P-40 Warhawk/Kittyhawk

[Colin1]

... 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.
Not THAT funny, I don't recall Jesus ever flying a P-40 but you might want to consider that line of response could well be offensive to any number of members on here.

I've seen that comparison made before- I know precisely 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.
Whether it's fair or otherwise, the P-40 belonged to the same mid-30s-designed range of fighters that the Hurricane belonged to. You will need to spell out exactly why you think the P-40 had more potential that it was given credit for and it won't do you any good trotting out the 'fit it with a Merlin' argument again - we've already shown you that in the P-40F and L it didn't exactly light the plane up.

...because the P-51 came about as a direct result of the British trying to buy P-40s. As Wikipedia says:

Originally Posted by Wikipedia
North American Aviation (NAA) was already supplying their Harvard trainer to the RAF, but were otherwise underutilized. NAA President "Dutch" Kindelberger approached Self to sell a new medium bomber, the B-25 Mitchell. Instead, Self asked if NAA could manufacture the Tomahawk under license from Curtiss.Kindelberger replied that NAA could have a better aircraft with the same engine in the air in less time than it would take to set up a production line for the P-40.
But don't you see why that damns your argument? Why did Kindleberger suggest something better (that didn't even exist yet!) if the P-40 had so much development potential left in it?

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.
I'd wager the other part was the lack of anything else to choose from; you can come close just by being the best of a bad bunch...

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.
We've yet to nail this elusive potential of yours...
I don't really see anything that provides any new clarity in the rest of the piece in fact, I'd say it rambles a bit

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?
I don't think anyone pointed that out.
The XP-40Q had a -121 Allison with two-speed supercharging and water injection good for around 1430hp - I'd call that a decently powerful powerplant. I'm not really sure what the rest of this piece is trying to tell me either.

Dude. The Fw190, with its radial engine, was a poorer high-altitude performer than the Bf109. And yet, the 190 was preferred because most dogfights took place below 15,000 feet, where the 190 was superior
At the time of the Fw190's introduction to the ETO it was pasting Spitfire Vs left, right and centre. The RAF was getting kicked in the teeth. It wasn't until the introduction of the Spitfire IX that they had a hope of engaging the Fw190 on something like level terms, or not, if they chose to remain at altitude. The 190, unlike the P-40, was able to develop into something that could redress the balance and kept developing until the end of the war. This is the train that you keep missing, development potential - the P-40 didn't have alot of it

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
That's still not a good enough reason to keep the P-40

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.
Fighter comparisons are usually made with all things being equal eg both at same altitude, both at their optimal cruising speed, both pilots see each other at the same time etc etc. The P-51 could be a thousand yards away before... yes and by that standard of comparison the P-40 could be tucked underneath the P-51 in his blind spot and gun him down before the P-51 knew what hit him. There are countless instances where a P-40 could shoot down a P-51 but my money's still on the P-51.

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.
That wasn't my logic at all (and alot of your argument seems to centre around this technique; I have to search my previous posts trying to figure out which of my responses you are countering). I did say that and I maintain that argument, it wasn't originally designed for that. But here comes that term again development potential - the P-51 evolved into the role. Pure interceptors on the other hand are simply the smallest possible airframe wrapped around the biggest possible engine, not alot of room for internal, range-extending fuel.
Neither the 109 nor the 190 series were obsolete and continued to be a headache for Allied escort pilots up until the end of the war.

 

[Colin1]

I guess this would depend on how much different the A-model mustangs were from the D-models that went into Germany.
There you are, some homework for you

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?
This is the corner you've fought yourself into; yes, I would like to see at least some documentation that supports this.

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.
No, I'm not arguing anything, you are arguing that the P-40 was a better multi-role (better than what, you don't say) fighter. You still haven't presented a case for the P-40 multi-role supremo

Yes, I eagerly await the rest of the forum telling me how an excellent power to weight ratio is not tremendously useful.
Excellent power to weight ratio? Presumably this explains the P-40's less than sparkling climb rate? However, you did, as ever, respond to a point I wasn't making, that of the Bf109 being inferior in every respect; I'm sure there more learned Bf109 students than I on here who will tell you exactly what a Bf109F would make of a P-40

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.
Wrong way around, the P-40 was pretty dirty, I don't believe the A6M could be described as very dirty. The rest of the piece is back in ramble mode I'm afraid, I'm not sure what you're trying to say

 

[Demetrious]

Not THAT funny, I don't recall Jesus ever flying a P-40 but you might want to consider that line of response could well be offensive to any number of members on here.

Yes, in the same breath that I mention Optimus Prime- thus establishing that I am referencing both as examples of supreme, unassailable power? Yes, what a shattering insult to the Christian faith, of which I am a member. I expect adults- especially the people I have been privileged to speak with on this forum- to be rational enough to understand what is being said.

You will need to spell out exactly why you think the P-40 had more potential that it was given credit for and it won't do you any good trotting out the 'fit it with a Merlin' argument again - we've already shown you that in the P-40F and L it didn't exactly light the plane up.[/B]

Listen very carefully, because I am tired of repeating myself.

• The P-40 had an excellent turn rate, better then most fighters of the war.
• The P-40 had an excellent roll rate, better then most fighters of the war.
• The P-40 was a very durabe fighter, able to absorb much damage.
• The P-40's performance suffered only because of insufficient engine power, which was easy to remedy with a more powerful powerplant.
• In short, the only aspect of the P-40s performance that was lacking was the powerplant. With the addition of a more powerful engine, the otherwise-excellent performance characteristics of the P-40 would have kept it a competetive fighter.

But don't you see why that damns your argument? Why did Kindleberger suggest something better (that didn't even exist yet!) if the P-40 had so much development potential left in it?

Because people disagree. Just because Kindleberger said the P-40 was tapped out doesn't mean it was. A disagreement between the Army and the Navy over the B-36 bomber led to something called the "Admiral's Revolt."

Oh, and lets not forget that by building their own fighter, North American Aviation wouldn't have to pay a licensing fee to Curtiss-Wright for each fighter built.

I'd wager the other part was the lack of anything else to choose from; you can come close just by being the best of a bad bunch...

It was, in fact.

We've yet to nail this elusive potential of yours...

It's only drawback was a weak engine. There. Put a better engine in it, you have a much better fighter. That's it.

The XP-40Q had a -121 Allison with two-speed supercharging and water injection good for around 1430hp - I'd call that a decently powerful powerplant. I'm not really sure what the rest of this piece is trying to tell me either.

That engine was needed in the production P-40s to improve their performance, not in some ill-conceived "P-51 clone."

This is the train that you keep missing, development potential - the P-40 didn't have alot of it

Prove it. Even the late Merlin-engined models received only 1200hp engines, not the 1500 hp ones they needed. You can't dismiss the P-40s potential simply because nobody actually used it.

That's still not a good enough reason to keep the P-40

The P-40 was tougher, more manuverable, and cheaper. Good enough?

There are countless instances where a P-40 could shoot down a P-51 but my money's still on the P-51.

You fail to understand the scenario that I am describing. Assuming a "fair fight," i.e, both aircraft head-to-head and spot each other at a good distance, the P-51 will not turn in a circle to fight the P-40, but will fly a distance off and turn around to make another pass, by which time the P-40 will be turned around to face it. It will be a series of head-on passes if the P-51 chooses to energy fight.

This is the corner you've fought yourself into; yes, I would like to see at least some documentation that supports this.

Cool, show me some documentation that proves that the P-40s development potential was used up.

Excellent power to weight ratio? Presumably this explains the P-40's less than sparkling climb rate?

You seem to have trouble with basic reading comprehension. I was talking about fighters that DID have good power-to-weight ratio, not the P-40. How could you make this error when I've spent the entire thread talking about how badly the P-40 needed a more powerful engine!?

No, I'm not arguing anything, you are arguing that the P-40 was a better multi-role (better than what, you don't say) fighter. You still haven't presented a case for the P-40 multi-role supremo

Mostly because the P-40 was more durable and was a better gun platform (the P-51 was notoriously twitchy on the controls.) It was a better gun platform because the sturdier wings didn't flex as much, though I don't know if this advantage was marked.

The success of the A-36 as a dive-bomber shows that the P-51 was just fine at jabo, however. I'm not saying the P-40 was "supreme" at multi-role, but there were some reasons to favor it in theaters where ground attack was borne by fighter-bombers instead of high-altitude bombers that required escort.

However, you did, as ever, respond to a point I wasn't making, that of the Bf109 being inferior in every respect; I'm sure there more learned Bf109 students than I on here who will tell you exactly what a Bf109F would make of a P-40

The P-40 had a superior turn and roll rate. The Bf-109 had much better power to weight ratio. I can tell you exactly what a P-40 would make of a 109. It'd save it's airspeed to put it's nose on target if the 109 tried to climb and attack from a dive; dive to the deck to make such attacks more difficult (the ground precludes a diving escape afterward, forcing either a more vulnerable zoom climb or a transition to a slower, more horizontal approach,) and then attempt to force a scissors or turn fight, where the P-40 is dominant. Alternately, the 109 pilot might insist on a series of head-on passes, in which case the victory is down to luck, nerve, and who is the better shot.

 

[drgondog]

I guess this would depend on how much different the A-model mustangs were from the D-models that went into Germany.

Well, the major differences in the A to the B were 1.) drop the wing and redesign the cowl to digest the Merlin, b.) redesign the radiator scoop/cowl, c.) add the 85 gallon fuselage tank, move the carburator intake from top of cowl to 'chin', d.) add about 400 pounds to the airframe.

To go from the A to the D - first add all the above, then redesign the turtledeck/birdcage canopy to accomodate teardrop canopy, add 2 x .50 cal and 600 rounds of ammo, provide structural beef up of vertical stabilizer spar, add wheel uplock kit, add tail ventral fin for models past the -5, change the incidence angle of the horizontal stabilizer, increase the Wing root chord to provide better strength in whell well area, add stronger wing hardpoints to permit 160 gallon ferry tanks or a 1,000 pound bomb.

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.

The 51A/B/C/D/K were designed for 8g Limit/12g Ultimate at 8,000 pounds gross weight. The P-51H was designed for 7.5 g Limit/11g Ultimate at 8,000 pounds gross weight. Source Gruenhagen "Mustang" and Wagner "Mustang Designer"

The 8g/12 g design targets were common US design specs, Both the Brits and LW adopted similar specs for fighter aircraft

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. )

There is no reason, nor is there a body of data, to suggest that one coolant system was 'better' than the other. There is no other frame of reference, including Limit/Ultimate design limits to suggest one is stronger than the other. There is definitely one hazard the 51 had that was more serious than the P-40 - namely Ditching.

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?

Slippery statements. The P-40 in equivalent gross weight operational conditions had slightly better wing loading which suggests that it could make a tighter turn as long as it had the power to sustain that turn in level flight - BUT the 51 was cleaner, had more power to weight, lost energy slower in a turn and could sustain a level turn longer for those reasons. Don't know if a P-40 can gain and SUSTAIN a turn advantage long enough to get on a 51 tail - pilot skill being equal. You have sources of comparative tests to prove your thesis?

As to roll, the P-40 might out roll the 51 at low speed, What is your source to suggest the P-40's superior roll capability and if, cited, for which flight regimes?

So, the 51 had a significant advantage of speed, accleration, climb - marginal advantage/disadvantage in horizontal turn, questionable advantage in roll. The 51 was a superior accelerator in a dive, could far out zoom the P-40 and could largely engage/disengage at will.

Usually one of those will work for you in combat.

I suspect that since the 51 did not fight the P-40 in combat that one has to look to ratios of P-40 versus Me 109/Fw 190 for aircraft similar in 51 performance for a clue. The P-40, relatively speaking, had a far lower air to air ratio in comparison to the P-51



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.

The A-36 was far different from the P-51B. It was a P-51A with dive Brakes. Had 2x .50s mounted below the Allison, had the Dive Brakes - that was about the sum of the differences between A-36 and P-51ASee above comments for differences between P-51A and P-51B


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.

The P-51A and Mustang Mk I and the A-36 fared well with the Allison Engine up to 15-18000 feet. Past the critical altitude for the Allison the top speed and acceleration and climb performance fell off rapidly. Ditto P-40

The P-51B basically outperformed the P-51A in every respect, some wide margins, some lesser margins through 15,000 feet then the P-51B had consistent huge margin of performance over the P-51A.

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.

Actually I believe the P-40E could carry a 1,000 pound bomb on CL and one 500 pounder on the single wing harpoint for a total of 2,000. Couldn't go very far because it had to sacrifice internal fuel for the extra external weight


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.

Can anyone on the forum name Fewer than 10 fighters that would be considered superior to a P-40 as a manueveing dogfighter?

The USSR had at least 5 if you stick with just the Yak and Laag, the Germans at least two without dipping into Fw 190D or Ta 152, the Brits at least three with Spit, Typhoon, Tempest, The Japanese with virtually every low wing fighter after the Type 97.

The Italians had several superior fighters also

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.

I am really curious why you think this. While mV>>2 is classic 'energy', Energy in ACM context is the ability to sustain Velocity in Manuever and to quickly change Energy states (i.e trade speed for altitude - with the better 'energy' going to the fighter that losses less V for the same H, or holds V for greater H) Why do you think the P-40 excels over the Zero in Energy Manueverability in any region except Dive?

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.

Can you step away from your strong affection for the P-40 and think through all the classic comparisons of ACM metrics (WL, Power to Weight Ratio, Roll Rate, Power profile of the Engines) and still make a case that the P-40 was as good as either the Me 109 or Fw 190 or P-51B?

 

[Colin1]

Yes, what a shattering insult to the Christian faith, of which I am a member. I expect adults- especially the people I have been privileged to speak with on this forum- to be rational enough to understand what is being said.
Your arrogance will be your undoing my friend, just because you don't find something offensive doesn't mean others won't. It's precisely because they're adults that you don't need to resort to overblown superlatives normally expected from a teenager

The P-40 had an excellent turn rate, better then most fighters of the war.
The P-40 had an excellent roll rate, better then most fighters of the war.
The P-40 was a very durable fighter, able to absorb much damage.
Yes it did, when did anyone say that it didn't?

The P-40's performance suffered only because of insufficient engine power, which was easy to remedy with a more powerful powerplant.
In short, the only aspect of the P-40s performance that was lacking was the powerplant. With the addition of a more powerful engine, the otherwise-excellent performance characteristics of the P-40 would have kept it a competitive fighter.
There was more to the P-40's lack of power than the engine, it was a dirty airframe and that's where it was out of favour with newer designs. These were complementing the better powerplants with cleaner designs and more efficient methods for dealing with losses around the airframe. That's why the Packard Merlin in the P-40F only made a difference over previous versions of the P-40; stacked up against similarly-engined but newer designs, it wasn't competing.

That engine was needed in the production P-40s to improve their performance, not in some ill-conceived "P-51 clone."
So if the 1500hp Packard wasn't doing it for the P-40, why do you think the 1430hp Allison would have?

Prove it
History

Even the late Merlin-engined models received only 1200hp engines, not the 1500 hp ones they needed.
Packard Merlins were not 1200hp

You can't dismiss the P-40s potential simply because nobody actually used it.
It was used, they wrung as much as they could get from the P-40 airframe and then they moved on.

The P-40 was tougher, more manuverable, and cheaper. Good enough?
No. It wasn't fast enough and couldn't climb well enough; it was turning into a boom and zoom victim for the newer fighters. Cheapness is what mainly kept it in production for so long after its obsolesence.

You fail to understand the scenario that I am describing. Assuming a "fair fight," i.e, both aircraft head-to-head and spot each other at a good distance, the P-51 will not turn in a circle to fight the P-40, but will fly a distance off and turn around to make another pass, by which time the P-40 will be turned around to face it. It will be a series of head-on passes if the P-51 chooses to energy fight.
Oh, I think I understand you; isn't that what Japanese fighters tried to do when the late-war USN fighters came scything through them?

Cool, show me some documentation that proves that the P-40s development potential was used up.
There's one set called NA-73

You seem to have trouble with basic reading comprehension. I was talking about fighters that DID have good power-to-weight ratio, not the P-40. How could you make this error when I've spent the entire thread talking about how badly the P-40 needed a more powerful engine!?
and you seem to have trouble with professional courtesy and manners when presented with an opinion counter to your own. You gave a very strong impression that you were referring to the P-40 when you said that

Mostly because the P-40 was more durable and was a better gun platform (the P-51 was notoriously twitchy on the controls.) It was a better gun platform because the sturdier wings didn't flex as much
Do you know this from your days on flight sims?

I'm not saying the P-40 was "supreme" at multi-role, but there were some reasons to favor it in theaters where ground attack was borne by fighter-bombers instead of high-altitude bombers that required escort
Actually you did, but ground attack, down low, would favour the P-40; let's leave it there and pretend you never said multi-role...

 

[Demetrious]

Can you step away from your strong affection for the P-40 and think through all the classic comparisons of ACM metrics (WL, Power to Weight Ratio, Roll Rate, Power profile of the Engines) and still make a case that the P-40 was as good as either the Me 109 or Fw 190 or P-51B?

Perhaps I'm not making myself clear. I have said- multiple times- that the P-40 was nigh crippled by it's very poor power-to-weight ratio. It had excellent performance in other categories- the airframe was inherently very manuverable- but without a proper engine, it's absolute disability in the vertical allowed aircraft like the Bf-109 to simply extend away, loop over the top, and make diving attacks from above with near impunity.

Now, in 1940, the P-40 was pretty evenly matched with the 109, having superiority in manuverability but inferiority in power-weight ratio. For reference, the A-81 A-2 Hawk had a power-to-weight ratio of 0.31 (Horsepower/Kg.) The Emil Meschersmitt had one of 0.45. By the time the Me-109 Gustav came out, however, the discrepancy in power-weight between the two ships had gone from significant to dominant. By 1942 the Gustav was sporting a 1400 hp engine, while the P-40s engine still labored around 1200hp, where it had been since 1940. (Engine upgrades in the P-40 seem to have improved high-altitude performance, but not actual raw power output on the deck.) This meant that the Gustav had a power/weight of 0.52 hp/kg while the P-40 stayed at 0.31. The discrepancy went from an edge for the Bf-109 to a dominant advantage that the Bf-109 could exploit at will.

A proper powerplant upgrade would have allowed the P-40 to counter the vertical advantage of later Bf-109s with some ability- by giving it enough power to reliably keep it's nose in the air long enough to meet a diving Bf-109 (or Fw-190, for that matter.) The necessity of meeting diving attacks by climbing to meet them was first observed by Boelcke in 1918. This wasn't as important in 1940, when the ability of the Bf-109 to get in such a position, as well as it's ability to extend far enough away to try it, wasn't as pronounced, but by the time the Gustav model came out, it was imperative.

This same analysis can be applied to both the P-51B and Fw-190. Even though neither of these aircraft were known to be great climbers, the P-40 was such a poor one that it really didn't matter.

I took some time to type up this explanation, so I'd appreciate it if you didn't dismiss it as my "affection for the P-40."

Now, on to Colin!

Your arrogance will be your undoing my friend, just because you don't find something offensive doesn't mean others won't. It's precisely because they're adults that you don't need to resort to overblown superlatives normally expected from a teenager

It's called hyperbole, and it is a useful literary technique.

There was more to the P-40's lack of power than the engine, it was a dirty airframe and that's where it was out of favour with newer designs. These were complementing the better powerplants with cleaner designs and more efficient methods for dealing with losses around the airframe.

Agreed. The P-40 was not, and never would be, a high-speed energy fighter. The issue of the powerplant was simply that it required mediocre, adequate performance in speed and power-to-weight ratio, elsewise it's advantages could be neutralized handily.

Packard Merlins were not 1200hp

Which models received 1500hp Merlins? Wikipedia says that even the late-model N production runs were still being fitted with Allisons. Did any other model besides the experimental Q prototype mount a Packard Merlin? I throw myself upon the greater knowledge of my fellows here, for I know not.

So if the 1500hp Packard wasn't doing it for the P-40, why do you think the 1430hp Allison would have?

Who says the 1500hp Packard wasn't doing it for the P-40? Just because the P-40 so equipped wasn't as fast as the P-51? A P-40M Warhawk with a 1500hp engine would have had a power-weight ratio of 0.51 hp/kg. Or the 1400hp Allison, which would yield a ratio of 0.47, still much better. (I'm still curious as to why that Allison engine in the P-39 was never put in the P-40- technical difficulties, perhaps?) The Allison in the P-39 was most certainly available by 1942.

No. It wasn't fast enough and couldn't climb well enough; it was turning into a boom and zoom victim for the newer fighters.

All which could have been greatly alleviated by a better powerplant. This is what I'm trying to say- all the reasons that you give for why the P-40 was lacking could have been addressed with a better powerplant. It wouldn't have eliminated them, but they would have been far less problematic.

Oh, I think I understand you; isn't that what Japanese fighters tried to do when the late-war USN fighters came scything through them?

Scything? Not even a Hellcat driver was eager to pit his ship against the firepower of the Zero's 20mm cannons. No, the scything owed much more to other factors, not the least of which being the Zero's high vulnerability and the rapid attrition of trained Japanese aviators.

Ask any WWII pilot what attack he'd prefer- a head-on attack, or an angle where the enemy couldn't shoot back at him- and I think you'll get the latter reply every time.

There's one set called NA-73

I addressed that already.

and you seem to have trouble with professional courtesy and manners when presented with an opinion counter to your own

If I didn't want your opinion I'd hardly be discussing the matter with you! It's simply very frustrating to spend so much time and effort making these verbose and detailed posts, only to have my meaning inverted 180 degrees several times by accident.

Do you know this from your days on flight sims?

While we're discussing politeness, we might say a few things about your condescending, high-handed attitude. I try not to read too much into these things- much is lost in translation in the textual medium, after all- but it's poor form to call me impolite and then use an insult yourself in the next breath.

 

[Demetrious]

Sorry for the double post ladies and gentlemen, but Colin requested proof of the P-40s structural strength, and I was able to find it for him:

On the whole, because of their durability and flight range, the pilots liked both the Tomahawk and the Kittyhawk. The strength of its 5-longeron wing became legendary after an aerial engagement on 8 April 1942 [19]. On this day, flight commander Lieutenant Aleksey Khlobystov rammed German aircraft two times in a single engagement. He cut off the tail assembly of one Messerschmitt in an overtaking maneuver and severed a portion of the wing of a second Messerschmitt. Both times he struck the enemy aircraft with the same right wing panel. Both Messerschmitts went down and the Tomahawk landed safely at its airfield, where it was repaired without any particular difficulty. Its pilot, who did not suffer even a scratch, was recommended for the HSU rank and received the monetary bonus of 2000 rubles for two destroyed enemy fighters.

The source is here:

The P-40 in Soviet Aviation

This confirms the claim of a five-spar wing, and the strength offered by it. Finding similar data to compare the P-40 to the P-51 might be difficult, but I'll see what I can find regarding the P-51 in mid-air collisions- or even wing diagrams showing the number of spars.

The best I can do for now is this: http://img155.imageshack.us/img155/7608/1222905782388.jpg

I think that diagram shows a two-spar wing, but I can't be sure. In any case, it makes a lovely desktop.

 

[Colin1]

...ladies and gentlemen, but Colin requested proof of the P-40s structural strength, and I was able to find it for him

It won't take much detective work for your ladies and gentlemen to realise that I made no such request. I do however, recall saying this:-

The P-40 was structurally a strong aircraft... ...it was a robust fighter in a whole inventory of robust fighters

I don't require any such proof and neither I suspect, does anyone else.

Its structural strength wasn't enough to prevent the P-40 from being rendered obsolete.

 

[Demetrious]

It won't take much detective work for your ladies and gentlemen to realise that I made no such request.

All anybody has to do is scroll up to see this:

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?
This is the corner you've fought yourself into; yes, I would like to see at least some documentation that supports this.

Your reply, as per your standard practice, is the one in bold- specifically requesting documentation to support my comparison of durability.

In any case, the same article, in the footnotes, says that a one or two spar wing was the norm in those days. I think it's a safe assumption that the P-40 paid for the extra structural strength from three additional spars with equivalent weight.

drgondog: An apology is in order, I missed 9/10ths of your last post, because it was in a quote box. I didn't realize you'd replied in bold.

Well, the major differences in the A to the B were 1.) drop the wing and redesign the cowl to digest the Merlin, b.) redesign the radiator scoop/cowl, c.) add the 85 gallon fuselage tank, move the carburator intake from top of cowl to 'chin', d.) add about 400 pounds to the airframe.

To go from the A to the D - first add all the above, then redesign the turtledeck/birdcage canopy to accomodate teardrop canopy, add 2 x .50 cal and 600 rounds of ammo, provide structural beef up of vertical stabilizer spar, add wheel uplock kit, add tail ventral fin for models past the -5, change the incidence angle of the horizontal stabilizer, increase the Wing root chord to provide better strength in whell well area, add stronger wing hardpoints to permit 160 gallon ferry tanks or a 1,000 pound bomb.

Thank you! So the D-model Mustang gained a lot of weight, but the cutting down of the fuselage behind the cockpit eliminated some weight in turn and improved the aerodynamics of the ship? I'd assume the D model was faster, but the B model, lighter (and probably the better climber,) and the A model, even more so.

There is no reason, nor is there a body of data, to suggest that one coolant system was 'better' than the other.

Agreed. A liquid cooled system is a liquid cooled system is a liquid cooled system. The only real difference is how much armor any given plane had installed around it.

Can anyone on the forum name Fewer than 10 fighters that would be considered superior to a P-40 as a manueveing dogfighter?

The USSR had at least 5 if you stick with just the Yak and Laag, the Germans at least two without dipping into Fw 190D or Ta 152, the Brits at least three with Spit, Typhoon, Tempest, The Japanese with virtually every low wing fighter after the Type 97.

What?

The P-40 was one of the tightest-turning monoplane fighters of the entire war. It could do a 360 in 20 seconds, whereas most Bf-109 variants required 23. It could also outroll the Spitfire (at higher speeds,) easily outroll the Tempest, and the roll rate of the Zero was just hopeless (the Type 97 was a bit better.) The only ship that could really out-turn the P-40 was the Spitfire (I've seen numbers from 17-19 for the Spitfire.) I'll try to find a single chart that compares the P-40 and P-51 turn radius/rate (so don't be surprised if I edit.)

EDIT: Righto, I've found some data given by our fellows on this very forum in days past; attributed to Soviet testing:

Soviet Testing of the P-40. That seems to confirm my "19-20" second figure, at any rate. I'll see if I can find us data on the P-51s rate.

EDIT THE SECOND:

The turning characteristics of the subject aircraft are substantially the same as the P-40F and the P-39D. None of these appears to have any definite superior turning characteristics.\

In close "dog fighting" the subject aircraft has the very decided advantage of being able to engage or break off combat at will. However, if neither airplane attempts to leave the combat, the P-40F is considered to have a slight advantage.

Source: World War II Aircraft Performance.

"Turn rate," is only one axis of manuverability. Roll rate is more important, since every aerobatic maneuver starts with a roll. For this reason I'd rate the Fw-190 as superior in maneuverability, because even though the P-40 could out-turn it without much trouble, nothing, absolutely nothing, could touch the 190s roll rate.

Slippery statements. The P-40 in equivalent gross weight operational conditions had slightly better wing loading which suggests that it could make a tighter turn as long as it had the power to sustain that turn in level flight - BUT the 51 was cleaner, had more power to weight, lost energy slower in a turn and could sustain a level turn longer for those reasons. Don't know if a P-40 can gain and SUSTAIN a turn advantage long enough to get on a 51 tail - pilot skill being equal. You have sources of comparative tests to prove your thesis?

Well, pretty much everything I've read gives the P-51 24 seconds to make a 360 degree turn- but I'll say now that that usually doesn't tell the whole story, since there are so many other factors effecting turn rate.

What is this about "sustaining a level turn longer?" Planes don't just turn and turn until they fall out of the sky, they have a "sustained turn speed," at which the difference between induced drag by high AoA and engine power balance out. The sustained turn speed for the P-51 is most certainly higher then the P-40, for all the reasons you named- it's a cleaner ship with a bigger engine. Another consideration is that pure wing loading doesn't tell the whole story with the '51- the laminar flow wing made for less drag then another wing with the same wing loading, allowing the '51 to keep a higher energy state then another aircraft with the same wing loading- and thus make a faster turn.

However, that higher speed meant the turn radius would be larger, as well, so the P-40 would be able to turn inside the -51. This explains the phenomena nicely.

As to roll, the P-40 might out roll the 51 at low speed, What is your source to suggest the P-40's superior roll capability and if, cited, for which flight regimes?

You're in luck, some nice people in another thread just showed me this: Roll rates. Observe how the P-40 is superior to the P-51 until about 280MPH, where they balance out. The Mustang is truly designed to work with speed.

I am really curious why you think this. While mV>>2 is classic 'energy', Energy in ACM context is the ability to sustain Velocity in Manuever and to quickly change Energy states (i.e trade speed for altitude - with the better 'energy' going to the fighter that losses less V for the same H, or holds V for greater H) Why do you think the P-40 excels over the Zero in Energy Manueverability in any region except Dive?

Oh, simple. really. Since mV>>2 determines total energy, and the P-40 had more mass then the Zero, at the same airspeed, the P-40 had more energy stored in it then the Zero. This meant that it could bleed off more during violent maneuvers and still have some left to work with. Since both aircraft had about the same wing area- and thus induced about as much drag at any given angle of attack- the P-40 held more energy simply because it entered the fight with more.

The superior power to weight ratio of the A6M, however, meant it could replace energy much faster. P-40 pilots had to make very sure they didn't bleed off too much energy with needless maneuvers, because replacing it without trading altitude would be hard.

Again, all the P-40s problems come calling right back to the power plant, don't they?

 

[claidemore]

Again, all the P-40s problems come calling right back to the power plant, don't they?

Actually the P40 had a few other problems.
Stability comes to mind, something they finally addressed with the N models by lengthening the fuselage.
They also required constant trimming, something that made them somewhat dangerous in the ground attack role, particularly for bombing, and something that kept the P40 pilot task overloaded in a dogfight.
Here's a quote from Wing Commander James Edwards who flew Kittyhawks in North Africa.

On the P40 series:

"... not an easy aircraft to fly properly and as a result, we lost a good number of pilots while training."
"In the first few months after conversion to Kittyhawks, all the squadrons lost heavily to the 109s."
"I found that one had to have a very strong right arm to fly the Kittyhawk I during most maneuvers. In dive-bombing, the aircraft would pick up speed very quickly in the dive, but it had a great tendency to roll to the right. One could trim this out reasonably well with the left hand, but even then when one pulled up, it wanted to roll to the left quite viloently. So I learned to trim about halfway in the dive and hold the control stick central by bracing my right elbow against my right leg and the right wall of the cockpit. It was also distracting to have one's left hand on the trim all the time, when it should be on the throttle."
"In a dogfight, with violent changes of speed, it was all one could do to fly the aircraft."
"Kittyhawk II... was a definite improvement in lateral stability over the Kitty I."
"Eventually, with the Mk IIIs, the Kittyhawk became a good, stable fighting aircraft, although it never did have enough power or climbing ability compared to the 109s or the Spitfire."

Also a quote about reliability of armament in desert P40's.

A new, and deadly, problem cropped up for the Kittyhawk pilots. Under the high-g forces of dog-fighting and severe dust conditions their six .50 caliber guns would often develop stoppages. They would get in a few bursts and then nothing. In the middle of a dog-fight they would be left without guns. No doubt, many Kittyhawks and pilots were lost because of this problem. The problem never was completely fixed on Kittyhawks, the guns were always unreliable in the desert.

The landing gear was also 'relatively narrow' which did lead to some accidents. The 109 and Spitfire had the same fault, though for some reason the Spit never got a rep for ground accidents.

 

[Colin1]

Originally Posted by Colin
As to roll, the P-40 might out roll the 51 at low speed, What is your source to suggest the P-40's superior roll capability and if, cited, for which flight regimes?

Though irritating
it's one thing to suggest I submitted a post when people can check that I clearly didn't, it's quite another to doctor a post to make it look as if I posted it.

Your incoherent ramblings are beginning to cross the line of decent behaviour, kindly refrain from this in future.

 

[Demetrious]

Actually the P40 had a few other problems.
Stability comes to mind, something they finally addressed with the N models by lengthening the fuselage.

They also required constant trimming, something that made them somewhat dangerous in the ground attack role, particularly for bombing, and something that kept the P40 pilot task overloaded in a dogfight.
Here's a quote from Wing Commander James Edwards who flew Kittyhawks in North Africa.

Clive Cadwell, highest scoring Aussie ace and a pilot in the African theatre, had this to say:

The highest-scoring P-40 ace, Clive Caldwell (RAAF), who scored 22 of his 28.5 kills in the P-40, said the type had "almost no vices", although "it was a little difficult to control in terminal velocity".

That seems to confirm that the P-40 was tricky in the dive, but (seems) to conflict on stability. Not that surprising, however- P-47 pilots transferring to the P-51 often complained about how twitchy and sensitive the controls were, when even the official evaluations of the P-51 praised it's exceptionally stable handling.

All in all I'm inclined to believe that the P-40 was on the unstable side, because the N-models weren't lengthened for giggles, after all. Clearly it was a difficult aircraft to exploit to it's fullest.

By all accounts the P-40 was a good gun platform (owing primarily to the strength of the wings, which didn't vibrate as much, and the weight of the aircraft,) but problems with inherent stability would counteract that. In any case it doesn't seem to be as good a jabo fighter, if only for the problems in a dive.

Another issue with it's ground attack ability is an anecdote I recall from God is My Copilot, where it was said that a dive angle of over 30 degrees was avoided, because the centerline mounted bomb might strike the prop as it separated.

Hmm, perhaps the P-51 and variants really were the better Jabo fighters!

Also a quote about reliability of armament in desert P40's.

Was this a problem attributable to the P-40s design, or the M2 Brownings? Maintenance of machinery in a desert environment is notoriously difficult, since sand is so damaging and gets into everything. Designs that expose too many critical components don't help, however.

Though irritating
it's one thing to suggest I submitted a post when people can check that I clearly didn't, it's quite another to doctor a post to make it look as if I posted it.

Your incoherent ramblings are beginning to cross the line of decent behaviour, kindly refrain from this in future.

My apologies, sir. In trying to respond to both you and drgondog at the same time, I accidentally typed your name into those quote tags instead of drgondog. This is a typo, nothing more.

I can only assume that you thought that quote was the request for technical information I asserted you had requested. You were asking after comparative durability, not roll rate, of course, and you asked for that verification in this post (most recently.) You were well within your rights to request supporting data, I might add.

 

[drgondog]

All anybody has to do is scroll up to see this:

In any case, the same article, in the footnotes, says that a one or two spar wing was the norm in those days. I think it's a safe assumption that the P-40 paid for the extra structural strength from three additional spars with equivalent weight.

Hard to say D - the spar design approach is a shear web with caps top and bottom. The 'taller' the spar, the more effective it is in taking out bending loads - but also heavier.


Thank you! So the D-model Mustang gained a lot of weight, but the cutting down of the fuselage behind the cockpit eliminated some weight in turn and improved the aerodynamics of the ship? I'd assume the D model was faster, but the B model, lighter (and probably the better climber,) and the A model, even more so.

About 600 pounds, and conversely the H brought the weight back down.

Almost 50% of the extra weigt in the D was in 2 extra 50's plus six hundred more rounds. The aerodynamic differences were negligible with perhaps a slight nod to the D teardrop canopy

What is this about "sustaining a level turn longer?" Planes don't just turn and turn until they fall out of the sky, they have a "sustained turn speed," at which the difference between induced drag by high AoA and engine power balance out.

In a Free Body Diagram of this system, the force balances are T=D and Drag has components of Induced Drag and Parasite Drag. Thrust is Hp related and is a function of velocity and Hp performance, which in turn is a function of air density and performance of the supercharger system.

Parasite Drag will dominate at high speed and induced Drag dominates at low speed. In addition, the wild card factors are stick forces for elevator and rudder as well as Trim drag component of Parasite Drag as the elevator/rudder deflections increase in the manuever - which ones do you want to talk about?

The sustained turn speed for the P-51 is most certainly higher then the P-40, for all the reasons you named- it's a cleaner ship with a bigger engine. Another consideration is that pure wing loading doesn't tell the whole story with the '51- the laminar flow wing made for less drag then another wing with the same wing loading, allowing the '51 to keep a higher energy state then another aircraft with the same wing loading- and thus make a faster turn.

You are correct that no combat manuever would be flown with an attempt to remain at a constant altitude. Having said that, that IS one metric of best turn Time .

That being said D- are you 'engineering' in a 'no engineering zone'. While I agree with much of what you just said I am curious regarding how deep you want to go in the math?



Oh, simple. really. Since mV>>2 determines total energy, and the P-40 had more mass then the Zero, at the same airspeed, the P-40 had more energy stored in it then the Zero. This meant that it could bleed off more during violent maneuvers and still have some left to work with.

You care to display the math? Start with Thrust = Drag. Supply the CD0 of both ships and look up Cl as f(AoA) so we can get Induced Drag at all velocities of interest, Lets get the Hp charts, the gross weights you want to talk about and forget about trim drag at high AoA for the moment.

Prove your thesis?

Since both aircraft had about the same wing area- and thus induced about as much drag at any given angle of attack- the P-40 held more energy simply because it entered the fight with more.

If it entered the engagement with approximately the same velocity it has more initial system energy by virtue of extra mass. The problem with the P-40 is that the Wing Loading is much higher, it has less Hp/mass to transfer continuously to Thrust Req'd to sustain the rate turn of the Zero.

If the P-40 engages in turning manuever a) it loses velocity faster than the Zero, and b.) the only remaining manuever the P-40 may perform to re-generate system energy is to intially trade altitude (potential) energy by diving to regain velocity. The Zero may outclimb, out accelerate, out turn the P-40 as ACM options. When the speed of the ships reduces below 300mph the Zero also out rolls the P-40.

Usually one of those manuevers will work for you.

The superior power to weight ratio of the A6M, however, meant it could replace energy much faster. P-40 pilots had to make very sure they didn't bleed off too much energy with needless maneuvers, because replacing it without trading altitude would be hard.

Hmmm. You just spent a couple of lines describing why the P-40 had energy to burn in violent manuevers

Again, all the P-40s problems come calling right back to the power plant, don't they?

No D, they also reduce to aerodynamics. In ACM, stick forces for roll and turn are also important and differed quite a bit between various WWII ships. ALL airframe design is a study in performance trade-offs for the target mission but all things being equal you are better served with the cleaner airframe.

 

[Colin1]

...the P-40 could keep more of it in the first place through violent manoeuvres

...P-40 pilots had to make very sure they didn't bleed off too much energy with needless manoeuvres

So which?

 

[Colin1]

My apologies, sir. In trying to respond to both you and drgondog at the same time, I accidentally typed your name into those quote tags instead of drgondog. This is a typo, nothing more.

I can only assume that you thought that quote was the request for technical information I asserted you had requested. You were asking after comparative durability, not roll rate, of course, and you asked for that verification in...

Fair enough
though I'm not sure what this 'sir' thing is all about...
I do recall the post, but it was some documentation from a general call for any documentation to support your notion in its entirety; what can you see that the 1940s powers-that-were couldn't see in the P-40? I'm reasonably well-versed in how the US thought fighters should be built

 

[Demetrious]

Hard to say D - the spar design approach is a shear web with caps top and bottom. The 'taller' the spar, the more effective it is in taking out bending loads - but also heavier.

Interesting. We'd probably need more detailed schematics to be sure.

Parasite Drag will dominate at high speed and induced Drag dominates at low speed. In addition, the wild card factors are stick forces for elevator and rudder as well as Trim drag component of Parasite Drag as the elevator/rudder deflections increase in the manuever - which ones do you want to talk about?

All of them, actually...

That being said D- are you 'engineering' in a 'no engineering zone'. While I agree with much of what you just said I am curious regarding how deep you want to go in the math?

As far as you can take me! Some months ago I heard some people calling the P-51 a mediocre turner, and started investigating wing loading data. I suspected that wing loading was far from the only determinator of turn rate, and soon I was into drag coefficients. And then there was turn rate vs. turn radius to consider...

Suffice it to say I still don't understand the aerodynamic principles effecting turn performance nearly as well as I'd like to.

You care to display the math? Start with Thrust = Drag. Supply the CD0 of both ships and look up Cl as f(AoA) so we can get Induced Drag at all velocities of interest, Lets get the Hp charts, the gross weights you want to talk about and forget about trim drag at high AoA for the moment.

Prove your thesis?

Assuming an equal playing field- that is, both aircraft at co-alt, and having had time to build to their maximum speed at the given altitude (which was pretty much the same for the Zero and the P-40 for much of the war,) the P-40 will have more initial kinetic energy simply because it has more mass.

If it entered the engagement with approximately the same velocity it has more initial system energy by virtue of extra mass. The problem with the P-40 is that the Wing Loading is much higher, it has less Hp/mass to transfer continuously to Thrust Req'd to sustain the rate turn of the Zero.

Sustain the turn rate? I never suggested the P-40 could keep a sustained turn with a Zero, never (and if I did, I was telling lies.) The wing loading of a Zero is insanely low.

If the P-40 engages in turning manuever a) it loses velocity faster than the Zero, and b.) the only remaining manuever the P-40 may perform to re-generate system energy is to intially trade altitude (potential) energy by diving to regain velocity.

Are you saying that the P-40, while having more initial energy, also bleeds it off faster in any given maneuver? Fast enough to negate it's advantage?

When I speak of energy fighting, I speak of maneuvers that take advantage of instantaneous turn rate, but not ones that continue long enough to continually sap energy. Simply put, I imagine a P-40 pulling a hard instantaneous turn to gain lead on a Zero for a shot, and yet still keep enough kinetic energy that it will be safely out of guns range by the time the Zero reverses to put it's nose on target.

The Zero may outclimb, out accelerate, out turn the P-40 as ACM options. When the speed of the ships reduces below 300mph the Zero also out rolls the P-40.

This chart from WWII aircraft performance has the Zero rolling significantly worse then the P-40 at all speeds, at 10,000 feet.

Your sources may vary, of course. I sadly haven't found any other roll comparison charts yet to compare with this one.

Agreed on the climb and accelerate parts, however. A P-40 pilot really has to be careful not to let a Zero boom and zoom them (thankfully they're not the best at that,) and use their roll rate to turn a defensive situation into an offensive one. That, and keep their speed up, with the exception of guns defense break turns.

Hmmm. You just spent a couple of lines describing why the P-40 had energy to burn in violent manuevers

So which?

The P-40 started a fight with a Zero with a superior cache of energy, but once that energy was gone, it was gone. This principle of course applies to all energy fighters and all energy fighting- no aircraft can accelerate fast enough to escape an enemy right on their six that they've foolishly slowed down to furball with- but in the P-40s case the underpowered engine made this rule an absolute. Where other fighters could burn off a little more energy and replace it with good acceleration, the P-40 simply could not.

EDIT:

Fair enough
though I'm not sure what this 'sir' thing is all about...
I do recall the post, but it was some documentation from a general call for any documentation to support your notion in its entirety; what can you see that the 1940s powers-that-were couldn't see in the P-40? I'm reasonably well-versed in how the US thought fighters should be built

I call everybody sir. It's polite.

I think the powers that be back in the 1940s could see plenty in the P-40- it was just that by the time they had proper engines available for the P-40, they also had brand-new fighters available as well. I certainly can't fault them for going the route they did; that's just the way history played out.

 

[Glider]

Its understandable that we tend to emphasise the fighter abilty of an aircraft. However its worth remembering that the P40 was a very capable GA aircraft able to carry a payload that at the time, few other aircraft could carry.

Yaks, Zero's, Ki43, Me109's Spitfires and Hurricanes couldn't match it.

For that alone it deserves bonus points.

 

[slaterat]

Hurricanes lugged 2 x 500lbs, I thought the P40 was only good for a single 500lber.

slaterat

 

[Glider]

I have seen pictures of P40's carrying 3 x 500lb bombs and even 6 x 250lb bombs but the most I have seen on the Hurricane was 2 x 250lb.
I believe the impact on range was greater on the Hurricane than on the P40 and often in the Far East the Hurricane carried one bomb under one wing and a drop tank on the other, the same with 4 x rockets on a wing.

Certainly could be wrong on this and any information welcome

 

[Elvis]

Demetrious,

You aluded, in a post that appears on page 8 of this thread, that the V-1710-63 engine, used in the P-39D, made 1600HP.

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.

Actually, it made 1325HP @ 3000 RPM on take-off 1150HP @ the same RPM @ 11800 ft.
It seems that Curtiss skipped this particular version of that engine and went straight to the "-73", going on to mount the "-81" and finally, the "-99" versions of this engine in successive models of the P-40.
The "-73" differs from the "-39" in that there is no gun synchonizer installed and it has improved take-off ratings.
Performance for "-73" is as follows:
1150HP @ 3000RPM - take-off
1150HP @ 3000RPM @ 11800 ft.
The "-81" differed from the "-73" in the supercharger's gear ratio and and it was equipped with an automatic boost control.
Performance for the "-81" is as follows:
1200HP @ 3000RPM - take off
1125HP @ 3000RPM @ 14600 ft.
The "-99" differed from the "-81" due to an "engine regulator" (define that as you will. Sounds like a governer to me) and an automatic manifold pressure regulator.
Performance for the "-99" is as follows:
1200HP @ 3000RPM - take off
1125HP @ 3000RPM @ 15000 ft.

On page 9, you stated you were unaware that a 1200 HP Packard-Merlin engine was used.

Wikipedia says that even the late-model N production runs were still being fitted with Allisons. Did any other model besides the experimental Q prototype mount a Packard Merlin?

The "F" and "L" versions of the P-40 both utilized the Packard-Merlin engine.
I understand the practice was halted due to engine manufacture needed for P-51 use.
Also, the Packard-Merlin used in those P-40's was the 20 ("XX") series engine, which only made about 1300HP.

Here's the link to the Allison engine info - ModDesig

Here's the link to the Packard-Merlin engine info - http://www.raafwarbirds.org.au/targetvraaf/p40_archive/pdfs/1650-1.pdf

Here's the link to the P-40 info - Perils P40 Archive Data


Ok, that was all.
Pardon the intrusion.





Elvis