DCS: Spitfire Mk LF IXc Discussion

[SKR]

Privet SKR,

 

 

 

Ok, You are saying the data is converted to some standard atmosphere. Any idea what those "standard conditions" are in the report?

 

The AIAA publishes a list of "standard atmosphere's" IIRC, there are 37 standard models in common use in that reference atmosphere guide. For subsonic imcompressible flow, the important things do not change much.

 

That being said, it would be nice to see the VVS "standard atmosphere" model parameters.

 

For now, let's move on.

 

The data is within + or - 3% of the RAF Merlin 66 +18lbs data and the Merlin 66 was not using +15lbs as a published Manifold pressure limit....that only corresponds to the Merlin 63 engine 5 minute rating.

 

So that is why SKR, the +15lbs rating is difficult to digest. It was never a rating for the Merlin 66 engine issued by Rolls Royce. It is lower but not by much than the +18lbs so you are saying the VVS de-rated the engine.

 

It would be nice to see the original document!

 

The VVS curve for Merlin 66 Spitfire follows BS 543 closely and is at most only 1.5% behind which does gives good agreement with a Merlin 66 +18lbs aircraft.

 

That leads me to believe it is a Merlin 66 engine as it is labeled but the 15lbs boost limit is still not clear.

 

What would clear it up is the document stating the 15lb boost limit or a VVS Pilot Operating Instructions for the Spitfire Mk IX Merlin 66.

What makes you think that Merlin 66 does not use 15 lb boost? If you pour into it 100 octane fuel will be 15 pound, pour 130 octane get 18 pound, pour 150 octane get 25 pounds.

Here is the complete document (kurfyust already spread its part) http://rghost.ru/6TYDPHYfn

 

Now look over here

Surprisingly in the USSR and Spitfires with Merlin 61

[Crumpp]

What makes you think that Merlin 66 does not use 15 lb boost?

 

The Spitfire Operating Instructions for the Spitfire Mk IX series only clears the Merlin 63 for +15lbs.

 

 

You can get your own copy, here:

 

http://www.zenoswarbirdvideos.com/Spitfire9_Manual.html

[Friedrich-4B]

The Spitfire Operating Instructions for the Spitfire Mk IX series only clears the Merlin 63 for +15lbs.

 

 

You can get your own copy, here:

 

http://www.zenoswarbirdvideos.com/Spitfire9_Manual.html

 

Better still, they can be downloaded from here:

 

http://forums.eagle.ru/showpost.php?p=2313908&postcount=378

 

As Crumpp has pointed out elsewhere, engines could be tuned for different applications http://forums.eagle.ru/showpost.php?p=2347617&postcount=76;

 

The connection to the German engines is the fact is it not unusual for a manufacturer to make a single engine and tune that basic engine for different applications. Junkers certainly did this for the Jumo 213 series.

 

The engines will created different amounts of power based on that specific application.

 

the Merlin 66 was a derivative of the redesigned, reinforced Merlin 63, so it looks as though the British were sending slightly detuned versions of the Merlin to Russia - possibly swapping slightly less power for better reliability under extreme conditions.

 

Very interesting, and thanks for the information SKR.

 

Sorry for OT, I just finished reading Invasions Without Tears, it's a great book! Is the Johnnie Johnson book good? I've read Wing Leader, his autobiography, which is quite good, but not that one.

 

Dilip Sarkar's book on Johnnie Johnson is a really good read, complementing and supplementing Johnson's autobiography extremely well.

Edited March 12, 2015 by Friedrich-4/B
add Sarkar

[Crumpp]

Surprisingly in the USSR and Spitfires with Merlin 61

 

I noticed there was no data on the Merlin 66 Spitfires.

 

Also, are you sure this is a TASGI report?

 

It looks like something a modeling enthusiast might have put together. It talks about post war designs and the aircraft serving thru 1955!!

 

That is a lot for two TASGI reports from 1944 and 1945. The NKVD were good but that good? :huh:

[Crumpp]

the Merlin 66 was a derivative of the redesigned, reinforced Merlin 63, so it looks as though the British were sending slightly detuned versions of the Merlin to Russia - possibly swapping slightly less power for better reliability under extreme conditions.

 

I agree. However the Merlin 63 is a different designation and I would think the VVS would know the engines they have.

 

Additionally, the performance gives good agreement with the published performance figures for the Merlin 66 series at +18lbs.

 

Look at that document. I do not think it is an original TASGI report at all.

[NineLine]

How good are Spitfire I and Spitfire II The Canadians? Strangely enough I never got to read them...

 

I have the first one, I love it.

[Crumpp]

Not if the engine has the different, low altitude supercharger and injection carbie of the Merlin 66.

 

That is the definition of the Merlin 63 Fredrich.

 

It is a Merlin 61 with a Merlin 66 supercharger.

 

The engine data plate will say...MERLIN 63.

 

I am sure the VVS were smart enough to know what engines they used.

[Crumpp]

There is no need to continue back and forth over this either, Fredrich. If you wish to believe the VVS could not tell which engine was in their aircraft, I have no issue or desire to persuade you otherwise.

[Friedrich-4B]

There is no need to continue back and forth over this either, Fredrich. If you wish to believe the VVS could not tell which engine was in their aircraft, I have no issue or desire to persuade you otherwise.

 

I don't think Crumpp actually read what I wrote: :dunno:

 

the Merlin 66 was a derivative of the redesigned, reinforced Merlin 63, so it looks as though the British were sending slightly detuned versions of the Merlin to Russia - possibly swapping slightly less power for better reliability under extreme conditions.

 

Of course the VVS would have known the differences between a Merlin 61 or 63 and the slightly detuned Merlin 66s they were getting in their L.F Mk IXs. :music_whistling:

Edited March 13, 2015 by Friedrich-4/B
Add Merlin 63 data

[Crumpp]

Of course the VVS would have known the differences between a Merlin 61 or 63 and the slightly detuned Merlin 66s they were getting in their L.F Mk IXs.

 

Then we can agree that if they do not say they have Merlin 63 and we have NO Evidence of them using +15lbs AND the performance agrees with a Merlin 66 +18 engine....

 

They probably had Merlin 66 +18 engines.

 

Looks like a duck, walks like a duck etc etc...

 

It is probably a duck.

 

But Kurfurst posted it,

 

He did not post the entire article, just the charts from it so stop with the childish innuendo's. I have LOTS of Russian data from friends over there including some original TASGI reports.

 

Most of it is snippets and clips. Some of it is even rewritten because the archivist did not have a way to copy it at the time it was viewed (~8 years ago). They poor guy had to copy what was in the reports himself.

 

The performance reported by the VVS at 528kph or 328mph at sea level is only 2.3% behind BS543 in this report:

 

http://www.spitfireperformance.com/bs543.html

 

http://forums.eagle.ru/showthread.php?p=2122488

 

The British aircraft, BS543 is 150 lbs lighter than the VVS aircraft. Factor that in and the difference between them becomes even less.

 

The VVS data gives good agreement with the RAF examples.

[SKR]

I noticed there was no data on the Merlin 66 Spitfires.

 

Also, are you sure this is a TASGI report?

 

It looks like something a modeling enthusiast might have put together. It talks about post war designs and the aircraft serving thru 1955!!

 

That is a lot for two TASGI reports from 1944 and 1945. The NKVD were good but that good? :huh:

Yes, the report is prepared and ЦАГИ. The report used data received November 18, 1944*в НИИ ВВС КА(!)

Вы еще меня будите Русскому языку учить? По моему мне виднее, что там написанно.

Edited March 13, 2015 by SKR

[SKR]

Then we can agree that if they do not say they have Merlin 63 and we have NO Evidence of them using +15lbs AND the performance agrees with a Merlin 66 +18 engine....

 

They probably had Merlin 66 +18 engines.

 

Looks like a duck, walks like a duck etc etc...

 

It is probably a duck.

 

 

 

He did not post the entire article, just the charts from it so stop with the childish innuendo's. I have LOTS of Russian data from friends over there including some original TASGI reports.

 

Most of it is snippets and clips. Some of it is even rewritten because the archivist did not have a way to copy it at the time it was viewed (~8 years ago). They poor guy had to copy what was in the reports himself.

 

The performance reported by the VVS at 528kph or 328mph at sea level is only 2.3% behind BS543 in this report:

 

http://www.spitfireperformance.com/bs543.html

 

http://forums.eagle.ru/showthread.php?p=2122488

 

The British aircraft, BS543 is 150 lbs lighter than the VVS aircraft. Factor that in and the difference between them becomes even less.

 

The VVS data gives good agreement with the RAF examples.

Here I will notice that VVS wasn't frequent opportunities to make tests of speed of SL, it did on 300-600 meters

[Friedrich-4B]

I have LOTS of Russian data from friends over there including some original TASGI reports.

 

And none of the Spitfire IX reports.

 

Most of it is snippets and clips. Some of it is even rewritten because the archivist did not have a way to copy it at the time it was viewed (~8 years ago). They poor guy had to copy what was in the reports himself.

 

Thus of no use at all, unless the accuracy of the transcripts can be compared with the originals.

 

There is no need to continue back and forth over this either...

 

Got it in one. :thumbup:

 

How good are Spitfire I and Spitfire II The Canadians? Strangely enough I never got to read them...

 

Spitfire II is also a good read, because it's full of absorbing stories from not only fighter pilots, but PR pilots as well.

 

Plus, it's going for a low price here, with postage = US$4.99. Recommended.

[Crumpp]

Вы еще меня будите Русскому языку учить? По моему мне виднее, что там написанно.

 

Укажите, пожалуйста, точно место, где говорится, что давление наддува +15.

 

Here I will notice that VVS wasn't frequent opportunities to make tests of speed of SL, it did on 300-600 meters

 

Yeah, the ground tends to prevent that for everyone. The data is reduced mathematically by the engineers to sea level.

 

Because of that it makes a great point for use to compare performance as that point is not effected by atmospheric modeling. It is mainly just instrumentation error.

 

True airspeed = Equivalent airspeed at sea level. The results above that point are due to atmospheric modeling, which is why I asked you about the specific details of the atmospheric model the VVS was using.

 

Comparing that Equivalent Airspeed the VVS data gives good agreement with the British data for a Spitfire Mk IX Merlin 66 at +18lbs.

[Kurfürst]

Comparing that Equivalent Airspeed the VVS data gives good agreement with the British data for a Spitfire Mk IX Merlin 66 at +18lbs.

 

That, or that the full throttle heights in the test results that correspond to M66 / +18 boost. Besides AFAIK the Soviets only received Mk IXs with M66s (and a couple of Mk Vs). With M61 the FTHs would be much higher also. Neither it was possible for a +15 two staged spit to achieve climb rates in the order of 22-23 m/sec..

[SKR]

Укажите, пожалуйста, точно место, где говорится, что давление наддува +15.

 

 

 

Yeah, the ground tends to prevent that for everyone. The data is reduced mathematically by the engineers to sea level.

 

Because of that it makes a great point for use to compare performance as that point is not effected by atmospheric modeling. It is mainly just instrumentation error.

 

True airspeed = Equivalent airspeed at sea level. The results above that point are due to atmospheric modeling, which is why I asked you about the specific details of the atmospheric model the VVS was using.

 

Comparing that Equivalent Airspeed the VVS data gives good agreement with the British data for a Spitfire Mk IX Merlin 66 at +18lbs.

Page 20, first it says that it was Merlin 61 engine, and secondly on the same page there is data on the engine and maximum paint Power said in 1520 hp

Boost in Russia are inclusive of normal atmospheric pressure (760 mm Hg) by not tricky calculations, namely 1535 mm Hg - 760 mm Hg = 775 mm Hg that corresponds exactly to 15 pounds of boost

[Kurfürst]

The document describes the development of the Spitfire as well. The page you are showing does not seem to relate to the tested aircraft results, rather just some general specs table for various other Spitfire variants, Mark V and IX.

[SKR]

The document describes the development of the Spitfire as well. The page you are showing does not seem to relate to the tested aircraft results, rather just some general specs table for various other Spitfire variants, Mark V and IX.

Judging from the text it is still relate to the tests (see page 17)

[Crumpp]

Page 20, first it says that it was Merlin 61 engine, and secondly on the same page there is data on the engine and maximum paint Power said in 1520 hp

 

The Merlin 61 used and was approved for +15lbs.

 

I do not see how that proves the VVS Merlin 66 curve is only for +15lbs? The VVS Merlin 66 data agrees with the RAF Merlin 66 data at +18lbs.

[SKR]

The Merlin 61 used and was approved for +15lbs.

 

I do not see how that proves the VVS Merlin 66 curve is only for +15lbs? The VVS Merlin 66 data agrees with the RAF Merlin 66 data at +18lbs.

Yes, I understand, and in many respects this is not particularly trust the Soviet tests.Yes, I understand, and in many respects this is not particularly trust the Soviet tests. Very strange that's it. US tests need Spitfire

[Crumpp]

That, or that the full throttle heights in the test results that correspond to M66 / +18 boost. Besides AFAIK the Soviets only received Mk IXs with M66s (and a couple of Mk Vs). With M61 the FTHs would be much higher also. Neither it was possible for a +15 two staged spit to achieve climb rates in the order of 22-23 m/sec..

 

Exactly, I think everyone agrees it the VVS data gives good agreement with the RAF flight test's when converted to the same conditions and weight.

 

:thumbup:

[Kelevra]

here's what the spitfire going to look like :D

 

https://www.haraldjoergens.com/panoramas/spitfire-td314/files/

[Crumpp]

Nice find, Keelvra!

[Alicatt]

Yeah Harald does some very good interactive cockpits love his Lightning one too

[klem]

Yeah Harald does some very good interactive cockpits love his Lightning one too

 

and the Canberra.....

 

https://www.facebook.com/TangmereMAM/app_190322544333196