F4U F6F P-38 P-47 or P-51 Which plane was best by war's end

[cheddar cheese]

There is NO reference anywhere that YIPPEE was "Hopped up". The plane Tony LeVier used in the ETO for exhibitions was available off the line there. There is no reason to belive the red plane was different. The aircraft Mattern used for the same purposes was also picked out of delivered aircraft supplies. wmaxt

I believe you are quite correct. After Tony LeVeir retired he ran an aviation safety consulting company out of the old Burbank Facilities, my ex-wife worked close to his office. Back then I did some part-time freelance writing for a local aviation newspaper called Aerotech News and Review. I interviewed LeVeir on two occasions and remember him taking about "YIPPEE." It was stock and he, "Fish" Salmon and Milo Burcham all flew that aircraft around at one time or another. I remember him telling me that only thing special about "YIPPEE" was the paint.

Everything I have read so for back up these statements. Does anyone know the planes exact serial number?

 

[FLYBOYJ]

S/N 44-23296 - Yippiee's S/N

 

[FLYBOYJ]

Also that it was carefully polished, the non flush rivets were filed flat, and it had no armor and faked guns.

=S=

Lunatic

While true that YIPPEE had no guns, armor, a fancy polished paint job, I could tell you with deep conviction that no rivets were filed flat! This is a major no-no!

Most of the rivets on the P-38 (and most American planes of the day) were either AN 430 Button Head rivets, AN470 Universal Head rivets, or AN426 100 degree countersunk rivets. Engineers specify the location of these rivets based on strength requirements. While the countersunk rivets are desirable for aerodynamic purposes, the button head and universal head rivets are used where strength is an issue. The AN470 rivet head is a bit streamlined and is used much more than the standard button head, hence it's name. You just can't go replacing an AN470 with an AN426 without weakening the rivet joint, but you could the other way around providing you drill out the entire countersink before driving the universal rivet and go up to 2 sizes larger in diameter, if possible.

Now on the AN426 (flush) rivets, the only thing you could do to the head is a process called "micro shaving." When driving flush rivets, sometimes the rivet doesn't always seat flush in the countersink, especially if the countersink is "dimpled" in lieu of forming a countersink into the skin material. This process is accomplished with a special milling tool called a "micro-shaver," and when using this tool you normally could only shave about .002 from the head of a countersunk rivet to get it flush, however on very large countersunk rivets you could go as deep as .015. This process is carefully monitored so the operator doesn't mill into the adjoining skin.

ANY FILING OR ALTERATION ON THE HEAD OF A BUTTON OR UNIVERSAL HEAD RIVET IS CAUSE FOR REJECTION!

The only thing that possibly could of been done in this situation is an engineering authorization to allow the replacement of the button or universal head rivets with the countersunk rivets, but I believe by doing so would for set up restrictions in some of the performance envelope (G loading) because the structure would not have been as strong.

Overall I doubt this was done during this period because although "YIPPEE" was a great PR and marketing tool, the time to go through the structure and drill out each universal head rivet and replace it with a countersunk rivet would of been immense. To do it on the production line would of been a nightmare because that would of generated dozens of engineering changes for a "one shot deal."

At that time (1944) the commitment was to roll off the assembly lines as many P-38s as possible, not custom modify one aircraft for demo purposes, unless the government wanted it done and was paying for it, and I don't think that was the case for "YIPPEE" 8)

 

[Anonymous]

Also that it was carefully polished, the non flush rivets were filed flat, and it had no armor and faked guns.

which would have had a huge effect on top speed as was shown with that specail Bf-109 that i believe it was alder posted the stats for, and it's rediculous to believe stats from a plane with no armour, heavily polished and had fake guns, as being the same as data a combat ready plane could reach...........

Well, I know it was carfully polished. I think it had fake guns and the pilot armor removed - but I cannot find the article on the YIPPEE to confirm this.

=S=

Lunatic

 

[FLYBOYJ]

Yippee had guns, see the photo. It was at this time when some manufacturing engineers at Lockheed got into polishing aircraft. Yippee was probably amoung the first, the XP-80R is a well know expamle of this.

 

[the lancaster kicks ass]

yes but that picture shows what appear to be guns, it does not show if they're fake or not..........

 

[FLYBOYJ]

I would think that those are real guns. During that time (1944) I don't think anyone wanted to waste time fabricating fake guns and removing them would mean plugging the gun port holes and adding ballast to take up the gun weight for weight and balance purposes. I think the easiest thing to do was to leave them installed. I think those are real guns are installed and possibly deactivated.

 

[Anonymous]

I believe the barrels were cut off and for show only. I saw a photo of the YIPPEE from its tour through Europe with the 431st FS showing booze packed into several compartments of the plane. One compartment was the nose section and it had a caption that said something like "Extra ballast was needed to keep the YIPPEE properly balanced" (in reference to the other photos showing booze packed into the tail boom compartments and behind the pilot).

As for actual balance, the plane would be in balance w/o the rear armor. As for the dificulty in "fabricating" guns, it would be easy to cut barrels, or even use full barrels, and only use the foward part of the mounts to secure them.

 

[FLYBOYJ]

I believe the barrels were cut off and for show only. I saw a photo of the YIPPEE from its tour through Europe with the 431st FS showing booze packed into several compartments of the plane. One compartment was the nose section and it had a caption that said something like "Extra ballast was needed to keep the YIPPEE properly balanced" (in reference to the other photos showing booze packed into the tail boom compartments and behind the pilot).

As for actual balance, the plane would be in balance w/o the rear armor. As for the dificulty in "fabricating" guns, it would be easy to cut barrels, or even use full barrels, and only use the foward part of the mounts to secure them.

Agreed - see the photo. Cutting barrels could be messy (I think the only way you're going to do that is with a cutting torch). Even in that photos of YIPPEE those barrels look pretty intact. You're not going to separate the front part of the gun barrel, its probably one piece, so I think the guns would remain in tact.

Removing armor plate is generally not a problem, the worse thing you would have to do is add ballast forward or aft of the datum line

 

[wmaxt]

I believe the barrels were cut off and for show only. I saw a photo of the YIPPEE from its tour through Europe with the 431st FS showing booze packed into several compartments of the plane. One compartment was the nose section and it had a caption that said something like "Extra ballast was needed to keep the YIPPEE properly balanced" (in reference to the other photos showing booze packed into the tail boom compartments and behind the pilot).

As for actual balance, the plane would be in balance w/o the rear armor. As for the dificulty in "fabricating" guns, it would be easy to cut barrels, or even use full barrels, and only use the foward part of the mounts to secure them.

Agreed - see the photo. Cutting barrels could be messy (I think the only way you're going to do that is with a cutting torch). Even in that photos of YIPPEE those barrels look pretty intact. You're not going to separate the front part of the gun barrel, its probably one piece, so I think the guns would remain in tact.

Removing armor plate is generally not a problem, the worse thing you would have to do is add ballast forward or aft of the datum line

Ballast was added in the Droop Snoots and any P-38 that did not have Guns or cameras to maintain the center of gravity.

wmaxt

 

[wmaxt]

You know guy's I agree 1 set of info is suspect to a point. Manufactures data can be suspect, even if it is published by a respected author.

To this point the arguments have been derogatory, inuendo, supposition, antagonistic and a lot of I"ve never seen this data so it has to be bad. Let's look at what we have so far.

1) I've never seen this data - So all that means is that you've never seen it before - not that it doesn't exist or that it isn't good.
2) I've never seen this data before and it's suspect as is manufactururs data to sell the aircraft.
a) It's been used here before, at least the chart on roll rate. Do we only use data we like?
b) Lockheed did NOT have to sell the P-38 in mid '44 they already had a contract for as many P-38s they could build. The P-38 was in demand everywhere but the 8th airforce. The war was expected to last another 2+ years at this point in mid '44, and a second source was in the works at this time (Consolidated which built 113 L models).
c) This data was for internal use only.
d) The military was also known for biased tests of aircraft it liked/disliked.
3) The demonstration aircraft were off the line - why would they build special aircraft for their testing?
4) Why is 125hp extra so hard to accept from a new series of engine that can handle a little more boost. Remember the K model, with High Output engines of the series (-15) the P-38G used, 1,875hp for max projected speeds of 450+ and a climb rate of 5,000+ feet initial? the data for the L is in the middle of the J/K data where it should be.
5) The L model should be better than the J why would you send out an airplane with less performance than that of its predessor? You wouldn't, not into combat!
6) A lot of new data has come out since the '80s, mostly through the freedom of information act. Just because this comes from Lockheed makes it automaticaly wrong and if so by how much? Maybe they are high but again by how much? Using the standard 414mph as the ultimate top speed of the P-38L is also crap especiale since it is at METO power!
7) I've already shown the numbers are reasonable. To discount them because we haven't seen them before is rediculous. Though I agree that until they are verified they need to be taken with a grain of salt.

The biggest question I have at this point is why is it so important to some to disscount this data as out of hand? It is certainly not to give the P-38 its true performance capabilities.

wmaxt

 

[Anonymous]

You know guy's I agree 1 set of info is suspect to a point. Manufactures data can be suspect, even if it is published by a respected author.

To this point the arguments have been derogatory, inuendo, supposition, antagonistic and a lot of I"ve never seen this data so it has to be bad. Let's look at what we have so far.

1) I've never seen this data - So all that means is that you've never seen it before - not that it doesn't exist or that it isn't good.

Agreed, that alone is not enough to discount it.

2) I've never seen this data before and it's suspect as is manufactururs data to sell the aircraft.
a) It's been used here before, at least the chart on roll rate. Do we only use data we like?

The roll rate chart matches other data reasonably, and therefore is more easily accepted.

b) Lockheed did NOT have to sell the P-38 in mid '44 they already had a contract for as many P-38s they could build. The P-38 was in demand everywhere but the 8th airforce. The war was expected to last another 2+ years at this point in mid '44, and a second source was in the works at this time(Consolidated which built 113 L models).
c) This data was for internal use only.
d) The military was also known for biased tests of aircraft it liked/disliked.

"d" is only slightly true and not in the context of altering the test data.

"c" I agree with, the problem is we do not no the full conditions of the test nor do we have the specifics of the test or any comment that the data is based on an actual flight test. Compilation data is often much more favorable than a standard test where everything but occassionaly the service cieling data is collected in a single run under specified conditions.

Finally, there is also the argument of company pride. Lockheed is a very proud company (rightfully so) and the desire to make its famous P-38 stack up against other WWII fighters as well as possible in a comparison would be high. The fact that this data was released so long after the war, but before the FoIA laws required it, with no real verfiable documentation, tends to cast suspicion on why it was released and thus the validity of the data.

3) The demonstration aircraft were off the line - why would they build special aircraft for their testing?

Lots of "special aircraft" were configured for testing - the P-38K is a case in point. Surely many minor variations were tried on test aircraft. But... this was not a test aircraft, it was a demonstration aircraft. The desire to wow the audience, especially pilots, would have been significant.

4) Why is 125hp extra so hard to accept from a new series of engine that can handle a little more boost. Remember the K model, with High Output engines of the series (-15) the P-38G used, 1,875hp for max projected speeds of 450+ and a climb rate of 5,000+ feet initial? the data for the L is in the middle of the J/K data where it should be.

It's not. What is questionable is that this is enough added HP given the weight difference to justify a decrease in the time to climb to 20k of 18%.

Also, as I said before, I believe the YIPPEE was a J series plane with L series engines. Some sources list it as having been an L for this reason. Quite a few sources indicate that the late model J series was the best performing of the service P-38's.

5) The L model should be better than the J why would you send out an airplane with less performance than that of its predessor? You wouldn't, not into combat!

Increase fuel supply and thus range, but also weight, mean less performance. The P-51B performed better in most respects than the P-51D, so this argument is obviously invalid.

6) A lot of new data has come out since the '80s, mostly through the freedom of information act. Just because this comes from Lockheed makes it automaticaly wrong and if so by how much? Maybe they are high but again by how much? Using the standard 414mph as the ultimate top speed of the P-38L is also crap especiale since it is at METO power!

I agree, the P-38L was faster than 414 mph, all I'm saying is that we simply don't have any good data concerning its true performance.

7) I've already shown the numbers are reasonable. To discount them because we haven't seen them before is rediculous. Though I agree that until they are verified they need to be taken with a grain of salt.

The biggest question I have at this point is why is it so important to some to disscount this data as out of hand? It is certainly not to give the P-38 its true performance capabilities.

wmaxt

The numbers are reasonable but high. As I've said before, I suspect they reflect a J series plane with the L series engines (or J series engines modified to L series specs) that was polished up and carefully tuned for improved demonstration performance. But we just don't know for sure.

In general, I'm just opposed to taking company figures as fact. We do this all the time for many planes - especially Axis planes. However I don't think such figures reflect actual combat performance. I'm opposed to taking such data, or any data that is not obtained from actual flight tests of aircraft under known conditions, as "truth". To accept the Lockheed data, as presented, would set a bad precident.

=S=

Lunatic

 

[FLYBOYJ]

Ballast was added in the Droop Snoots and any P-38 that did not have Guns or cameras to maintain the center of gravity. wmaxt

This is common on any WW2 or post war civilian operated combat flighter aircraft when removing armament and any armor plating.

Post war jets (Migs, F-86 etc.) and helicopters are REAL critical in this area!

 

[wmaxt]

Does anyone know where to go to gain access to information that would back this data up either for or against?

RG, the military aircraft tests were biased, that was my point and it is still true. You are the one pushing the "Modified Test Aircraft".

The graph on roll rates is acceptabe bucause it matches other released data? The graphs accompaning it also have data that matches other released data. Are we back to choosing what we like? All of these points only add to the likely hood that this info is correct.

As to the K, yes new modifications and improvements were tried - I notice that it is designated that way too.

The P-51D was essentialy of the same performance catagory as the B model, a lateral move not a downward one. The extra visability was considered worth the slight loss of speed esp with the H model on the horizon. My comment on not sending less capable aircraft still stands.

As for releasing this data before the FoIA, it was almost 50 years since production endded, and what 10 P-38s were still flying? Are you infering that Lockheed was trying to sell more P-38s.

My biggest issue here is that in order to debunk this info (that is probably true) the only recourse is to accuse Lockheed of cheating. The only indication of cheating is that some people don't like the information as presented.

A funny part of this is that YIPPEE was a demonstration aircraft not a test aircraft or racer and every thing it did, could and was done by any P-38 chosen (in military demonstrations the plane used was aquired from the nearest depot in reguards to the demonstration point, and in some cases off the line). To make it slicker would actually be a hinderance in any maneuver requiring a dive as the speed increase is, in most cases, a problem near the ground.

I for one would really like to know the truth. I know I'm not the only person that thinks this data is close if not completely valid but confirmation would be appreciated either way.

wmaxt

 

[Anonymous]

Does anyone know where to go to gain access to information that would back this data up either for or against?

If you can gather enough info about the test - where it was done, when it was done, who did it, name of the test, etc... then you can do an FoIA inquiry, it's pretty cheap. The less info you have the more expensive the research request, as they charge by the hour after the initial fee is used up, and the odds of getting back anything of value go way down.

RG, the military aircraft tests were biased, that was my point and it is still true. You are the one pushing the "Modified Test Aircraft".

Explain how. USN tests were very strait forward. Usually an instructor and 3 fresh flight school grads took up for fresh planes and conducted the tests according to the specified test methods. Full internal fuel was loaded, climb tests were conducted, speed tests were conducted, and finally if fuel provided altitude tests might be conducted. That was pretty much it.

The P-51D was essentialy of the same performance catagory as the B model, a lateral move not a downward one. The extra visability was considered worth the slight loss of speed esp with the H model on the horizon. My comment on not sending less capable aircraft still stands.

Climb to 20k took about 1 minute longer. Top speed was down by almost 10 mph. Turning capability was inferior. Vision, firepower, and range were increased.

With the P-38L vs. the late J, the range was increased, so the performance may have dropped slightly. Why would this not be possible? If they accepted a slight reduction in combat performance in the P-51D vs. the P-51B for an increase in range, why not for the P-38L vs. the P-38J?

As for releasing this data before the FoIA, it was almost 50 years and what 10 P-38s were still flying? Are you infering that Lockheed was trying to sell more P-38s.

Actually, IIRC this data came out in 1972, about 27 years after the end of WWII.

No, I'm implying that Lockheed is a proud company and one of its people may have seen the data being released as not giving the P-38 it's due and decided to rectify this. Not everything is about money.

My biggest issue here is that in order to debunk this info (that could very well be true) the only recourse is to accuse Lockheed of cheating. The only indication of cheating is that some people don't like the information as presented. The funny part is that YIPPEE was a demonstration aircraft not a test aircraft or racer and every thing it did, could and was done by any P-38 chosen (in military demonstrations the plane used was aquired from the nearest depot in reguards to the demonstration point). To make it slicker would actually be a hinderance in any maneuver requiring a dive as the speed increase is, in most cases, a problem near the ground.

Cheating? Not quite, simply presenting the most favorable information without presenting the full information so it could be put in proper context.

As for the dive's, the YIPPEE was a late mode J, it had dive recovery flaps, so that's not a problem.

I for one would really like to know the truth. I know I'm not the only person that thinks this data is close if not completely valid but confirmation would be appreciated either way.

It's time the P-38 took its rightfull place in the hierachy of WWII piston aircraft.

wmaxt

Well, in general I agree. I believe the P-38's performance was better than that generally reported. However, I simply don't like the idea of setting a precident of always using the best data available no matter the source, and no matter the number of unknowns about the conditions of the test.

What we really need to do is try to get a hold of a primary source document that confirms the performance claims from Lockheed.Unfortunately, Lockheed does not answer questions about is history. So the only sources will be the military or secondary sources.

=S=

Lunatic

 

[wmaxt]

YIPPEE was a J-10 without the flaps (though they could have been retrofitted).
Also, most demonstrations are at altitudes below 10,000ft so they can be seen easily, the dive flap requirement in negligable. This was not a test aircraft.

Every account comparing the J to the L is that it was a Significantly better aircraft in every way. Until we get data that matches this we don't have the correct data!

So are you suggesting the we continue to use data that is off by 20+ mph and climb data that's off by 1 to 2 minuets to 20k? That's worse than using information from a respected Author.

I wonder if there's any way to contact Warren Bodie, who probably has the information we need? I belive he was born in the '20s so time is running out if it hasn't already.

wmaxt

 

[FLYBOYJ]

Warren Bodie would be the best guy to contact. With the Burbank facilities closed and demolished, I know much of the archived stuff (old drawings, engineering papers etc.) are gone. There used to be an excellent library at the Burbank facilities, in the early 80s I spent hours in there looking over all kinds of papers, company periodicals and engineering reports. Even then (1982), much of the old brass was gone or getting ready to retire and the custodians of the library really didn't appreciate the value in saving much of this archived information.

I believe if any significant archived stuff exists, it would be either at the Lockheed Martin Georgia facilities or the Skunkworks facility in Palmdale CA. If someone has an "in" with Brodie, he might know who to talk to today and find out where you could get some is this P-38 performance information.

Keep this in mind; In 1990 the Chino Air Museum requested some P-38 data for repairs to their museum's P-38, the brass at Burbank denied this request. When I heard about this I queried my boss and volunteered to help. He told me that even if I was doing this on my time, there was still an "outlay of overhead" and the company couldn't afford to spend overhead on "freebie"projects! Several months later close to 6,000 people were layed-off (me being one of them). As RG stated, you're going to get little or no help from Lockheed unless you're lucky enough to have someone like Warren Brodie who might know who to direct these requests to!

 

[Anonymous]

Every account comparing the J to the L is that it was a Significantly better aircraft in every way. Until we get data that matches this we don't have the correct data!

I've read that the late J series was the best P-38 version, and that some of the very late J series planes had the same engine power coupled with the dive brakes, power ailerons, but without the extra fuel tanks and thus weight of the L series.

So are you suggesting the we continue to use data that is off by 20+ mph and climb data that's off by 1 to 2 minuets to 20k? That's worse than using information from a respected Author.

wmaxt

No. I believe both sets of data should be considered. What we do have is known military test results for the P-38J, and company tests for the L.

=S=

Lunatic

 

[FLYBOYJ]

Food for thought; the US military, 60 years ago or today will not put out a "TO" (Technical Order) which is essentially the pilot's manual (and all other flight and maintenance manuals) unless what is in that book matches exactly what the aircraft is advertised to do. The data in the pilot's manual should be the basis of any analysis. If any test reports exist showing higher over-all performance, so be it, but be rest assured, as far as the USAAF was concerned, what was in the pilot's manual is gospel - period!

 

[Anonymous]

Food for thought; the US military, 60 years ago or today will not put out a "TO" (Technical Order) which is essentially the pilot's manual (and all other flight and maintenance manuals) unless what is in that book matches exactly what the aircraft is advertised to do. The data in the pilot's manual should be the basis of any analysis. If any test reports exist showing higher over-all performance, so be it, but be rest assured, as far as the USAAF was concerned, what was in the pilot's manual is gospel - period!

Perhaps higher performance levels were not issued, but TO's were issued restricting performance to something below the advertised levels. I know there were several such TO's w.r.t. the P-39, for example.

The F4U-4 pilots manual lists 4.9 minutes to 20k (based on 1946 flight tests), where Vought lists 5 minutes to 20K (based on 1944 flight tests). Not sure what's up there???