109 article (from www.virtualpilots.fi)

[Oldman731]

Originally posted by Seeker
Gripen;

You sure (and I mean this well; I generaly read your posts avidly); you really sure you're not being a bit of a Barbi here?

Give the guy a break; and respect what the page is...

An historical document that is worthy of research in of it's self; it's not presented as the product of research.

These guys will soon be gone; and it's important we harvest thier recollections while we have them.

We can spend the next hundred years arguing over how we should interpret them......

( I'm just jealous I haven't found a similar collated collection of Spit drivers reminisences.)

As always (....well...as ALMOST always) Seeker speaks wisely.

- oldman

[Kurfürst]

Originally posted by Angus
Hello Kuffie.
How do you do ?

Thanks, fine. More festivals here in August than I can handle!

Anyway, the slats and general performance on some 109's ROCK, and the same occurs on some 109's the other way around?[/B]

Sorry? You mean production differences between individual planes - yes of course. I found some clue about production quality of Bf 109s as late as 1945, it has been said to be better than the 262s in an allied report, and acceptance tolerances are also mentioned.

Does the 109 climb at max with slats open BTW?[/B]

No, slats open at high loads/AoA, climb is performed at normal AoA. The slats can be open at landing otoh. The 109s climb is more laying its power-to-weight ratio and low drag.

[gripen]

Originally posted by Oldman731
As always (....well...as ALMOST always) Seeker speaks wisely.

My understanding is that it's wise to check primary sources for all kind of works (serious or not so serious).

gripen

[Charge]

What are the primary sources concerning 109s?

-C+

[Furball]

It is interesting to note that Handley Page bombers could not use the slats, as Bomber Command required all bombers to have leading edge cable cutters installed on the wing.

[gripen]

Originally posted by Charge
What are the primary sources concerning 109s?

As an example Kokko's report on MT-215 and RAE test report on AE479 are primary sources. At least my copy of the Kokko's report  gives different top speed than the 109 Myths article, apparently the authors have not even checked the sources they allready have.

gripen

[FalconSix]

The RAE test report on AE479 is toilet paper, nothing more. It's funny that your idea of "primary sources" on a German aircraft is two non-German sources.

[BlauK]

Looks like Kokko's speed result should say 636kmh at 6300m.. or should it say 640-690kmh at 6700m? What do you think grippen?

In any case those two mentioned tests are just samples of 2 used planes in certain conditions. They may give some ideas, but certainly not a general truth or even an average. They are simply samples.

[gripen]

Originally posted by BlauK
Looks like Kokko's speed result should say 636kmh at 6300m.. or should it say 640-690kmh at 6700m?

What ever the authors can prove with documentation and quote correctly.

BTW Kokko's report gives the altitude also as CINA and that's the one to use.

Originally posted by BlauK
What do you think grippen?

Nothing to think here, I'm merely saying that the authors should check the facts from primary documentation and quote them correctly.

Originally posted by BlauK
In any case those two mentioned tests are just samples of 2 used planes in certain conditions. They may give some ideas, but certainly not a general truth or even an average. They are simply samples.

The authors are most wellcome to bring in data if they are not happy with the mentioned tests.

Hint: Erla set contains about dozen samples.

gripen

[BlauK]

It is funny that you claim to have copies of this and that source, but you never quote them... almost like they would be worn if you share the info. Or do you experience it as a financial loss if you have paid for it and you write the numbers ina public place  

You said that speed numbers were wrong, but did not say what would be correct in your opinion. That is why I asked what you think about Kokko's report and which one of those two figures should be used when quoting that particular report. Why is he giving two differing figures?  ... 636kmh  and 640-690kmh?

Simply being happy about the 2 tests does not make them the truth or make them the primary sources of 109:s That is like doing 2 interviews, beeing happy with them and claiming that they represent the opinions of the whole population of a country.

[Kurfürst]

Originally posted by BlauK
Looks like Kokko's speed result should say 636kmh at 6300m.. or should it say 640-690kmh at 6700m? What do you think grippen?

Keep in mind Kokko`s 109G-2 'MT-215' had locked down tailwheel - this would account for 12 kph speed loss at SL, and about 15 kp loss at 6km - and already saw quite some service, including in the Luftwaffe. IIRC Kokko`s test was done in March 1943, but the G-2 production already run between June - November 1942. It was alos run at only 1.3ata 30-min rating.

Adding 15kph to the Kokko figurs yields 651 kph, very much in line with what was measured in Rechlin with the same rating (649 kph), and subpar with Soviet test results on a captured G-2 with again 1.3ata, ie. 666 kph.

There are some other data from June 1942 at full 1.42ata power, these are calculations for 109G-2, extrapolated from 109F-4 figures, these tell 700 kph max speed. But I belive these are proably not compressibility corrected, and perhaps wheel well doors were also taken into account (+10 to 15kph) which was planned for the G series, but was only seen on a few airplanes with the Industriestaffel and with LW units guarding Ploesti/Rumania.

I`d say the correct speed rating of a G-2/4 was around 650 kph until 1.42ata was cleared in 1943.

[gripen]

Originally posted by BlauK
It is funny that you claim to have copies of this and that source, but you never quote them...

I'm saying that the authors should not trust "unconfirmed internet sources" like me but check the facts from primary sources. So there is no reason to claim anything.

Originally posted by BlauK
almost like they would be worn if you share the info. Or do you experience it as a financial loss if you have paid for it and you write the numbers ina public place  

Let's quote Mr. Kurfürst (one of the sources for the 109 myths article) from above:

"Well I think the situation is quite clear about the article, there are some people with strong agenda against the Bf 109 and attempt to describe it as a worthless POS at every opportunity, the MiloMoron, gripen, paseolati, guppy, Mike Williams etc. They manipulate the evidence and primary sources to create new myths, while some others create new ones simply because they don`t know the design very well and rely on old books that ever since become obsolate references."

So I'm not claiming the numbers nor offering the data because there is a possibility that I have manipulated it or something.

But if I tell where to find the data, it's certainly not manipulated by me, right?

Originally posted by BlauK
You said that speed numbers were wrong, but did not say what would be correct in your opinion.

Actually I said that:

"At least my copy of the Kokko's report gives different top speed than the 109 Myths article"

and the measured value can be read from Kokko's report. This has nothing to do with my opinions. IMHO Raunio's analysis in the SIHL is well founded and based on quite large amount of data if somebody wants to know my opinion.
 

Originally posted by BlauK
That is why I asked what you think about Kokko's report and which one of those two figures should be used when quoting that particular report. Why is he giving two differing figures?  ... 636kmh  and 640-690kmh?

They made one speed measurement flight and the results are in the report. Read it from there.

Originally posted by BlauK
Simply being happy about the 2 tests does not make them the truth or make them the primary sources of 109:s That is like doing 2 interviews, beeing happy with them and claiming that they represent the opinions of the whole population of a country.

AFAIK Raunio's analysis is based on roughly 30 samples.

gripen

[Porta]

Originally posted by gripen
IMHO Raunio's analysis in the SIHL is well founded and based on quite large amount of data if somebody wants to know my opinion.

AFAIK Raunio's analysis is based on roughly 30 samples.

Hi gripen,

Can you post a summary of Mr. Raunio's findings on Me 109 G performance, as well as the sources he used?

I've studied myself a lot of performance reports (from Mtt AG, Daimler-Benz and Rechlin) and I don't come close to such number of samples (performance tests of clean Me 109 Gs are rather scarce).

Porta

[BlauK]

Porta,
have you not noticed yet, that gripen does not want to talk numbers, he only tells you to go somewhere to find the source

gripen,
If it has not become clear to you yet, I do have the report. If you also have it, you can read it and also find how Kokko reports the 640-690kmh max. speed. That 363kmh can be read from charts.

So, are you saying that Raunio has an answer to that particular question of mine. If so, thank, I'll read it when I have time... since you would not give the answer anyway. I am starting to guess who you are...

[gripen]

Originally posted by Porta

Can you post a summary of Mr. Raunio's findings on Me 109 G performance, as well as the sources he used?

The article serie is published in the "Suomen Ilmailuhistoriallinen Lehti" (something like The Aviation history magazine of Finland) and it's written in finnish. To get it you can contact the magazine:

Suomen Ilmailuhistoriallinen Lehti
Mäkelänkatu 5 B 10
00550 Helsinki
FINLAND

I can only sum up the references I'm aware, I have merely collected data for Raunio, I don't know about other data. Anyway here is a rough summary of those I'm aware:

MT-215 test data
MTT test on G-6/Trop (several configurations)
MTT test on AS proto (contains also G-5 curve)
Erla set (13 samples)
Flugleistungen Me 109G-Baureihen (20 samples)
British tests on G-2 and G-6
Various curves from MTT
His own calculations based on Hörner, DB data and MTT data (and more)

Originally posted by BlauK

have you not noticed yet, that gripen does not want to talk numbers, he only tells you to go somewhere to find the source  

That's exactly what I have been promoting throughout this thread; the authors should check the (unaltered) primary sources instead believing "unconfirmed internet sources" like me, Mr. Kurfürst or Mr. BlauK.

Hopefully it's finaly clear to Mr. BlauK.

Originally posted by BlauK

If it has not become clear to you yet, I do have the report. If you also have it, you can read it and also find how Kokko reports the 640-690kmh max. speed. That 363kmh can be read from charts.

To me it's unclear if you actually have the report; there is an exact top speed reached in the speed test done in Malmi 5.4.1943 klo. 12.15-13.05 (the only one they made) and it is not "roughly 645 km/h" nor "640-690 km/h" nor "363kmh". Please read it correctly or get the report.

Originally posted by BlauK
So, are you saying that Raunio has an answer to that particular question of mine. If so, thank, I'll read it when I have time... since you would not give the answer anyway.

I highly recommed reading it, IMHO it's by far best study on the flying qualities of the Bf 109G so far and pretty much entirely based on primary sources.

Originally posted by BlauK
I am starting to guess who you are...

Thanks for making this personal. If my personality matters you so much, all you need to do is ask it from Mr. LLv34_Camouflage, I have shared some data with him.

gripen