P-40 Warhawk/Kittyhawk
- Thread starter archerynut
- Start date
Ad: This forum contains affiliate links to products on Amazon and eBay. More information in Terms and rules
drgondog
Major
Colin - although I agree your points in the prior post, the P51B/C/D/K all had the same wing (NACA/NAA 45-100) with one exception. The root chord was extended on the D/K to give a little more structural strength at the root and a little more room for the Wheel and a slightly different door cover. The effect of lengthening the root chord would have had the effect of increasing very slightly the maximum thickness from root to the point where the swept portion intersected with the leading edge of the rest of the wing.
At that point the thickness and space available for the guns and planform of the wing are exactly the same for A-K models.
The A,B,C all had space to insert one more M3 in the same bay as the paired .50's and curiously had the ability to mount the guns vertically - as they were in the D/K/H/P-82
The H (and G,J) had a slightly different wing with just a little camber in addition to a slight difference in thickness at root and tip.
IIRC the primary root causes for the jams were lubricant freezing for both the 50's and the feed belt boost motor when the heater failed to operate properly. The High G turns also contributed to feeding issues and jams - mostly resolved with the upright M3's and a better heater.
The Fighter Group Armorers also developed better QC processes for sorting unlinked ammo and then linking them in the June 1944 timeframe.
Regards,
Bill
At that point the thickness and space available for the guns and planform of the wing are exactly the same for A-K models.
The A,B,C all had space to insert one more M3 in the same bay as the paired .50's and curiously had the ability to mount the guns vertically - as they were in the D/K/H/P-82
The H (and G,J) had a slightly different wing with just a little camber in addition to a slight difference in thickness at root and tip.
IIRC the primary root causes for the jams were lubricant freezing for both the 50's and the feed belt boost motor when the heater failed to operate properly. The High G turns also contributed to feeding issues and jams - mostly resolved with the upright M3's and a better heater.
The Fighter Group Armorers also developed better QC processes for sorting unlinked ammo and then linking them in the June 1944 timeframe.
Regards,
Bill
Colin1
Senior Master Sergeant
Hi Bill
thanks for that, interesting
My bad, I thought the wing was both thickened (the jamming issue) and strengthened to take hard points and the combination of changes were the reason flight commanders were crying 'foul' once they realised their flights (still in Bs and Cs) were 3-5mph faster than they were.
Thanks for that, I'll do the homework on it.
renrich
Chief Master Sergeant
As was mentioned before, the H81(P40B) was the fastest of all P40s produced although not many were built. It was not really war ready so comparing it to operational Zekes is not really appropriate. According to Lundstrom, Thach worked out his beam defense maneuver(Thach weave) at home on the dining room table with match sticks. The USN got reports if memory serves on the Zeke in October 1941.
drgondog
Major
Can you offhand cite an opponent the P-40 faced in 1943 (and beyond) which had Less Energy? I can't, but am sure wasn't a contemporary F190, Me 109, A6M, etc? IFAIK the p-40 was reasonably close to 1:1 vs the LW in Africa as most of the battles were at low altitude where a P-40 might be able to contain the fight to the horizontal but it did not do well against the LW in USSR and certainly not against IJN Zero's.
drgondog
Major
Mustang by Gruenhagen is the best single source, Mustang Designer by Wagner is also good but more about Schmeud but does touch on many design issues.
I thought at one time that the H had a slightly Thinner wing (NACA 66-(1.8) 15.5 root) but I researched it more and it actually had a 15.5/12% thickness at Root/tip whereas the 51A-K (NAA/NACA 45-100) had 15.1/11.4% at root/tip.
Colin1
Senior Master Sergeant
Thanks Bill
drop the ISBNs by when you have time
renrich
Chief Master Sergeant
I think that the best thing the P40 had going for it was that it was available and operational when the war for the US began. In spite of it's short comings it could give a decent account of itself if used with it's strengths in mind but, in spite of all Curtis's efforts it just did not have much "stretch." It was in action on the 7th of December, 1941 and it soldiered on under many flags until the end. It and the Wildcat had similar careers and probably deserve the sobriquet supposedly from Darrell Royal, "ole ugly is better than ole nothing."
drgondog
Major
Amen.
imalko
Chief Master Sergeant
I agree.
I have read somewhere that "P-40 was a useful fighter rather than outstanding" and that "it was available in numbers exactly when it was needed". (At the beginning of the war for the US that is.)
I think that's about sums it up.
Except the P-40n was not available in the beginning of the war and it was the most prolific of all the models.
Colin1
Senior Master Sergeant
Ha! I've just re-read my post
I did indeed say chord, I meant thickness - not that it matters if that didn't change either
drgondog
Major
The change in root chord length for the D from the A/B would have the effect of increasing very slightly the actual thicknes of that section of the wing over the shorter chord of the B (but not the %) from the root chord to the wing station where it blended in with the rest of the leading edge just inboard of the first machine gun...
from that point outboard the airfoil/chord/thickness is exactly the same for A/B/C/D/K all the way to the tip.
Elvis
Chief Master Sergeant
I didn't see anyone else address this particular question (apologies if you did and I overlooked your response), so I'd like to take a stab at it, as I believe understanding the powerplant is essential to understanding why the P-40 (and the early 51's) are remembered in the way that they are.
You have to remember is that the Allison was originally designed as an airship powerplant.
Used in that fashion, it would be treated almost like a generator powerplant, in that it would see hours and hours of "steady state" crusing, without a whole lot of fluctuation in engine speed.
This means it doesn't have to be built as "stout" as an engine that would see a lot of wide ranging variences in throttle settings over a short period of time, which can be very stressful on an engine.
I believe this is one reason why the Allison was about 300-400 lbs. lighter than the Merlin, even though it displaced an extra 60 cubes.
Granted, it ended up being developed into quite a usable mill, almost too late to make a difference in the war, the development was most likely slow due to the fact I stated above, compounded by the fact that the British already had a suitable powerplant that was ready to go....and they were more than happy to let us use it.
Here's something else:
A few years ago, I traded some E-mails with a guy who used to crew on some Unlimited Hydroplanes during the 1970's, an era where literally all of those boats were powered by either an Allison or a Merlin V-12.
He told me that, although he didn't know exactly why, the mechanics could ALWAYS pull more power out of the Merlin than the Allison.
This eventually led to the favouring of the Merlin, and later the Rolls Griffon, in most Unlimited's towards the end of the "piston engine" era.
It was just the way those engines were set up from the get-go.
...I suspect, to some degree, that was because of the more stout design of the Merlin, too.
Still, that being said (and I hope that answers your question), I would've still liked to have seen the P-40N and the P-51 B/C's outfitted with an Allison fitted with a single stage, two-speed, intercooled supercharging system featuring impeller size in the 12" to 15" range, and a better prop for high altitude work (of course, this means that the "G" motor would've had to come to fruition more quickly than it did).
Anyway, I think this would've improved the upper altitude performance of both planes and while I think the 51, at least, would've eventually found itself mated with the Merlin, that particular event would've probably happened later, AND, the P-40 might be remembered as a more favourable match to the 109, the Zero and the Tony.
--------------------------------------------------
One more thing....
I saw quite a few references from someone about the P-40Q in particular.
Wasn't that one a one-off experimental version that was built at the behest of the P-40's designer, to show how "equal" it was to a similarly outiftted 51?
(I think the P-51D was the model being compared to, at that time)
The jist I got from those posts were that the "Q" version was built in number and implemented into the war effort, which is not how I understand it.
Am I wrong? Please enlighten me.
Elvis
Clay,
You have to remember is that the Allison was originally designed as an airship powerplant.
Used in that fashion, it would be treated almost like a generator powerplant, in that it would see hours and hours of "steady state" crusing, without a whole lot of fluctuation in engine speed.
This means it doesn't have to be built as "stout" as an engine that would see a lot of wide ranging variences in throttle settings over a short period of time, which can be very stressful on an engine.
I believe this is one reason why the Allison was about 300-400 lbs. lighter than the Merlin, even though it displaced an extra 60 cubes.
Granted, it ended up being developed into quite a usable mill, almost too late to make a difference in the war, the development was most likely slow due to the fact I stated above, compounded by the fact that the British already had a suitable powerplant that was ready to go....and they were more than happy to let us use it.
Here's something else:
A few years ago, I traded some E-mails with a guy who used to crew on some Unlimited Hydroplanes during the 1970's, an era where literally all of those boats were powered by either an Allison or a Merlin V-12.
He told me that, although he didn't know exactly why, the mechanics could ALWAYS pull more power out of the Merlin than the Allison.
This eventually led to the favouring of the Merlin, and later the Rolls Griffon, in most Unlimited's towards the end of the "piston engine" era.
It was just the way those engines were set up from the get-go.
...I suspect, to some degree, that was because of the more stout design of the Merlin, too.
Still, that being said (and I hope that answers your question), I would've still liked to have seen the P-40N and the P-51 B/C's outfitted with an Allison fitted with a single stage, two-speed, intercooled supercharging system featuring impeller size in the 12" to 15" range, and a better prop for high altitude work (of course, this means that the "G" motor would've had to come to fruition more quickly than it did).
Anyway, I think this would've improved the upper altitude performance of both planes and while I think the 51, at least, would've eventually found itself mated with the Merlin, that particular event would've probably happened later, AND, the P-40 might be remembered as a more favourable match to the 109, the Zero and the Tony.
--------------------------------------------------
One more thing....
I saw quite a few references from someone about the P-40Q in particular.
Wasn't that one a one-off experimental version that was built at the behest of the P-40's designer, to show how "equal" it was to a similarly outiftted 51?
(I think the P-51D was the model being compared to, at that time)
The jist I got from those posts were that the "Q" version was built in number and implemented into the war effort, which is not how I understand it.
Am I wrong? Please enlighten me.
Elvis
From Baugher page
"The proposed production models of the P-40Q were to have carried either six 0.50-inch machine guns or four 20-mm cannon, but the XP-40Q was still inferior to contemporary production Mustangs and Thunderbolts, and development was therefore abandoned. Consequently, the production life of the P-40 ended with the N version."
"The proposed production models of the P-40Q were to have carried either six 0.50-inch machine guns or four 20-mm cannon, but the XP-40Q was still inferior to contemporary production Mustangs and Thunderbolts, and development was therefore abandoned. Consequently, the production life of the P-40 ended with the N version."
Elvis
Chief Master Sergeant
Thanks Vincenzo, that's what I thought.
Elvis
Elvis
Demetrious
Airman 1st Class
- 104
- Aug 22, 2007
...I am a hopeless fanboy who is completely prepared to argue that the P-40 could whip the FW-190, the P-51, La-7, Jesus, and Optimus Prime all at the same time.
Oh God, not another one...
... I'm going to assume you're being funny here, because if you actually missed the "your base assumption is" part preceding that, then you make me sadface, sir.
I've seen that comparison made before- I know percisely where you're coming from- but I'm not so sure it's an accurate one. Simply put, I don't know if it's fair to regulate the P-40 to the same era of out-dated aircraft that the Hurricane belonged to. I personally think the P-40 had more potential then it was given credit for.
Fair 'nuff!
You show me where in NA-73 it stipulates long-range escort capability.
Perhaps not long range escort, but long range, certainly. I'd wager that simply because the short range of the Spitfire was very limiting, so the British request for a new aircraft would likely include better range. This is interesting, in fact, because the P-51 came about as a direct result of the British trying to buy P-40s. As Wikipedia says:
Wikipedia said:
Earlier in the article it says that the only American aircraft that came close to what the RAF purchasing commission required was the P-40. I'd wager that a good range was part of that requirement.
In any case, though, the fact that North American Aviation chose to develop the P-51 rather then build P-40s is a direct vindication of your insistence that the P-51 was a generation above the P-40. Nobody disputes that, certainly. I just think that the P-40 had much potential then most people give it credit for, and the reason it wasn't fully realized is that the American war machine was going all out- current fighters were being built and upgraded even as several new designs were being built. America had more resources available in terms of production lines and such then Germany, or England. If Germany had had the resources, they would have thrown all their resources into building FW-190s and 190Ds instead of continuing to upgrade the Bf109, but it was easier to upgrade a proven design then work out the kinks in an entirely new one.
The P-40Q, as others have just pointed out, was an attempt to make the P-40 into a clone of the P-51, which it would never, ever be. The P-40 just didn't have it in it to be a high-altitude high speed fighter. However, simply adding a decently powerful powerplant to an already proven design would have improved it's usefulness drastically for very little invested in R&D costs- and time, always a crucial factor when you need every fighter at the front right away. After all, the Curtiss factory was going all-out even as the P-51 was entering production. Now, the P-39D2, in 1941, had a 1600 horsepower Allison V-1710-63 engine in it, a massive improvement over the 1100 horsepower Allison it had before. The P-40E of the same era only had the Allison V-1710-39, with an anemic 1150HP. Why couldn't they get the Allison -63 into the P40? Does anybody know the reason?
Dude. The FW-190, with it's radial engine, was a poorer high-altitude performer then the Bf-109. And yet, the 190 was preferred because most dogfights took place below 15,000 feet, where the 190 was superior.
The US needed a high-altitude fighter to escort the bombers, the P-51 excelled here. In every other theater, low-altitude fighting was the norm- for example, Italy and Africa.
And consider that Luftwaffe pilots found that the Mustangs performance advantages were only at altitude, and that they disappeared the closer to the ground you got.
Yes. Yes, I know, hence my anecdote about the Aces High Spitfire pilots who moan and demand the P-51s come furball with them (to my infinite amusement.)
But that doesn't mean for one second that the energy fighter (in this case, the P-51) could dominate the fight. The Mustang could be a thousand yards away before the P-40 could turn to face him, but that also means that the P-40 will always have plenty of time to get his nose on target with the P-51 for the next pass. In this case, the fight degenerates into a series of head-on passes, and that's not good. You've got a 50/50 chance of coming out on top, even if you have better guns- and that's just a wash.
But gee, I thought you said that the P-51 was never originally designed to be a long-range escort fighter! But it had the potential to grow into a long-range fighter, and the 190 didn't.
Therefore, by your logic, both the 109 and 190 were obsolete.
The Bf-109s performance increased impressively throughout the war. The Bf-109 "Emil," that fought the Battle of Britain, turned 360 degrees in 24 seconds and had 1,000 HP to work with. By 1942, the "Gustav" Bf-109 had 1400 HP and could turn 360 degrees in only 20 seconds. Later war models had even better performance.
There's some debate on that, since German engineers loaded the aircraft down with hundreds of pounds of extra weight as the design advanced, with negated some of the advantage it could have gained from the power upgrades. In the end though, the late Bf-109s had marked performance increases over the first ones.
(post too long, continued below)
Demetrious
Airman 1st Class
- 104
- Aug 22, 2007
I guess this would depend on how much different the A-model mustangs were from the D-models that went into Germany.
Let me guess, unless I can dig up extensive technical documents or pilot accounts comparing the durability of the P-40 to the P-51, you're going to cry foul?
No. Even after extensive googling I'm unable to find even maximum g-limits for the P-51 OR the P-40. Even the basic data is hard to find, much less esoteric information comparing the number of wing spars. I know the P-40 had five wing spars, but I cannot even find that data for the P-51. The best I have is a desktop made from a promotional poster for the P-51 that shows a wing cross-section in which it appears that the P-51B only has two wing spars. (If anybody wants that desktop, holler- it's a nice one.)
Somebody here might be able to find that data, but it's not me. If the general consensus in the literature that the P-40 was more durable then the P-51 isn't good enough for you, then too bad. (And I mean this honestly, because pilot anecdotes often ARE not good enough! But the simple fact is that this data is just very, very hard to find. It really is too bad.
)Are you really going to argue that the P-51 was a better low-altitude fighter then the P-40? When the P-40 could out-turn and out-roll the P-51, and the P-51's speed advantage was slimmest on the deck?
In any case, I find it very interesting that the P-51 actually was deployed as a purpose-built fighter bomber- the A-36! It was used in North Africa, and was basically a P-51B with dive brakes. By all accounts, they fared quite well. This demonstrates, I think, that the P-51 wasn't a bad low-altitude fighter- it's just that the Pony does a lot better at altitude. On the deck it's equal, at 30,000 feet it shines.
Actually, Wikipedia says that the P-40E could carry two-thousand pounds of ordinance, and had two wing hardpoints, which was news to me. Wikipedia seems to have it's cites in order on this article, but I remain skeptical.
Yes, I eagerly await the rest of the forum telling me how an excellent power to weight ratio is not tremendously useful.
It wasn't the cleanest ship, not by a long shot- but it WAS a superior energy fighter to the Zero, only because the Zero was a very dirty ship with that big radial, and was so very light. Against pretty much every other fighter of the war, the P-40 was a furballer- slow, but manuverable. The Zero is the only exception, because the Zero was right on the extreme end of the scale.
Yep, that's what I've been saying. In the actual engagement, if one chose to stay and fight, the energy retention was the deciding factor, but if you want to flat out run for it, yeah, it's decisive.
drgondog said:
Zeros. The Zero would enter the fight at the same speed but with less energy, since it was a much lighter plane, and thus had less mass. Once the fight commenced, the P-40 could hold it's energy rather better.
Against everything else, as you say, the P-40 had significantly less energy then the Bf-109 (which had awesome power-weight, really. Try it in a simulator sometime- you give that baby the gas and she just steps-) and the 190. The P-40 could dominate the 109 in a scissors or turn fight, but could never catch it. A better engine would have reduced that single deficiency nicely and really given the 109 trouble, even more then it did historically. The 190 had the P-40 in roll rate, on the other hand, the 190's power-weight wasn't as good. This didn't matter, though, because it was still leagues ahead of the P-40s anemic engine. As you say, victory really depended on forcing a horizontal fight, and that was best achieved by diving to the deck and dueling there.
