Author Topic: Perk the P51 B (Read 1892 times)

Vermillion · « **Reply #60 on:** September 13, 2002, 04:02:21 PM »

Nope, F4UDOA its the exact opposite. AH uses quality control test flight data that is quite inferior to the data to which you are referring.

Pongo · « **Reply #61 on:** September 13, 2002, 05:13:35 PM »

by inferior you mean that the planes dont rate as well as the factory stats..not that the data is inferior...right?

F4UDOA · « **Reply #62 on:** September 13, 2002, 05:25:17 PM »

Verm,

Your saying that the VVS a/c had better stats than what are used here?

That is not my current understanding. Do you have this data anywhere viewable?

Wilbus · « **Reply #63 on:** September 13, 2002, 06:11:48 PM »

"In his flight report Major Kubyshkin stated that compared with the standard La5FN, the La7's rate of climb had improved considerably. A maximum speed of 680 kmh (422mph) at an altitude of 6000 meters (19,685 feet) was recorded with the La7 prototype - at the time the best performance for a soviet fighter."

Also on the prototype, flown by test pilot G.M Shiyanov on the second of Feburary 1944.

"A maximum speed of 597 kmh (371 mph) was recorded at sea level. This was markedly superior to the La5FN's speed of 546 kmh (339 mph) and the Focke Wulf Fw-190A-8's speed of 560 kmh (347 mph) at the same altitude."

Both those speeds were with the prototype.

Reading further...

"The Standard production La-7 had a top speed of 592 kmh (367 mph) at sea level - 46 kmh (28.5 mph) more than the La-5FN and 72 kmh (44.7 mph) more than the Focke Wulf Fw 190A-3. The improved performance was due to the aerodynamic refinements of the airframe and a weight reduction of some 82kg (180 lbs). At 6100 --ters (20,000 feet) the La-7 had a top speed of 655 kmh (407 mph), 35 kmh (21.7 mph) more than the La-5FN. The La-7 was also 15 kmh (9 moh) faster then the Focke Wulf Fw 190A-8, the latest version of this German fighter to be deployed of the Eastern front"

To me it seems like the low alt modelling for the La7 is in the "prototype" Stage while the 20k modelling is right on with 407mph.

A speed of 380 mph level at the deck was obviously never reached with the La7, prototype nor the production series.

Source of information: La 5/7 Fighters in action.
ISBN: 0-89747-392-2

funkedup · « **Reply #64 on:** September 13, 2002, 07:22:45 PM »

This book has comparisons of top speeds, maximum climb rates, and other data for prototype and production Soviet fighters. I haven't looked at it for a while but last time I checked the HTC Soviet planes were closer to production figures than prototype.

Pongo · « **Reply #65 on:** September 13, 2002, 07:39:24 PM »

"The flight tests conducted at the LII in July 1944 showed that the mazimum speed had fallen to 344 mph at sea level and 397 mph at 6000m, which meant that the la7s speed was not signifigantly greater than that fo th a production la-5fn..

..
lists production reasons why...

When tested at the LII a production La-7 with these defects remedied reasched 361mph at sea level and 418mph at 6000m;figures conforming to the prototype. It only remained to realise this performance in the production aircraft, but as it transpired this was not an easy task. Both plants had built about 400 la-7s when productoin aircraft made by plants 21 and 381 where flight tested at NII VVS in eafly sptember 1944. At a weight of 7164 pounds the readched a speed of 355.4 to 359 mph at sea level (with augmented power speed increased to 380mph and 407 to 408 at 6000m.
"
From Soviet Combat Aircraft of the second world war, Volume 1 single engine fighters.

seems like these numbers suport the AH numbers..for a late 1944 production La-7.

Mino · « **Reply #66 on:** September 13, 2002, 08:05:01 PM »

Sigh

funkedup · « **Reply #67 on:** September 13, 2002, 10:44:57 PM »

Quote

Originally posted by Pongo
"The flight tests conducted at the LII in July 1944 showed that the mazimum speed had fallen to 344 mph at sea level and 397 mph at 6000m, which meant that the la7s speed was not signifigantly greater than that fo th a production la-5fn..

..
lists production reasons why...

When tested at the LII a production La-7 with these defects remedied reasched 361mph at sea level and 418mph at 6000m;figures conforming to the prototype. It only remained to realise this performance in the production aircraft, but as it transpired this was not an easy task. Both plants had built about 400 la-7s when productoin aircraft made by plants 21 and 381 where flight tested at NII VVS in eafly sptember 1944. At a weight of 7164 pounds the readched a speed of 355.4 to 359 mph at sea level (with augmented power speed increased to 380mph and 407 to 408 at 6000m.
"
From Soviet Combat Aircraft of the second world war, Volume 1 single engine fighters.

seems like these numbers suport the AH numbers..for a late 1944 production La-7.

Yep that's how I remember it from last time I looked at that book. The key is augmented power AKA WEP.

F4UDOA · « **Reply #68 on:** September 13, 2002, 11:55:47 PM »

That's a big if. Is augmented WEP or over boost. Because as we know WEP is modeled but overboost is not.

And frankly most of what I have just read says top speed on the deck is about 360MPH. And the comment about the La-5 top speed mentioned as 339MPH. It is clearly about 350MPH in AH. What is that based on??

It's not like these A/C never had a chance to prove themselves against the western world. In fact the La-7/11 and Yak-9 saw plenty of action in Korea. Frankly I see nothing to support the claims of performnce seen here.

I have made the request to see some of the AH source data if it could be scanned or faxed/Emailed on request (I would pay for this). But some of the data in here is a little suspicious to say the least.

Doesn't anyone have a chart for the VVS a/c tested by a non soviet block country??

Pongo · « **Reply #69 on:** September 14, 2002, 12:06:17 AM »

the top speed of the production la7s is listed in the tabels in the back of the book at 380 on the deck..why is that so hard to believe with the post I made above. production la7s went 380 on the deck...say it 3 times...
lol

funkedup · « **Reply #70 on:** September 14, 2002, 03:37:49 AM »

Quote

Originally posted by F4UDOA
That's a big if. Is augmented WEP or over boost. Because as we know WEP is modeled but overboost is not.

WEP and overboost and augmented power are the same thing dude.

Wilbus · « **Reply #71 on:** September 14, 2002, 03:45:53 AM »

Cool, it's an La7 thread now

Guppy · « **Reply #72 on:** September 14, 2002, 04:44:06 AM »

Quote

Originally posted by F4UDOA
And frankly most of what I have just read says top speed on the deck is about 360MPH. And the comment about the La-5 top speed mentioned as 339MPH. It is clearly about 350MPH in AH. What is that based on??

Doesn't anyone have a chart for the VVS a/c tested by a non soviet block country??

I didn't keep a copy of the link, but a translation of a German test of an La-5 (Rechlin Test Centre, Test No. 90014) was posted to allaboutwarfare.com's forums a while back.

The La-5's speed was given as follows:

323 mph TAS @ SL, emergency power
304.5 mph TAS @ SL, rated power
335.5 mph TAS @ 1 km, emergency power
348 mph TAS @ 5 km, rated power
338.7 mph TAS @ 6.5 km, rated power

Hristo · « **Reply #73 on:** September 14, 2002, 05:17:28 AM »

Umm, La-5 or La-5FN ? There is quite a difference, so I have heard.

Guppy · « **Reply #74 on:** September 14, 2002, 05:30:46 AM »

Quote

Originally posted by Hristo
Umm, La-5 or La-5FN ? There is quite a difference, so I have heard.

Thanks for catching that. The La-5 in the report is listed with an 1 850 hp M-82FN engine, which would make it an La-5FN.