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RAF74_Buzzsaw
11-07-2004, 02:34 PM
Hello Oleg

Thankyou and Luthier for all your hard work on PACIFIC FIGHTERS. It is a worthy addition to the IL-2 series.

There seems to be a bug with the Corsair however:

I noticed that it seems to perform very well so I did some tests.

The tests showed it is exceeding the historical climbrate.

Here is a U.S. Documents which show the Climbrate and other performance figures for the F4U-1D:

http://web.cetlink.net/~howardds/27328170.gif

You can see the climbrate at Sea Level with Combat power is 3370 Feet per Minute. The climb time to 10,000 ft, (3048 meters) is 3.3 minutes or 3 minutes 18 seconds. The climb time to 20,000 ft, (6096 meters) is 7.1 minutes or 7 minutes, 6 seconds.

My tests started with a fully loaded, (100% fuel, default load) Corsair F4U-1D at Sea level. Starting speed was 300 kph. I climbed at approximately 280 kph, 270kph over 10,000 ft. I changed to Supercharger stage 2 at 10,000 ft.

My climb times were:

1 minute 4 seconds sea level to 5,000 ft (1524 meters) That is an average climbrate of 4687 Feet per Minute between sea level and 5,000 ft.

2 minutes 35 seconds sea level to 10,000 ft (3048 meters). That is an average climbrate of 3871 feet per minute between sea level and 10,000 ft.

5 minutes 41 seconds sea level to 20,000 ft (6096 meters) That is an average climbrate of 3519 feet per minute between sea level and 20,000 ft.

The performance tests show that the F4U-1D definitely exceeds its historical limits.

I am wondering if there could be a problem and perhaps the programmer used the climb peformance figures from the later model F4U-4? The test results are almost exactly what a F4U-4 might have achieved.

I tested the sea level speed of the F4U-1D and got 366 kph or 354 mph, which is only slightly less than what the historical speed should be, so that is not a problem.

I also tested the stall speed of the F4U-1D and got exactly the correct figure. (87.5 mph or 140 kph for no power stall) So the wing lift seems to be very well modelled.

I have not yet done tests for the earlier model Corsair F4U-1 and F4U-1A.

Once again thankyou for your hard work and I am looking forward to the patch and the addons.

I can mail you the test records if you require them.

RAF74_Buzzsaw
11-07-2004, 02:34 PM
Hello Oleg

Thankyou and Luthier for all your hard work on PACIFIC FIGHTERS. It is a worthy addition to the IL-2 series.

There seems to be a bug with the Corsair however:

I noticed that it seems to perform very well so I did some tests.

The tests showed it is exceeding the historical climbrate.

Here is a U.S. Documents which show the Climbrate and other performance figures for the F4U-1D:

http://web.cetlink.net/~howardds/27328170.gif

You can see the climbrate at Sea Level with Combat power is 3370 Feet per Minute. The climb time to 10,000 ft, (3048 meters) is 3.3 minutes or 3 minutes 18 seconds. The climb time to 20,000 ft, (6096 meters) is 7.1 minutes or 7 minutes, 6 seconds.

My tests started with a fully loaded, (100% fuel, default load) Corsair F4U-1D at Sea level. Starting speed was 300 kph. I climbed at approximately 280 kph, 270kph over 10,000 ft. I changed to Supercharger stage 2 at 10,000 ft.

My climb times were:

1 minute 4 seconds sea level to 5,000 ft (1524 meters) That is an average climbrate of 4687 Feet per Minute between sea level and 5,000 ft.

2 minutes 35 seconds sea level to 10,000 ft (3048 meters). That is an average climbrate of 3871 feet per minute between sea level and 10,000 ft.

5 minutes 41 seconds sea level to 20,000 ft (6096 meters) That is an average climbrate of 3519 feet per minute between sea level and 20,000 ft.

The performance tests show that the F4U-1D definitely exceeds its historical limits.

I am wondering if there could be a problem and perhaps the programmer used the climb peformance figures from the later model F4U-4? The test results are almost exactly what a F4U-4 might have achieved.

I tested the sea level speed of the F4U-1D and got 366 kph or 354 mph, which is only slightly less than what the historical speed should be, so that is not a problem.

I also tested the stall speed of the F4U-1D and got exactly the correct figure. (87.5 mph or 140 kph for no power stall) So the wing lift seems to be very well modelled.

I have not yet done tests for the earlier model Corsair F4U-1 and F4U-1A.

Once again thankyou for your hard work and I am looking forward to the patch and the addons.

I can mail you the test records if you require them.

lbuchele
11-07-2004, 03:29 PM
Good work,RAF74.
Please,post those informations on the PF bugs topic , where Oleg can read it,OK?
I think it will be very useful.

SkyChimp
11-07-2004, 04:02 PM
Buzzsaw:

Your numbers are significantly different than mine. To get the numbers on that chart you posted, YOU MUST conduct the climb in the same manner that produced them.

The best climb speed for the F4U-1D was 144mph IAS (125 knots, 231 km/h). That means you enter the climb at 144mph IAS at seal level. Apply combat power and continue to climb at such an angle that you maintain no more and no less than 144 mph IAS. That's how those numbers on that document were obtained (BTW, it isn't test data, it BuAer specs).

If you conduct the climb test appropriately, you will come up with more appropriate numbers. I've conducted the test on several occassions in the manner I've described and came up with (on average):

3:20 to 10,000 feet (should be 3:18 seconds)
7:03 to 20,000 feet (should be 7:06 seconds)


Oleg has gotten the climb rate of the F4U-1D remarkably accurate. He shouldn't change a thing.

KGr.HH-Sunburst
11-07-2004, 04:04 PM
send him a mail and post it in ORR aswell

ChrisMcGee2004
11-07-2004, 04:46 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by SkyChimp:
Buzzsaw:



Oleg has gotten the climb rate of the F4U-1D remarkably accurate. He shouldn't change a thing. <HR></BLOCKQUOTE>

The only thing he should change is the flickering on the canopy in F2 view. ; )

Athosd
11-07-2004, 07:19 PM
SkyChimp - something with those tests has me scratching the old noggin.
I agree the tests must be done the same way for truly valid comparison. However if Buzzsaw was able to exceed the posted optimal climb rate by such a large amount (2 min quicker to 10,000 ft), doesn't that indicate that something is a little off?

Salute

Athos

SkyChimp
11-07-2004, 07:31 PM
Reducing the time-to-climb numbers is not hard. It could be done in real life. The climb must begin at 144 mph IAS. If it begins faster than that, for example by flying along just off the deck at 350 mph then pull into a climb then you will exceed the time-to-climb figures. The plane should eventually bleed down to the right climb speed and correct climb rate, but the time-to-climb numbers will be off all the way to the top of the climb. This will give the appearance of a faster that accurate climb.

Again, the climb must begin at the correct climb speed and end at the correct clim speed.

Athosd
11-07-2004, 08:05 PM
Ah yes, all is clear now - thanks SkyChimp.

Buzzsaw's test shows an initial speed of 300kph (Knots? correct notation is "Kn" or "Kt" is it not?).
Which equals ~345Mph/550Kmh - really spanking along.

I don't see the any reference on that document to the 144mph best climb speed - which may be why Buzzsaw went for the fastest possible ascent for his test.

Salute

Athos

actionhank1786
11-07-2004, 08:29 PM
i've heard Oleg and crew used US flight data, and test data for the flight models so it should be pretty close to the real thing

faustnik
11-07-2004, 09:08 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by SkyChimp:


Again, the climb must begin at the correct climb speed and end at the correct clim speed. <HR></BLOCKQUOTE>

SkyChimp,

I was wondering if you did a climb test comparison between the F4U-1D and the Fw190A5 since we have such a detailed test available to us on them?

CV8_Dudeness
11-07-2004, 09:15 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by SkyChimp:
Oleg has gotten the climb rate of the F4U-1D remarkably accurate. He shouldn't change a thing. <HR></BLOCKQUOTE>
wouldnt this be close to being a first ?

i was amazed at how nice the Corsair flew but Oleg posted in the ORR that he was very impressed with the US data on the Corsair that he recieved

if the corsair is as close to RL specs as Skychimp found , wouldnt this be close to being a first for FB/PF ?

RAF74_Buzzsaw
11-07-2004, 09:57 PM
Salute

First of all, I am surprised to hear such a specious argument from SkyChimp. He is usually interested only in the facts. This is the type of argument which was previously used to justify some of the ridiculously overmodelled 109 climbrates.

The issue here is MAXIMUM RATE OF CLIMB. The speed at which that maximum rate of climb is achieved is irrelevant.

The speed which SkyChimp mentions, ie. 144 mph, or 230 kph is the speed at which the Corsair achieved its maximum rate of climb HISTORICALLY.

Since this is a game, not real life, it just so happens that the maximum rate of climb for the virtual Corsair F4U-1D is achieved at a slightly different speed.

HOWEVER... I am prepared to indulge such ridiculous arguements because whether the climb is done at 230 kph or 280 kph, the Corsair still climbs too fast.

I re-did the tests using the following criteria:

Starting speed: 230 KILOMETERS (not knots) per hour. (144 mph)

Starting height: Sea level.

Climb Speed: 230 kph.

Following climb times were achieved:

5000 ft (1524 Meters): 1 minute 12 seconds, for an average climbrate between sea level and 5000 ft of 4166 feet per minute, or clearly too high.

10,000 ft (3048 meters): 2 minutes 45 seconds, for and average climbrate between sea level and 10,000 ft of 3636 feet per minute.

20,000 ft (6096 meters): 6 minutes 2 seconds, for an average climbrate of 3314 feet per minute between sea level and 20,000 ft.

Climb times to 10,000 ft are 33 seconds too fast.

Climb times to 20,000 ft are 1 minute 1 second too fast.

So the fact remains, whether we choose to cripple the climbrate test of the Corsair or not, it climbs too fast.

Records of my tests are available for anyone who PM's me.

Athosd
11-07-2004, 10:08 PM
Buzzsaw - can I just point out that consistent units would help a lot, in the original post you used kph for both Knots (Kn) and Kilometres per hour (Km/h).
Not trying to twist your tail sir - I'm very interested in these types of discussion.

Salute

Athos

RAF74_Buzzsaw
11-07-2004, 10:51 PM
Salute Athosd

I would suggest you go back and re-read my post.

I have never mentioned Knots. Mph, (miles per hour) and Kph (Kilometers per hour) are the only speed figures I used. The only speed figures mentioned in the U.S. test reports are Mph. I convert them to Kph because the aircraft speeds in this game are in Kph.

ZG77_Lignite
11-07-2004, 10:54 PM
Athosd, I'm not sure what your refering to (though I could easily have missed it). Buzzsaw uses kph (kilometers per hour) throughout his post, with (I assume) one typo of a 3 accidentally replacing a 5 (566kph=354mph, he mistyped a 366kph).

LEXX_Luthor
11-07-2004, 10:56 PM
We suggest km/hr and mi/hr to avoid any future Confuscation

Athosd
11-07-2004, 11:09 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by LEXX_Luthor:
We suggest km/hr and mi/hr to avoid any future Confuscation <HR></BLOCKQUOTE>

Is that the royal "We"? http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

Salute Buzzsaw - my bad http://forums.ubi.com/groupee_common/emoticons/icon_redface.gif, as noted by Lignite I mistook an innocent typo for a more grave error (and compounded the mistake by not noticing that the "Knots" figure should have been smaller than the Mph).

Cheers

Athos

geetarman
11-08-2004, 08:37 AM
Buzzsaw - you checked max speed at sea level and found it spot on. Check the max. speed at best altitude (about 21,000'). It should be about 417mph. I can't get it there at all. I can get just under 400 mph TAS with rads closed, throttle firewalled, flaps up, etc.