P-38 vs P-51: Full internal fuel dogfighting

[GregP]

You could be right. But, there were no P-51Hs in combat in WWII, unlike the thousands of P-38s that did see combat. I was speaking of wartime birds.

In point of fact, I have never seen comparisons of post-war birds that were in the last generation of big pistons, like the Sea Fury, P-51H, Seafang. I have also never seen an evaluation of the last German planes like the Ta-152 (and it makes a difference whether the Ta is a C or an H) versus any other aircraft. I have seen only one opinion on the Lavochkin La-9, and that was from Ray Hana, who liked it VERY much and said the power and acceleration was second to no other warbird he had flown to date.

It would be great to see comparisons of the last of the big pistons. But if they haven't surfaced to date, I seriously doubt we're going to get to read them due to the fact that any survivors, if they are flyable, are very carewfully taken care of and would not be available for "flogging" in a performance comparison test. Should they actually BE available, they almost 100% are NOT in military stock configuration and are quite a bit lighter than combat-ready airplanes.

But I'd still love to find comparisons ...

I'll make a statement that I can't prove. I'd assume the last of the big piston fighters are probably the best of the breed in most categories. I have never sought to prove that, but it makes sense that new models would be improvements. If not, why build a new model?

 

[parsifal]

would either type gain advantage as the altitude increases. ive played wargames that suggest the P-51 was superior in horizontal manouver over the p-38. im curious if these rough summaries contained in games have any basis at all.

Games are about as close as ill ever get to the real thing.

 

[GregP]

I have my doubts that a flight simulator not specifically-designed for realism faithfully replicates the flight characteristics of a real aircraft. I have flown a T-38 simulator, but never a real T-38. Perhaps Biff could tell us if the T-38 and the T-38 simulator, or F-15 sim/plane are faithful simulations.

I watched a programmer one day change the flight chrracteristics in a sim, and he did it because he wanted it to fly better, not because it was "real." I have NO idea if the commercial game sims are good aerodynamic replications or not, but one Cessna 172 sim I used flew quite similarly to the real thing except for being easier to fly and having unlimited fuel and oil. When I say easier to fly, I mean I did some really bad landings on purpose and got away with it, apparently without damage.

The C-182 was also not easy to damage, even when landing nose gear first, unlike the real airplane.

I never DID take one to Sedona, Arizona on a warm summer day and see if it flew like the ones I used to land there, but I really doubt it.

On your question above, both had good altitude capability, and I'm not sure which one would retain better feel at, say, 25,000 feet. The P-38L had a service ceiling of about 44,000 feet and the P-51D was about 41,900 feet, so you can say the P-38 was probably better at 42,500 feet and be on solid ground. But both were flying on the razor edge up there and anything like a hard turn would probably see both falling for thousands of feet.

I'd think the P-38 would be better way up high, if only due to higher aspect ratio, which comes into effect at high altitudes, but I also wouldn't be surprised to find out the P-51 was better in the real world. We know the Mustang was faster.

In the end, I don't know for sure. Good thing they were on the same side!

 

[wuzak]

I have my doubts that a flight simulator not specifically-designed for realism faithfully replicates the flight characteristics of a real aircraft. I have flown a T-38 simulator, but never a real T-38. Perhaps Biff could tell us if the T-38 and the T-38 simulator, or F-15 sim/plane are faithful simulations.

I would suggest training simulators are a lot closer to reality than computer game simulators.

 

[wuzak]

On your question above, both had good altitude capability, and I'm not sure which one would retain better feel at, say, 25,000 feet. The P-38L had a service ceiling of about 44,000 feet and the P-51D was about 41,900 feet, so you can say the P-38 was probably better at 42,500 feet and be on solid ground. But both were flying on the razor edge up there and anything like a hard turn would probably see both falling for thousands of feet.

I'd think the P-38 would be better way up high, if only due to higher aspect ratio, which comes into effect at high altitudes, but I also wouldn't be surprised to find out the P-51 was better in the real world. We know the Mustang was faster.

We also know that the P-38 had a lower critical Mach number - I wonder if that would have any influence on the high altitude comparison.

In terms of performance, it looks like both were capable of ~300mph @ 40,000ft.

http://www.wwiiaircraftperformance.org/mustang/p-51h-64182-fig16a.jpg

http://www.wwiiaircraftperformance.org/p-38/p-38l-25092-level.jpg

The Spitfire XIV appears to be superior in speed to both - at least to 38,000ft.

http://www.spitfireperformance.com/JF319-level-speeds.jpg

 

[GregP]

I think you'd want a P-51 if you were planning on a high-speed dive, for sure. I'd also bet that even if you tried to stay in the horizontal, any fight up near 40,000 feet would work its way downward in the course of the fight. no matter which aircraft you were in. I really like the P-38, but would personally choose a P-51 if I had to choose.

It is pretty good everywhere and the P-38 is pretty good except for a few glaring weaknesses. I wouldn't want to try to fight a P-51 when it was heavy with fuel in the 85-gal fuselage tank. And I wouldn't want to try fighting in a P-38 when a half-roll into a steep dive is the order of the day.

Overall, the P-51 was and is the better fighter, but specifically at 35,000 feet, I don't know. I'd lean toward the P-51, but that's purely from personal knowledge of them seen through eyes with no flying experience in either as pilot in command.

I know this, though. The video above with Chris Fahey is typical of WWII fighter responses. That is, if you were expecting them to do snap rolls like a Sukhoi-31, then you'll be disappointed with ALL of them. They all have slower roll response than sport aerobatic aircraft. At 280 mph, most are in the 40° - 80° per second category of roll, with more being on the slower side than you might imagine of you haven't studied it. It wsn't a handicap when most were siomilar in roll response, but very few are serious rollers like the Fw 190 series were supposed to be.

The roll response in a Cessna 310 looks like the P-38 respponse when the 310 tip tanks are full. That is, you put the wheel over and nothing much happens for a moment, then it starts to roll, and you have to lead the roll with active stop, or you will over-roll. They're MUCH more friendly when the tip tanks are empty. In the P-38, the Allisons don't go away, so it probably hesitates all the time. Probably less at higher speed, but with slower response as the speed increases. It would be good to see an in-cockpit view of an aerobatic display in the P-38.

The strangest characteristic I have heard about the P-38 is that it has very little down elevator, so if you stop a roll inverted and more or less level, you can't really push forward to stop the descent. You have to come out by rolling out or pull through with elevator. That doesn't work very well if you are 100 feet. At least that is what has been told to me by people who should know.

If you want to know and ever come to our airshow, you could always ask Chris Fahey yourself. He's very friendly and approachable unless he is getting ready to fly. Then he has to concentrate on that. He flies a few of our planes including the MiG-15 and F-86, and was an F-16 pilot before coming to the Planes of Fame. Good guy.

 

[Peter Gunn]

I would think there are regimes / envelopes where the P-38 would have an advantage due to little to no adverse yaw / torque with it's unique arrangement. IIRC didn't Lynch have a habit of getting slow with his opponents? I also think it contributed to his demise due to not jettisoning his belly tanks while getting slow.

Cheers,
Biff

I'm not sure if it was Lynch or Mcguire <sp?> that got slow with his opponents, could be both. Lynch was killed in a strafing attack but Mcguire did keep his tanks (Supposedly) in a low and slow dogfight, which is said to have contributed to his end.

 

[drgondog]

Simply stated, McGuire chose not to drop his external tanks (presumably less than half full to near empty) and engage on the deck. The eyewitness report stated that he appeared to stall out trying to stay with the Japanese fighter.

 

[drgondog]

I just edited the above post due to latent and lingering brain fart. Lynch IIRC got mad at a flak tower and the flak gunner won.

 

[BiffF15]

I have my doubts that a flight simulator not specifically-designed for realism faithfully replicates the flight characteristics of a real aircraft. I have flown a T-38 simulator, but never a real T-38. Perhaps Biff could tell us if the T-38 and the T-38 simulator, or F-15 sim/plane are faithful simulations.

I watched a programmer one day change the flight chrracteristics in a sim, and he did it because he wanted it to fly better, not because it was "real." I have NO idea if the commercial game sims are good aerodynamic replications or not, but one Cessna 172 sim I used flew quite similarly to the real thing except for being easier to fly and having unlimited fuel and oil. When I say easier to fly, I mean I did some really bad landings on purpose and got away with it, apparently without damage.

The C-182 was also not easy to damage, even when landing nose gear first, unlike the real airplane.

I never DID take one to Sedona, Arizona on a warm summer day and see if it flew like the ones I used to land there, but I really doubt it.

On your question above, both had good altitude capability, and I'm not sure which one would retain better feel at, say, 25,000 feet. The P-38L had a service ceiling of about 44,000 feet and the P-51D was about 41,900 feet, so you can say the P-38 was probably better at 42,500 feet and be on solid ground. But both were flying on the razor edge up there and anything like a hard turn would probably see both falling for thousands of feet.

I'd think the P-38 would be better way up high, if only due to higher aspect ratio, which comes into effect at high altitudes, but I also wouldn't be surprised to find out the P-51 was better in the real world. We know the Mustang was faster.

In the end, I don't know for sure. Good thing they were on the same side!

Greg,

The T-38 sim flew fairly close to the jet IIRC. The Eagle sim is fixed base, or doesn't move, so doesn't compare. The 757 / 767 / A320 / A319 sims I have flown are very close. The FAA allows you to get a type rating in them without ever having flown the jet.

Cheers,
Biff

 

[soulezoo]

While I have not flown the C-5, I did fly the sim. Very realistic to me and confirmed by pilots.

I can tell you it's hell trying to land a Galaxy in 30kt cross winds and heavy rain at McChord AFB... with an inboard engine out!!

 

[Glider]

I would suggest training simulators are a lot closer to reality than computer game simulators.

I should damn well hope so

 

[drgondog]

Just a couple of thoughts on high altitude flight (from theoretical POV of course). First, the cruise speed for level flight narrows to a 'stall speed' the higher you climb and you are changing angle of attack to increase CL (density being critical factor in the Lift equation) - until you can't. For the same reason, the higher you go the faster you reach CLmax of Any turn.- same reason.

Long ago and far away I had a friend that was a retired USAF U-2 driver. Listening to him talk about the U-2 was an eye opener (before I got my Aero education) to understand how little margin of error the U-2 (or any vehicle requiring Lift in the fluid we name 'air') had for level flight and even more so for a turn at max altitude. Literally had to descend to be able to turn.

 

[GregP]

I read that the original Learjet that got certified for flight at 51,000 feet was seriously in the "cofin corner," with some 4 knots higher to critical Mach numbers asome 4 lower to stall. So, if the pilot wasn't REALY on his airshpeed, he could stall or "lawn dart" when he exceeded critical Mach.

I never carefully checked out those claims because I never expected to be flying in one, but the newer jets, such as the Gulfstram 650, have a LOT of wing area, and have somegthing like a ±30 - 35 knot range before getting into trouble at either extreme.

I've read stories from U-2 pilots who said they were really AT the corner, with 1 - 2 kts before being too fast or slow, but never have confirmed it, and have no way to do so as I don't know any U-2 pilots. If I did, I seriously doubt they'd reveal anything they shouldn't. I worked on proximity fuzes for the Navy Standard Missile and would get VERY suspicious if anyone started asking about exact frequencys or specific test points. General curiosity is one thing, but technical detail questions rasie hackles when someone specifically asks about them.

I've always thought the U-2 / TR-2 flight specifics were "classified," but you can find a 1959 Pilot's Operating Handbook online. Scary to think it is a +2.5, -1 g airplane! A Cessna 172 is stronger than that!

 

[BLine22]

I rad that the original Learjet thath got certified for flight at 51,000 feet was seriously in the "cofin corner," with some 4 knots higher to critical Mach numbers asome 4 lower to stall. So, if the pilot wasn't REALY on his airshpeed, he could stall or "lawn dart" when he exceeded critical Mach.

The Lear 31 that I currently fly is certified up to FL510. You would have to be so light to get that high that you would have almost no fuel left. Its a 3.5hr airplane. I've never been above 430 and usually cruise around FL400. By contrast the GIV is certified to 450 and you can usually get there after a couple of hours, but its a 9.5hr airplane.

 

[grampi]

How did we go from P-51s to U2s and Lear jets?

 

[Shortround6]

the almost standard forum thread drift

 

[drgondog]

The discussion focused on ceiling performance - and the various reasons for differences, including examples.

 

[GregP]

The P-38L had a service ceiling of 44,000 feet, but I wonder how may ever actually GOT that high. The bombers in the ETO started out high and, when bombing accuracy was bad, went lower. After that, I wonder how many missions were actually flown way up high, other than perhaps recon missions. Likewise the P-51D had capability for over 40,000 feet. I doubt they spent a lot of time even at 35,000 feet, but could easily be wrong. I'm thinking mid 20s mostly after the initial high-altitude forays.

I would think that the P-38s in the PTO maybe started out up and 30,000 feet with the B-29s, but wound up down at 20,000 or below later in the war as the B-29s started coming down for better bombing accuracy and higher speeds over the target. That is, shallow dives at higher power levels after bombing the target.

So, once the ETO was won, I am thinking high-altitude missions for all the fighters virtually came to a halt sometime in 1945, but had been trending that way for some time.

Anyone know for sure? Bill Marshall? Did they start to drop a bit, or did they stay high?

 

[Peter Gunn]

Not to nitpick but more a question, I thought PTO B-29 escort was the domain of the Mustang and maybe the N model Thunderbolt. Did the 38 ever get tasked shepherding Supefortress's over Japan?