 
I've read the item 'Water' (124 lbs) on the table at pg. 285 of AHT book, and then there is another item named 'Water', on the same table but lower, and this item weights 248 lbs (or zero lbs for 'Design' mission profile). Anyone up to clear it to me why two items of same name are listed there - 248 lbs would indeed be the ADI liquid.



> The P-38 system seems to be a 24x2 gallon system. This system was not where the leading edge tanks were but most likely located in the wheel wells and/or outboard of the nacelles behind the main spar. The fixed weight of the systems seems very high for the capacity.



I'd love to see a proper description of the system myself; the 2 x 24 gall system does make much more sense. BTW, if the ADI tank is located behind the main spar, it might cut into the inboard (main) fuel tank, or may dictate different construction/location of the dive flaps.
The paragraph 5 from the linked document says that Lockheed assessed that weight penalty will be 600 lbs for the ADI system, out of which 400 lbs is to be water(/methanol).


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## Jugman (Sep 24, 2013)

tomo pauk said:


> Many thanks for pointing me at power setting used.
> If I'm reading the report right, the RoC (all altitudes) and speed (at lest from 35000 up?) was only because a better prop was installed?



Yes.



tomo pauk said:


> Thanks again.
> I've read the item 'Water' (124 lbs) on the table at pg. 285 of AHT book, and then there is another item named 'Water', on the same table but lower, and this item weights 248 lbs (or zero lbs for 'Design' mission profile). Anyone up to clear it to me why two items of same name are listed there - 248 lbs would indeed be the ADI liquid.



The top part of the table is for early models with the 15 gallon tank and the bottom is for later models with the 30 gallon tank.



tomo pauk said:


> I'd love to see a proper description of the system myself; the 2 x 24 gall system does make much more sense. BTW, if the ADI tank is located behind the main spar, it might cut into the inboard (main) fuel tank, or may dictate different construction/location of the dive flaps.
> The paragraph 5 from the linked document says that Lockheed assessed that weight penalty will be 600 lbs for the ADI system, out of which 400 lbs is to be water(/methanol).


 
Nothing in the report suggests that the normal fuel capacity was reduced in any way. My best guess is the system had two 12 gallon tanks per engine located in side the main wheel wells just in front of the supercharger intakes.


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## tomo pauk (Sep 24, 2013)

Jugman said:


> The top part of the table is for early models with the 15 gallon tank and the bottom is for later models with the 30 gallon tank.



Indeed, thanks.



> Nothing in the report suggests that the normal fuel capacity was reduced in any way.



Reading the 1st post here, the (X)P-38K prototype was a modification of the P-38G, ie. no leading edge tanks present - 300 gals internal fuel.



> My best guess is the system had two 12 gallon tanks per engine located in side the main wheel wells just in front of the supercharger intakes.



That would allow for maybe 7-8 min operation only (25 gals giving 15 min of operation in the P-63), but I guess the space would've been at premium. 
Unfortunately, apart from mentioning the ADI sytem twice in the 'Vee's for victory', and 'more than 1875 bhp' by Bodie, is there any firm document about the P-38K ever using the ADI? The Vee's do not give more than 1600 HP at 3000 rpm, 60 in Hg MAP for the P-38K (= same as P-38J/L) , war emergency power.


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## Jugman (Sep 25, 2013)

That would be 14-16 minutes per engine (remember it's 12X2=24 gallons per engine). The ADI flow rate for the P-38 would be lower because the P-38 had intercoolers. So more like 18-24 minutes.


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## silence (Sep 26, 2013)

What's "ADI"?


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## Aozora (Sep 26, 2013)

silence said:


> What's "ADI"?


 
Anti-Detonation-Injection; a system whereby either pure water or a water/methyl alcohol mix is injected into the engine. The German MW 50 (50% water 50% Methanol) was one such system; Pratt Whitney R-2800s with ADI used the suffix W; eg: R-2800-16W.


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## tomo pauk (Sep 26, 2013)

The BMW-801 used the fuel (C3) as ADI liquid - engine was found not to be suitable for usage of the MW-50?


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## OldSkeptic (Sep 26, 2013)

Not quite, the BMW system was actually a C3 feed before the supercharger. Yes it richened the mixture but also charge cooled the air in the supercharger (ah lah the Merlin).
The combination of the richer mixture and the cooler supercharger outlet meant you could run higher boost without detonation. 

Basically, in their complex way they copied the RR system, but only for emergencies. And in their complex way they still maintained all the individual feeds to each piston ????

The correct way was fuel injection into the supercharger inlet, as per the Merlin 100 series (late 44), which the Germans could have done very successfully in 1939.....

Funny design attitude.


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## Shortround6 (Sep 26, 2013)

Once a company or country starts down a design path it is hard to change. Germans believed the fuel injection gave better economy for power produced and given the Germans fuel situation they may have been right. The high compression used in German engines was also good for economy but limited ( in some cases severely) the max amount of boost that could be used. 
The Allison is often considered to have _lost_ about 10% of it's max boost/power capability due to it's higher compression and it was nowhere near as high as the later German engines. The Allison did have better spc than the Merlin.


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## tomo pauk (Sep 26, 2013)

OldSkeptic said:


> Not quite, the BMW system was actually a C3 feed before the supercharger. Yes it richened the mixture but also charge cooled the air in the supercharger (ah lah the Merlin).
> The combination of the richer mixture and the cooler supercharger outlet meant you could run higher boost without detonation.
> 
> Basically, in their complex way they copied the RR system, but only for emergencies. And in their complex way they still maintained all the individual feeds to each piston ????
> ...



I'd like to see exactly where BMW copied RR? Being single stage engine, that never used intercooler, but used C3 as ADI? 
Some people still consider sleeve valves as funny design attitude, as well as 'their complex way'.

C3 feed before the supercharger still counts as ADI, no?


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## Shortround6 (Sep 26, 2013)

Maybe yes, maybe no 

A lot of American ( and some others) ran _really,really_ rich at max power settings, so rich than when water injection was introduced and used, fuel consumption was cut back using a "de-enrichment circuit" in the carburetor. 

The extra fuel ( way more than could be burned in the available quantity of air) acted as a charge coolant and internal coolant to the engine. Even if supplied by the "normal" carburetor would the excess fuel be considered "ADI". 

Pictures or videos of these planes taking off and trailing black exhaust plumes show the extra fuel being used even at take-off power.


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## swampyankee (Sep 26, 2013)

Water injection was used in the jet engines on a number of airliners and multi-engined military jets. Oddly enough, it was frequently called ADI, even though gas turbines don't have anything akin to engine knock. They'd mix water and alcohol to get the lowest freezing point. Thankfully, especially for people who live within a few miles of an airport, high-bypass fans don't tend to need water injection.


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## silence (Sep 26, 2013)

Aozora said:


> Anti-Detonation-Injection; a system whereby either pure water or a water/methyl alcohol mix is injected into the engine. The German MW 50 (50% water 50% Methanol) was one such system; Pratt Whitney R-2800s with ADI used the suffix W; eg: R-2800-16W.



Thanks!


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## Jugman (Sep 27, 2013)

"Anti-Detonation Injection" AKA "water injection"


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## JtD (Sep 28, 2013)

Should be noted that the C3 injection was dropped for the erhöhte Notleistung, because it was found the engine could manage the increased boost without the extra fuel and charge cooling.


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## tomo pauk (Sep 28, 2013)

Could you share some details, please?


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## IdahoRenegade (Oct 2, 2015)

I have a question about the '38K I wonder if someone can answer. Most of our top fighters were originally equipped with fairly narrow, 3-bladed props at the start of the war if I remember correctly. I'm pretty sure the P-51-A and the F4U at the least did, not so sure about the '47. Anyway, in every plane except the '38, when "high activity" paddle props were installed, they were all 4-bladed (Corsair, '47 and '51). The pictures I've seen of the '38K still show it with a 3-bladed prop, just a wider one. Any reason they didn't use a 4-bladed one? Seems like the one (with spinner) from the '51 might have been adapted.

The other oddity for me was the way the '38 was treated by the War Production Board. By late 40 to early 41 it should have been obvious that the only AAC plane in the work that was both a match for the best enemy fighters and had useful range was the '38. At that time the '51B (Merlin version) wasn't even a pipedream. It was obvious early on the '47 wasn't going to have the range to provide escorts or any kind of long range fighter sweeps. It seems odd that a 2nd source of production for the '38 was never set up until the VERY end of the war (Vultee made a very few hundred in '45). Had this been done early, significant numbers of '38s could have been in Britain (without shorting the SWPA and MTO) to start providing long range bomber escort in early '43. More planes, with time for the ground crews to get used to servicing them, and for the pilots to gain experience, would have made a huge difference in effectiveness when they were finally allowed to escort the bombers. Moreso, as it was the '38s were available as escorts only in very low numbers by late '43, they were often outnumbered 5 or even 10 to one. An extra few hundred fighters would have made a huge difference. In addition, that extra production capacity would mean that one line at a time could have been shut down and converted to K production. The Bell p-39 plant could have been converted, both enhancing production of the '38 and avoiding the "waste" of some V1710s in the under-performing P-39.


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## IdahoRenegade (Oct 2, 2015)

Oh as far as the K model making the '51 and F4U unnecessary...maybe. It could certainly have provided adequate escort for the bombers had it been available in volume. And it was much more versatile than the Mustang, with a far higher bomb load (4000lbs) and it was much more "survivable", with dual engines. Don't forget the '51 was not going home with one hit anywhere in the Merlin's cooling system. In addition, the cluster of guns in the nose made it much more effective in ground attack than any fighter dealing with gun convergence of a wing-mounted gun. With regard to the Corsair, yes, it was eventually cleared for carrier ops, but not until late '44. It was primarily a land-based plane operated by the Marines. The '38K could certainly have provided similar capability, with the redundancy of twin engines, a higher weapons load and much longer range. As far as carrier ops, the Hellcat could have been used throughout the war. Though it wouldn't have been nearly as effective chasing down Kamikaze planes due to it's much lower top speed.


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## drgondog (Oct 2, 2015)

IdahoRenegade said:


> Oh as far as the K model making the '51 and F4U unnecessary...maybe. It could certainly have provided adequate escort for the bombers had it been available in volume. And it was much more versatile than the Mustang, with a far higher bomb load (4000lbs) and it was much more "survivable", with dual engines.
> 
> *If you suspend all skepticism and postulate the P-38K availability in combat level deployment in early 1942 and further suspend a 'reality check' based on Lockheed's inability to keep up with demand in all theatres in 1943, and then you remove the requirement for 2x cost, 2x operating expense, 1.5 x training expense - then the top AAF leadership might not have ever purchased the Merlin based P-51B.
> 
> ...



The P-38s in the 20th, 55th and 364th P-38s suffered much higher losses while strafing LW airfields than P-51B's (All three 8th AF P-38s converted to P-51s in July, 1944. The 479th did not have as high percentage losses to strafing as the other 3 and were closer to Mustang average loss per aircraft destroyed on the ground.

The twin engines were a definite advantage for loss of engine in a non lethal strafing environment but consider that the F4U and P-51 losses in Korea per sortie (ALL CAS for both ships) was about the same with 51 very slightly higher - one with coolant/one without. The P-38 was a huge (and slower) target on the deck with not only greater number of vulnerable surface areas and internal components(Fuel cells of internal fuel, supercharger systems, two radiators/oil coolers, coolant lines - all vulnerable to fire from explosive 20mm flak. 

But, True - that if hit in a coolant line and that engine is shut down immediately the P-38 will survive where the P-51 will not.

The P-38K does Not solve the following
1.) Has very small window between top speed in a chase from 22000+ ft to compressibility in a dive. If dive flaps are deployed, the Critical Mach increases slightly but far short of the P-51, P-47, Bf 109 and FW 190. It can't chase nor can it evade from a dive initiated at high altitude. 8th AF operations required high altitude performance envelope and the P-38 was least suited of the Big 3 for Germany. The J-15 solved many of the mechanical issues but could do nothing for the aerodynamic issues of the NACA 23018 wing near transonic.
2.) It is HUGE and easily spotted long before the P-38 driver spots the other guy - giving the other guy a tactical advantage.
3.) It P-38J/L had less Combat Radius than the P-51B/C/D/K (not by much, 675mi to 750mi) limiting target escort options for 8th AF (and 20th AF) Planners. For example no P-38J with additional 110 gallons in LE fuel cell went past the Berlin/Leipzig/Munich line when P-51s were going to Stettin and Posnan Poland and Brux, Czechoslovakia. Even if the K had been configured for a Merlin 1650 it would consume even more gas than the V-1710 and further reduce Combat Radius..


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## drgondog (Oct 2, 2015)

BTW - it would be interesting to see a real flight test report on the P-38K to understand a.) what the load out looked like, b.) understand the magic of overcoming the drag rise as the Propeller tips way exceeded M=1 at 29,000 feet at the alleged 450mph, c.)understanding the math of a theoretical 10-15% range improvement due to prop selection. If true, that change would have been as easy as selecting and installing the Aero Products prop/Spinner on the P-51K.

I suspect Bodie was waxing euphoria and sunshine and unicorns - again. Seeing the Flight Tests and write ups would silence my skepticism

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## tomo pauk (Oct 2, 2015)

IdahoRenegade said:


> I have a question about the '38K I wonder if someone can answer. Most of our top fighters were originally equipped with fairly narrow, 3-bladed props at the start of the war if I remember correctly. I'm pretty sure the P-51-A and the F4U at the least did, not so sure about the '47. Anyway, in every plane except the '38, when "high activity" paddle props were installed, they were all 4-bladed (Corsair, '47 and '51). The pictures I've seen of the '38K still show it with a 3-bladed prop, just a wider one. Any reason they didn't use a 4-bladed one? Seems like the one (with spinner) from the '51 might have been adapted.



Don't know the reasoning of not installing the 4-bladed prop, but the new prop was also of greater diameter than the old one - 12'6" vs. 11'6". As I understand by posts in this forum, the increased diameter of the prop will mean more than increased number of blades, efficiency-wise, so they judged that going for 4-bladed is not necessary? The choice of prop was probably undoing of the P-38K, since it required also the new reduction gear, that required change of cowling, that required halt of production line by couple of weeks - ain't going to happen when P-38 was in such a demand. Maybe it's too bad the new prop didn't retain the diameter, but went to 4 wider blades? Merlin Mustang was outfitted with the prop of 11'2" diameter, a small change from 10'9" of the Allison P-51.



> The other oddity for me was the way the '38 was treated by the War Production Board. By late 40 to early 41 it should have been obvious that the only AAC plane in the work that was both a match for the best enemy fighters and had useful range was the '38. At that time the '51B (Merlin version) wasn't even a pipedream.



Not having the second source for P-38 is surely a shame. The 'useful range' was not that a big thing for the USAF of 1940/41, since then current doctrine was that fighters are for defense. Nobody was talking much about escorting the bombers since it was expected the high flying + plenty of HMGs will mean safe bombers, and we know now that id didn't paned out that way.



> It was obvious early on the '47 wasn't going to have the range to provide escorts or any kind of long range fighter sweeps.



Im afraid that here you are wrong - the P-47 have had the ingredients for long range work, as we know the combat range was 300 miles with small external fuel tankage, then 400 (all in 1943), 450 and then 600 (early and mid 1944), while the P-47N was managing 1000+ in mid-1945. Where the USAF made a mistake was not specifying wing pylons from P-47C at least.


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## Mike Williams (Oct 2, 2015)

drgondog said:


> BTW - it would be interesting to see a real flight test report on the P-38K to understand a.) what the load out looked like, b.) understand the magic of overcoming the drag rise as the Propeller tips way exceeded M=1 at 29,000 feet at the alleged 450mph, c.)understanding the math of a theoretical 10-15% range improvement due to prop selection. If true, that change would have been as easy as selecting and installing the Aero Products prop/Spinner on the P-51K.
> 
> I suspect Bodie was waxing euphoria and sunshine and unicorns - again. Seeing the Flight Tests and write ups would silence my skepticism



The following document was referenced earlier but is interesting and gives performance data of the P-38J and the prototype P-38K obtained from flight tests carried out by Lockheed.

Additional Performance of P-38J Airplanes, 11 March 1944

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## Balljoint (Oct 2, 2015)

This may be redundant; I don’t recall it being specifically cited other than quotes.

Whatever Happened To The P-38K ?


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## drgondog (Oct 2, 2015)

Mike Williams said:


> The following document was referenced earlier but is interesting and gives performance data of the P-38J and the prototype P-38K obtained from flight tests carried out by Lockheed.
> 
> Additional Performance of P-38J Airplanes, 11 March 1944



1.AAF testing not performed to validate Lockheed tests.
2.The values from Lockheed are derived from a 'light' P-38K at 16,200 versus fully loaded I(nternal fuel plus ammo)GW of 17,600 pounds which is an 8% reduction in Wing Loading. Would also result in a reduction to Induced Drag when compared to normal combat loaded P-38J-15 and higher dash number. Net result of lower wing loading is much faster climb and slightly more speed in the comparison than valid for equal Load Out between J and K..
3. They discuss Water Injection for the F-29 engines and the subsequent penalty in performance should the 600 extra pounds (tank, water, lines) be added to 17,600 pound Combat weight (without external fuel) as well as suggesting replacing 55 gallon fuel in each leading edge for the water, compromising range for hoped for performances.
4. The Mystery of the drag rise of the prop tips for greater diameter prop is answered with changing 2:1 to 2.36:1 ratio ------> reducing prop RPM from 1500RPM to 1271 RPM
5. The ROC for the P-38K would still be impressive, as well as increase in ceiling but look carefully at the 20000 to 30000 foot window for ROC. Both the speed and the ROC are virtually identical at MP and WEP at those altitudes for the 1475Hp and 1600Hp ratings (without WI) and close to the P-51B in climb with 1650-7 and 72" for WEP

Summary - In other words the Paddle Blade didn't do much where it counts just by looking at the data, and you have to keep in mind that the stated load out for the P-38K was 1400 pounds shy of the comparable J/L.

Next consideration - Allison finally put out a V-1710-143/-145 two speed/two stage engine for the P-82 to replace the V-1650-9 with W/I. It did not work well, never achieved the reliability of the Merlin and forever lived its existence limited to 61".. the implication is that the 1710-F29 would not have realized its design Power output predicted for WI and high octane fuel - or even improved on the 1710-89/91 on the J/L.

Bodie doesn't touch on those details for either the Flight Test by Lockheed (unseen) or the geneology of the F-29 V-1710 which IIRC was a modified V-1710-75/77.

I remain highly skeptical of either range or speed or even climb virtues (could probably get near same with P-38J-15 at same load out) as claimed by Lockheed as sufficient to proceed at that stage of the war. It was dead in the 8th AF, just waiting to convert to P-51 when the report Mike Williams just submitted was written (11 March, 1944). After 8 March, 1944 I can find no example where a P-38 Group was providing Target Escort for Munich-Regensburg-Dresden-Berlin radius.

Final thought - If the P-38K replaced the J-15 LE fuel tanks with water tanks for WI, they would have been near the existing P-47D-21 Combat Radius and relegated strictly to Penetration and Withdrawal escort in ETO and MTO.. but would have been fine in the 9th and 12th AF for CAS. 

Most of the long range escort for 15th AF would be taken over by Mustangs from the P-38 Groups similar to US. Only in PTO would the twin engine safety factor be important enough to pay 1.5 X (1945 $$)more as well as CAS.


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## drgondog (Oct 2, 2015)

tomo pauk said:


> Not having the second source for P-38 is surely a shame. The 'useful range' was not that a big thing for the USAF of 1940/41, since then current doctrine was that fighters are for defense. Nobody was talking much about escorting the bombers since it was expected the high flying + plenty of HMGs will mean safe bombers, and we know now that id didn't pan out that way.
> 
> *The loss of the prototype was the biggest single factor because it delayed even the consideration of mass production tooling and training for at least 18 months. Additionally the P-38 was a very complex design with respect to modularity and ease of assembly*
> 
> Im afraid that here you are wrong - the P-47 have had the ingredients for long range work, as we know the combat range was 300 miles with small external fuel tankage, then 400 (all in 1943), 450 and then 600 (early and mid 1944), while the P-47N was managing 1000+ in mid-1945. Where the USAF made a mistake was not specifying wing pylons from P-47C at least.



The AAF senior leadership was curiously enough against the concept of long range fuel tanks for combat. IIRC Colonel Ben Kelsey snuck in the design mod under the guise of Ferry Tanks in 1942 but by that time the P-47C design was complete and Republic was trying for second source manufacturers. Even if Republic had the vision, AAF exhibited no interest until 1943 when it became apparent that a.) losses for deep penetrations would be prohibitive, and b.) there was a market for a P-47 with more internal fuel also as a requirement for Combat Radius extension.


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## IdahoRenegade (Oct 2, 2015)

drgondog said:


> The P-38s in the 20th, 55th and 364th P-38s suffered much higher losses while strafing LW airfields than P-51B's (All three 8th AF P-38s converted to P-51s in July, 1944. The 479th did not have as high percentage losses to strafing as the other 3 and were closer to Mustang average loss per aircraft destroyed on the ground.
> 
> The twin engines were a definite advantage for loss of engine in a non lethal strafing environment but consider that the F4U and P-51 losses in Korea per sortie (ALL CAS for both ships) was about the same with 51 very slightly higher - one with coolant/one without. The P-38 was a huge (and slower) target on the deck with not only greater number of vulnerable surface areas and internal components(Fuel cells of internal fuel, supercharger systems, two radiators/oil coolers, coolant lines - all vulnerable to fire from explosive 20mm flak.
> 
> ...



Combat losses are difficult to directly compare, especially when attacking well defended ground targets. Were the targets comparably defended? Were the attackers bounced by enemy fighters? Was the number of attacking planes comparable (the '38 was typically available in lower quantities than the Mustang)? Did the pilots have comparable experience? Was similar damage done to the targets (was one group pressing an attack harder than the other)?

By all records, the '38 had a significantly longer ACTUAL combat range than either the P-51 or P-47, at least in the hands of experienced pilots that knew how to operate it. In the Pacific, long range missions were the rule. A combat RADIUS of 1000 miles was not uncommon with later models of the '38, and some attacks on the Borneo oil fields were about 1200 miles one-way. Remember that the '38 could, and did, carry up to (2) 310 gallon external tanks.

This link makes for some interesting reading, though I can not vouch for it's accuracy: The P-38 (C.C. Jordan; MakinKid; CDB100620)

Also keep in mind that, while the '51 had a higher dive speed (due to a later onset of comprehensibility) it was a fairly poor climber vs the '38 (4750fpm vs 3200) meaning that the '38 climbed nearly 50% faster (even without the K model). Climbing ability makes it possible to gain an energy advantage quite quickly.


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## IdahoRenegade (Oct 2, 2015)

drgondog said:


> The P-38s in the 20th, 55th and 364th P-38s suffered much higher losses while strafing LW airfields than P-51B's (All three 8th AF P-38s converted to P-51s in July, 1944. The 479th did not have as high percentage losses to strafing as the other 3 and were closer to Mustang average loss per aircraft destroyed on the ground.
> 
> The twin engines were a definite advantage for loss of engine in a non lethal strafing environment but consider that the F4U and P-51 losses in Korea per sortie (ALL CAS for both ships) was about the same with 51 very slightly higher - one with coolant/one without. The P-38 was a huge (and slower) target on the deck with not only greater number of vulnerable surface areas and internal components(Fuel cells of internal fuel, supercharger systems, two radiators/oil coolers, coolant lines - all vulnerable to fire from explosive 20mm flak.
> 
> ...



Combat losses are difficult to directly compare, especially when attacking well defended ground targets. Were the targets comparably defended? Were the attackers bounced by enemy fighters? Was the number of attacking planes comparable (the '38 was typically available in lower quantities than the Mustang)? Did the pilots have comparable experience? Was similar damage done to the targets (was one group pressing an attack harder than the other)?

By all records, the '38 had a significantly longer ACTUAL combat range than either the P-51 or P-47, at least in the hands of experienced pilots that knew how to operate it. In the Pacific, long range missions were the rule. A combat RADIUS of 1000 miles was not uncommon with later models of the '38, and some attacks on the Borneo oil fields were about 1200 miles one-way. Remember that the '38 could, and did, carry up to (2) 310 gallon external tanks.

This link makes for some interesting reading, though I can not vouch for it's accuracy: The P-38 (C.C. Jordan; MakinKid; CDB100620)

Also keep in mind that, while the '51 had a higher dive speed (due to a later onset of comprehensibility) it was a fairly poor climber vs the '38 (4750fpm vs 3200) meaning that the '38 climbed nearly 50% faster (even without the K model). Climbing ability makes it possible to gain an energy advantage quite quickly.


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## Mike Williams (Oct 2, 2015)

IdahoRenegade said:


> Also keep in mind that, while the '51 had a higher dive speed (due to a later onset of comprehensibility) it was a fairly poor climber vs the '38 (4750fpm vs 3200) meaning that the '38 climbed nearly 50% faster (even without the K model). Climbing ability makes it possible to gain an energy advantage quite quickly.



Not really...

P-51B - 9,335 lbs.: "In climb the low blower critical altitude for 75 in. HG. manifold presure and 3000 RPM was 2,200 ft. At this altitude the airplane attained a maximum rate of climb of 4380 ft/min. at 75 in. Hg. manifold pressure and 3,820 ft/min. at 67 in. Hg. manifold pressure. "

FLIGHT TESTS ON THE NORTH AMERICAN P-51B-15 AIRPLANE, AAF NO. 43-24777 

P-51B-15 43-24777 Rate of Climb vs Altitude

P-38J - 17,363 lbs.: "At sea level a maximum rate of climb of 4040 ft/min was attained at 70" Hg. manifold pressure and a rate of climb of 3570 ft/min at 60" Hg. manifold pressure and 3000 RPM."

Flight Tests on the Lockheed P-38J Airplane, AAF NO. 43-28392 

P-38J-15 43-28392 Rate of Climb


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## IdahoRenegade (Oct 2, 2015)

Interesting. This correlates more closely with what I've read for the Mustang: P-51 Mustang Performance

What was the rated boost pressure at military power? I haven't found that yet, but am looking.


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## GregP (Oct 2, 2015)

The P-51 was not approved for 75 inches until more than halfway through it's wartime use. The P-38 was around from the beginning, and was in combat before the P-51 was even on a piece of paper ... but you know that. So for a good deal of the time, the P-38 would handlily outclimb the P-51. Later, when 75" was approved, the P-51 could just about climb with the P-38. Some were possibly a bit better, some not.

In speaking with MANY WWII pilots, I have yet to run across many who ran their engines at 75 inches unless in actual combat. The ones who admitted doing it while not in combat were universally over their home airfield.

In any case, thanks for the charts!

Hi Renegade,

The rated boost for Military depends on the time period. For most of its service life in WWII, Military was 61" MAP and so-called WER was 67" MAP. Near the end, they upped the maximum to 75" MAP.

The Allisons were usually rated at 57" but late in the war were approved for 70" MAP while many pilots ran them in combat at 75" MAP.

Running a piston engine hard when you are 300+ miles from home and possibly over water was not something to take lightly. I had several US "muscle cars" back in the day, and I always took them to a drag strip once they were broken in and did 1 - 3 quarter-mile runs. Mostly, I drove pretty sanely on the road. A quarter-mile run in a big-block was usually on the order of 12 - 13 seconds, and that's not much stress overall.

It's a FAR CRY from taking a P-51 with a V-1650-3/7 and running it at 75" MAP for 10+ minutes and expecting nothing bad to happen. After this event, you still had to fly home for several hours. You could do it, sure. You also might be spending a lot of time in a POW camp or shot in you parachute while descending.

From all the guys I have asked, they took care of their engines whenever they could. They never max-climbed when they could cruise-climb, and cruised at greatly reduced power when they did not expect to be attacked. They only ran them up to high cruise when they entered what they believed was hostile territory and where they expected action. Running at best ecomony was a good way to get to Berlin and back with gas to spare. The only time you have too much gas, especially at the end of a mission, is when you're on fire.

But when they needed the P-51 to growl and show some teeth, it certainly could and would. I am given to understand they cruised at the bottom end best-economy settings for 45 minutes out of the hour and ran it up to max coutinuous for 10 - 15 minutes to ensure the plugs didn't foul, and then went back to best economy settings for another 45 minuties, and followed that cycle for duration of the mission.

This is from ETO P-51 pilots and was for cruising about over the bomber stream when no action was anticipated. Naturally, when the enemy was sighted, they would run up to Mil power as gradually as the situation allowed, turn on the gunshight and guns, clear the guns, and accelerate for combat. If they saw imminent action coming, they then dropped tanks, assuming they weren't over the bomber stream or high and in its path. It was incumbent on the P-51 guys to make sure they were safe to drop tanks.

Most is common sense, but you'd be surprised how many idiotic things were done without thinking of the planes around you. More than one bomber gunner fired into a neighbor following an attacking fighter with his guns. More than one escort got caught at best economy with gunsight / guns off and tanks on, and more than one escort had a mid-air with a bomber or another fighter when not looking where he was going. It was a crowded sky in the ETO, not so much in the PTO. The other side had the same issues, although not in vast bomber streams. They had people do idiotic things, too.

Some 20 years back we had some former Luftwaffe aces come to see a Bf 109 restoration and flight, and they talked a lot among the pilots about the stupid things that happened. After they left, our pilots related some of those stories and it was remarkable how similar the idiotic things were between the two sides. Must be human nature to do stupid things with equipment once in awhile. One pilot was buzzing his own farm when he left a prop blade on his father's tractor and bellied in on one of his own family farm's fields. The Bf 109 was later retrieved and flew again, and he had the satisfaction of having mom's saurbratten before being slapped by his superior for being stupid.

Sounds familiar somehow, doesn't it? ... except maybe for the saurbratten part ... well, maybe in Minnesota or places named "Germantown."


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## wuzak (Oct 2, 2015)

Greg, I think you must mean that the P-51B was not on a piece of paper when the P-38 first went into combat?

Certainly the concept behind the P-51B was being discussed around the time that the P-38 first flew in combat. The Mustang X flew less than 6 months after the P-38 entered combat, and teh P-51B prototype flew a couple of months after that.

Maximum climb was used for two reasons - in combat and for climbing to an interception. It certainly wasn't used to climb to form p ready for a long range mission.


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## wuzak (Oct 2, 2015)

IdahoRenegade said:


> By all records, the '38 had a significantly longer ACTUAL combat range than either the P-51 or P-47, at least in the hands of experienced pilots that knew how to operate it. In the Pacific, long range missions were the rule. A combat RADIUS of 1000 miles was not uncommon with later models of the '38, and some attacks on the Borneo oil fields were about 1200 miles one-way. Remember that the '38 could, and did, carry up to (2) 310 gallon external tanks.



Over sea and with no enemy fighter of anti-aircraft opposition the P-38 in the Pacific theatre could fly at the optimum speed and altitude for maximum range. A speed and altitude that would be a problem in the European theatre, as flak batteries would have good target practice and the P-38 would be very vulnerable to being bounced.


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## GregP (Oct 2, 2015)

The P-38's first flight was 27 Jan 1939. It was introduce into service July 1941. The overseas introduction was Sep 1942.

The P-51's first flight was 26 Oct 1940 and service introduction was Jan 1942. P-51's started with the Eight Air Force in the winter of 1943 - 1944.

So the P-38 was flying in combat for more than ayear before the p-51's hit overseas deployment. It didn't take long for the P-51 to earn it's reputation, but it also wasn't cleared for 75" MAP until well into fall 1944. so what I said above still stands.

Nobody can argue the P-51 wasn't a great fighter, but it only got clearance for high-power late in the game when the German fighters were making that necessary. The Bf 109 was always a strong climber and the Fw 190 was close to the P-51 in climb and a better turner according to both sides. 

So stretching the P-51's powerband a bit gave the P-51 pilots a bit more performance when it was needed. If it wasn't, they stayed well below 75", as any sane pilot several hundred miles from home would do.

P-38's weren't any more vulnerable to being bounced than any other aircraft. They got bounced early-on because they were being flown by green combat pilots who didn't know any better. Planes aren't vulnerable to being bounced ... green pilots are. I believe if the P-38 had stayed on the ETO the pilots flying them would not have stayed green for too long and they would have come to grips as veterans by watching for the Hun in the sun, thus avoiding being bounced. Getting surprised was only done one or, at best, a few times. You either learned or died not learning it.

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## Mike Williams (Oct 2, 2015)

IdahoRenegade said:


> Interesting. This correlates more closely with what I've read for the Mustang: P-51 Mustang Performance
> 
> What was the rated boost pressure at military power? I haven't found that yet, but am looking.



Military power for the Merlin engined P-51s was 61" Hg. According to the P-51 Tactical Planning Characteristics Performance Chart:
Climb of the P-51B (V-1650-7) on Military Power at 9,000 lbs was 3,480 ft./min at 5,000' and 2,200 ft./min at 25,000'
Climb of the P-51B (V-1650-7) on Military Power with fuselage tank at 9,800 lbs was 3,200 ft./min at 5,000' and 2,030 ft./min at 25,000'
Climb of the P-51D (V-1650-7) on Military Power with fuselage tank at 10,100 lbs was 3,060 ft./min at 5,000' and 1,860 ft./min at 25,000'

Military power for the P-38J was 54" Hg. 
According to the P-38 Tactical Planning Characteristics Performance Chart:
Climb of the P-38J on Military Power at 16,450 lbs was 3,425 ft./min at 5,000' and 2,500 ft./min at 25,000'.
Climb of the P-38J on Military Power with L.E. tanks at 17,650 lbs was 3,200 ft./min at 5,000' and 2,200 ft./min at 25,000'

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## wuzak (Oct 2, 2015)

GregP said:


> The P-38's first flight was 27 Jan 1939. It was introduce into service July 1941. The overseas introduction was Sep 1942.
> 
> The P-51's first flight was 26 Oct 1940 and service introduction was Jan 1942. P-51's started with the Eight Air Force in the winter of 1943 - 1944.
> 
> So the P-38 was flying in combat for more than ayear before the p-51's hit overseas deployment



You said the P-38 was _in combat_ before the P-51 was even on a piece of paper.

The first combat seen by a P-38 was in August 1942. That was more than 2 years after the P-51 was "a piece of paper", and certainly months after the Mustang X and P-51B programs had begun.





GregP said:


> It didn't take long for the P-51 to earn it's reputation, but it also wasn't cleared for 75" MAP until well into fall 1944. so what I said above still stands.



And when was the P-38 _cleared_ for 75inHg MAP?



GregP said:


> The Allisons were usually rated at 57" but *late in the war* were approved for 70" MAP while many pilots ran them in combat at 75" MAP.






GregP said:


> Nobody can argue the P-51 wasn't a great fighter, but it only got clearance for high-power late in the game when the German fighters were making that necessary. The Bf 109 was always a strong climber and the Fw 190 was close to the P-51 in climb and a better turner according to both sides.



I would have thought the first combat introduction of 75inHg was in response to the V-1 flying bombs?




GregP said:


> P-38's weren't any more vulnerable to being bounced than any other aircraft. They got bounced early-on because they were being flown by green combat pilots who didn't know any better. Planes aren't vulnerable to being bounced ... green pilots are. I believe if the P-38 had stayed on the ETO the pilots flying them would not have stayed green for too long and they would have come to grips as veterans by watching for the Hun in the sun, thus avoiding being bounced. Getting surprised was only done one or, at best, a few times. You either learned or died not learning it.



I didn't say that P-38s were more vulnerable to being bounced, but rather that a P-38 being flown at best altitude and speed for range, which conditions in the PTO allowed, would be more vulnerable than a P-38 flown in the ETO with different requirements for cruising.

The ETO demanded a higher cruise speed in enemy air space than was required for maximum range, as well as the altitudes required for escort work being higher.


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## Mike Williams (Oct 2, 2015)

wuzak said:


> I would have thought the first combat introduction of 75inHg was in response to the V-1 flying bombs?



This document below shows that in February 1944 Eisenhower was pushing for 150 grade fuel which allowed for a significant improvement in the performance of fighter aircraft. He wanted it for the invasion of the continent. 75" Hg. MAP was cleared for the P-51 by April 1944 (see also  here). As it turned out the 8th AF Fighter command went over to 150 grade within a week of the landings in Normandy.

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## IdahoRenegade (Oct 2, 2015)

Mike Williams said:


> Military power for the Merlin engined P-51s was 61" Hg. According to the P-51 Tactical Planning Characteristics Performance Chart:
> Climb of the P-51B (V-1650-7) on Military Power at 9,000 lbs was 3,480 ft./min at 5,000' and 2,200 ft./min at 25,000'
> Climb of the P-51B (V-1650-7) on Military Power with fuselage tank at 9,800 lbs was 3,200 ft./min at 5,000' and 2,030 ft./min at 25,000'
> Climb of the P-51D (V-1650-7) on Military Power with fuselage tank at 10,100 lbs was 3,060 ft./min at 5,000' and 1,860 ft./min at 25,000'
> ...



Thank you for providing accurate info. I should know better than to get lazy and ever trust Wiki. I was under the impression that the '38 was a considerably better climber. Though I seem to remember that early J models were quite a bit heavier than the H's and previous ones. Do you know if the J25s or Ls were any lighter or better climbers?

Another point I saw discussed, I'm wondering if anyone can provide enlightenment on. The discussion involved engine HP at various altitudes. The '51 had a 2-speed mechanical supercharger. IIRC high boost was engaged at ~18k where it provided maximum boost pressure. Being a fixed speed blower, it dropped off steadily above that altitude. The discussion on the '38 was that the turbos, with their boost regulators (were they waste gates? How were they controlled?) could maintain full boost up to a considerably higher altitude. IIRC they would overspeed at 28k or so at full boost, due to the lower mass of air, and hence load, on the compressors. Is this even close to right?

(btw, this is a great forum, I'm learning a ton, thanks all)


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## EKB (Oct 2, 2015)

Going from Schiffer’s unit diary, the 370th Fighter Group was not impressed with the P-51 in the ground attack role, after trading in their P-38s. The headline for Chapter 21 says it all: _We Don’t Want Mustangs!_ …


Snuffy Owens, 401st FS: 
_“ The P-51 was a great airplane, but if you had to compare them I would say, this is my opinion, the 38 was ideal for what we did. That was dive-bombing and ground support. The 51 wasn’t worth a damn down on the deck. It was too easy to knock down. It was great air-to-air. That’s the one thing I asked them when they told me we were going over to 51s. I said, ‘And what? Are we going to be escorting or down on the deck?’ ‘Everything will be escort from here on out.’ The first mission was right back on the ground.”_


Rod Colton, 402nd FS:  
_“ The only thing that really bothered me about the P-51 is that on our dive bombing, in a P-38 you’d come in, drop your bombs and strafe, and when you pulled that thing up it would zoom up to 10,000 feet in just nothing flat. When I was coming in on a P-51, the first day I ever strafed an installation where they were shooting at us, I pulled up and at about 3,000 feet here is this P-51 going 250 miles an hour. I could see tracers coming up from the ground and I’d have to kick a right rudder and skid it and weave my way back up into the sky. You never had to do that in a P-38 because you got out of the fire zone so damn fast. It just really reached for the sky.”_


Elbert Lineker, 402nd FS: 
_“ They flew a bunch of P-51s in and just said, ‘Here they are’. I remember I asked, ‘How about some tech orders about how to fly the thing’. They said, ‘We don’t have a thing on paper for you’. I was Operations Officer by then so I took one out and took it off to fly it and give the guys some idea on what to do, because we’d never had torque … I remember the first dive-bombing. We had a little dive-bombing field cut out of the forest. It was about 20 acres and there was a little shack right on the middle of it. We used the shack for a target. I remember the first time I tried to dive bomb it, I missed the whole field with both the bombs. I started diving and the torque took over and I threw the bombs clear off in the forest. We got better, but we never did get as good as we did with the 38s.”_



See p.292-293
Jay Jones. *The 370th Fighter Group in World War II: In Action over Europe with the P-38 and P-51*. Schiffer Books, 2003.

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## GregP (Oct 2, 2015)

Hi Wuzak,

You are correct, I did say the P-38 was in combat before the P-51 was on paper. Actually it was FLYING before the P-51 was on paper. I didn;t say when the P-38 was cleared for extra boost because it wasn't relevant. The P-38 out climbed the P-51 in all cases until the 75" was approved, regardless of max boost the P-38 was using.

If I am not mistaken the clearing of engines for extra boost was not tied to V-1's, but to 150 grade fuel. I could be wrong there but, if you don't have the fuel performance to handle the boost, all turning up the boost will do is destroy the engine.

The pilots I have spoken with who flew in the ETO did NOT cruise faster than best economy except to clear the plugs or for combat, which includes getting ready for imminent combat, too. It wasn't necessary for much of the trip. When it was, they did. There was good radar coverage and they pretty much knew when and from where the enemy was coming from most of the time. So if there is a large gaggle of enemy A/C about 20 miles in front of you, you might as well arm 'em up, turn on the gunsight, increase rpm, increase manifold pressure, and get ready to drop the tanks and clear guns when prompted.

Now these guys could be wrong, but nobody alive except the pilots who did it can prove it. Their statements are good enough for me, if for nobody else. Up until he passed away Bud Mahurin was a regular at the museum and described things many times. We all miss him.


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## wuzak (Oct 3, 2015)

IdahoRenegade said:


> Another point I saw discussed, I'm wondering if anyone can provide enlightenment on. The discussion involved engine HP at various altitudes. The '51 had a 2-speed mechanical supercharger. IIRC high boost was engaged at ~18k where it provided maximum boost pressure. Being a fixed speed blower, it dropped off steadily above that altitude. The discussion on the '38 was that the turbos, with their boost regulators (were they waste gates? How were they controlled?) could maintain full boost up to a considerably higher altitude. IIRC they would overspeed at 28k or so at full boost, due to the lower mass of air, and hence load, on the compressors. Is this even close to right?



Geared superchargers had a critical altitude for each gear ratio used. For a Merlin 60-series, as found in the P-51, there were two - these were known as LO and HI in the USAAF, but Medium Supercharged (MS) and Fully Supercharged (FS) in the RAF. 

(As an aside it was also possible to have a Low Supercharged gear, but it was rare. AFAIK the only engines to be rated with an LS gear were the three speed Griffon 100-series, with LS, MS and FS gears.)

The maximum allowed boost could be obtained at sea level in LO, the boost being maintained up until the critical altitude. The boost was controlled by the throttle plate, which choked the intake to the supercharger. At critical altitude the throttle plate was open fully (why it was known as Full Throttle Height in the RAF). At this point the maximum power for the engine in that gear was being produced. After that altitude the boost and power fell away. 

Early Merlins used only one gear. But that meant compromises - geared for low altitudes the engine lacked performance at high altitudes, and geared for high altitudes the low altitude performance suffered. Adding a second gear helped teh high altitude engine to fill in the performance at lower altitudes.

The critical altitudes were dependent upon boost. For war emergency (67inHg MAP/+18psi boost) the critical altitude was lower than for military power (61inHg MAP/+15psi boost) or max continuous (usually +7psi boost).

The highest power that the engine produced was in the lower gear.


The turbo in the P-38 maintained pressure to the carburettor equivalent to sea level, which enabled the engine to be set for sea level and make the maximum amount of power possible. 

This could be held up until the turbocharger's critical altitude - which was defined by the turbo's rpm. The control method was a wastegate, which would bleed off exhaust gases to make sure that the turbine would only have the amount it needed to drive the compressor. Theoretically the exhaust back pressure in the turbo system would be equivalent to ejector exhausts, but practically I don't think this was the case.

Critical altitudes for the B-series turbos used in P-38s improved from around 25,000ft to around 30,000ft.

Teh actual boost that the engine saw came from the supercharger mounted to the engine. In the V-1710 it was a single stage single speed unit. The gear ratio of the supercharger for the P-38 was lower than for the P-39 or P-40 (ie the supercharger was run at lower rpm).

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## Mike Williams (Oct 3, 2015)

wuzak said:


> And when was the P-38 _cleared_ for 75inHg MAP?



A Materiel Command Memorandum, dated 16 March 1944, on Flight Tests of Fighter Aircraft with 44-1 Fuel noted that the V-1710-89 and V-1710-91 as installed in the P-38J were cleared to operated at 75" MAP.

A Materiel Command report, dated 27 March 1944, on the Preliminary 7-1/2 Hour War Emergency Rating Test of the Allison V-1710-91 Engine Operated on Grade 104/150 Fuel concluded that the Allison V-1710-91 satisfactorily completed a 7-1/2 hour preliminary War Emergency Approval Test at a rating of 2000 b.h.p. and 75 inches MAP.

A subsequent report, dated 22 April 1944, on an Attempted 7-1/2 Hr. War Emergency Rating of Allison V-1710-89 Engine as Installed in P-38J Airplane Operated on Grade 104/150 concluded that the Allison engine connecting rods failed and that the connecting rods were probably near their ultimate strength.

A Material Command Report, dated 13 May 1944, on Preliminary Flight Tests of Fighter Aircraft Using PPF 44-1 Fuel at Increased War Emergency Ratings concluded that based on the preliminary flight tests, that satisfactory operation was experienced on the P-38J airplane at 70" hg.

A Materiel Command Memorandum, dated 20 June 1944, on Project P.P.F. - Installation and Operating Instructions noted that final release had been made approving 70" MAP for the P-38.

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## drgondog (Oct 3, 2015)

The P-51B was tested with 44-1 150 octane fuel in April 1944 and cleared for 75". The Fuel arrived in ETO in mid June and 8th AF reduced the 75 to 72" boost at WEP. Pilot to note on Form 4 any deviation from MP (61") and duration.. more than 5 minutes almost always mandated an engine change. The 8th was flying combat missions with 150 octane fuel in very late June, 1944 - or late spring, not fall, 1944

One notable 355th pilot Ben Johnston had just shot down two 190s for #3 and 4 and was chasing the fifth when his engine blew. Post war review indicated WEP for 10-15 minutes.

A couple of RAF P-51B's were modified to install the Rolls 100 and ran 419mph at 1600 and 454 at 18000 ft(IIRC?). It had an ROC in the 4500fpm range at 25pounds of boost at 2K (all from memory which is notoriously leaky at the moment).. this was to be a V-1 chaser. Full combat load except No fuel in 85 gallon tank..

Greg - the Mark I reached UK in January, deployed to AFDU in late April 1942 (about the time Hooker recommended that a Rolls Merlin be installed after test flying it), first combat victory credit by Hollis at Dieppe in August 1942. First Mark X test flight in October, 1942 and first XP-51B flight November 30, 1942. First delivery of the P-51B-1 in May 1943, first delivery to UK in September 1943, first deployment to 9th AF 354FG in November 1943, first combat mission (including returned Lend Lease RAF Mustang III's) December 1, 1943. First 8th AF Mustang Mission 357FG 11 February 1944.

The discussion of the P-38K as a world beater probably should be considered in light of the fact that the first P-38J-15 with Leading edge 55 gallon fuel tanks didn't fly combat in ETO until late February 1944 and the first J-25 in October, 1944 (dive flaps, boosted ailerons). 

Consider that the first XP-51F flew about the time the J-15s were still dribbling into ETO in May 1944 and the P-51H contract was awarded in April 1944.

Why would AAF Material Command want to slow down delivery of the existing P-38s for the P-38K when they had already made the decision to a.) replace all ETO Fighter Group P-47 and P-38s with P-51s as they became available (yes the 56th held out), and b.) that most fighter groups flying P-38 and or P-47D in the CBI/PTO engaged in long range escort would receive P-51D and P-47N, then P-51H for the invasion of Japan?

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## tomo pauk (Oct 3, 2015)

drgondog said:


> The loss of the prototype was the biggest single factor because it delayed even the consideration of mass production tooling and training for at least 18 months. Additionally the P-38 was a very complex design with respect to modularity and ease of assembly



I've never held the rivet gun, let alone being in the aircraft business myself - but Lockheed managed to churn out almost 4200 P-38s in 1944 from one (granted, a big one) factory. Almost as much as Bell produced P-39s in 1943, or Curtiss' production of P-40s in the same year, both much simpler aircraft. Lockheed have had more than 1300 P-38s ordered before Sept 1940, yet both USAAF and Lockheed missed the opportunity to have either a second source of P-38s, and/or to have the production of the Hudsons and the like outsourced. Eg. Boeing was second source for early Boston III (~A-20) bombers.
For comparison sake, in Sept 1940, the USAF ordered 733 P-47, by Oct 14 1941 the order is totaled at 850, and 3 factories are to produce it.



> The AAF senior leadership was curiously enough against the concept of long range fuel tanks for combat. IIRC Colonel Ben Kelsey snuck in the design mod under the guise of Ferry Tanks in 1942 but by that time the P-47C design was complete and Republic was trying for second source manufacturers. Even if Republic had the vision, AAF exhibited no interest until 1943 when it became apparent that a.) losses for deep penetrations would be prohibitive, and b.) there was a market for a P-47 with more internal fuel also as a requirement for Combat Radius extension.



The vision from the AAF is required more, I'm afraid  
We know that Lockheed simply installed wing racks on the P-38F (and retrofitted it on the P-38Es in service) and that NAA installed not just racks, but also air brakes on the A-36, so I'd say that it was much more down to the current doctrine (dogma?) whether the wing racks will be on the P-47, rather than it is about the Republic's capabilities.


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## gjs238 (Oct 3, 2015)

GregP said:


> P-38's weren't any more vulnerable to being bounced than any other aircraft. They got bounced early-on because they were being flown by green combat pilots who didn't know any better. Planes aren't vulnerable to being bounced ... green pilots are. I believe if the P-38 had stayed on the ETO the pilots flying them would not have stayed green for too long and they would have come to grips as veterans by watching for the Hun in the sun, thus avoiding being bounced. Getting surprised was only done one or, at best, a few times. You either learned or died not learning it.




Colonel Harold J. Rau might disagree with that...

_20th Fighter Group Headquarters
APO 637 U.S. Army
(E-2)

3 June 1944

Subject: P-38 Airplane in Combat.

To: Commanding General, VIII Fighter Command, APO 637, U.S. Army.

1. The following observations are being put in writing by the undersigned at the request of the Commanding General, VII FC. They are intended purely as constructive criticism and are intended in any way to "low rate" our present equipment.

2. After flying the P-38 for a little over one hundred hours on combat missions it is my belief that the airplane, as it stands now, is too complicated for the 'average' pilot. I want to put strong emphasis on the word 'average, taking full consideration just how little combat training our pilots have before going on as operational status.

3. As a typical case to demonstrate my point, let us assume that we have a pilot fresh out of flying school with about a total of twenty-five hours in a P-38, starting out on a combat mission. He is on a deep ramrod, penetration and target support to maximum endurance. He is cruising along with his power set at maximum economy. He is pulling 31" Hg and 2100 RPM. He is auto lean and running on external tanks. His gun heater is off to relieve the load on his generator, which frequently gives out (under sustained heavy load). His sight is off to save burning out the bulb. His combat switch may or may not be on. Flying along in this condition, he suddenly gets "bounced", what to do flashes through his mind. He must turn, he must increase power and get rid of those external tanks and get on his main. So, he reaches down and turns two stiff, difficult gas switches {valves} to main - turns on his drop tank switches, presses his release button, puts the mixture to auto rich (two separate and clumsy operations), increases his RPM, increases his manifold pressure, turns on his gun heater switch (which he must feel for and cannot possibly see), turns on his combat switch and he is ready to fight. At this point, he has probably been shot down or he has done one of several things wrong. Most common error is to push the throttles wide open before increasing RPM. This causes detonation and subsequent engine failure. Or, he forgets to switch back to auto rich, and gets excessive cylinder head temperature with subsequent engine failure.

4. In my limited experience with a P-38 group, we have lost as least four (4) pilots, who when bounced, took no immediate evasive action. The logical assumption is that they were so busy in the cockpit, trying to get organized that they were shot down before they could get going.

5. The question that arises is, what are you going to do about it? It is standard procedure for the group leader to call, five minutes before R/V and tell all the pilots to "prepare for trouble". This is the signal for everyone to get into auto rich, turn drop tank switches on, gun heaters on, combat and sight switches on and to increase RPM and manifold pressure to maximum cruise. This procedure, however, does not help the pilot who is bounced on the way in and who is trying to conserve his gasoline and equipment for the escort job ahead.

6. What is the answer to these difficulties? During the past several weeks we have been visited at this station time and time again by Lockheed representatives, Allison representatives and high ranking Army personnel connected with these two companies. They all ask about our troubles and then proceed to tell us about the marvelous mechanisms that they have devised to overcome these troubles that the Air Force has turned down as "unnecessary". Chief among these is a unit power control, incorporating an automatic manifold pressure regulator, which will control power, RPM and mixture by use of a single lever. It is obvious that there is a crying need for a device like that in combat.

7. It is easy to understand why test pilots, who have never been in combat, cannot readily appreciate what each split second means when a "bounce" occurs. Every last motion when you get bounced is just another nail in your coffin. Any device which would eliminate any of the enumerated above, are obviously very necessary to make the P-38 a really effective combat airplane.

8. It is also felt that that much could done to simplify the gas switching system in this airplane. The switches {valve selector handles} are all in awkward positions and extremely hard to turn. The toggle switches for outboard tanks are almost impossible to operate with gloves on.

9. My personal feeling about this airplane is that it is a fine piece of equipment, and if properly handled, takes a back seat for nothing that the enemy can produce. But it does need simplifying to bring it within the capabilities of the 'average' pilot. I believe that pilots like Colonel Ben Kelsey and Colonel Cass Huff are among the finest pilots in the world today. But I also believe that it is difficult for men like them to place their thinking and ability on the level of a youngster with a bare 25 hours in the airplane, going into his first combat. That is the sort of thinking that will have to be done, in my opinion, to make the P-38 a first-class all around fighting airplane.

HAROLD J. RAU
Colonel, Air Corps,
Commanding._

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## FLYBOYJ (Oct 3, 2015)

gjs238 said:


> Colonel Harold J. Rau might disagree with that...
> 
> _20th Fighter Group Headquarters
> APO 637 U.S. Army
> ...



This document has been posted here before. It's obvious Rau was not a fan of the P-38 and I would bet he also didn't like to fly multi engine aircraft. While He writes this memo the 475th FG is making history with the P-38..

_"During World War II, the 475th Fighter Group, in combat for approximately two years, completed 3042 missions, (21,701 Sorties) and shot down 551 Japanese aircraft. On the other hand, the Group lost only 56 Planes to the Japanese. During the war, the Group took part in seven campaigns, and was awarded three Distinguished Unit Citations for outstanding performance of duty in action. In addition to Major McGuire, the unit boasted such "Aces" of the Pacific War as Col. Charles MacDonald (27), Capt. Daniel T. Roberts (14), Lt. Francis J. Lent (11), Lt. Col. John S. Loisel (11), and Capt. Elliot Summer (10), plus many more."_

Aces


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## eagledad (Oct 3, 2015)

Greetings!

This is what a P-38 commander in the MTO had to say about the P-38: 

Col Oliver Taylor, commander of the 14th fighter group in Italy during the first half of 1944 had the following to say about the P-38 his group flew: (as recounted in “P-38 Lightning” by Jeff Ethell)

*Bad Points:* 
Ease of Handling: It required at least twice as much flying time, perhaps more to achieve the level of skill which was necessary to realize the full capability of he ship compared with a single engine fighter. Only after about 150 to 200 hours could a man hope to be an expert but when he reached that point he could be unbeatable in a 38. (Italics added by me).

Vertical Dives: The 38 could not be controlled in a vertical dive if allowed to build up speed, and that happened awfully damned fast, with speed rapidly building up thereafter until something came apart. The (Axis) knew this well.

Distinctive silhouette: The (Axis), on seeing a lone plane off in the distance would generally leave it be unless he had absolutely nothing else in prospect at the moment. On seeing the unique P-38 silhouette, however, there would be no doubt at all and after it he would go knowing that it would not be a waste of time.

*Good Points:*
Stability: The plane could be turned into a tight turn, essentially right at the stall point, without snapping out or dropping. The counter rotating props eliminated any torque problems when passing through a range of speeds…..

Maneuverability: Generally we found that the 38 could out-maneuvered anything, friend or foe, between 18,000 and 31,000 feet (5490-9450 meters). Below 18,000 it was sort of a toss-up except that very near the ground we could run (the Axis) right into the dirt, since he apparently couldn’t get quite such a fast pull-out response as we could.

Range: a 500 mile (800km) distant target was easily reached allowing for 30 to 45 minutes for possible diversions….

Single Engine Flight: The 38 was just as controllable turning into as away from a dead engine.

Engine Configuration: Aside from having another engine to bring you home in case one is lost, the two-engine arrangement provided exceptionally good visibility forward for the pilot and provided protection from flanking enemy fire , especially during low-level strafing runs.

Rugged Construction: The 38 could take a phenomenal amount of beating up and still make it home. One was hit by an ME-109, one wing of the 109 having slashed along the inside of the right boom, carrying away the inside cooler and slicing the horizontal stabilizer/elevator assembly in two. The 109 lost its wing and crashed. The 38 flew 300 miles (480km) on one engine to belly land …at base. (the pilot was Lt Thomas W Smith, 37th squadron; the mission took place on Jan 16, 1944. (Something similar happen to Jack Ilfrey a pilot in the 20th Group on May 24, 1944)

Ease of Maintenance: …The general feeling seemed to be that both the P-38 and the Allison engines were very easy to maintain. In our group we had an exceptionally high level of experienced ground crew types, and they did an extraordinary job. .....

Eagledad

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## drgondog (Oct 3, 2015)

tomo pauk said:


> I've never held the rivet gun, let alone being in the aircraft business myself - but Lockheed managed to churn out almost 4200 P-38s in 1944 from one (granted, a big one) factory. Almost as much as Bell produced P-39s in 1943, or Curtiss' production of P-40s in the same year, both much simpler aircraft. Lockheed have had more than 1300 P-38s ordered before Sept 1940, yet both USAAF and Lockheed missed the opportunity to have either a second source of P-38s, and/or to have the production of the Hudsons and the like outsourced. Eg. Boeing was second source for early Boston III (~A-20) bombers.
> For comparison sake, in Sept 1940, the USAF ordered 733 P-47, by Oct 14 1941 the order is totaled at 850, and 3 factories are to produce it.
> 
> The vision from the AAF is required more, I'm afraid
> We know that Lockheed simply installed wing racks on the P-38F (and retrofitted it on the P-38Es in service) and that NAA installed not just racks, but also air brakes on the A-36, so I'd say that it was much more down to the current doctrine (dogma?) whether the wing racks will be on the P-47, rather than it is about the Republic's capabilities.



We all agree it was within Republic's capabilities to 'design and build' a wing rack capable of holding bombs or external fuel tanks. Perhaps a design philosophy of installing all fuel in the fuselage hindered their thinking of 'easy approaches' than re-designing and entire wing - whereas the Mustang never had that barrier.

The A-36 was THE key contract for the NAA as it enabled two key facets to the ultimate development of the P-51. Very importantly it prevented a cessation of operations on the Mustang airframe - but - it also provided NAA with the necessary funding to capitalize on production Lessons Learned to speed up the line. Secondly the NAA engineers capitalized on the Bomb load requirement as a dive bomber to integrate external to internal fuel transfer, thus enabling the P-51A and all subsequent versions to nearly double internal capacity with 75 gallon drop tanks..

From April 1943 to EOW Lockheed produced approximately 6600 P-38's from the H-1 and above.
From April 1943 to EOW NAA Inglewood produced 500 A-36, 310 P-51A, 1988 P-51B, 6502 P-51D-NA, 555 P-51H, (not to mention B-25, AT-6 etc) for a total of 9855 Mustangs. Dallas built (from August 1943) another 4850 P-51C/D/K's.


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## wuzak (Oct 3, 2015)

FLYBOYJ said:


> This document has been posted here before. It's obvious Rau was not a fan of the P-38 and I would bet he also didn't like to fly multi engine aircraft. While He writes this memo the 475th FG is making history with the P-38..
> 
> _"During World War II, the 475th Fighter Group, in combat for approximately two years, completed 3042 missions, (21,701 Sorties) and shot down 551 Japanese aircraft. On the other hand, the Group lost only 56 Planes to the Japanese. During the war, the Group took part in seven campaigns, and was awarded three Distinguished Unit Citations for outstanding performance of duty in action. In addition to Major McGuire, the unit boasted such "Aces" of the Pacific War as Col. Charles MacDonald (27), Capt. Daniel T. Roberts (14), Lt. Francis J. Lent (11), Lt. Col. John S. Loisel (11), and Capt. Elliot Summer (10), plus many more."_
> 
> Aces



The point I was making to Greg was that flying in teh Pacific and the ETO had different challenges.

In the Pacific a long range could be achieved because much of a flight would be over water with no anti-aircraft below and little chance f being bounced from above. So they could use the most economic cruise settings.

IN the ETO, on the other hand, that was not feasible.


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## FLYBOYJ (Oct 3, 2015)

wuzak said:


> The point I was making to Greg was that flying in teh Pacific and the ETO had different challenges.
> 
> In the Pacific a long range could be achieved because much of a flight would be over water with no anti-aircraft below and little chance f being bounced from above. So they could use the most economic cruise settings.
> 
> IN the ETO, on the other hand, that was not feasible.



While it is recognized that there were different challenges in the Pacific when compared to the ETO, what Rau was complaining about was the actual operation of the aircraft. If one was to look at the cockpit configuration of the P-38 there were two of everything, just like any other multi engine aircraft of the period. While Rau complained about the aircraft other pilots operated it with little issues. Rau said it himself.

_After flying the P-38 for a little over one hundred hours on combat missions it is my belief that the airplane, as it stands now, is too complicated for the 'average' pilot._

As mentioned before, there was little multi engine transition training during the beginning of the war. Some of the better P-38 pilots had multi engine time in other higher performing aircraft


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## drgondog (Oct 3, 2015)

IdahoRenegade said:


> Combat losses are difficult to directly compare, especially when attacking well defended ground targets. Were the targets comparably defended? Were the attackers bounced by enemy fighters? Was the number of attacking planes comparable (the '38 was typically available in lower quantities than the Mustang)? Did the pilots have comparable experience? Was similar damage done to the targets (was one group pressing an attack harder than the other)?
> 
> *The statistics I gave you are extracted from Missing Aircrew Reports, parsed for strafing losses - both airfield and in support of Invasion from June-August when 8th AF had mixed escort and Fighter Bomber role. All P-38 Groups in 8th AF converted to P-51 (except 479th) They are not reduced to losses per sortie because many losses were experienced as random drop to the deck and strafe on the way home. Most of the strafing losses occurred when strafing heavily guarded LW airfields. The point I will make is that despite the arguably better P-38 armament and twin engine 'safety factor' the ratio of aircraft destroyed on the ground per P-38 lost was one third of the P-51. Spoken another way the P-38 strafing credit to loss ration was ~ 1.5:1 where as the P-47 was 3.7:1 and the P-51 was 5.6:1 *
> 
> ...



You should be Very careful when comparing climb rates as the internal fuel and GW should be compared directly and not cherry pick a 'light' P-38J versus P-51B as an example. As noted above the Flight test report recapitulating Lockheed Claims for P-38K did not have a full internal load of fuel at the beginning of the Flight ---> thereby inflating the performance against the fully Combat loaded P-38J. Also the presence or absence of wing racks is about a 10-12mph drag factor.

Next - go to Mike Williams site P-51 Mustang Performance and take a look at the P-51B-15 test with 265 gallons of internal fuel but only the 67" War Emergency Power settings - not 75" Boost. Go also to the 5 July 1944 Flight Test of the P-38J-15 at similar combat GW loading of 17,363 Pounds with 410 gallons 
http://www.wwiiaircraftperformance.org/p-38/p-38j-28392-climb.jpg

Note that at 60" WEP for the P-38J-15 at combat load the ROC is:
[email protected]
[email protected]
[email protected]
[email protected] and 
[email protected]

P-51B-15 20 May 1944 report full Combat load at 9355 pounds and 67" WEP
[email protected]
[email protected] --------> P-38 110fpm faster --- or approx. 2 ft per sec
[email protected]
[email protected]
[email protected]> extremely close at WEP without 150 Octane fuel boosted to 70" (P-38 ) and 75" (P-51)

The P-51B1-5 is out climbing the P-38J-15 at most of the altitudes. Check for yourself.


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## GregP (Oct 4, 2015)

Asking spec manifold pressure is fraught with timeframe issues. The Allison had early. mid-war, and late war type models. The early Allisons were rated for rpms less than 3000 even though they were designed with a 4000 - 4500 rpm failure limit. When I worked with Joe Yancey we rarely had any over 45” MAP on the test stand because we were breaking them in and seating the rings. If we got that high it was on very briefly, for a few seconds. Once the rings seated, out run-in was done and it was the customer’s turn to run the engine, install it and go fly.

The Pilot’s Operating Handbook for the P-38J lists the War Emergency manifold pressures as:
P-38J, L and
P-38H F-5B
Altitude--------B-13 turbo-----	B-33 turbo-------------	B-33 turbo
7,000------------60----------------60---------------------60
20,000-----------55----------------55---------------------60
25,000-----------45----------------52---------------------60
30,000-----------35----------------49---------------------53
35,000-----------30----------------44---------------------45
40,000-----------20----------------36---------------------37

Takeoff was 54” at sea level, 3000rpm. WER was 60” at 10,000 ft, 3000 rpm. Military was 54”at 24,900 ft, 3000 rpm. Max continuous rated power was listed at 44” at 34,000 ft and 2,600 rpm. Max cruise was listed as 35” at 2,300 rpm at 38,000 ft. All that was with ram except takeoff, which was with no ram. 

At max cruise, fuel flow in auto-lean was 63 US gal.hr. War Emergency was 180 US gal/hr.
The above were for the V-1710-89 (right hand turning) and V-1710-91 (left hand turning). These engines were rated at 1,425 HP for takeoff and military and 1,600 HP at WER.

Later Allison came out with the G-series engines for the F-82, it never went into a P-38. WER was 2,250 HP at 3200 rpm at 101” MAP with ADI. Some have been raced at 110” MAP and 3600 rpm with twin turbos (tractors and boats). One of the tractor guys in Europe is turning his 4500 rpm … but a tractor pull is short duration. On the order of some 10 – 15 seconds max.

Some of the dash 89/91/100 series were able to safely be operated at 75” in the planes and were actually cleared for 70” MAP after 150 PN avgas was made available. The only thing limiting then to 70” was the throttles and the pilot. They were all easily able to exceed that.

Our P-38J is cleared to 60" MAP and Steve Hinton has flown airshows with it at up to military power in a show with the horsemen. See below. They flew this show for three days straight. These days they are mostly doing it in F-86s.


_View: https://www.youtube.com/watch?v=Yc94Tj7SP8o_

Steve is easily able to pull more power, but there is no need during an airshow and he only very rarely gets it that high. As a museum aircraft it never needs to see WER again and only hits military on rare occasions. He was mostlly at slightly reduced MAP and rpm from miltary to give the wingmen surplus power to easily keep formation, as one might expect. These guys are good. They flew at higher power settings to make the loops big and round and didn't get slow going through the vertical. They went over the top with plently of airspeed and no mushing. That's never good in formation.

The three Horsemen these days are Steve Hinton, Dan Friedken, and Ed Shipley. Ed is a founding member of the Horsemen. You should see Dan's P-51 up close. It is beautifully detailed and immaculately kept. Ed's ain't bad, either. Pretty birds.

Unsurprisingly, our museum P-51s are also operated conservatively since WE are paying for the Merlins. One is Ed Maloney's P-51 (Spam Can) and the other is Steve's P-51 (Wee Willy). Steve's occasionally sees higher power settings, but not often or for long durations. Mostly for "fun time."

We have two P-38s, three P-51s, and two B-25's operating from Chino, plus quite a few other warbirds and even jet warbirds. They are normal sights at the airport. We see everything from Fouga Magisters to F-86s , a MiG-15, a CT-133 Silver Star, several L29s and L-39s (mostly L-39s) plus assorted piston warbirds from T-28s to our own museum fighters. We even get a regular visit from a guy who flies a French Max Holste Brussard. That's a bit of a rare warbird. One guy flies a Folland Gant occasionally. It is still in the Red Arrows paint scheme. We have one Embraer Tucano operating from Chino, too. It has a full Garmin glass panel complete with GTN 650/750 for both seats. Now THERE is a well-equipped turboprop. We should all be so lucky.

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## drgondog (Oct 4, 2015)

I will comment on the article by Corey Jordan - a pilot I respect very much. Having said that it is curious regarding referencing Woods career as a major "P-38" reference. I am not denigrating Woods' record but will point out some facts missed by Corey.

1. Woods flew P-40 and P-38 in PTO for a complete tour. He achieved 2-1-0 air VC's in 112 missions. He returned to States and then joined 479th FG (Olds/Zemke) to fly another tour of 48 missions P-38-J-15, plus 12 missions in P-51. He achieved 1-0 VC's on the ground before returning on Leave again. He joined the 4th FG in February, 1945. He achieved 5-0-0 Air (one mission) and 2-5 ground in 9 missions before hit by flak strafing on April 16, 1945 - POW. 

He was flying the P-38 in ETO in a target rich environment as Group Ops and PTO in a target rich environment as a Flight leader and Squadron CO.

Total Record in P-38? 2-1-0 air, 1-0 ground in 172 missions. P-51? 5-0-0 air, 2-5 ground In 21 missions... for one loss to flak (himself).

Questions about the narrative? The P-38 (C.C. Jordan; MakinKid; CDB100620)

Quote from article

"Sidney flew P-40s and P-38s with the 49FG. He participated in the Battle
of the Bismark Sea. He flew 112 combat missions with the 49th. After a
rest stateside, he went to the 4th FG in Europe. He flew 68 combat
missions in Europe in P-51s. I don't know what he may have flown
stateside.

Sidney shot down two Japanese planes with the 49th and 10 with the 4th
(one of these on the ground, as the USAAF in the ETO counted aircraft
destroyed on the ground as kills. AAF in the PTO did not). Five of
the air kills were FW-190s. Among the medals awarded him that I know
about, were the Silver Star, the DFC, the Croix de Guerre and the Air
Medal. *DSC, DFC(2),Croix de Guerre in P-51 in ETO; SS, DFC in P-38 in PTO*

*ETO record as above was 0-0-0 air, 1-0 ground 479th, 5-0-0 air, 2-5 ground 4th) for total ETO of 5-0-0 air; 3-5 ground*

Sidney described the Mustang as a super P-40. He did not consider it in
the same class with the P-38. He often said that the P-40 and P-51
represented pre-war air combat thinking, and that the P-38 represented the
future. That's a broad statement, and I can't recall his specific reasons
for making it, but it does give you a sense of his feeling for the
aircraft.
Sidney said that were he flying the P-38 in Europe he could have shot down
more planes than he did. On more than one occasion, for example, he noted
that while he was closing in to wing-gun range an FW would execute one of
its fabulous snap-rolls and split-S away. Had he been in a P-38 he could
have opened fire seconds earlier, gained strikes for certain, possibly
destroying the aircraft.

*]Woods flew P-38s for the entire operational P-38 experience for the 479th FG from May through September 28, 1944 - 48 missions in P-38 by him personally. He then transitioned to P-51s just like Zemke and Olds for his last 12 missions before leave to US in December, 1944. How could Woods forget that? or possibly did Jordan mis-remember the narrative? So, in 48 missions in the vaunted P-38J-15 described above, Woods scored 0-0-0. *

Sidney believed the poor showing of the P-38 in the ETO was the result of
AAF brass, who, pre-war were wedded to the unescorted heavy bomber
concept, and didn't dare admit, in the face of terrible bomber losses,
that they had a perfectly capable fighter capable of escorting their
bombers from day one to the farthest target they ventured to--but they
chose not to use it. Instead, they mutually, if unconsciously, fixed on
every reason they could find to discount the P-38 as a capable fighter.
They could then say they had no choice but to go unescorted until the P-51
came along. Had they said, Yeah, we had a good escort fighter in the P-38
but decided not to use it, congressional committees would have been
demanding to know who screwed the pooch (his phrase).

*Nope. The very first operational mission for the P-38 in ETO was the day after Black Thursday - October 14, 1943. After that experience following Regensburg/Schweinfurt the AAF RECOGNIZED that escort all the way to the target was required. Additionally the P-38H did not have leading edge fuel cells and could go no further than medium radius targets like Brunswick, Stuttgart until late February when the J-15s were in the 20th and 55th FG's just in time for Berlin. Even the J-15 was limited to 100+ miles shorter radius than the P-51B with 85 gallon tank. In summary, 8th AF commanders were Desparate for hoped for success in the P-38, but the P-38 was Never capable of flying escort to the farthest targets in ETO using combat tactics of fast but economical cruise above, and level with B-17 bomber altitudes. Neither Sidney Wood (nor Robin Olds)ever flew a mission past Berlin range (550 miles) while flying a P-38. Woods was, however, shooting up an airfield at Prague when he was shot down (~675 miles from Debden).

The 'Brass' didn't 'have it in for' the P-38. It just couldn't do the escort job that the P-51B/D could achieve for 8th AF. The 9th AF and PTO were very happy with the P-38 because it did fit their profile of medium and low altitude. The P-38s were PLAGUED with major issues arising from cold, high altitude ops; compressibility issues and general unreliability as a result of both mechanical issues and maintenance complications in between missions.

One more point to ponder on. The 332nd FG (Redtails) were the Lowest scoring escort Fighter Group in ETO/MTO combined, but They scored more enemy aircraft in the air from their first day of combat ops than ANY P-38 Group after that day. That includes the Very good 1st, 14th, 82nd with rich combat experience and leadership compared to the 332nd. The P-38s in the MTO had been relegated to Penetration and Withdrawal support for long range targets from Italy - just like P-47s in the ETO. *

As far as a combat type went, I recall Sidney talking about how it was
impossible to overshoot an aerial target in a dive with the P-38. If you
saw that you were overtaking faster than you liked, you popped the speed
brakes. Couldn't do that with any other plane. He also liked the low
speed maneuvering flaps, the hydraulically boosted ailerons, and the overall
ruggedness of the airplane.

He felt that the AAF made a mistake in not standardizing the P-38 as "the"
fighter and having Republic and North American build it as well as
Lockheed."

So, my comments in bold above.

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## EKB (Oct 4, 2015)

Nothing succeeds like success, but a tally of enemy fighters was not the only measure. The basic idea of having escort fighters was prevent or reduce enemy fighter attacks on the bombers under protection by the escorts. 

Several German pilots testified that the unique shape of the P-38 allowed for quick identification, which made their job easier. They had more time to decide if they wanted to fight or flee. Single-engine fighters looked much the same until the pilots got close enough to see national markings. That is why so many were shot down in error by both sides.

It was almost impossible to mistake a P-38 for another aircraft, and it's easy to see how that sometimes worked in favor of the Lightning pilots. 

Because the P-38 was easily identified from a great distance, it was easily avoided by German fighters when numbers and position did not suit them. So on the debit side, Lightning pilots had fewer opportunities to engage enemy fighters. On the plus side, the bombers under escort by Lightnings were sometimes left unharmed because the Germans intentionally avoided contact with the P-38s and instead attacked bombers under escort by P-51s or P-47s. 

The P-38 pilots at the 479th Fighter Group gave mixed reviews for the P-51, which was often referred to as the “Spam Can”. Colonel Hubert Zemke said that he preferred the P-51, but he had very low hours on twin-engine fighters. The guys who liked the P-51 said that it could climb higher and fly further than a P-38. The guys who did not like the P-51 cited control problems and the uncomfortable seat, which was noticable on long flights.

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## IdahoRenegade (Oct 4, 2015)

EKB said:


> Nothing succeeds like success, but a tally of enemy fighters was not the only measure. The basic idea of having escort fighters was prevent or reduce enemy fighter attacks on the bombers under protection by the escorts.
> 
> Several German pilots testified that the unique shape of the P-38 allowed for quick identification, which made their job easier. They had more time to decide if they wanted to fight or flee. Single-engine fighters looked much the same until the pilots got close enough to see national markings. That is why so many were shot down in error by both sides.
> 
> ...



That was a double-edged sword. While the shape of the Lightning was unique and easily identifiable, not only could enemy pilots identify it, but so could our own. Several stories I've read from bomber pilots and crews indicated they preferred that, over the "pucker factor" of seeing a single engine fighter and not knowing if it was a 'Bolt or FW, or 109 vs '51. Equally important our AA crews (land and sea based) had far less of an issue identifying them. IIRC that was a major reason they were used so heavily to cover the Normandy landings.


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## drgondog (Oct 4, 2015)

At the end of the Day, historians will note that the objectives of the Combined Bomber Offensive and POINTBLANK was to destroy the ability of the LW to oppose Overlord. The P-38 was less effective than either the P-51 or the P-47.

The importance of the P-51 in ETO and MTO was that they successfully escorted the bomber force to the fsrthest reach of the Reich - including Czechoslovakia, Austria and Poland, dropping average losses from near 10% to 2% while destroying nearly as many LW Fighters as the P-38 and P-47 combined. 

The P-38 was designed as an interceptor - a role it virtually never assumed, was placed in the breach as a long range interceptor and air superiority fighter in the ETO and did not succeed to expectations because of technical and reliability issues. Its highest value in both the MTO and ETO was strangely CAS role - for which it was never conceived to perform. It replaced the P-40 and A-36 and competed with the P-47 - another Interceptor design.

The Mustang was designed as an all around fighter with better performance than the P-40 and P-39 and became to premier air superiority fighter in the ETO and MTO - and once again in the PTO over Japan.

It was a very strange war.


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## Koopernic (Oct 5, 2015)

IdahoRenegade said:


> That was a double-edged sword. While the shape of the Lightning was unique and easily identifiable, not only could enemy pilots identify it, but so could our own. Several stories I've read from bomber pilots and crews indicated they preferred that, over the "pucker factor" of seeing a single engine fighter and not knowing if it was a 'Bolt or FW, or 109 vs '51. Equally important our AA crews (land and sea based) had far less of an issue identifying them. IIRC that was a major reason they were used so heavily to cover the Normandy landings.



During the Normandy landings P-38's were the only combat aircraft allowed to use the first airfields established near the landing sites because it was thought that other aircraft would suffer unacceptably high blue on blue losses.

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## BobB (Nov 18, 2015)

A former B-17 pilot told me that he got his multi-engine training in AT-6's. That was early in the war and the multi-engine school that he was sent to hadn't received any twin engine trainers yet so they used AT-6's. Okay for instrument and formation training and he got multi-engine training in B-17 school. So if you decide to build P-38's instead of P-51's, you also need to build lots more twin engine trainers which we already weren't able to build fast enough. Since the aircraft engine industry was already working hard to build as many engines as possible, you'll have to settle for half as many P-38's as P-51's. Also, when looking at contract prices for aircraft, almost all military aircraft programs have engines, propellers, armament and instruments as Government Furnished Equipment and their cost is not included in the contract price for the aircraft.

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## bobbysocks (Nov 18, 2015)

no engine for trainers??...not a problem at all. the RAF perfected a work around for that in ww2....


_View: https://www.youtube.com/watch?v=izhlm5J1wKc_

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## FLYBOYJ (Nov 19, 2015)

BobB said:


> A former B-17 pilot told me that he got his multi-engine training in AT-6's. That was early in the war and the multi-engine school that he was sent to hadn't received any twin engine trainers yet so they used AT-6's. Okay for instrument and formation training and he got multi-engine training in B-17 school. So if you decide to build P-38's instead of P-51's, you also need to build lots more twin engine trainers which we already weren't able to build fast enough. Since the aircraft engine industry was already working hard to build as many engines as possible, you'll have to settle for half as many P-38's as P-51's. Also, when looking at contract prices for aircraft, almost all military aircraft programs have engines, propellers, armament and instruments as Government Furnished Equipment and their cost is not included in the contract price for the aircraft.



Multi engine training was lacking during the beginning of the war in all accounts, although you'll find that many of the more successful P-38 drivers got time in aircraft like the B-25 and A-20.


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