pbfoot
1st Lieutenant
Stocky Edwards flew the P40 in North Africa and one of his complaints was that when in a G turn the guns would jam if fired and it was the same for all the sqn aircraft
Bf-109 vs P-40
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renrich
Chief Master Sergeant
I think that having wing mounted guns jamming in a turn was not uncommon for a lot of AC.
MikeGazdik
Senior Airman
Stats and stories can be argued forever. But what I read from all of this is the fact that these two planes were very close adversaries. If you have altitude, advantage Messerschmitt, but down low, the Curtiss is at least an equal. Which is why the Russians had a better record perhaps than the USAAC or RAF.
While I love to read books and interviews of the pilots of WWII, you have to consider that the people writing or telling the story survived the war! So they were obviously either lucky, or very good at thier craft. But in either case, they are generally biased towards thier aircraft, techniques, and abilities.
The "tables" of performance, new or old, just tell us what the airplane may be capable of, they don't tell us what a pilot may be able to do with the machine.
A few seconds variance in turning, climbing or roll can certainly be a deciding factor in air combat. But the pilots abilities' count for much more in my opinion.
Its like getting in a modern gunfight. You have an old .357 magnum six shooter, and the other guy has an M-16 . He has all of the advantages. He also can make many mistakes that the six shooter guy cannot afford to make. But if you are good (or great), and he is foolish, you can win the battle. That is an extreme example. Now if the six shooter gets an AK47 to take on the M16 shooter, its all mostly in the hands of the operator. But if you compare stats, the M16 is far better.........on paper.
While I love to read books and interviews of the pilots of WWII, you have to consider that the people writing or telling the story survived the war! So they were obviously either lucky, or very good at thier craft. But in either case, they are generally biased towards thier aircraft, techniques, and abilities.
The "tables" of performance, new or old, just tell us what the airplane may be capable of, they don't tell us what a pilot may be able to do with the machine.
A few seconds variance in turning, climbing or roll can certainly be a deciding factor in air combat. But the pilots abilities' count for much more in my opinion.
Its like getting in a modern gunfight. You have an old .357 magnum six shooter, and the other guy has an M-16 . He has all of the advantages. He also can make many mistakes that the six shooter guy cannot afford to make. But if you are good (or great), and he is foolish, you can win the battle. That is an extreme example. Now if the six shooter gets an AK47 to take on the M16 shooter, its all mostly in the hands of the operator. But if you compare stats, the M16 is far better.........on paper.
claidemore
Senior Airman
P40, even with extra weight, has a lower stall speed than a 109 and a lower wing loading (35 lbs/sq ft compared to 40), so as energy bleeds off the advantage should actually go to the P40.
The 109 has LE slats, which are supposed to make up for it's higher wing loading, but consider the following:
The La5F in the Soviet tables, Table of ftrs 1943 has a similar (or same) Clark airfoil as the P40, weighs a bit less, has more horsepower, has LE slats on that 'similar' airfoil, has a wing loading of 38 lbs/sq ft, and is a Soviet produced plane (where some would assume the posted figures might show some national bias). All that being said, the chart shows the La5F with a turn time of 19-20 seconds, and the P40 (an American lend lease plane) is 18-19 seconds.
This indicates that the LE slats might not be giving the La5F a big turn advantage over the P40, and is strong evidence that there is little or no bias in the figures presented.
I'd also like to point out that any calculations, whether by HoHun, Soren or others, have to be based on historical data, so ignoring old data for the sake of new data,which is produced from old data, well....I think we can all see the point.
I also don't agree with dismissing data just because it is 60 years old. Einstein came up with his theories of relativity over 100 years ago, and we're still using those, (and they are after all only theories, not tested facts!).
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Claidemore,
Bare in mind the difference in slat wing design between the Bf-109 La-5. The La-5 has very small span slats and the wing features a high taper ratio, completely unlike the 109. And the high taper ratio is NOT good for turn performance, only nessicating the use of slats to prevent nasty tip stalls. Furthermore the La-5 features a high decrease in wing thickness ratio from root to tip, again not good for turn performance and also nessicating slats to prevent tip stalls. All of this makes sure that the slats can only bring the Clmax up to the same level as a low tapered thick wing without slats. So in effect the slats are just there to cancel out the detrimental effect on turn performance that the higher taper ratio and high decrease in thickness ratio the wing features in order to decrease drag in level flight.
The Bf-109 is entirely different with long span slats, low wing taper and a high thickness ratio from root to tip, all of which equals a very high Clmax. Hence why the Bf-109 easily outturned the La-5FN in German comparative flight tests. Even without the slats, thanks to the low taper and high thickness ratio, the 109's wing has a Clmax of 1.5 or higher, and with the slats it's in excess of 1.7, which is way above the approx. 1.45 Clmax of the P-40. And then comes the power loading,which is essential in prolonged turnfights, and the Bf-109 just has a HUGE advantage over the P-40 in this area.
All in all there is no chance that the P-40 is gonna prove any trouble in a turnfight for an experienced Bf-109 pilot.
Bare in mind the difference in slat wing design between the Bf-109 La-5. The La-5 has very small span slats and the wing features a high taper ratio, completely unlike the 109. And the high taper ratio is NOT good for turn performance, only nessicating the use of slats to prevent nasty tip stalls. Furthermore the La-5 features a high decrease in wing thickness ratio from root to tip, again not good for turn performance and also nessicating slats to prevent tip stalls. All of this makes sure that the slats can only bring the Clmax up to the same level as a low tapered thick wing without slats. So in effect the slats are just there to cancel out the detrimental effect on turn performance that the higher taper ratio and high decrease in thickness ratio the wing features in order to decrease drag in level flight.
The Bf-109 is entirely different with long span slats, low wing taper and a high thickness ratio from root to tip, all of which equals a very high Clmax. Hence why the Bf-109 easily outturned the La-5FN in German comparative flight tests. Even without the slats, thanks to the low taper and high thickness ratio, the 109's wing has a Clmax of 1.5 or higher, and with the slats it's in excess of 1.7, which is way above the approx. 1.45 Clmax of the P-40. And then comes the power loading,which is essential in prolonged turnfights, and the Bf-109 just has a HUGE advantage over the P-40 in this area.
All in all there is no chance that the P-40 is gonna prove any trouble in a turnfight for an experienced Bf-109 pilot.
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One moment please. Some questions: Where are theese Clmax are taken from?
What are the Bf-109, P-40, La-5 wing profiles respectivly?
Best regards
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Hello
While I agree with Soren that when comparing wings one must take in account all variables but again he used his propagandist tone, the LE slats of La-5, which took ca 38% of the wing span are described as "very small span slats" and the LE slats of Bf 109G, which took ca 40% of the wing span are described as "long span slats".
Juha
While I agree with Soren that when comparing wings one must take in account all variables but again he used his propagandist tone, the LE slats of La-5, which took ca 38% of the wing span are described as "very small span slats" and the LE slats of Bf 109G, which took ca 40% of the wing span are described as "long span slats".
Juha
Some people (Juha) just can't restrain themselves from offtopic under the belt attacks... says abit about how weak their argumentation has become.
VG-33,
If you wish to know the wing Clmax of the different US a/c you can look up the NACA Report nr.829, every US fighter is mentioned there. Hope that helps.
The Bf-109's Clmax is listed on a number of MTT documents: 1.7.
Furthermore the V-24 prototype, essentially a Friedrich with a much reduced wing span and no slats, recorded a Clmax of 1.48 at the windtunnel lab in Charlais Meudon. The V24 had like already mentioned a highly reduced wing span and therefore wing area (15.2 m^2), this increased the Aspect ratio and therefore decreased the Clmax compared to the full span wing. The full span wing had a Clmax of 1.5+, and most likely around 1.55. The slats increased this to 1.7+ when deployed.
VG-33,
If you wish to know the wing Clmax of the different US a/c you can look up the NACA Report nr.829, every US fighter is mentioned there. Hope that helps.
The Bf-109's Clmax is listed on a number of MTT documents: 1.7.
Furthermore the V-24 prototype, essentially a Friedrich with a much reduced wing span and no slats, recorded a Clmax of 1.48 at the windtunnel lab in Charlais Meudon. The V24 had like already mentioned a highly reduced wing span and therefore wing area (15.2 m^2), this increased the Aspect ratio and therefore decreased the Clmax compared to the full span wing. The full span wing had a Clmax of 1.5+, and most likely around 1.55. The slats increased this to 1.7+ when deployed.
I do see your point, and the other fundamental point is again whether the 'new' calculations have been verified by new or old tests at full scale. Not every single calculation has to be so verified, or there'd be no point in taking the short cut of a calculation rather than testing *every* possible thing at full scale. But some broad sample of full scale results must give evidence a calculation is really valid for similar cases, for there to be any credibility in a statement that a calculation overturns a full scale trial. An approach which says 'here's the calculation, and if it agrees with any full scale result, that full scale result must be correct, but if it doesn't agree that full scale result must be incorrect'... is just ridiculous, to put it bluntly. It shows a basic misunderstanding of the role and meaning of modeling and calculation in engineering.
Note I'm not saying the (more than one) full scale trial of WWII era purporting to show superiority in turn by the P-40 are 100% certainly correct. The point is just that you can't push them aside with calculations *you haven't proven agree with verifiable full scale results in a broad sample of similar cases*. Soren seems to at least somewhat understand this point, claiming weakly that 'all modern pilots' of warbirds agree the 109 turns better (but he hasn't provided evidence for that statement). Hohun is so busy taking any disagreement with him as a personal slight that he doesn't seem to even pay attention to this basic point. You can have a reasonably good sim game based on any reasonably realistic and internally consistent set of calcs you want to use; they don't actually have to agree with reality in all cases to make the game fun and apparently 'realistic' enough for the typical audience. Again I think that's actually the goal of most modern amateur calculators of a/c performance. But that's a completely different proposition than proving that historical full scale trials of real airplanes were wrong or probably wrong.
Joe
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Yes ofcourse.
Bf-109F Cl Cd0
There's plenty more stating the exact same.
Do you consider this to be a full scale 109F ?
Bf-109 V-24
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Tham
Recruit
Some years ago, I wrote to the Soldier of Fortune
expressing my shock, after reading an article in the
magazine about the puny 2.36 inch bazooka being
still used in the Korean war against T-34/85 tanks.
Their editor replied that "this goes to show that that
are many stupid people in the American military (there
still are)".
He was obviously referring to the penpushers.
Common sense using Murphy's Law would have
dictated that a warplane may be called upon to
fight at any altitude.
I would have considered using a turbocharger in
the P-40 right from the start, given the power-
draining disadvantages of crankshaft-driven
superchargers.
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Thanks once more, can we see more on that report, and what was the Clmax with full flaps, full slats open so?
Do you consider he's inside the Charlais-Meudon wing tunnel?Do you consider this to be a full scale 109F ?
In fact j just want to see the wind-tunnel report, not at
the planeGood evening
claidemore
Senior Airman
I would not say that Juha is incorrect with this statement.
The NACA 2R1 designation (for a modified Clark airfoil) is not a standard designation for NACA, it doesn't follow the 4 or 5 digit formula we are used to for wings from that era. The closest standard designation to the 2R1 would be 2314.8-2310.5 (Emil), or as Juha mentioned 2315-2309 for the F/G series.
P40 had a 2215-2209 wing, La5 a 23016-23010, Spitfire a 2213-2209.4 and the Yak had a Clark YH 14%-10% (another modified Clark airfoil).
I was incorrect that the P40 and La5 had nearly the same airfoil.
Juha is also correct in pointing out the difference in percentage of LE of the La5 and Me109 slats, 38% compared to (I believe) 43%?
"Chuckle Chuckle"
Now according to The Incomplete Guide to Airfoil Usage website says:
Messerschmitt Bf 109B NACA 2R1 14.2 NACA 2R1 11
Messerschmitt Bf 109C NACA 2R1 14.2 NACA 2R1 11
Messerschmitt Bf 109D Dora NACA 2R1 14.2 NACA 2R1 11
Messerschmitt Bf 109E Emil NACA 2R1 14.2 NACA 2R1 11
Messerschmitt Bf 109F Fredrich NACA 2R1 14.2 NACA 2R1 11.35
Messerschmitt Bf 109G Gustav NACA 2R1 14.2 NACA 2R1 11.35
Messerschmitt Bf 109K NACA 2R1 14.2 NACA 2R1 11.35
So the root profile stayed same from 109B to K, and how it was, French examined closely a 109B captured in Spain during the civil war and made a report on it
Quote:"Wings: Trapeziplanform with small roundings near tips, cross-section occupies interim place between cross-sections #2314 and #2315 systematically evaluated by NACA."
So at least French and Finnish specialist agreed on that.
Sources: Andrew Alexandrov and Gennadi Petrov: Messerschmitt Bf 109B p.5 in Skyways No. 29 Jan. 1994
Raunio: Lentäjän Näkökulma II
Juha
Now according to The Incomplete Guide to Airfoil Usage website says:
Messerschmitt Bf 109B NACA 2R1 14.2 NACA 2R1 11
Messerschmitt Bf 109C NACA 2R1 14.2 NACA 2R1 11
Messerschmitt Bf 109D Dora NACA 2R1 14.2 NACA 2R1 11
Messerschmitt Bf 109E Emil NACA 2R1 14.2 NACA 2R1 11
Messerschmitt Bf 109F Fredrich NACA 2R1 14.2 NACA 2R1 11.35
Messerschmitt Bf 109G Gustav NACA 2R1 14.2 NACA 2R1 11.35
Messerschmitt Bf 109K NACA 2R1 14.2 NACA 2R1 11.35
So the root profile stayed same from 109B to K, and how it was, French examined closely a 109B captured in Spain during the civil war and made a report on it
Quote:"Wings: Trapeziplanform with small roundings near tips, cross-section occupies interim place between cross-sections #2314 and #2315 systematically evaluated by NACA."
So at least French and Finnish specialist agreed on that.
Sources: Andrew Alexandrov and Gennadi Petrov: Messerschmitt Bf 109B p.5 in Skyways No. 29 Jan. 1994
Raunio: Lentäjän Näkökulma II
Juha
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Colin1
Senior Master Sergeant
So a turbocharger arrangement in the P-40, rather than specifically in the Allison V-1710?
The V-1710-11/15 was turbocharged for use in the XP-38 and required a fair bit of plumbing. If not the Allison, then which powerplant did you have in mind and I daresay you'll still have the plumbing issue.
The full document:
The Clmax with full flaps would've been much higher as full flaps can increase Clmax by as much as 70%. But the 109's Clmax with flaps down is probably around 2.3 to 2.35.
Do you consider he's inside the Charlais-Meudon wing tunnel?
In fact j just want to see the wind-tunnel report, not at
Good evening
I'm not sure there's a picture of the V24 inside the windtunnel VG-33. But I'll have a lok see in my books for it.
Meanwhile here's a picture from the Hermann Göring Aviation Research Institute in Völkenrode near Brunswick:
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