drgondog
Major
Great summary Shortround
The P-38J and L in the European theater.
Ad: This forum contains affiliate links to products on Amazon and eBay. More information in Terms and rules
OldSkeptic
Senior Airman
- 509
- May 17, 2010
Mitchell totally disagreed with the British and US 'boffins', hence he went for the thinnest wing he could get away with. So he was a lot smarter than they were. He was right, they were wrong. He also had a superb aerodynamicist (Shenstone) who who had spent a lot of time Germany examining their work. Mitchell being a great team leader amd manager listened to him.
One interesting part of the design is the small tailplane compared to other designs (inc the Mustang). This was because the air from the wings and underbelly is directed towards the tailplane by careful shaping. This, of course, helped lower total drag.
OldSkeptic
Senior Airman
- 509
- May 17, 2010
Well Willy and R.J didn't make that mistake....and they started earlier...so..it was a mistake. It had the worst mach limit of any significant fighter in WW2. Even the P-47 was better. I think even the Hurricane was better (I'd have to check, this is from memory) and that was just a converted Fury biplane.
And the only way to fix it would have been by a Typhoon to Tempest like conversion with a whole a new wing.
So P-38 lovers, it just wasn't a very good plane. Complex and expensive to build, hard to maintain, complex and hard to fly. Over and above the miserable mach limit it was as buggy as all heck. I'm amazed the design got accepted by the US.
drgondog
Major
Then your powers of perception, had you been placed in the decision making process in 1938 would have been flawed. When the P-38 prototype first flew its performance and potential were beyond any other aircraft the US military had seen to date and far exceeded expectations. The aerodynamic and performance analysis were completed in April 1937.
For your assertions that Kelly didn't get it right in contrast to "Willy and RJ" with respect to selecting a thinner wing because of foreknowledge of compressibility effect on aerodynamic center movement and associated CMac change to force Mach Tuck you would of course have eveidence that they knew about the phenomena well in advance of the rest of the Aero community... and that their prototypes achieved even near the performance demonstrated by the XP-38?
If the prototype had not been crashed by Kelsey in feb 1939, delaying any formal flight testing until Feb 1941 with the YP-38.. the issue would have been discovered and solved presumably tow years earlier and the fix(es) would have been applied by December 1941 instead of December 1943.
What RJ and Willy succeeded in designing were two of the best dual purpose fighters of the war. What Kelly Johnson designed became the best one of very few 'all purpose' fighters of the war, one that had a strategic footprint an order of magnitude over the Spitfire and Bf 109. The Mosquito, the F4U and perhaps the Mustang come to mind for different reasons.
I have reminded the passionate supporters of P-38J/L that it didn't succeed to its potential in the ETO because of a combination of factors, including political, that worked against achieving greater success in the Battle of Germany.
The 'fat' airfoil contributed to the problems with compressibility but the CDo of the P-38 was a little more than the Spit and greatly below the 109 pointing to Excellent aerodynamics for such a very large fighter, with very great range and very high speed, very high climb rate and very high ceiling.
Go back and compare the performance of the prototypes, then compare the design changes and engine upgrades required to match the prototype P-38 performance. Kelly Johnson broke a lot of new ground to make an unknown company a future giant in the Industry.
I worked as a co-op for him for a short time on an SR-71 computer modeling project and got to know him. I suspect without proof that neither "RJ or Willy" could have acquired, trained and managed a successful project as the SR-71 in which virtually ALL the design issues were 'Unknown' and breaking new ground, ranging from strength/weight requirements of titanium because of the temps and strengths required (as well as driving innovation in titanium machining), wing airfoils that changed in flight due to differential temperatures between top and bottom surfaces at Mach 3, variable geometry inlets to accommodate a 2000 mph range of shock wave geometry, etc, etc.
So yes, I suppose I do take deep offense at such an offhand derogatory remark against one of the Giants of the airframe design business.
Oldskeptic, you would have to be one helluva aerodynamicist with a track record of solving unknown issues beforehand to make a Valid comment regarding 'he shouldda known'.
Last edited:
FLYBOYJ
"THE GREAT GAZOO"
And I guess that's your own arm chair opinion? Have you ever flown a twin engine aircraft and analyzed the P-38's cockpit to really make a viable and intelligent assessment of this?
I know quite a few folks who flew both the Mustang and P-38 and loved both aircraft equally and at least one who preferred the P-38 over the P-51. I suppose the pilots of the 1,800 downed Japanese aircraft that fell under the P-38's might also agree with you.
When solution did Kelly Johnson propose?
FLYBOYJ
"THE GREAT GAZOO"
"Lockheed could not have anticipated this problem. In fact, Kelly Johnson probably knew as much about compressibility as anyone in the world at that time. Unfortunately, in 1937 no one could predict with any degree of certainty the effect of compressibility on aircraft control."
The P-38 Lightning
The P-38 Lightning
When did folks become aware of the problem?
From Wikipedia:
During a test flight in May 1941, USAAC Major Signa Gilkey managed to stay with a YP-38 in a compressibility lockup, riding it out until he recovered gradually using elevator trim.[19] Lockheed engineers were very concerned at this limitation but first had to concentrate on filling the current order of aircraft.
From Wikipedia:
During a test flight in May 1941, USAAC Major Signa Gilkey managed to stay with a YP-38 in a compressibility lockup, riding it out until he recovered gradually using elevator trim.[19] Lockheed engineers were very concerned at this limitation but first had to concentrate on filling the current order of aircraft.
And regarding the loss of the prototype on 11 February 1939:
Again from Wikipedia:
Lockheed's Chief test pilot Tony LeVier angrily characterized the accident as an unnecessary publicity stunt,[27] but according to Kelsey the loss of the prototype, instead of hampering the program, sped the process by cutting short the initial test series.[28] The success of the aircraft design contributed to Kelsey's promotion to captain in May 1939.
Again from Wikipedia:
Lockheed's Chief test pilot Tony LeVier angrily characterized the accident as an unnecessary publicity stunt,[27] but according to Kelsey the loss of the prototype, instead of hampering the program, sped the process by cutting short the initial test series.[28] The success of the aircraft design contributed to Kelsey's promotion to captain in May 1939.
About the statement that Hurricane was a converted Fury biplane - joke, right?
Silly Americans thought that a 400 mph aircraft, with decent climb and armament, and great range was an useful fighter. Instead to stick with P-40s; really silly.
Let's see how thick an airfoil, but for a twin-engined fighter, did Willy thought it would be okay. For the Bf-110, the thickness to chord ratio was 18.5% (root) and 11% at tip. Please note the 'Flugel' part in the attached table, where the wing profile was '2 R1 18.5' as at the root, and '2 R1 11' at tip. The Bf-109 was using the '2 R1 14.2' profile at the root, for example - ie. 14.2% thickness to chord ratio. Perhaps the Bf-110 would've been more competitive had Willy decided to go with 16% thick wing?
Supermarine design team thought that such a thick wing would be okay for the proposed 460 mph twin-engined fighter, Type 327 (picture kindly posted by wuzak in a related thread):
It is in the 18-20% TtC (root) range?
As for the damning with a faint praise ("Even the P-47 was better."), here is the dive limit table for the P-47N, that used same wing profile as the earlier P-47s:
drgondog
Major
What Kelsey can state that is true is the migration from Prototype to limited production ore for YP-13 WAS accelerated because of the crash a.) because Lockheed was not well off financially, b.) the initial performance results blew every other design away, and c.) getting Lockheed started on building more P-38s to progress with evaluation was to give them a contract.
What he didn't state is that Arnold saw the potential, saw what was happening in Europe, looked around at the existing airframes for comparison, and would have been an idiot to not proceed even if the prototype was not lost.
Losing the prototype cost the AAF two years of evaluation and performance enhancement recommendations.
The biggest problem was that Lockheed 'hand built' the p-38 and there was no money to invest in tooling and fixtures until an order was received.. so Lockheed started from scratch in 1939 to building a producable airframe.
What he didn't state is that Arnold saw the potential, saw what was happening in Europe, looked around at the existing airframes for comparison, and would have been an idiot to not proceed even if the prototype was not lost.
Losing the prototype cost the AAF two years of evaluation and performance enhancement recommendations.
The biggest problem was that Lockheed 'hand built' the p-38 and there was no money to invest in tooling and fixtures until an order was received.. so Lockheed started from scratch in 1939 to building a producable airframe.
Greg, you are in good company - it seems that many in the US had difficulty understanding this during the war.
From https://en.wikipedia.org/wiki/Lockheed_P-38_Lightning#European_theater:
Fleet Air Arm Captain and test pilot Eric Brown recalled: "We had found out that the Bf 109 and the Fw 190 could fight up to a Mach of 0.75, three-quarters the speed of sound. We checked the Lightning and it couldn't fly in combat faster than 0.68. So it was useless. We told Doolittle that all it was good for was photo-reconnaissance and had to be withdrawn from escort duties. And the funny thing is that the Americans had great difficulty understanding this because the Lightning had the two top aces in the Far East."
drgondog
Major
Not to take anything from either Bong or McGuire or any ace that flew F4U, F6F, P-38 or P-47 but those aircraft ALL were faster and performed better in airspeed higher than 300 mph against all the Japanese fighters likely be seen until 1944-1945. McGuire was killed because he was overconfident and apparently broke the golden rule of don't pick a fight low and slow - and had his external tanks on - to compound the problem.
The Lightning in Europe had no such clear advantages, were forced to fly at bomber altitudes where the pre-dive flap, pre-intercooler fix, P-38s were at a tactical disadvantage against adversaries that could nearly escape at will but had performance so excellent that once it had the advantage of a six O'clock position on the P-38, IT couldn't escape..
The PTO was Entirely Different. In the MTO the conditions were somewhat similar in that the bombers bomber lower and many escort missions were for medium bombers as well - so the mechanical problems were never as severe for MTO P-38s and at medium altitudes it matched up very well against the 190 and 109s.
It (ETO vs PTO) was further compounded by the fact that the Japanese were NEVER ordered to evade and it wasn't in their make up to flee when they could fight. I have not yet seen the same orders from Goering to MTO squadrons stipulating that the LW fighters avoid escorts like Defense of the Reich.
So, the Germans with at least as good a maneuver fighter, that could out dive to escape or shoot down the P-38 had more encounters with the P-38 in the MTO... and it was always so easy to see..
Do you understand that while the PTO conditions were perfect for the P-38 as an escort and air superiority fighter, it labored in high altitude, cold ETO conditions - until the J model?
The Lightning in Europe had no such clear advantages, were forced to fly at bomber altitudes where the pre-dive flap, pre-intercooler fix, P-38s were at a tactical disadvantage against adversaries that could nearly escape at will but had performance so excellent that once it had the advantage of a six O'clock position on the P-38, IT couldn't escape..
The PTO was Entirely Different. In the MTO the conditions were somewhat similar in that the bombers bomber lower and many escort missions were for medium bombers as well - so the mechanical problems were never as severe for MTO P-38s and at medium altitudes it matched up very well against the 190 and 109s.
It (ETO vs PTO) was further compounded by the fact that the Japanese were NEVER ordered to evade and it wasn't in their make up to flee when they could fight. I have not yet seen the same orders from Goering to MTO squadrons stipulating that the LW fighters avoid escorts like Defense of the Reich.
So, the Germans with at least as good a maneuver fighter, that could out dive to escape or shoot down the P-38 had more encounters with the P-38 in the MTO... and it was always so easy to see..
Do you understand that while the PTO conditions were perfect for the P-38 as an escort and air superiority fighter, it labored in high altitude, cold ETO conditions - until the J model?
Last edited:
GregP
Major
Hi Joe,
I agree. What I said above was to not let the speed get to the problem area. That limits the dive to non-dangerous territory and gives the P-38 a good zoom climb back to the bomber's altitude at the same time. I didn't to dive or not dive with the enemy, I said not to dive with them until the problem occourred. That means breaking it off before cirtical mach numberarrives, which also and coincidentally keeps the P-38 near the bombers. Their job was not to kill German fighters, if they were acting as escorts, their job was to protect the bombers.
So I DO agree that the P-38 should not be dived to critical mach, but don;t agree it was inconsistent with protecting the bombers at teh same time. If you can believe all the hype, the Tuskeegee Airmen employed those SAME tactics quite successfully ... stick with the bombers. It worked for them. Why not for the P-38's?
Hi gjs,
I have NO difficulty comprehending the issue. I don;t think it is all that big a limit unless youa re hell-bent on chasing the enemy aircraft down. If youARE< then yes, it is a major stumbling block. If you are there to protect the bombers instead of merely increasing your personal score, it isn't. Sorry, I don;t buy it at all ... unless the need is really to chase the enemy down and kill him. It wasn't the main mission.
You could argue it backwards. If top speed was paramount, why is the Hellcat the most successful aircraft at air-to-air combat uin the US arsenal of WWII? It shot down more than the P-51 in the air but comes in a number two if you add in ground kills. Rather unusual if speed was the main factor, don't you think?
I don;t feel maximum speed was all that important, and neither was a slower dive speed ... unless you were in a fight for a kill. If thaht was the case, you were probably ignoring your primary mission in the first place.
I agree. What I said above was to not let the speed get to the problem area. That limits the dive to non-dangerous territory and gives the P-38 a good zoom climb back to the bomber's altitude at the same time. I didn't to dive or not dive with the enemy, I said not to dive with them until the problem occourred. That means breaking it off before cirtical mach numberarrives, which also and coincidentally keeps the P-38 near the bombers. Their job was not to kill German fighters, if they were acting as escorts, their job was to protect the bombers.
So I DO agree that the P-38 should not be dived to critical mach, but don;t agree it was inconsistent with protecting the bombers at teh same time. If you can believe all the hype, the Tuskeegee Airmen employed those SAME tactics quite successfully ... stick with the bombers. It worked for them. Why not for the P-38's?
Hi gjs,
I have NO difficulty comprehending the issue. I don;t think it is all that big a limit unless youa re hell-bent on chasing the enemy aircraft down. If youARE< then yes, it is a major stumbling block. If you are there to protect the bombers instead of merely increasing your personal score, it isn't. Sorry, I don;t buy it at all ... unless the need is really to chase the enemy down and kill him. It wasn't the main mission.
You could argue it backwards. If top speed was paramount, why is the Hellcat the most successful aircraft at air-to-air combat uin the US arsenal of WWII? It shot down more than the P-51 in the air but comes in a number two if you add in ground kills. Rather unusual if speed was the main factor, don't you think?
I don;t feel maximum speed was all that important, and neither was a slower dive speed ... unless you were in a fight for a kill. If thaht was the case, you were probably ignoring your primary mission in the first place.
Last edited:
drgondog
Major
Please research Doolittle's biography "I could never be so lucky again", Eaker's biography "Air Force Spoken Here", Arnold's "Global mission" plus the collaboration of Arnold, Spaatz, Eaker and Andrews resulting in Copp's two volume set "Forged in Fire" and "A Few Great Captains".
I'm not nitpicking. If you want the background behind the situation in 1943, particularly the discussions at Casablanca - which Churchill described in Grand Alliance - all the way through to November 1943 when Eaker was promoted to run Med AF and Spaatz brought in to replace him plus pick up the 9th AF, then you need to understand all the deliberations and the command decisions.
By the folks that made them.
Last edited:
OldSkeptic
Senior Airman
- 509
- May 17, 2010
Their job was to kill the Luftwaffe, the bombers were really just bait to bring them up. That was the great innovation by the great (and always underestimated) Doolittle.
He realised that just chasing them away was pointless, the Luftwaffe pilots lived to fight another day and that would let it steadily build up strength, eventually to level that could overwhelm any escorts.
They had to be killed, chased and killed, setting in train the attrition on pilots and machines that finally killed the organisation.
Take a 'thought experiment'. Say the Luftwaffe had managed to build up to (say) 2,000 fighters over Germany...that would have ended the USAAF's daylight campaign, real fast.
At that sort of numbers they could have (a) intercepted the escorts as they headed towards rendezvousing with the bombers, forcing them to drop tanks and taking them out of the game, (b) staged multi pronged attacks, with enough to draw off the escorts and still enough left to hammer the bombers.
The USAAF then would have had to have built up far greater numbers of escort fighters to counter that (with escorts escorting other escorts at various points).
Mac knows best...
or not
From Wikipedia:
In July 1942, as a Brigadier General – he had been promoted by two grades on the day after the Tokyo attack, by-passing the rank of full colonel – Doolittle was assigned to the nascent Eighth Air Force. This followed the rejection of his name by General Douglas MacArthur as commander of the Southwest Pacific Area in place of General George Brett. Major General Frank Andrews first turned down the position, and, offered a choice between George Kenney and Doolittle, MacArthur chose Kenney.[5]
drgondog
Major
George Kenney, Frank Andrews and Jimmy Doolittle were all superb leaders.
Greg,
If you're still hot heavy about the P-38, there's a thread about P-38 erection you might like:
http://www.ww2aircraft.net/forum/ot...ech-/38-erection-maintenance-pages-20445.html
OldSkeptic
Senior Airman
- 509
- May 17, 2010
In all this the 8th and BC were aided by the poor tactics of the Luftwaffe defending Germany. I shake my head at times how just badly they did. Both of them were very lucky that the Luftwaffe didn't have a Keith Park.
Though the sheer resources that the US could bring would have meant air superiority being achieved in the end (by day), the Luftwaffe could have extracted a far higher price and dragged it out much longer than they did. The key was to 'strip off' (Park's term) the escorts. Given the long distances, the escorts (when they moved to the phased tactics) were terribly vulnerable to being bounced as they headed for their rendezvous with the bombers. Slow (most economical cruise), full of fuel and drop tanks. Ideal for bounces from high level 109s to disrupt them and make them drop their tanks. A squadron or two at the right places, with the proper ground control could have caused havoc amongst them.
The same applied even if they stayed with the bombers (wasting fuel doing so and reducing their range) right from the beginning (the pre-phased approach). Just a few squadrons, in the right place with the right tactics would have stripped them off the bombers.
Look at what Park achieved in doing that, with little warning, with the 109s right with the bombers and with, at times, escort/bomber ratios of 3:1 (even 5:1). Stripping them off and getting other planes right into the bombers.
Fortunately the culture of the Luftwaffe was against that sort of careful tactical control. Galland being a classic example of being an idiot in this, repeating Badar's mistakes in wanting to swan all over the sky with minimal ground control and creating large, unwieldy and easily disrupted 'big wings', which was amazing because he had so much fun shooting down such clumsy things over France. Just shows a great fighter ace often does not make a good tactician.
In the case of BC, I really think that with better tactics the Luftwaffe could have killed them by early '44 at the latest. They very nearly did as it was.
The key issue was getting large numbers of nightfighters into the bomber stream, when they did BC's losses were horrendous and unsustainable. BC's job was to avoid/misdirect/etc them.
There were two places where the Luftwaffe knew exactly where the bomber streams were. When they took off and formed up and when they landed. A more aggressive campaign, catching them as they formed up over England and heading out and then staying with them, including getting them when they returned would have taken BC out of the game pretty quickly. And there wouldn't have been much the British could have done about it unless they totally changed their 'counterforce' doctrine and totally unleashed their own (and better) nightfighters as intruders in massive numbers, pre-raids to clear the way (even then it would have been difficult). BC being BC I have great confidence that they would have already lost and given up before they managed to work that one out.
Though the sheer resources that the US could bring would have meant air superiority being achieved in the end (by day), the Luftwaffe could have extracted a far higher price and dragged it out much longer than they did. The key was to 'strip off' (Park's term) the escorts. Given the long distances, the escorts (when they moved to the phased tactics) were terribly vulnerable to being bounced as they headed for their rendezvous with the bombers. Slow (most economical cruise), full of fuel and drop tanks. Ideal for bounces from high level 109s to disrupt them and make them drop their tanks. A squadron or two at the right places, with the proper ground control could have caused havoc amongst them.
The same applied even if they stayed with the bombers (wasting fuel doing so and reducing their range) right from the beginning (the pre-phased approach). Just a few squadrons, in the right place with the right tactics would have stripped them off the bombers.
Look at what Park achieved in doing that, with little warning, with the 109s right with the bombers and with, at times, escort/bomber ratios of 3:1 (even 5:1). Stripping them off and getting other planes right into the bombers.
Fortunately the culture of the Luftwaffe was against that sort of careful tactical control. Galland being a classic example of being an idiot in this, repeating Badar's mistakes in wanting to swan all over the sky with minimal ground control and creating large, unwieldy and easily disrupted 'big wings', which was amazing because he had so much fun shooting down such clumsy things over France. Just shows a great fighter ace often does not make a good tactician.
In the case of BC, I really think that with better tactics the Luftwaffe could have killed them by early '44 at the latest. They very nearly did as it was.
The key issue was getting large numbers of nightfighters into the bomber stream, when they did BC's losses were horrendous and unsustainable. BC's job was to avoid/misdirect/etc them.
There were two places where the Luftwaffe knew exactly where the bomber streams were. When they took off and formed up and when they landed. A more aggressive campaign, catching them as they formed up over England and heading out and then staying with them, including getting them when they returned would have taken BC out of the game pretty quickly. And there wouldn't have been much the British could have done about it unless they totally changed their 'counterforce' doctrine and totally unleashed their own (and better) nightfighters as intruders in massive numbers, pre-raids to clear the way (even then it would have been difficult). BC being BC I have great confidence that they would have already lost and given up before they managed to work that one out.
Users who are viewing this thread
Similar threads
