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

[drgondog]

The P-38 groups that went operational in the spring of 1944 were not exclusively equipped with J-15 and newer Lightnings.

Didn't say that they were Exclusively operational. I cited the presences and the loss date to prove the existence of the P-38J and successive evolution in arrival into 8th and 9th AF fighter groups


IMHO, a P-38J-25/L flown by a well trained and experienced pilot would hold its own or more against most Luftwaffe piston-engined fighters. If those models had been available in late 43, early 44, they may have earned the P-38 a great reputation in the ETO. I do believe however, that by 1945, the Lightning had reached the end of its development potential, unlike the P-51D which morphed into the H, or the P-47D which could be developed into the M/N.

You could as easily say that there were no innovations of importance after the dive flap, intercooler, boosted ailerons and maneuver flap mods were introduced in the J-25 Production block - meaning early 1944 at Lockheed with deliveries to the ETO in February through August, 1944

Eagledad

As to the other question.. this is what I stated

Each was equipped with P-38J-15 with leading edge fuel tanks when they started combat ops in April and early May, 1944. I haven't yet found out whether P-38L's were delivered but all the J's received the filed modifications for both the boosted ailerons and the Dive flaps by late June when all the ETO P-38s were upgraded to the P-38J-25

What I meant, and should have clarified, is that all the P-38J's were scheduled to be upgraded with Field kits to install the dive flaps and boosted ailerons and bring them to the J-25 capability.Retrofit capability to redesign the intercooler and install the leading edge fuel cells would have been impossible at Service centers in England. However, AFAIK it would not have been impossible to retrofit the earlier J-5 or -10 because I'm not as familiar with the internal design features of the P-38J blocks.

As to the sources - multiple conversations with both John Landers and Robin Olds, curiously on this subject of "what if". Landers was certain that he had both dive flaps and boosted ailerons on his June 25, 1944 fight with 109s and 190s near Paris. He was equally certain that he was flying the -15. The last of those conversations were in the mid 80's. In the only conversation with Olds on this subject, Zemke (and Loisel and Landers) were also in it... either 1984 0r 1986 AFA Reunion in Tuscon. Zemke, Olds and Loisel recall flying the 'modified' J-15 also in the summer of 1944. Neither Olds nor Zemke recall a P-38L-1 at 479th but the first P-38L-1's were rolling into USAAF inventories in June, 1944.

As an aside to frame the P-38L-1 combat arrival discussion - PTO aces Bong, McGuire and McDonald all scored in L-1s in October/November 1944. Two aces of the 474FG in ETO scored with J-25s in August (Kirkland - two 109s 8/25) and Milliken - 2-0-3 FW 190s on 9/12/44)

EDIT - 9/27 I haven't found the source(s) yet that cite Lockheed producing several hundred dive flap kits in late 1943 to March 1944 and dispatch them to ETO/PTO and MTO. A friendly fire incident took down a AAF transport carrying 200 en route to England in early March, 1944. It is in one of Ethell's and one of Bodie's books but I'm looking for a Ben Kelsey memo dated April 1943 citing his satisfaction with the dive flap mod on one of the very early -5's

 

[Shortround6]

The latest sentence is dead on.
For the Griffo, we need also to add a substantial amount of exhaust thrust at such high altitudes, maybe equivalent of 20% of engine power? That woul make it about 1700 hp for military power at 27-30 kft?

I am not sure about the that much exhaust thrust. for 10,000ft difference in altitude you loose about 20% in air density (roughly) so you have 20% less exhaust mass. That gets balanced somewhat by the higher exhaust velocity because of the lower air pressure at the exhaust nozzles.
For the Merlin XX exhaust thrust (power) never exceeded 11.5% of brake hp. A two stage engine will show a higher percentage because you have the weight of the exhaust used to drive the supercharger but that is not a constant either, the Merlin XX needed 225hp to drive the supercharger at 20,000ft to give 12lb of boost. At 30,000ft the supercharger could only deliver a bit over 2lbs of boost . Charge flow(weight of air+fuel) had dropped from 144lb/min to 107.2lb/min and supercharger power requirement had dropped to 167hp.

I do have to apologize though, apparently I was looking at the wrong page in my book (and failed to check a second source) and a two stage Griffon will pretty much match at Late Turbo Allison at altitude (27-28,000ft).

 

[drgondog]

i Bill,
That's a lot of data that I'd LOVE to have access to. Your data on the P-38 in the ETO wouldn't happen to include the type missions they were assigned, would it?

I have the data but not in spreadsheet. The P-38 in 8th AF was tasked first to long range escort through its entire 8th AF career.

As I've often stated in here, the scrutiny applied to a select few, like Boyington, has not been applied to everyone. Until it is, I'll take the victories awarded in the war and not the revisionist numbers. I simply use different numbers.

Actually, the scrutiny by the USAF research team Was objective. The objective wasn't the record per se, but the larger question of "what does the distribution of air to air victory credits look like, what factors separated the individuals from those that did not achieve victory credits, and then in many cases "why him?" down to level of brothers, order of birth, sports achievements, etc" - The first step however, was to get the data 'Right' and high scoring aces scores were reduced when duplicate records were found.

As to you using 'different numbers' it has to be somewhat vexing when multiple researched and published data that agree each other, have conflicts with your stuff?

The numbers I have for the P-38 do not include aircraft attached to individual units and I'd love to have those data.

Greg - Frank Olynyk has that data. I do also for the ETO/MTO because I have the data for the transitions and the Encounter Reports for the early cross over periods for each group for MTO and ETO. I'm working PTO but my fallback of researching encounter reports is sketchy - while MACRs are pretty complete. I have taken the time to literally enter each line of data for USAF 85, then start the cross check process to ensure that the individual data is correct, then add the type fighter used, and where possible add the type aircraft destroyed.

From Francis Dean's "America's Hundred Thousand," I do have the numbers for USAAF aircraft in the ETO. Those numbers show the P-38 flying 60.7% of the sorties the P-51 flew while suffering 69.7% of the P-41's combat losses and dropping 355% of the bombs the P-51 did. That figure alone makes me wonder VERY hard about the missions assigned to the P-38 versus the P-51, and it points me to the supposition that the P-51 was selected for the missions that afforded higher opportunities for air combat, while bomb-laden P-38's were assigned what can only be support bombing duties with MUCH less chance of encountering a defender in the air that is searching for high-altitude strategic bombers.

I haven't corresponded with Dean on the subject of 'actual' sorties and hours. The Eighth AF records are the best of all the major WWII combat units - and constitute a major block of records for all the P-38, P-47, P-51 and P-61 sorties flown. There is no repository of such data AFAIK. Some individual record keeping at the Group level has surfaced (i.e for the 355th FG) but not anywhere close to uniform in either location or format or completeness. Short answer is that I don't yet believe any of the historical summaries or references in published books on aircraft that discuss "X" number of sorties, or "Y" hours, or "Z" credits for bombs dropped, etc. Some histories have it, others are silent.

I will say this. If you (or Dean) or any researcher makes a claim on sorties, early returns, or hours Without the Unit Tower Log AND Daily Engineering Reports - it is simply a number extracted from a dark place. An example - Kent Miller has done a magnificent job, similar to Freeman, in his two volume set on 8th AF Fighter Command. Yet he has a lot of errors on the 355th that only I can dispute simply because I have 30 years or research, hard research to match MACRs, available engineering logs, accident reports, 3000 plus a/c photos.It is like an archeological expedition. Now multiply that by 15 permanent fighter groups plus Scout Forces,
Summary - sortie and hour rollups are impossible IMO.

Summary - I posed Capacity based on Operational Potential of the P-38 vs P-51 FG's as Constituted, Not as Actually Flown. The records of dispatched vs effective are reasonably complete in some FG's (56th, 4th and 355th come to mind) but in many there is usually a lazy Intelligence officer that captured just enough to produce a flash mission report for Group HQ. You (or Dean) would have to go to an individual and detailed block of data like a well kept and complete Tower Log - Not the IO Mission Summary.

I think my supposition here is confirmed that the P-38's were supporting Army units. They would never replace strategic bombers and that leaves only ground support as the major mission.

Your supposition for even 9th AF, much less 8th would be wrong. The 8th and 9th both reported to Spaatz in December 1943. Spaatz placed 9th AF FC dotted line to 8th AF to augment bomber escort. All the P-47s, P-51s and P-38s performed Penetration, Withdrawal and Target Support escort roles through the end of May, 19444. The 9th then regained operational control to support the Tactical mission for the Invasion of France and beyond.

Simply there weren't enough long range escort fighters to support the 8th AF mission until fall of 1944 and some of the big LW days occurred in May, June, July when escort fighter coverage was too skimpy to cover all of the bombers to all of the targets.

So my opinion is they got what they assigned the two planes to do and both did OK. We don't KNOW how they would have dome if the missions were switched … they weren't switched, at least in the ETO.

Greg - more research, less speculation, is in order. Get the 20, 55, 364, 479FG histories and look at the tasked missions, get Kent Millers two volume set. Get the Mighty Eighth War Diary. Pull out The Mighty Eighth and re-read it.

The P-38 seems to have dome pretty well at what it was assigned and I see no evidence that would suggest to me that if the missions were swapped, we would have failed and lost the war.

Nobody claims that we would have 'lost the war' if the Mustang had not eventually replaced the P-38. What you can conclude is that a.) there would have been too few P-38 Groups to adequately prevent huge losses for the 8th AF EVEN if Doolittle had not tossed them in favor of the P-51, and b.) there would have been a very much stronger TO&E for LuftFlotte Reich when D-Day rolled around

To come to that conclusion, I'd want to see statistics for similar missions flown against similar defenders. I KNOW the P-51 was afforded missions with much higher probability of seeing enemy aircraft. Bombers draw enemy fighters and escorts will engage them. P-51's were primary escorts. Pretty easy there. Perhaps the planners did that on purpose because they though as you do. Could be.

No. There were more or as many operational P-38 FG's performing deep penetration bomber escort as P-51s from October, 1943 through February, 1944 and only one fewer through April, 1944, and as many through May, 1944 when all the 9th AF P-38 groups were performing escort.

The operational achievements for ALL the P-38s assigned to ALL 8th AF bomber missions through May 1944 was dismal with respect to engagements and victories against the LW when compared to a.) the shorter range P-47 and b.) the slightly longer range P-51. Remember the P-38 did perform primary target escort to Berlin as early as 3 March 1944, before the Mustang by one day. While some targets were beyond the P-38 range, they were Few.

The P-38 showed what it could do in the PTO and MTO and, if employed correctly, would have done just fine in my opinion in the ETO. It's not intended to try to convince you, Graugeist, or anyone else, it's MY opinion. The only data I have that shows late model P-38 employed in escort mission was in the PTO and MTO, so that's what I use for comparison.

But, by all means, if you have the data in the ETO about mission types, please post it. I have never seen it and would like to. I don't disbelieve you, but would like to have the sources!

See the above - all are publically available to those interested in digging out the facts. I would recommend Miller's two volume set as well as Freeman's War Diary

The P-38 in the ETO came in third in the ETO against all other USAAF types and that says it wasn't too bad. You guys can hate it and disrespect it all you want. It wasn't that bad in the final tally.

Greg - I Certainly do not hate the P-38, nor do I hold it in contempt or disrespect it. I do have an objective point of view relative to what I think - and vocalize what I say. Food for thought - look at the record of the 332nd FG in the MTO. Last to get Mustangs, did not come close to the records of other MTO Mustang FG's during the same period - but they outscored each of the remaining P-38 FG's (1st, 14th and 82nd) during that period. Those three P-38 FG's would have scored ahead of all 8th AF FG's except the 56/4 (82nd) and 352 (1st and 14th) but couldn't beat the low scoring 332nd from June, 1944 to EOW

I don't doubt your data. I might embrace it if had the sources. Cheers.

I still believe the critical factor in the ETO, and to a degree in the MTO, for strategic incursions into Germany on bomber escort was simply that the LW fighter pilots were ordered to not engage escort - and the big freaking P-38 was easy to spot and avoid... and they did. But they had no such defense against the P-51.

The net - the P-38 escorted well and nobody came to the party. When they did engage, the 109 and 190 could both outdive and maintain control in the dive to easily escape many combat situations with the P-38. Until the dive flap and boosted ailerons, the P-38H and J were also at a maneuvering disadvantage except for a steep climbing turn to the right.. it was nowhere near as ideal as P-38 vs A6M, Ki 61, etc combat.

 

[drgondog]

[

IMHO, a P-38J-25/L flown by a well trained and experienced pilot would hold its own or more against most Luftwaffe piston-engined fighters. If those models had been available in late 43, early 44, they may have earned the P-38 a great reputation in the ETO. I do believe however, that by 1945, the Lightning had reached the end of its development potential, unlike the P-51D which morphed into the H, or the P-47D which could be developed into the M/N

Eagledad

From my perspective this statement represents the 'average' concensus for the advocates of "The P-38 coulda done better in the ETO, if only.. - fill in the blanks -"

Here's the thing. For the Pre P-38J-15 which first started arriving in February 1944 to fill (maybe late January) operational squadrons in the ETO, there were two sets of issues, one group Objective, the other Intangible that hindered achievement of the Lightning versus the Bf 109 and FW 190. Thos two represented the primary adversaries with relatively equal performance at the altitudes in which the 8th AF bombers were escorted..

Mechanical/Aerodynamic - tangible and objective
* Intercooler issues resulting in mechanical engine failures
* Immediate entry into compressibility and uncontrollable dive when diving from high speed cruise.
* Lack of roll and turn maneuverability in comparison.

Intangibles
* Cockpit comfort due to frigid cockpit/lack of adequate heating resulting in increased fatigue
* Huge size and distinctive plan form making it uniquely identifiable from great distances
* Significant areas of rear and down aft visibility diminished by tail boom geometry
* Combination of twin engine operation and complicated control processes to move from cruise to combat state in short time.

In addition One Major Intangible representing External factors beyond Engineering solution
****** Luftwaffe High Command instructions to avoid bomber escort

So, on paper the entry of the 55th FG in October with the improved P-38H that still had all the above Tangible issues resulted in:
Operational issues reducing effective mission strength below that of comparable 8th AF P-47s (P-51s subject to this also as bugs were being fixed in first several months of operations).
* combat performance versus mainstream LW fighters well below P-47 when engaged.
* loss rate to mechanical problems and initially higher accident rate due to complexity and training required to operate twin engines versus single engine fighter.
* Twice as expensive to operate versus single engine fighters

Positive Factors - but intangible to the analyst wondering why the P-38 wasn't doing as well against the LW.
* The escort missions seemed successful because fewer attacks SEEMED to occur when P-38s were escorting specific bomber groups.. This is somewhat anecdotal but my own research of individual 8th AF Fighter Group Histories points to more Mission Summary Reports, Para H. Claims for A/c destroyed" cite the phrase 'NIL" far more than the P-51 and P-47 groups - even if in same general area and time as the other groups.

My conclusion is and has been for some time, that the avoidance of combat order by Goering was very easy to obey because the P-38 was mostly visible to the LW before the LW was visible to the P-38s. Secondly, until the dive flap was installed, avoidance of a P-38 even when engaged was relatively easy by simply pushing the 109 and 190 into a sharp roll and split S. If the P-38 even tried to follow, it would spend a long period of frustration until it reached sufficiently dense air to recover from the dive - due to the tuck issue following onset compressibility shock wave moving the CMac.

In the PTO, the Japanese fighters did not have either the speed or diving ability to escape from a P-38 and the combats were far more in middle altitudes where the .68M speeds were not often encountered even in a dive for some time or very steep dive angle. Nor were the Japanese inclined to avoid combat. Those are three factors for me which I think illustrates the relative effectiveness of the PTO P-38 versus the ETO/MTO long range escort utilization of the P-38 for attacks against Germany, Austria and Balkans.

 

[FLYBOYJ]

Combination of twin engine operation and complicated control processes to move from cruise to combat state in short time.

Excellent assessment Bill but I have issues with this one. I think it's obvious that a twin is more complicated to operate than a single engine fighter - two of everything. If you look at the placement of some of the controls on the P-38 and compare them to other twins of the day (and those developed after the P-38 ) some are in the same location and worked the same way. I think with training, a competent pilot could handle the work load and configure his aircraft to be combat ready in a required amount of time to defend himself, but this will go back to the complexity argument of operating a twin (let alone the time and cost to train pilots to handle the complexity of a twin). I never read much about PTO P-38 drivers complaining about the time it took to go from cruise to combat state. I think Rau's letter addressing this situation was a bit exaggerated, but funny that he talks about a new pilot with only 25 hours in the P-38, where AFAIK PTO P-38 drivers had a hell of a lot more time in type before they were cut loose to fly combat.

 

[drgondog]

Excellent assessment Bill but I have issues with this one. I think it's obvious that a twin is more complicated to operate than a single engine fighter - two of everything. If you look at the placement of some of the controls on the P-38 and compare them to other twins of the day (and those developed after the P-38 ) some are in the same location and worked the same way. I think with training, a competent pilot could handle the work load and configure his aircraft to be combat ready in a required amount of time to defend himself, but this will go back to the complexity argument of operating a twin (let alone the time and cost to train pilots to handle the complexity of a twin). I never read much about PTO P-38 drivers complaining about the time it took to go from cruise to combat state. I think Rau's letter addressing this situation was a bit exaggerated, but funny that he talks about a new pilot with only 25 hours in the P-38, where AFAIK PTO P-38 drivers had a hell of a lot more time in type before they were cut loose to fly combat.

Hi Joe. I honestly do not know how much time the average replacement P-38 pilot had when a.) they got to England, and b.) how much time they got in the 496th FTG at Goxhill before moving into 8th and 9th AF P-38 groups. IMO the extra training and flight time translated to fewer mistakes making the multiple moves required to drop the tanks, run the RPM and throttle up, and go do sumtin' fast, but not significantly reduce the time.

But - it was definitely more steps than a 51 or a 47 with the attendant possibility of a mistake along the way.

At the Fighter Conference at Patuxent River in October 1944, the P-38L was ranked as the 'worst cockpit and control layout' and only 2 of the 28 ranked maneuverability as good, 10 'fair' and 16 'poor' when compared to the other fighters flown at the Conference. Note that this was the latest P-38, it was after the last one flew combat for the 8th AF and just then reaching combat units in the PTO.

At the end of the day your points make sense Joe - but begs the question "If I have to invest more time in training, more time to train maintenance procedures, more average time to maintain it on a daily basis, spend more money on fuel, drain the fuel storage 2x faster, fight with an opponent that is still more maneuverable, can still out dive me - when I have a single engine fighter (the Mustang B/D) that doesn't have those problems.. would I want the first one to fight with?"

I think Doolittle answered the question in January 1944 and would have answered it the same way even if he had more experience with the J before making the decision. Remember he came from 12th AF and 15th AF where the P-38 combat in the Africa and Med campaigns didn't expose the P-38F and H as much as European high altitude escort conditions..

At any rate, it is an interesting discussion.

 

[GrauGeist]

Here's a good overview of the P-38 from a pilot who flew them: Capt. Robert DeHaven, 7th FS, 49th FG (14 victories: 10 w/P-40 - 4 w/P-38):

After training I requested duty in the Pacific and I requested being posted to a P-40 squadron and both wishes were granted. This was early in 1943 and most pilots already desired more advanced types and some thought my decision a mistake. Yet I had been inspired by the deeds of the Flying Tigers. We had also heard accounts that the P-38 was difficult to bail out of because of its twin-boom tail and that it was difficult when flying with one engine. I also knew that P-38s were still rare in the theater and I wanted to get into the war as soon as possible. That wish, too, was granted. I never regretted the choice.

If you flew wisely, the P-40 was a very capable aircraft. In many conditions, it could outturn a P-38, a fact that some pilots didn't realize when they made the transition between the two aircraft. The P-40 kept me alive and allowed me to accomplish my mission. The real problem with it was lack of range. As we pushed the Japanese back, P-40 pilots were slowly left out of the war. So when I moved to P-38s, an excellent aircraft, I did so not because I believed that the P-40 was an inferior fighter, but because I knew the P-38 would allow us to reach the enemy. I was a fighter pilot and that was what I was supposed to do.

The P-38 was very unusual. Imagine what I felt when first climbing on board that airplane. Sitting on that tricycle landing gear, it was very high off the ground. There was a stepladder that dropped out of the tail end of the fuselage pod, and you took two steps up this ladder and the third step was onto the wing next to the canopy. ... It was a good sized airplane. In comparison the P-39 was a midget, almost like a toy.

It was very fast and had good firepower. That gave a lot of people false confidence when they first went to P-38s. Their limitations on tactics were the same as those we were accustomed to in the P-40s, but even more so. You did not go looking for a close-in dogfight with an Oscar or Zero. Japanese planes were quicker ... at slow speed. But new pilots did not always realize the consequences. If the speed bled off a P-38, which happened very easily, it could be in serious trouble against a Japanese fighter. Many of our men found out the hard way, particularly when we first started receiving the P-38s.

 

[tomo pauk]

I am not sure about the that much exhaust thrust. for 10,000ft difference in altitude you loose about 20% in air density (roughly) so you have 20% less exhaust mass. That gets balanced somewhat by the higher exhaust velocity because of the lower air pressure at the exhaust nozzles.

For the Merlin XX exhaust thrust (power) never exceeded 11.5% of brake hp. A two stage engine will show a higher percentage because you have the weight of the exhaust used to drive the supercharger but that is not a constant either, the Merlin XX needed 225hp to drive the supercharger at 20,000ft to give 12lb of boost. At 30,000ft the supercharger could only deliver a bit over 2lbs of boost . Charge flow(weight of air+fuel) had dropped from 144lb/min to 107.2lb/min and supercharger power requirement had dropped to 167hp.

Yep, 20% of extra power should be a bit too much, somewhere around 15% should be available at 30000 ft?
Could you please elaborate a bit about the bolded part?
If I'm reading this chart right (for Jumo 213E), whenever the boost and RPM are at certain level, and the engine/plane is at ever higher altitude, the exhaust thrust is also increasing. That is despite the ever increasing power needed to drive a S/C.
Highest line is for the 'Sondernotleistung' (ie. use of MW-50; only available for lower 2 S/C gears), next one is for 'Notleistung', the bolded one is for 'Kampfleistung'.

The chart for the BMW-810D - despite greater need for the S/C, the exhaust thrust is cosiderably greater in second S/C gear, than in 1st:

 

[drgondog]

Nothing about an engine change dramatically re-sets to table for the P-38 save reducing mechanical issues from the combination Intercooler/Turbosupercharger/engine issues. A Merlin 60 series IMO would do just fine as The alternate future 'what if' universe of possibilities, but

1. Doesn't change the 'whoops I shouldn't have pushed the nose down" issue
2. Doesn't make me roll (or transition into the Roll) appreciably faster - so the 190 and 109 cand still flick away as before.
3. Doesn't make my big fat planform shrink from a size 14 to a size 3
4. It Does reduces the range a bit as the Allizon was better on fuel conservation but yanking the intercooler and turbo out provides for more internal fuel or reduces weight for better climb and range.
5. Cockpit control procedures are the same
6. It is still 2x to fly and maintain but less so w/o Turbo to worry about
7. Reduced performance beyond 30,000 feet w/o turbo

But below 30K, say at 20-24K to FTH it is a wee bit faster - but also pushes it closer to the .68M limit for compressibility..

Now - change the wing to a 12% or less and a LOT of problems go away.

 

[wuzak]

Now - change the wing to a 12% or less and a LOT of problems go away.

Or use a laminar flow profile.

Now that we are changing the wings, would there be an advantage to trimming the wing span?

The P-38's wingspan was

• 3' less than the XP-67 (which was heavier, with 6 x 37mm cannon!)
• 2' 2" less than the Mosquito's (a bomber)
• 2' greater than the Fw 187 (which was lighter at max take-off than the P-38 was empty!)
• 7' greater than the Whirlwind (which was lighter at max take-off than the P-38 was empty!)
• 7' greater than the Hornet (which was had a similar max take-off weight to the P-38)
• 10' greater than the XF5F/XP-50 (which were much lighter)
• 10' 5" greater than the Tairov Ta-3 series prototypes, which used two big fat radials and was still lighter at max take-off than the P-38 was empty
• 12' greater than the proposed Supermarine Type 327 (which also would have been much lighter)

The XP-49 tidied up some of the details of the P-38 but used the same wing and dud engines (the IV-1430).

 

[GregP]

Pretty good response, Bill, and I bow to your research on the data. I have never had access to it and still don't. Good stuff.

What I CAN say is the P-38 has little trouble staying with the stock P-51 when flown as they are today. The guys I know who fly it are all amazed by the P-38. None have ever been attacked by anybody while doing it. No doubt they aren't using full power or, especially, WER. These are privately-owned aircraft, even ours (owned by the museum).

All the people who give talks on it praise the P-38's ability to spit ammunition out the front that ins't converging. All say it rolled very well if you were a strong armed guy, and our own P-38 has NO trouble rolling with our Mustangs and P-40 ... it just takes some muscle.

So, modern operational data collides with your war information. Plus, it WAS the mount of the two highest-scoring aces for the U.S.A.

I hope to GET some of your sources (Thanks for the thread on sources) but feel that verbal recollections from real WWII pilots trump modern revisionist books EVEY time. The pedestrian P-40 "woke up" when flown at 75" of MAP according to guys who DID it and that set of operations was responsible for a significant portion of the P-40's success. And that difference made the P-40 formidable when flown at WER power. I'm sure the P-38 guys had a similar experience as they have described it almost the same way on numerous occasions in live talks at the museum. Overboosting was common under certain circmstances, such as when you are about to die if you don't overboost.

Meanwhile, my opinions are in flux with your data shown ... and I can't verify them all at once ... so I'll refrain at this time.

I'm still a huge P-38 fan, but understand the data you posted. It speaks to me of ETO tactics versus PTO/MTO tactics. The latter were VERY effective. The former much less so, at least with the P-38. My jury is still deliberating ... but your data, if true, is somewhat telling.

Maybe you can tell me how the 60% of P-38's versus P-51's dropped 355% of the bomb tonnage if they were not on gound support missions?

 

[wuzak]

Greg, how warbirds are flown today bears no resemblence to how they were in the heat of the battle 70 years ago.

I assume if teh same extra muscle required to make the P-38 roll quick was used in the P-51 or P-40 they would roll quicker too.

 

[OldSkeptic]

Note sure why people are even continuing this.

Griffons in a P-38, when the std engines in a late model meant max level speed was about 20mph off of the critical mach limit...
So it was aerodynamically limited.

Even if you could, then give it the gun ...and fall out of the air into an uncontrollable dive. That is what mach limits are..you lose total control of the aircraft....
You go into a dive you cant pull out off..lawn dart time.

Be in level flight...hit the limit and the nose goes down..and down. Your only hope is that, if it holds together that as you hit thicker air then the high mach limit mean you can start to regain control.

The only answer was to, which they did in the end, keep it to operations under 20,000ft, preferably 15,000ft, where the gap between the mach limit and the planes speed was much larger.

Totally flawed plane and you can't excuse Lockheed over this. Using the same data, at roughly the same time, Messerschmitt created the 109 with a 0.75-0.8 mach limit, Supermarine created the Spitfire with a 0.85 mach limit.

Lockheed were like Hawker, with the Hurricane having a 0.7'ish mach limit (and the Typhoon similar). Took them until the Tempest to get into the 0.8 region.

So, sadly Kelly Johnston (and Camm) cannot excuse their design mistakes, because others didn't.

 

[Shortround6]

A little harsh considering that the "boffins" at the RAE and the scientists/researchers Langley (NACA) didn't know there was problem with those airfoils in 1938-39-40. Neither company, in fact neither country had wind tunnels working at those speeds.

Building 400mph at sea level seaplanes may tell you that the thick airfoils may have more drag than the 'Boffins' are saying but it doesn't tell you about mach tuck either.

The P-38 had about all the engine power in 1944 that it could stand.

as for "Using the same data, at roughly the same time, Messerschmitt created the 109 with a 0.75-0.8 mach limit, Supermarine created the Spitfire with a 0.85 mach limit."

There was NO data, just guesses and some were better than others.

 

[drgondog]

Or use a laminar flow profile.

Now that we are changing the wings, would there be an advantage to trimming the wing span?

A laminar flow airfoil should cut down the drag and move the Mcr from .68M to a higher value even at 16% T/C. Should also diminish the Mach Tuck issue by pushing the shock wave formation region farther aft of the aerodynamic center.

Reducing wing span would increase the Induced Drag but reduce Zero Lift Drag and reduce the available lift. Should increase top speed, reduce range potential, reduce climb performance - but those are gross generalizations as the introduction of the laminar flow airfoil should reduce zero lift drag even more than reducing wingspan which should tend to improve L/D and restore range potential..

 

[tomo pauk]

...

Totally flawed plane and you can't excuse Lockheed over this. Using the same data, at roughly the same time, Messerschmitt created the 109 with a 0.75-0.8 mach limit, Supermarine created the Spitfire with a 0.85 mach limit.

Lockheed were like Hawker, with the Hurricane having a 0.7'ish mach limit (and the Typhoon similar). Took them until the Tempest to get into the 0.8 region.

So, sadly Kelly Johnston (and Camm) cannot excuse their design mistakes, because others didn't.

What aircraft did you designed, so you have the credentials to throw mud on people that really designed aircraft?

 

[drgondog]

Totally flawed plane and you can't excuse Lockheed over this. Using the same data, at roughly the same time, Messerschmitt created the 109 with a 0.75-0.8 mach limit, Supermarine created the Spitfire with a 0.85 mach limit.

What data are you referring to? Although the Existence of Shock wave phenomena were known, first discovered by Ernst Mach, the application of low speed wind tunnel data to theoretical analysis did not extend to high speed compressibility predictions - and there was no way to model the airfoil at the subsonic/supercritical region analytically at that time.

The Ames 16 foot supersonic wind tunnel was built in 1941 and had the capability of driving velocities up to 680mph.. it COULD have been useful had it been built and open for business four years earlier - but not useful prior to preliminary design of the P-38 and selection of the airfoil based on known theory and experimental data below Mcr for that airfoil. There were no public papers on the subject AFAIK until 1944 - at least not in the US

Having said that, it took until 1945-1946 to solve the issue of transonic shock waves bouncing off the walls and playing havoc with the instrumentation for both the 8 foot and 16 foot Transonic tunnel.

Lockheed were like Hawker, with the Hurricane having a 0.7'ish mach limit (and the Typhoon similar). Took them until the Tempest to get into the 0.8 region.

So, sadly Kelly Johnston (and Camm) cannot excuse their design mistakes, because others didn't.

Respectfully Kelly needs zero excuses and to label the 23016 airfoil a 'design mistake' is silly given the state of the aerodynamics 'art' of 1937-1938.

Once Kelly figured out the problem in 1942 he proposed the solution, but the War Production Board said 'no'.

 

[drgondog]

Pretty good response, Bill, and I bow to your research on the data. I have never had access to it and still don't. Good stuff.

What I CAN say is the P-38 has little trouble staying with the stock P-51 when flown as they are today. The guys I know who fly it are all amazed by the P-38. None have ever been attacked by anybody while doing it. No doubt they aren't using full power or, especially, WER. These are privately-owned aircraft, even ours (owned by the museum).

There was no problem with acceleration or airspeed comparisons between the two until the drag rise tipped the favor in the 51's favor.

So, modern operational data collides with your war information. Plus, it WAS the mount of the two highest-scoring aces for the U.S.A.

Re-read the comments from the 1944 Fighter Conference at Patuxent River to work with 30 experienced fighter pilots and test pilots flying at war time conditions.. Then ask yourself 'who is pushing the airplane and who is babying it? Wartime or peacetime investors? Then ask yourself why the Bearcat, Corsair, Mustang and Thunderbolt always ranked ahead of the P-38 in every category except Fighter Bomber?

My 'information is revealing to the extent of combat operations comparisons between two types of fighters, fighting the same enemy on the same mission types.

I hope to GET some of your sources (Thanks for the thread on sources) but feel that verbal recollections from real WWII pilots trump modern revisionist books EVEY time.

Of the sources I posted, which do you consider 'revisionist"?



The pedestrian P-40 "woke up" when flown at 75" of MAP according to guys who DID it and that set of operations was responsible for a significant portion of the P-40's success. And that difference made the P-40 formidable when flown at WER power. I'm sure the P-38 guys had a similar experience as they have described it almost the same way on numerous occasions in live talks at the museum. Overboosting was common under certain circmstances, such as when you are about to die if you don't overboost.

Meanwhile, my opinions are in flux with your data shown ... and I can't verify them all at once ... so I'll refrain at this time.

I'm still a huge P-38 fan, but understand the data you posted. It speaks to me of ETO tactics versus PTO/MTO tactics. The latter were VERY effective. The former much less so, at least with the P-38. My jury is still deliberating ... but your data, if true, is somewhat telling.

Maybe you can tell me how the 60% of P-38's versus P-51's dropped 355% of the bomb tonnage if they were not on gound support missions?

The P38 in the MTO flew a lot of fighter bomber missions from the very beginning of the African campaign to the end of the war. The P-38/P-47 and P-51 flew some fighter bomber mission, about the same number, in the 8th AF but the prime mission was Escort. The 9th AF flew fighter bomber missions almost exclusively but following D-Day had one Mustang fighter Group (354) and one Recon Group (363) plus several recon P-38 and P-51 and Mosquito squadrons.

Pretty simple math when you contrast the 8th and 9th AF mission side by side, the look at the daily mission profile for 9th AF P-38s vs 8th AF P-51s

 

[drgondog]

Excerpts concerning introduction of the Dive Flaps, the kits, and last a pice about Col CY Wilson killing a 109 from a dive with a recently modified P-51J-15 on JUNE 25, 1944.

Der Gabelschwanz Teufel - Assessing the Lockheed P-38 Lightning
The complaints were relayed to the Lockheed factory, and design changes were incorporated in the P-38L. Prior to the arrival of the "L's" at Wormingford, many modification kits were shipped to Langford Lodge, North Ireland, for field modifications of the "J" model Lightning then arriving in the theater. Unfortunately, an early shipment aboard a DC-4 was lost at sea when the Brits shot the cargo plane from the sky. It took several months to replace the lost modification kits. Early P-38J-5-LO's were modified at Langford Lodge by the addition of the replacement kits. The kits added dive recovery flaps under the wings, outboard of the engines, and a 3000psi hydraulically boosted aileron system. The P-38L's were now coming down the production line with the aileron boost and "speed boards" installed.

The P-38J resolved the intercooler efficiency problems of the earlier subtypes via the use of a core type intercooler in the forward nacelle chin. While prototypes were being tested in early 1943, P-38H production continued. The new nacelle chin provided increased oil cooling capacity, and automatic control of the intercooler vent, resulting in the full availability of the 1,600 HP War Emergency rating of the F-17 powerplant. Other design changes were introduced, including enlarged glycol radiators in the tail booms, in later build aircraft additional outboard leading edge tanks, and two major control system changes. These were hydraulically boosted ailerons which decreased control forces by a factor of six, and electrically actuated dive flaps under the wings which cured the dive compressibility problems. The latter were fitted standard from the P-38J-25-LO, sadly almost all retrofit kits intended for earlier P-38J subtypes were lost in a friendly fire incident in early 1944, thereby delaying the introduction of this important modification to theatre units by several months. Curiously, the modification entered production as a kit in late 1943, yet was not incorporated into production aircraft for another six months, until the P-38J-25-LO, although some P-38J-10/15-LO aircraft were retrofitted in the field.

P-38 Lightning Aces of the ETO/MTO - John Stanaway - Google Books this references a victory on June 25 by Col Cy Wilson with an upgraded P-38J-15 after installation of the Dive flaps Mod kit.

I'll have to dig up the references from the library - but the summary is that the second batch of kits arrived in late April and the installation process on the J-15's started in June, and proceeded all the way through September until the 479th converted 100% to Mustangs and the 479th P-38s went to 9th AF as replacements to 367, 370 and 474FG's. The J-25s arrived in September and the L's in October at various 9th AF Lightning Groups. Only the 474th finished ops with the P-38L's

 

[Shortround6]

Once Kelly figured out the problem in 1942 he proposed the solution, but the War Production Board said 'no'.

And something to consider here before too many people cast bricks/stones at the War Production Board.

They built almost 3 times the number of P-38s in 1942 than they did P-47s.
The P-47Bs were rather quickly relegated to use as trainers.
P-47C production didn't exceed P-38 production on a monthly basis until the spring of 1943 with any regularity.
Total number of P-47s produced doesn't pass total number of P-38s until about Oct/Nov of 1943. About the time P-51Bs first start showing up in Europe.
For a good part of 1942-43 is was P-38s or P-39/P-40s with very little else. Delays in P-38 production would have had serious consequences.

By Winter of 1943/44 The Mustang was passing BOTH the P-38 and P-47 by. Perhaps at this time the P-38 could have been "fixed" but then we come up against the cost factor. While a P-38 might NOT have been that much more expensive than a P-47, it certainly was much more expensive than a P-51.

Please remember not only factory lead times but transport times for US aircraft to war zones. It took weeks if not several months to get a fighter plane form the factory door to a combat theater so needs/wants had to be planned for several months in advance and hope there were no big surprises.