P-40B Climb rate to low...

[Krusty]

FYI: according to WRG:

"Climb to 14,000 ft.: 6 minutes 42 seconds
Service Ceiling: 31,000 ft. (9450m)"

Do the math, 14000 / 6.75 = 2074.074...

This is a plane with a weaker engine than its contemporaries, yet it was massively heavier than its contemporaries. HT has mentioned before in one of those long winding technical threads that climb is a product of excess power. Well this plane wouldn't have any. Even if it weighed as little as a spitfire or 109 it still wouldn't climb anywhere near as well because it has a weaker engine (without boost, to boot) with a draggier design.

The p40 was considered obsolete in most cases. Hell the P40B didn't even have bomb shackles or a GUNSIGHT. It had a ring-and-ball sight, which AH did away with (good call).

I don't think this plane would EVER do 3000 fpm. The physics don't add up when considering lighter planes with more powerful engines were barely reaching 3000 fpm.

[StarOfAfrica2]

Umm.  Krusty.  This is an airplane, not a boat.  Power to weight ratio is not the only factor involved in ROC.  I'm not going to pretend to know off the top of my head what kind of drag a P40 has, nor do I know how much lift the wings produce.  Many things seem improbable at first glance, but work just fine in spite of that.  Lets get some facts on the physics of the design and not just opinion?  Anyone?

[Krusty]

Hey, I'm just recounting what HT himself posted. He posted this a couple months back if I'm not mistaken but I can't remember in which thread.

[StarOfAfrica2]

I understand that sir.  But you need to broaden your idea of what constitues "energy".

[Karnak]

Krusty,

You forgot the "Divine Favor" trait that American aircraft are all granted by God.  

[Squire]

In fairness it had a reflector gunsight, the ring and bead was a backup just like it was in other designs, like the A6M2. As for lack of bomb racks, it wasn't designed as a fighter-bomber.

The rest of it I agree with, it has an unboosted engine and weighs 1000-1500lbs more than a Spit IA or a Bf 109E, and so there is simply now way it can climb as fast.

The production P-40s did not have turbo superchargers, same as the P-39s, and for the same reason its performance was sub par.  The unboosted Allison was simply in no way a contemporary of a Merlin or a DB601.

The info I have is that the YP-40 had a 3000 fpm climb rate, but does not say (as I suspect) that that was with a non standard supercharger installed, and a lighter design than a P-40B.

They said the same thing about the YP-39, it was fast and had pretty good performance, and then the design they built for the USAAC had no supercharger, and added weight, and was a dog as a result above 10k.

Imho its unforgivable that the USAAC agreed to recieve th P-40 and P-39 with unboosted engines, what they were thinking I have no idea. Hell of a thing to save money on in a fighter.

[Krusty]

I found one source that listed the XP-40 stats, it had only 4 guns (2x 50cal under cowling, 1x 30cal in each wing) and it had a supercharged engine, which was NOT on the production model.

[Widewing]

Originally posted by Squire
In fairness it had a reflector gunsight, the ring and bead was a backup just like it was in other designs, like the A6M2. As for lack of bomb racks, it wasn't designed as a fighter-bomber.

The rest of it I agree with, it has an unboosted engine and weighs 1000-1500lbs more than a Spit IA or a Bf 109E, and so there is simply now way it can climb as fast.

The production P-40s did not have turbo superchargers, same as the P-39s, and for the same reason its performance was sub par.  The unboosted Allison was simply in no way a contemporary of a Merlin or a DB601.

The info I have is that the YP-40 had a 3000 fpm climb rate, but does not say (as I suspect) that that was with a non standard supercharger installed, and a lighter design than a P-40B.

They said the same thing about the YP-39, it was fast and had pretty good performance, and then the design they built for the USAAC had no supercharger, and added weight, and was a dog as a result above 10k.

Imho its unforgivable that the USAAC agreed to recieve th P-40 and P-39 with unboosted engines, what they were thinking I have no idea. Hell of a thing to save money on in a fighter.

All Allisons were supercharged. Allison's V-1710-33 and -35 had a single stage, single speed supercharger. So, they were "blown". Both had critical altitudes of 12,000 and 15,000 feet respectively. That is the altitude where they make max rated power. Performance fell off above that level, but was still adequate up through 17,000 and 20,000 feet, again, respectively. Those are the altitudes where performance really was suffering to extent that they were no longer competitive. You can't make max power at 15k without a supercharger. By the way, the XP-40's Allison V-1710-19 was rated at 10,000 feet for critical altitude.

You keep arguing that the P-40B was too heavy and underpowered to climb well. Of course, you haven't provided one fact to support that, just opinion. Well here's another fact you might not like. A standard P-39D-5, with a 1,150 Allison V-1710-35, weighing 7,631 pounds could climb at 2,400 to 2,500 fpm from the deck up thru 12,000 feet. I'm looking at the AAF climb chart now. It could also attain 365 mph at 12,000 feet, which is faster than the Spitfire Mk.I or the Bf 109E-4. Meanwhile, the P-40B was slightly faster than either of these two at 15,000 feet (352-355 mph) as well. Tomahawks began delivery in September of 1940, as the BoB was winding down. The first P-39C/D types were delivered in January of 1941, before the Spitfire Mk.V entered production.

When it went into combat (December 7, '41 at Pearl Harbor), the P-40B was not the best fighter in the world by any measure, but it was capable of holding its own, which it did.

I don't care who argues what, the fact remains that the Aces High P-40B flight model is incorrect, being at least 20 mph too slow at critical altitude. This is indisputable.

Climb is less than any flight data I have seen, and I've done some digging.

Unless someone has some data that differs from what I've seen, and what I presented to HTC, this debate is hollow.

My regards,

Widewing

[Widewing]

Originally posted by Krusty
FYI: according to WRG:

"Climb to 14,000 ft.: 6 minutes 42 seconds
Service Ceiling: 31,000 ft. (9450m)"

Do the math, 14000 / 6.75 = 2074.074...

This is a plane with a weaker engine than its contemporaries, yet it was massively heavier than its contemporaries. HT has mentioned before in one of those long winding technical threads that climb is a product of excess power. Well this plane wouldn't have any. Even if it weighed as little as a spitfire or 109 it still wouldn't climb anywhere near as well because it has a weaker engine (without boost, to boot) with a draggier design.

The p40 was considered obsolete in most cases. Hell the P40B didn't even have bomb shackles or a GUNSIGHT. It had a ring-and-ball sight, which AH did away with (good call).

I don't think this plane would EVER do 3000 fpm. The physics don't add up when considering lighter planes with more powerful engines were barely reaching 3000 fpm.

Krusty, the Allison V-1710-33 made 1,060 hp at 15,000 feet. That is very competitive with the Merlin III and Merlin XII. The DB 601A made about 1,150 hp, which is the same as the V-1710-35... It was only inferior at higher altitudes. In 1941, the P-40 was something to be reckoned with at lower altitudes.

People forget that the Allison was a very advanced design, having pentroof-type combustion chambers with four valves per cylinder, overhead camshafts with forked roller cam followers actuating pairs of valves in each cylinder.

P-40s had reflector gunsights. When it was introduced, the P-40 was not obsolete. It was still serving in front line combat units well into 1944, and maintained a positive kill to loss ratio, even againt the Luftwaffe in Italy. It wasn't great, but it was adequate when adequate was enough.

My regards,

Widewing

[Squire]

"Of course, you haven't provided one fact to support that, just opinion"

Actually I have provided comparisons of the A6M2, P-40B, Bf 109E and Spit IA engines and weights and climb specs.

As far as its comparison to what date it saw service or how long it saw service, thats irrelevent to the topic, I dont care.

The P-40 had no turbosupercharger, and neither did the P-39. GE could not make enough of them so they went to other designs. That was a USAAC call.

As far as proof goes the onus is on you to prove its climb rate is too slow in AH2, since it has a 2200 fpm initial climb rate in the game.

Its a 1050 hp engine at MILITARY power, in a 7300 lb airframe. If you still want to claim that it had a climb rate of an A6M2 Zero go ahead, wave your pom poms, but good luck convincing HTC.

[Widewing]

Originally posted by Squire
"Of course, you haven't provided one fact to support that, just opinion"

Actually I have provided comparisons of the A6M2, P-40B, Bf 109E and Spit IA engines and weights and climb specs.

You provided numbers extracted from pulp aviation books substantiated by opinion. That's not research, that's humbug.

You keep going on and on about the wonderfull Allison engine, except that your the only one that thought it was great.

I said that the Allison was very advanced, which is a fact.

The P-40 had a supercharger, but I will quote what I have on it "in May 1940 the first P-40s began to come off the production line, the initial 3 being used for testing. These differed from the XP-40 with a less powerfull supercharged Allison V1710-33 engine". In other words, the stats for the XP-40 are not the stats for a P-40 or a P-40B.

The XP-40 was powered by the V-1710-19, which was rated at 1,150 hp at 10,000 feet. At 15,000 feet, the V-1710-33 made 1,050 hp, but the V1710-19 had dropped off to 910 hp at that height. At sea level both engines made 1,050 hp. there's no significant difference. What is your source? Also, did you know that the XP-40 was not flush riveted? Production P-40s incorporated flush rivets, which reduced drag enough to gain 12 mph in max speed. That's right, the P-40B was 12 mph faster than the lighter, but draggy XP-40.

snip-

The fact that is soldiered on in Burma untill 1944 has Jack to do with anything. It faced the Japanese, where their slower and underpowered Ki-43s could still be faced with an obsolete design.

The P-51A with the Allison went to the ETO in 1942 and was also rejected for fighter duty out of hand. Only when it got a Merlin in 1943 did it get serious consideration as a ETO fighter.

I guess you missed the part where I mentioned that P-40s served with distinction in Italy. P-40s were in front line service in Italy well into 1944. Indeed, P-40s performed much of the medium altitude patrols over the Anzio beachhead. There were 3 groups operating the P-40 in Italy, all with the 12th AF. It wasn't until mid summer of '44 that all P-40s in Italy were replaced by newer model fighters. Even the RAF was flying Kittyhawks in Italy until July of '44. P-40s more than held their own against the Luftwaffe, maintaining a 3.5/1 kill to loss ratio against Axis aircraft.

As far as proof goes the onus is on you to prove its climb rate is too slow in AH2, since it has a 2200 fpm initial climb rate in the game.

Its a 1050hp unboosted engine, in a 7300 lb airframe.

IT'S NOT "UNBOOSTED"!! Or don't you understand what "boosted" means?

Both USAAF and Curtiss test data state that the climb rate should be at 2,680 fpm, at the least. I have submitted documentation to HTC establishing that the FM is incorrect. On the other hand, you have quoted nothing but third order sources to argue that the climb rate is correct as it is. Perhaps this never dawned in you, but since the maximum speed of incorrect by a substantial amount, don't you think that the equation used may also directly impact climb and acceleration? I'll wager that it does. So, if they add another 23 mph to max speed, you can bet that the climb rate will increase, as will the rate of acceleration. I have no idea why you insist on arguing this point. We have PROVEN that the flight model is incorrect simply by testing the plane and finding it 20-23 mph slower than it should be.

So, as I said before, unless you have some document that shows an initial climb rate of 2,100 fpm (the best rate I've measured), you're wasting your time arguing.

My regards,

Widewing

[Squire]

WEP, whatever you want to call it...

Btw the P-38G does @ 2700 fpm at MIL so like I said, good luck with that.

Must have special anti-g thrusters in that P-40B.

[EdXCal]

Well lets see, Widewing has used the USAAF and Cuirtis data for fact and all you can do is "comparisons" of other aircraft that have far more facters then power to weight ratio that effect climb.

Posting what another plane can do in comparason has nothing to do with the fact that Widewing has the only actully facts here, you havn't shown a single shred of REALLY documented proof against the P-40's climb rate. Another planes climb has NOTHING to do with the P-40, you have drag, weight (Gravity),  lift (overall wing area) and power to worry about...  Weight and power are half of the ratio, not to mention the prop or gear rations in the engine... Or the airfoil of the wing, look at the P-51, do to it's airfoil it was horrable at low speed even with 233sq ft of wing area, even the lighter models were bad at low speed yet they were a dream at high speeds.

Basicly it comes down to, do you agree with the USAAF and Cuirtis data on the aircraft? If not post your actully documentation that that will prove otherwise... Not comparasons, not quotes, offical documentation, weather it be from USSR, RAF, RAAF, China or USAAF, they all used the P-40 and so they should have some kind of info on the plane, search for it as Widewing did.

Edward

[EdXCal]

Also I too tested the P-40B in AH2, it took me 8 minutes and 15 seconds to reach 15k and once at alt I could only get to 331mph with full fuel. The posted speeds I've seen are 352mph at 15k, so it seems that at the very least I agree that it's if nothing else far to slow, I wonder if this happend in the trasfer from AH1 to AH2?

Edward

[StarOfAfrica2]

Originally posted by Squire
WEP, whatever you want to call it...

Btw the P-38G does @ 2700 fpm at MIL so like I said, good luck with that.

Must have special anti-g thrusters in that P-40B.

"War Emergency Power" and "boost" and "supercharger" and  "turbosupercharger"  are not all interchangeable terms.  "WEP" in game terms implies something you can turn on and off, or runs out after a time limit.  Like nitrous oxide injection, or methanol/water injection systems.  Just because a plane didnt have what you might think of as WEP, does not mean it did not have "boost".  A simple turbo provides "boost" without anything other than air and fuel.  So does a supercharger.  So does a turbosupercharger.  None of those require "WEP" as you may think of it.  Some engines have multi-stage superchargers for different altitudes.  Just because the P40 was relegated to a mid-alt fighter by its lack of a high alt supercharger, does not mean it was obsolete, or incapable.  It was merely limited.  But within those limits it did its job quite well.