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Kwiatos
11-23-2004, 05:30 AM
Hi!
I interesting how real performance had P-39 D. In game expecially version P-39 D-2 has very good climb rate and not bad speed. Recenlty i flew Fw 190 D-9 (1944 year) and was attacked by P-39 D-2 (from 1941 year). I dont turn with him and try escape in level fligh. I was flying about a few minutes at full powet (with Bost) and when i check six Cobra still was ab 700m behind me. In cobra was my friend and we was at comm. He said that he is able to keep distance 700 m behind me. We was about 3-4km alt. Then i started to climb and for my wonder P-39 start to catch im in climb??? Is everything ok with these bird?
I tried myself P-39 D-2 and must say it have very good climb rate and not bad speed.

As i found for P39 D-1 version:
Specification of Bell P-39D Airacobra:

Engine: One 1150 hp Allison V-1710-35 twelve-cylinder liquid cooled engine. Performance: Maximum speed 309 mph at sea level, 335 mph at 5000 feet, 355 mph at 10,000 feet, 368 mph at 12,000 feet, and 360 mph at 15,000 feet. An altitude of 5000 feet could be reached in 1.9 minutes. It took 5.7 minutes to reach an altitude of 15,000 feet and 9.1 minutes to reach 20,000 feet. Service ceiling was 32,100 feet. Maximum range (clean) was 600 miles at 10,000 feet at 231 mph. Range with one 145.7 Imp gal drop tank was 1100 miles at 196 mph. Weights: 5462 pounds empty, 7500 pounds gross, and 8200 pounds maximum takeoff. Dimensions: Wingspan 34 feet 0 inches, length 30 feet 2 inches, height 11 feet 10 inches, and wing area 213 square feet. Armament: One 37-mm cannon in the nose with 30 rounds. Four wing-mounted 0.30-inch machine guns with 1000 rpg, two fuselage-mounted 0.50-inch machine guns with 200 rounds per gun. One 250 lb, 325-lb, or 500-lb bomb could be carried underneath the fuselage"

http://home.att.net/~jbaugher1/p39_4.html

Other problem what i found is that performance of P-39 should drop very noticeable above 15000ft. But in FB/PF these is not true - P-39 keep its performance like belove these alt.

I cant find performance for P-39 D-2 maby someone have it?

Kwiatos
11-23-2004, 07:36 AM
Ok i made test of climb time:
- map Crimea, 100%fuel, radiator opens.

----------P-39 D-1------------P-39 D-2---------Bf 109 F-4------
-------100%----90%--------110%------100%-------110%-----100%----
1km.---1:12----1:13-------0:53------1:16-------1:00-----1:17----
2km.---2:19----2:21-------1:43------2:24-------1:55-----2:28----
3km.---3:22----3:25-------2:28------3:27-------2:49-----3:38----
4km.---4:30----4:33-------3:17------4:34-------3:43-----4:50----
4.5----5:08----5:09-------3:42------5:13-------4:12-----5:25----
5km.---5:46----5:53-------4:11------5:54-------4:40-----6:01----
6km.---7:19----7:28-------5:18------7:24-------5:36-----7:18----


So we see that P-39 D-2 is even better than one of the best climber in 1941 year - Bf 109 F-4.

According to RL data P-39 D reach 20 000 ft (6km) in 9.1 min. IN PF P-39 D-1 reach 6km in 7:19 min (100 %power) and D-2 reach 6km in 5:18 min !!!!
Everthing is ok?

Saburo_0
11-23-2004, 07:53 AM
Kinda makes you wonder what the Beta testers do don't it ?

mortoma
11-23-2004, 08:06 AM
I've found the FM of the P-39Ds to be on the optimistic side, not just in climb either. But it should be fairly fast at low altitudes.

JG77Von_Hess
11-23-2004, 08:12 AM
http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif LOL Kwai, give up mate!! Peeps dont care as long as the evil jerry or jap goes down in flames all is fine. If u really want to shock ur self make a climb test with the beauF. and c what results u get from SL to around 20000 FT.

Regards.

VH.

Kwiatos
11-23-2004, 08:19 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Saburo_0:
Kinda makes you wonder what the Beta testers do don't it ? <HR></BLOCKQUOTE>

yea exacly what they are doing?

SilverWings25th
11-23-2004, 08:39 AM
How are you coming up with those #'s? Are you using a Vy that is for that particular plane or just a constant speed for all of them?

Each plane as a different best rate of climb. I dont see those #'s written down anywhere.

Also the D-2 has been modeled with 1500HP I believe, check the encylopedia in the game.

Kwiatos
11-23-2004, 08:54 AM
If you would have experience in climbing in FB/PF you will be know that best climb speed here dont work like should. Planes could climb with marigines about 50 km/h without changes in there climb rate. Of course in RL is much different but not in these game.
BTW i found that something like best climb for Cobra is ab. 250- 240 km/h at seal level. For F-4 speed near the same.

AND what i found there wasn't P-39 D-2 with 1500 HP but
- The P-39D-2 introduced the uprated 1325 hp V-1710-63 (E6) engine.

JG77Von_Hess
11-23-2004, 09:22 AM
Well since Kwai. dont give up so easy id better back him up a bit. http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

Lets take an example:
Mig3(40)
The difference in climing at 260TAS vs 180TAS
is as low as 12.6%
In real life u would be penaliezed with
a figure like 40-50%+ for climbing that close to stall speed.

Test conditions:
50% Fuel Rad open Max Power settings.
Map Crimea noon.

So in IL2 we climb at low speed more then 2 times better
vs real life.

Using the Ingame Ency. is not a good option vs real life either.

Regards.

VH.

Stiglr
11-23-2004, 10:57 AM
We should have expected this, since we've been LIED to about the P-39N and Q in IL-2.

This plane is one of the poster children of "politicized modelling".

mortoma
11-23-2004, 11:50 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Kwiatos:
If you would have experience in climbing in FB/PF you will be know that best climb speed here dont work like should. Planes could climb with marigines about 50 km/h without changes in there climb rate. Of course in RL is much different but not in these game.
BTW i found that something like best climb for Cobra is ab. 250- 240 km/h at seal level. For F-4 speed near the same.

AND what i found there wasn't P-39 D-2 with 1500 HP but
- The P-39D-2 introduced the uprated 1325 hp V-1710-63 (E6) engine. <HR></BLOCKQUOTE>You are exactly correct. The best rate of climbs for all planes in this sim is a non-exact science, with a wide margin in the speed envelope where a given plane obtains it's best climb. I don't believe this, I've actually been agreeing with the infamous Kwiatos!! Someone check my temperature!! Is there a doctor in the house?? http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif But I'm afraid his observations on this subject, although a tad on the whiney side, are 100% correct.

JG77Von_Hess
11-23-2004, 12:20 PM
http://forums.ubi.com/groupee_common/emoticons/icon_smile.gifNo offence ment here!

But how can what Kwai say in this tread be a bit on the whiney side, hes expirencing some thing in the game and post his opinion on it like everybody else posting here. He even take time to do a bit of research and in game testing. Absolutely not whining in my book.

Regards.

VH.

Stiglr
11-23-2004, 12:37 PM
Well, Hess, some people view anything that goes counter to "The Gospel According to Oleg" as 'whining', no matter how little or how much data or support you provide for the argument.

I always say, it's not whining if you have a point, even if it's NOT backed up by scads of declassified data and charts (although, I'd agree that all that data will be necessary to have any chance to get it fixed). Anybody who can read can find that the P-39 family had major performance issues, climb rate being just one of them. But if you fly one in IL-2, you don't exactly find yourself gasping for air, do you?

It simply bears examination, that's all. And that, my friend, is not 'whining'. It's merely asking the question of why the sim planes' performance seem to exceed the historical performance.

geetarman
11-23-2004, 12:43 PM
Um, though I tend to let the modelling lie as it is in the game and not worry about it, I have to admit that I always thought that the P-39 was modelled a little optimistically.

The USAAC pilots really thought it was a dog and didn't like to fly it. They can't all be wrong. The one attribute it did have in the Pacific was a faster low level speed than the Zero, according to a number of accounts I've read.

Yes, I know the Soviets liked it. It's still kind of a mystery to me, the huge differences of opinion on this plane. I don't fly it, and it can be easily brought down.

JG77Von_Hess
11-23-2004, 12:46 PM
Rgr That Stiglr.

Regards.

VH.

jazman777
11-23-2004, 12:57 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Saburo_0:
Kinda makes you wonder what the Beta testers do don't it ? <HR></BLOCKQUOTE>
We all know that company beta testers all over the world are sitting around reading Slashdot. Which makes us, the end users, the front line of real beta testing.

Stiglr
11-23-2004, 03:45 PM
Couple things:

1) Oleg and team tend not to listen to the beta testers on issues as fine as this. He tends to get feedback from them on crash issues, graphics bugs, and other things that are "broken", and affect gameplay. Perhaps I should say "tendED" as this comment was based on my experience on the IL-2 beta team and there have been several releases (or beta teams, I suppose) since then.

2) Independent of how the East Front P-39s are modelled, there is NO DOUBT WHATSOEVER that the Pacific versions should be worse in almost all aspects, what with all that weight the Soviets stripped out of theirs. Same would hold true for F2A Buffalos (as flown by the Dutch and Americans) and the B-329 as flown by the Finns.

ICDP
11-23-2004, 04:39 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Stiglr:

Independent of how the East Front P-39s are modelled, there is NO DOUBT WHATSOEVER that the Pacific versions should be worse in almost all aspects, what with all that weight the Soviets stripped out of theirs. Same would hold true for F2A Buffalos (as flown by the Dutch and Americans) and the B-329 as flown by the Finns. <HR></BLOCKQUOTE>

This is a fairly common misconception. The Russians did not strip their initial P39's of anything that the USAAC wouldn't commonly strip from P39's in New Guinea. It was quite common for the USAAC to strip wing Mg's and even armour plating from their P39's to aid performance.

The main reason for the dissparity at the hands of the Russians v the USAAC was the conditions in which the P39 was used. The USAAC in New Guinea had to operate well above the P39's optimum altitude, couple this with the fact that the USAAC aircrew in New Guinea were completely green when deployed. They had to fight against well trained and highly experienced Japanese pilots at altitudes that suited the Japanese aircraft. These green P39 pilots would routinely engage in turn fights with Oscars and Zeros, any aircraft in the USAAC inventory at the time would have suffered the exact same fate. Despite this they gave a very good account of themselves under these very difficult circumstances.

In contrast the P39's in Russia were flown at altitudes that suited the P39 and in a lot of cases by some very experienced aircrews.

Please don't make the mistake of assuming that the P39 in New Guinea and the P39 in Russia were two different aircraft. They were the exact same aircraft used in totally different circumstances. The P39 was not suited to combat over New Guinea were range and altitude were of paramount importance. This was the exact opposite on the East Front were the P39 was in its element of low altitude fights at short ranges.

Stiglr
11-23-2004, 04:55 PM
Well, Dmitri Loza begs to differ.

In "Attack of the Airacobras", he details how Pokryshkin developed tactics that emphasized altitude; 4km (13K feet) and higher, which was not much lower than Japanese were operating in New Guinea.

Also, Airacobras were supposedly NOT used in the ground attack role in Russia. That seems logical, they had Sturmos for that.

VW-IceFire
11-23-2004, 05:24 PM
Armament is a little wonky too. P-39D-1 should have 20mm (and does) and evidence points that the P-39D-2 should have 37mm but this is only an option...but I'm told that the cannons were not field equipped but factory equipped.

P-39s have a tough time being modeled in this game.

I think the "Iron Dog" thing was a bit of a misnomer for the reasons that ICDP points out. The P-39 wasn't all that bad...it had some nasty points but not all bad. Like the P-40. But in any case, its probably a bit too good from the looks of it.

Nubarus
11-24-2004, 04:54 AM
Every bug post on this board get's treated as a whine thread by some people for different reasons.

I have even seen a reason stating "Our axis plane is even more borked then your allied one so STFU"

I for one am not going to post any bugs anymore here and mail em directly to the PF bug report mail address.

At least you don't get A-holes cr@pping in your thread with their BS like that.

Kwiatos
11-24-2004, 05:34 AM
If you dnot notice i would ask community about some sources etc about P-39 D-2. Everhying else was my test and what i found. Of course i send e-mail to 1C and have replay from Oleg M. As i write in the begginig i ask for help for proof and sources.
BTW thx for OLeg. M for replay in my e-mail. Its good to know that Oleg still is interesting in modelling accurate performance of planes in FB/PF.

VVS-Manuc
11-24-2004, 05:50 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Kwiatos:
If you dnot notice i would ask community about some sources etc about P-39 D-2. Everhying else was my test and what i found. Of course i send e-mail to 1C and have replay from Oleg M. As i write in the begginig i ask for help for proof and sources.
BTW thx for OLeg. M for replay in my e-mail. Its good to know that Oleg still is interesting in modelling accurate performance of planes in FB/PF. <HR></BLOCKQUOTE>

just curious...what did Oleg answer in his mail?

Saburo_0
11-24-2004, 06:09 AM
"Its good to know that Oleg still is interesting in modelling accurate performance of planes in FB/PF."

That's why i don't freak out when something is wrong. They really do try to get it right.
And a S! to all you guys who take the time to test these FMs & collect data! This sim wouldn't be half as good without your input!

geetarman
11-24-2004, 08:50 AM
Re: the P-39 in the SWP: The funny thing is, the P-40 was more loved than the P-39. This was despite the fact that P-40 was also not a great high altitude fighter.

In other words, both of these planes hit their strides at modest altitudes and did not do well up high. Nonethless, the P-39 was considered the dog. More pilots liked, and continued to fly P-40's into early-mid 1944 even though it shared one of the main shortcomings of the Airacobra.

In game, the performance of the P-39 at low alts seems a lot better than the P-40.

Stiglr
11-24-2004, 10:56 AM
Well, whether some think it's "whining" to point out inaccuracies, I couldn't care a whit. They almost always have an agenda to keep "their plane" with its unnatural advantage.

Fact is, if you don't speak up, loud and (usually) long, you will simply be ignored. This includes "just sending an email to the dev team". Sometimes they'll respond, sometimes not, even though you may be right. While I agree that they DO make an effort to get it right, they are not above having some "pet planes" and "pet modeling". The muzzle flash is a prime example. The FW190 canopy is another. The "yellowed glass" is still another. One, after much screaming, got fixed. Another, to this day, is still wrong. The third has been toned down on some planes, but foisted upon a new plane in PF. Well, 33% is better than none.

You have to come out here, in public, and be prepared to state your case if you really expect anything to be done.

ICDP
11-24-2004, 11:15 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Stiglr:
Well, Dmitri Loza begs to differ.

In "Attack of the Airacobras", he details how Pokryshkin developed tactics that emphasized altitude; 4km (13K feet) and higher, which was not much lower than Japanese were operating in New Guinea.

Also, Airacobras were supposedly NOT used in the ground attack role in Russia. That seems logical, they had Sturmos for that. <HR></BLOCKQUOTE>

The typical operating altitude for the Japanese in New Guinea was around 18K - 22K feet. This is certainly well above the optimum altitude of the P39. It was not until around 15K feet (IIRC) that the perforamce started to suffer, so well within the operating limits of the Russian aircrews. The P39 had a higher ROC than the P40 (and most other early US fighters) but was dissliked by many of the USAAC pilots despite bing better in a lot of areas than the P40.

The main point of my post was to refute your claim that the USAAC and Russian P39's were totally different aircraft, they were the exact same aircraft used in different environments. Both the USAAC and the VVS would routinely strip P39's of armour/armament to improve performance so that argument is moot. I have already outlined the resons why there was such a dissparity in effectiveness with the P39 in the hands of the USAAC and the VVS, there is no need to do so again. The Russians did iunfluence the design of later P39's to better suit their needs but they didn't fly a different P39 than the USAAC, they just had cause to use it were it would perform at its optimum.

I also agree that the P39 was not primarily used in the ground attack role, at no point did I state otherwise (not sure if you directed that comment at me).

Regards