Jumpin on the P-38 bandwagon

[gripen]

bolillo_loco,
You can see from the flight envelope of the P-38 that the ability to sustain gs drops throughout (IAS) speed range while the altitude increases. But for example in the case of the P-47 the ability to sustain gs stays constant at low (IAS) speeds when altitude increases (so far I have not found a reliable flight envelope for the P-51). Also effectivenes of the combat flaps decreases with altitude because Clmax decreases when altitude increases. The turbos give a theoretical advantage keeping power constant up to the critical altitude but in the case of the P-38 this benefit is partially lost because propeller blade tip speeds are quite high (just look speed curve of the P-38, the speed starts to drop below critical altitude, rammed or unrammed). Also the P-51 was very well streamlined and able to keep it's energy level up during maneuvers.

There are a lot unfair comparisons on WWII fighters but IMHO it's the P-51 which suffers most in these comparisons. The P-51 had a pretty good range even without fuselage tank,  better than early P-38 or P-47, much better than P-40, P-39 or P-63. Also the P-51B performed somewhat better than later D model. Generally the P-38 climbed better than the P-51 at normal ratings, but the difference is not so great as some comparisons indicate, main difference is that the P-38 could climb at high angle and slow speed (good for spiral climb). Actually the P-51B-1 (67") outclimbed the P-38J-1 (60") in the USAF test (also outdived, outrolled, outturned at all altitudes without combat flaps, zoom climbed better from the dive, maintained speed longer after dive, outrun and even out accelerated at level flight after initial stage where the P-38 was better).

gripen

[Tac]

"outdived"

Of course. But the P-38 will outdive it initially due to its higher accel, but only initially.

"outrolled"

duh, what doesn't?  

"outturned at all altitudes without combat flaps"

Exactly. Without combat flaps. Above 250mph the p51 eats the 38 in turns. Below that, the 38 eats the pony.

"zoom climbed better from the dive"

Perhaps it from a 500mph+ dive.

"maintained speed longer after dive"

Of course, the pony retains far more E than the 38 ever will

"outrun"

I thought that was the pony's main strength. Of course  
 
"and even out accelerated at level flight after initial stage where the P-38 was better"

Define intitial stage. The p38 will reach from 0 to 200 mph far faster than the p51. After 200mph the p51 will accel a tad faster thanks to its airframe. That is why a slow (200mph or less) pony has no chance in hell against a P-38 unless it dives to run away.

[hazed-]

Just thought id remind you that the term 'forked tailed devils' was invented and used by the LW transport aircraft in the mediteranean theatre  

They was not called devils by the fighters.In fact Galland actually said he prefered to fight them to any other allied fighter.

Yes they were good aircraft but they were never considered the best air to air fighter the allies had.

Now you have a flying tank it seems.It is far tougher to shoot down now than almost any other plane ive attacked since the patch and Ive flown them and taken almost an entire loadout of bullets from a spitfire.Lost flaps,gear 1 engine fuel tanks rudders ailerons but it just kept flying.
I was in agreement the tail was a little weak but it seems pyro has made the ENTIRE aircraft tough as old boots now.

And one thing i would like to say is this...

when Ive questioned performance or durability etc of any LW plane in the past I get mostly abuse and the old 'AH has it modelled "by the numbers" and it is therefore correct' (gun issue) or that we must have proof or documents to ask for changes.
Well if the 'numbers' were all correct how was the p38 wrong? I agree it didnt FEEL right getting your tail blown off so easy but i had no evedence to SHOW US just HOW wrong it may be.I also called for a bit of toughening of the P38 but now I want to know how this degree of toughening was done BY THE NUMBERS?.Were the numbers for armour wrong? was it a bullet calculation problem? a bug in the software?
If they are going to decide which plane is correct by how they feel/number of complaints/questions, then compare to what we can all read about them then there is a problem looming I fear.

I think pyro has no data in this area right? its all down to what HTC decide is right in this area, I assume they calculate armour thickness/penetration of bullets/explosive power structural strengh? how durable area hit is?.Well somewhere along the line it becomes a guess-timate right? As it is too many complaints and they up the durability a touch? I hope not but suspect this must be how its done.If this is so Im not going to listen to this SHOW US THE EVIDENCE crap anymore i can tell you!  

I want to take this oppertunity to re-mention the well known fact that the P51 was very susceptable to (even) light calibre ground fire.You guys notice that when you fly it?
I dont, but i sure do in other planes that i thought or read were tough to bring down.

As the p38 issue has been adjusted could HTC PLEASE give us the parameters they use to DECIDE which aircraft is 'right' for durability?

btw although this may sound like an attack it isnt.I merely want to know how this was all decided.Lets not pretend any longer that if someone feels something is wrong he may very well be right?? and not a WHINER??

god i hate that word  

[gripen]

Tac,
The USAF test results are quite clear, the P-51B had the better acceleration in the dive. Theoretically we can argue forever about how dive entering method (zero g or what ever) affects to the results. About combat flaps you have still some things to learn, those can be used up to 250mph IAS but they really gave advantage at much lower speed, around 140mph and below. The combat flaps also wasted energy and in fact there are claims using them might put a plane tactically bad low energy situation. The effectivenes of the combat flaps decreased when the altitude raised and the P-51 could outturn the P-38 at high altitude by using flaps. In the zoom climb from cruising speed the P-38 and the P-51 were equall, from the dive the P-51 was superior. For the definition of the acceleration you should consult USAF documents, anyway I quess we are not interested what happens between 0-150mph. Generally the P-51 could do pretty much everything better than the P-38 above 25k specially if it keeped speed up. Generally I tend to wonder those claims about benefits of the P-38 at low speeds, it could turn well then but ailerons were really slow (normal or boosted).

hazed,
IIRC the USAF made somekind of study about vulnerability of those planes, it was based on interviews of the shot down pilots and statistics. The results were something like that the P-47 was best and the P-51 and the P-38 were about equall. Anyway, there has been some discussion about the term "forked tail devil", but so far noone has come out with clear evidence who invented it. Some Germans certainly used it during war but among the Luftwaffe the P-38 was allways known as the Lightning.

gripen

[Tac]

hazed, i agree with you with that the 38 is quite durable now. but think about it. its a flying wing for all that matters. If you hit the wing section (which is where most hits land), you're either taking out the wingtips or hitting the big 'ole engines.

Most 38's I see out there have smoking engines because of that. Mostly again, cuased by MG fire (cannon birds kill the engine or break the 38's wing off).

Wingtip loss is another very common damage in the 38, as well as aleiron and flap damage...well, you're hitting the big 'ole wing.

Now compare that to a P-47. You can literally PUMP 400 rnds of .50 at the fuselage of a jug and it'll take it. But if you hit its wings, its gone. The 109 also takes a good deal of damage on fuselage, so does the spit. But again, hit their wings and they go down. A p38 has no fuselage to speak of (and if you hit the cockpit, you kill the pilot), and its wings are very strong as they hold the engines.

Yet, I kill other 38's just as easy as I kill any other plane, it takes a few good pings in one place. I was used to spraying at a 38 , watching 3 or 4 flashes and watch it break apart, now I see it take those flashes and start smoking up, lose parts of the wings, etc. a few more pings and it goes down.

And this is with mg's. The 190a5 I flew last night wacked 38's left and right with a few hits.. with the 4X20mm loadout.

I'd say its about right now. next on list is dive flaps and all will be well.  

[Guppy]

This is a pretty interesting thread.  

If that test showing the P-51B outclimbing the P-38J is the same one I've come across, it also states that the P-51B climbed at 3,900 fpm at sea level, which is far and away the highest figure I've ever seen for it. Curiously, the same report quoted the P-51's military climb rate as only 2,500 fpm.

About the combat flaps--P-38 pilots on Guadalcanal, at least, found them at times useful well above 250 mph in combat. No indication whether the 250 mph lock was removed in the field or simply never fitted. (Of course, the drag penalty of flaps, even Fowlers, at 300+ mph would be considerable.)

One big plus for P-51s in actual combat seems to have been the introduction of the K-14 lead-computing gunsight (fitted to many P-51s as well as late-model P-47s, can't find any reference to it ever being used on P-38s). It apparently made a big difference in gunnery accuracy.

[gripen]

Guppy,
Yeah, it's the same one and couple writers have quoted this same report in their books (J.Ethell and K. Delve). Actually if you dug a bit, you can find even better numbers for the P-51:

Mustang III 4700fpm +25lbs grade 150 fuel(Rolls Royce test)
Mustang IV 4500fpm +25lbs grade 150 fuel (A&AEE)
Mustang I 4090fpm 60" (A&AEE, F4R, 8200lbs)

About combat flaps I stated that those gave advantage (over the P-51) at slow speed, flaps certainly helped at higher speeds too. The speed limit is IAS speed and it's probably a structural limit. At high altitude and high speed use of combat flaps probably caused compressebility effects due to high Clmax.

gripen

[Captain Virgil Hilts]

The P-51B had only four 50 caliber machine guns, slightly less armor, and did not have the 85 gallon fuel tank in the fuselage behind the cockpit. No doubt it was light and climbed well. But it had less than adequate armor, armament, and range.

The P-51 NEVER had a range advantage over a contemporary P-38, EVER. Especially not on internal fuel.

No, the P-38 was never equipped with the gyroscopically stabilized lead computing gunsight. Just like it was never equipped with the Hamilton Standard prop.

The P-38 was clearly superior to the P-51 at altitudes of over 30K feet. With a much lower stall speed, a much better turn rate at lower air speeds, and a clear power advantage at high altitude.

Critical Mach is just that, critical Mach. Other than a limit of handling at high speeds, it means nothing. Critical Mach means only that at or above that speed, the plane no longer responds to control input, and is therefore incapable of controlled flight. It does not affect handling at altitude, other than peak controllable speed.

As a matter of fact, the P-51 was known to spin out of fights at higher altitudes, and to do it more often than the P-38.

The P-38J-15-Lo had boosted ailerons and was able to roll faster than the P-51 above 325 MPH.

The P-38J and later at normal power would out climb the P-51D at military power, and the distance between the two at WEP was even greater.

The P-38L was faster than the P-51D at altitudes above 25K feet. The P-38J was faster than the P-38L.

The power curve of the Merlin in the P-51D began to level off and then turn downward as altitude increased over 18K feet while the Allison with its turbocharger actually had as good or better power even up to 28K feet.

Try using something other than just USAAF test data, as it was notoriously incorrect and biased.

[laz]

Wow, 1 whole week with a deem pc crash... and i am finally back.  I am looking into new pc this weekend... so i am waiting to download the game onto it.  Ok... back to the topic..  I agree with tac.  you guys that are saying p38 does not outturn a jug/51 may be a little mentally challenged  .. how often do you fly p38.  I am one of the worst pilots in p38.... and even I can outturn those planes with it.  It just takes brains to do it, which spitfire pilots ect.. do not have.  Go fly p38 nonstop for awhile, and you should find it pretty darn easy to turn with those planes.. AND 109's and MAYBE a n1k... they are not as much a threat  to p38 after 1.08.   Well, happy flying... hope to see you all in the air real soon.

Lazer  

=375th=

[Tac]

lazer good to see ya. They're talking about the real 38 here if you hadnt noticed  

P38 faster than 51D at high alts? uh-uh. Nope.

"The P-51 NEVER had a range advantage over a contemporary P-38, EVER. Especially not on internal fuel"

Huh? Pony on full internal fuel had
more range than the 38 on internal.

[ 12-04-2001: Message edited by: Tac ]

[funkedup]

Wow Gripen, I didn't know they tried a Basta Mustang!  I'd love to fly the Spit VIII with that motor.  

[bolillo_loco]

thank you for the explanation gripen, does a web page exist that shows this flight envelope data? something like the naca web site? I would like to see the condition of the P-51 in question.

The mustang to my knowledge for example was out climbed by the P-47D-40 and D-40 and all versions of the P-38H and later. The 3,475fpm (for the P-51D) initial and higher figures are always taken from mustangs that are 1,000 plus lbs lighter at take off and then compaired to max rate of climb for the 38 and 47 taking off under max weight no external stores. not a fair compairison. same can be said for the max g load. I have seen usaf charts that list max g load, but the mustang's weight is only 8,000 lbs.

again interesting reading could somebody point me out to some ulrs and or books which state this.

[Montezuma]

Originally posted by hazed-:
Lets not pretend any longer that if someone feels something is wrong he may very well be right?? and not a WHINER??

god i hate that word    

Sung to the theme from 'Flipper'...

They call him Luftwhine! Luftwhine!
Whines about lightnings,
No-one you see,
Complains more than he!

And we know Luftwhine, message board poster
Flying for Fuhrer,
Cries to HT!

[ 12-05-2001: Message edited by: Montezuma ]

[Sachs]

Ah yes Montezuma to the rescue to spread his euphoric sense of stupidity.  

I think the 38 has been fixed to a point of perk?    J/K I like it now.  It needed the fix and I hope others are looked into as well.

[Guppy]

Mustang III 4700fpm +25lbs grade 150 fuel(Rolls Royce test)
Mustang IV 4500fpm +25lbs grade 150 fuel (A&AEE)
Mustang I 4090fpm 60" (A&AEE, F4R, 8200lbs)

I've come across the first two figures before. The climb rates are about 1,000 fpm above the normally accepted climb rates, which is quite consistent with similar RAF tests on Spitfires with 150 grade fuel.

The 8,200 lb. Mustang I is over a thousand pounds lighter than a Merlin Mustang without fuselage tank. Were it heavier by that much (10-15%), its climb rate would most likely be somewhere in the mid-3,000 fpm area.

The tests I've seen consistently show the P-38 at around 3,800 fpm plus or minus 100 fpm or so. In my opinion, the balance of evidence is that the P-51B/D was in the 3,500 fpm class. The gap seems to widen on military power--3,200 fpm for the P-38J/L vs. 2,500 fpm for the P-51B/D.

I agree the flap IAS limit was probably a structural limit. However, in at least one case this was exceeded by 100 mph without trouble, and some pilots felt quite free to exceed the limit by a fair margin. (Whether this would make you popular with your maintenance crew is unrecorded.   )

[ 12-05-2001: Message edited by: Guppy ]