[ACE-OF-ACES]

I think, we got a good discussion going here! As a professor myself, I think that we are approaching the topic from opposite ends. Ace, and perhaps Lucky, too, you seem to approach it from an engineering/science perspective, while I come at it from the point of view of a historian.

Actually I fancy myself a bit of a WWII historian with a minor in human nature. The WWII historian stemming from the fact that ever since I was a kid listing to all the WWII vets that lived on our street and all the books I have read on it, The human nature aspects stemming from 12 years in the military followed up with 5 years in academia followed by 15 years in aerospace and 50 years of life in general.

As I said earlier, I do think that this kind of work and attention to detail is important and I am glad that Ace took this on. However, the point I wanted to make is this: Yes, the number five will always be the number five. How and why one arrives at that number is another matter,

Maybe is some aspects of life that can be an issue

But in the case of the top speed a rate of climb testing

The number 5 stems from the recording device

With some minor curve fitting between the data points

Therefore I don

[TheGrunch]

I'm sorry, but you can't use the AI as a good indicator of aircraft performance relative to a human-flown aircraft. They're always perfectly trimmed and do not experience overheating.

[Thee_oddball]

Never mind all this...lets just use X-plane to model the capabilities of all the planes in il2...

[bohr-r]

Hi Ace,

I really appreciate your detailed reply. I was just wondering if you have come across this book and if it might be useful for general purpose reading on WW II aviation: Luftwaffe test pilot: Flying captured Allied aircraft of World War 2, by Hans-Werner Lerche? I used to own a German copy of it a long time ago, but I don't have it anymore.

With all this, I have another comprehension question. How are aircraft performance data gathered? What I mean is, are the data that show up in the graphs from only a single flight (that would be unlikely, wouldn't it?), or are they an average, calculated from several performances under similar conditions?


bohr-r wrote:
The context in which the data were gathered and published or disseminated is important, too.

Ace: "Well I already covered the gathered aspect and how it is unlikely that they would knowing fake the numbers

But I am interested in how you think the numbers would change due to publishing or dissemination?

Do you have an example?"

RB: At the moment I don't. I will let you know when I find one. I was thinking of discrepancies between prototypes and production aircraft. On top of that, at least in Germany, there was plenty of in-fighting between different aircraft manufacturers and various branches of government and the military. For example, in regard to the He-219, or the Ta-154 Moskito. I think that it is possible that in the course of these internal conflicts data may have been tampered with for political reasons. However, at this point, I cannot prove it, so it's a only theory at the moment. Nonetheless, based on descriptions of the political climate of a "culture of fear," that I heard from my relatives, friends and acquaintances who lived through the war in Germany, I think such things are entirely possible.

Ace: "It is know that the AI does not have over heat issues, thus they can push their planes harder than a real person could, so maybe your seeing that."

RB: All the time!
:wink:

Ace wrote: "In that I think the state of the other plane and pilot is important

Very important

And that is my point

Not knowing anything about something that important is what makes most if not all combat reports useless wrt determining the performance of a plane."

RB: I see. Are you saying that because the pilots were not necessarily in a neutral, or objective state of mind, the technical value of their observations is difficult, if not impossible to ascertain?

By the way, do you have any information on how performance data recorded in the 1940s would compare to performance data of restored aircraft of the same type flying today? Or is that not a valid comparison?

Thanks again.

Regards,

RB

[ACE-OF-ACES]

I really appreciate your detailed reply. I was just wondering if you have come across this book and if it might be useful for general purpose reading on WW II aviation: Luftwaffe test pilot: Flying captured Allied aircraft of World War 2, by Hans-Werner Lerche? I used to own a German copy of it a long time ago, but I don't have it anymore.

No I don't have that book, but I do have a couple of other test pilot books.

With all this, I have another comprehension question. How are aircraft performance data gathered? What I mean is, are the data that show up in the graphs from only a single flight (that would be unlikely, wouldn't it?), or are they an average, calculated from several performances under similar conditions?

I allready answered/covered those questions in my previous posts

RB: At the moment I don't. I will let you know when I find one.

Ok

I was thinking of discrepancies between prototypes and production aircraft. On top of that, at least in Germany, there was plenty of in-fighting between different aircraft manufacturers and various branches of government and the military. For example, in regard to the He-219, or the Ta-154 Moskito. I think that it is possible that in the course of these internal conflicts data may have been tampered with for political reasons. However, at this point, I cannot prove it, so it's a only theory at the moment.

I understand

We got more theories than anything else

Which is why I like to stick with the hard data

Nonetheless, based on descriptions of the political climate of a "culture of fear," that I heard from my relatives, friends and acquaintances who lived through the war in Germany, I think such things are entirely possible.

I covered that allready too

Where the case being if they knew in advance that thier data would never be validated by anyone else

All the time!

That is not a flight model issue as much as a game AI issue that allows the AI to do things real poeple can not do

I see. Are you saying that because the pilots were not necessarily in a neutral, or objective state of mind, the technical value of their observations is difficult, if not impossible to ascertain?

No

Just that the story is one sided, your only hearing the story from one pilot's prospective

The fact that he might be neutral or not objective or not does not mater as much as you know nothing from the pilot in the other plane

By the way, do you have any information on how performance data recorded in the 1940s would compare to performance data of restored aircraft of the same type flying today? Or is that not a valid comparison?

I dont know of anyone that would put thier restored aircraft threw such hell

But if they did you would be hard pressed to find a restored aircraft that matches the WWII configuraitoin

Something as simple as removing the WWII radio that was the size of a foot locker with a modern radio that is the size of a shoe box could make a big difference.

I only know of a few restored P51s that still have the guns and ammo trays mounted in the wings along with a gun sight in the cockpit

[BillSwagger]

Ace: "Well I already covered the gathered aspect and how it is unlikely that they would knowing fake the numbers

But I am interested in how you think the numbers would change due to publishing or dissemination?

Do you have an example?"

http://www.kurfurst.org/Tactical_trials ... g1940.html

Note: the spitfire uses a two speed metal prop in this test.

Climb times to 4 km:

Bf 109 E 4.4 min,

Spitfire 5 min,

Curtiss 5.2 min.

Hurricane 5.6 min,


In this test, the data for the spitfire using a two speed metal prop is as follows:

http://www.spitfireperformance.com/n3171.html

5.5 minutes to 10,000ft
8 minutes to 15,000ft

4000m = ~ 13,123 ft


Which is real world data?

[ACE-OF-ACES]

Ace: "Well I already covered the gathered aspect and how it is unlikely that they would knowing fake the numbers

But I am interested in how you think the numbers would change due to publishing or dissemination?

Do you have an example?"

http://www.kurfurst.org/Tactical_trials ... g1940.html

Note: the spitfire uses a two speed metal prop in this test.

Climb times to 4 km:

Bf 109 E 4.4 min,

Spitfire 5 min,

Curtiss 5.2 min.

Hurricane 5.6 min,


In this test, the data for the spitfire using a two speed metal prop is as follows:

http://www.spitfireperformance.com/n3171.html

5.5 minutes to 10,000ft
8 minutes to 15,000ft

4000m = ~ 13,123 ft


Which is real world data?

Both are real world data

The www.kurfurst.org link does not come up

But I would allways take anything from kurfurst's sight with a grain of salt, he has been know to fudge the numbers in the past

But what does this have to do with the quote you replied to?

I dont see how this is an example of how the data change due to publishing or dissemination

To show that I would expect you to show me some values from 'one' flight test that were changed when presented to someone else

All these two seperate tests prove is there was something different about the 'two' Spitfires or the 'two' test method

[BillSwagger]

doesn't Oleg also have a background in aerospace engineering?




The link to Kurfurst site should work fine, unless you are banned.

Anyway, how would you go about determining the proper data to use for comparison?



I'm still highly skeptical of your K data used in the graphs in the beginning of the thread. Can you just post the link(s) or other verifiable sources that include the performance data you referred to. I was not able to locate a PDF file, so please just post them here, for all of us to see.


thanks

Bill



"Just cause I'm a doctor, doesn't mean they'd give me a scalpel"

[ACE-OF-ACES]

doesn't Oleg also have a background in aerospace engineering?

Not sure what your asking?

I think you know that he does.. don't you?

The link to Kurfurst site should work fine, unless you are banned.

Or unless I am at work and they block forien sites

Anyway, how would you go about determining the proper data to use for comparison?

I would have to read both of them in detail and see if I can find out what the differences were that caused the differences

I'm still highly skeptical of your K data used in the graphs in the beginning of the thread.

Good

You should be skeptical of everyone!

But, can you give me a little more info?

What is it that you are skeptical off?

The real world data I provided?

Or the in-game data I provided?

Can you just post the link(s) or other verifiable sources that include the performance data you referred to.

No, once is enough

I was not able to locate a PDF file,

At the bottom of my first post there it says

"INDIVIDUAL TEST"

Below that it says

"REALISM RATING of the HSFX 4.1 Bf-109K-4"

Click on it

It is a link to the pdf file

so please just post them here, for all of us to see.

No need

In that it has been there since day one

thanks

Your welcome

[BillSwagger]

thanks i found the PDF, and the graphs. Where did you get those from? Naca? there's no reference material in your pdf.

Now, i guess what i'm trying to get at is the graph must have more information, perhaps translated details that explain more about the plane, the propellers used, ata rating, supercharger, etc.

http://www.spitfireperformance.com/spit14v109.html

Doesn't mike make the same reference to these tests. In fact, he even provides translated material. If you read starting the middle of the page where he shows the charts for the late spit and 109k.

He says the K never used 1.98 ata in service but that it was proposed and tested as we see here. 1.8 was used operationally.

"Unfortunately, flight trials of Me 109 Ks appear not to exist. The following Me 109 K curves were produced by Messerschmitt's Project Bureau at Oberammergau. While the curves are rather simplistic estimates (the effect of the hydraulic coupled supercharger being absent for example), they should give some idea of potential, however, they should be treated with reserve. "

And how much better would the presence of a hydraulic coupled supercharger be over the one used in the test?

I think your realism rating has too large a margin of error to make any significant conclusion.

To fill the gaps, Ace, i think you might need to read into some pilot accounts or other means, not only test data using experimental propellers and engine ratings that may have never been used in service.

Its difficult to mesh the methods of science with the historical data, you are always gonna have error. As is the case with many German aircraft, there is not sufficient test or trial data to make unadjusted conclusions from.

There is no reason to think your realism rating of the 109k is more or less accurate than the games, at least with the data you've provided.

I guess i need to see more than one graph and one chart, with out some of the obscurities mentioned by mike williams. He says that information doesnt exist.

Bill

[LuckyOne]

"Just cause I'm a doctor, doesn't mean they'd give me a scalpel"

I am from South of Europe,and I see that disrespect of professional occupation is present on the West too.I am surprised and disappointed.
Why do not listen ACE....He is professional and he did not finished research yet.I am also waiting to ask some questions.
@bohr-r
Greetings to my colleague historian.

[BillSwagger]

"Just cause I'm a doctor, doesn't mean they'd give me a scalpel"

I am from South of Europe,and I see that disrespect of professional occupation is present on the West too.I am surprised and disappointed.
Why do not listen ACE....He is professional and he did not finished research yet.I am also waiting to ask some questions.
@bohr-r
Greetings to my colleague historian.

noted. I can respect what ace is doing, and i know he is very knowledgeable. Still, i question the results of this particular plane.

Its the history vs science debate. I think to some extent there will be error in the science because of the context of the performance tested.



Bill

[ACE-OF-ACES]

thanks i found the PDF, and the graphs.

Your welcome

Where did you get those from? Naca? there's no reference material in your pdf.

No not NACA

Note they are writen in German

As to ware, probally the same guy Kurfurst got them from

Now, i guess what i'm trying to get at is the graph must have more information, perhaps translated details that explain more about the plane, the propellers used, ata rating, supercharger, etc.

Sounds good

Let me know what you find out

http://www.spitfireperformance.com/spit14v109.html
Doesn't mike make the same reference to these tests. In fact, he even provides translated material. If you read starting the middle of the page where he shows the charts for the late spit and 109k.

He says the K never used 1.98 ata in service but that it was proposed and tested as we see here. 1.8 was used operationally.

"Unfortunately, flight trials of Me 109 Ks appear not to exist. The following Me 109 K curves were produced by Messerschmitt's Project Bureau at Oberammergau. While the curves are rather simplistic estimates (the effect of the hydraulic coupled supercharger being absent for example), they should give some idea of potential, however, they should be treated with reserve. "

In short he says what I said in the pdf summary

i.e. that these (Bf109K-4 1.8ata) values are calcualted estimates of performance

And how much better would the presence of a hydraulic coupled supercharger be over the one used in the test?

Or worse!

I think your realism rating has too large a margin of error to make any significant conclusion.

To fill the gaps, Ace, i think you might need to read into some pilot accounts or other means, not only test data using experimental propellers and engine ratings that may have never been used in service.

Been there done that years ago

It is a rabbit hole that produces no fruit

On that note

So many people

[ACE-OF-ACES]

"Just cause I'm a doctor, doesn't mean they'd give me a scalpel"

I am from South of Europe,and I see that disrespect of professional occupation is present on the West too.I am surprised and disappointed.

To be honest I was a bit surprised too

Just not like Bill

So I decided to just delete it from my reply back to him

Why do not listen ACE....He is professional and he did not finished research yet.

I know

I was suprised too to find out he had not even read the pdf file yet

Kind of sad really, that some feel the need to comment on things they have not even took the time to read

But, in this line of work I am use to it

I am also waiting to ask some questions.

Anytime

But the way this thread is going

You might want to just PM me were we can talk in private

[BillSwagger]

thanks i found the PDF, and the graphs.

Do you have anything to support that theory beyond your gut 'feelings'?

Its not so much a gut feeling as it is i'm left asking questions that haven't been resolved by the data provided.

The 12199 prop was an experimental thin bladed prop. Thin blades are typically used for speed and dives, are they not?

If the 12159 is the one that was used in service, how did its characteristics differ? Did it offer better climb at the expense of top speed?



Those kind of questions.


Bill