[ACE-OF-ACES]

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

The HSFX4.1 Bf−109K−4 is a stock IL−2 flight model. It is intended to be a Bf−109K−4 running B4 fuel at 1.8ata.
With regards to the top speed, even though it is a little low for most of the altitudes, it does fall within the generally accepted 5% error window. In short the plane is generally under performing in speed.

With regards to the rate of climb, the rate of climb exceeds the 5% error widow for all but the highest altitudes, with a max error of around 32% at 17,000ft and an average error of about 16%. In short the plane is generally over performing in rate of climb.

What compounds these errors is the real world data is

[Fireskull]

hock:


Is this real??? That is a large discrepancy!! It blows my mind!!

[ACE-OF-ACES]

hock:
Is this real???

No IL2 is a 'simulation'!

That is a large discrepancy!!

Agreed 100%

It blows my mind!!

What blows my mind is all the 109 drivers that call the Spit 25 uber when the 109K-4 is the poster boy of uber wrt roc!

[Strafe]

Great, but I would like to see same charts to russian planes

[ACE-OF-ACES]

Great,

Thanks

but I would like to see same charts to russian planes

Me too

But I can only work at the speed of 'free'

[BillSwagger]

Is the speed data taken from mike williams page?

If it is, his site also explains that the speed plots used are projections used by the Messerschmitt company for this aircraft. .

"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. "

[ACE-OF-ACES]

Is the speed data taken from mike williams page?

No

The speed is from the real world data charts that I provided in the the pdf document (see link at bottom of first post)

If it is, his site also explains that the speed plots used are projections used by the Messerschmitt company for this aircraft.

"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. "

I also explaned that, where I said in my first post, and in the pdf document

[quote="Me"][i]To make maters worse, the real world data provided consists of

[bohr-r]

Hello All,

First off, a big thank you to ACE OF ACES for the work on performance data. I appreciate this attention to detail, even though I have to admit that for the most part, I don't even know how to read all these charts. When it comes to comparing flight data, I am rather sceptical to begin with. In another thread with a similar discussion topic, somebody mentioned that the stock flight models for IL-2 were designed in such a way that their in-game performance is balanced to that of other aircraft. Sometimes, compromises in regard to the representation of actual flight data had to be made, so that aircraft would still retain a semblance of their actual, historical traits compared to each other, while still fitting into the performance parameters that the game engine allows.

With all these discussions about flight data, the first thing that comes to my mind is how and for whom these data were obtained. I don't think that any particular set of performance data can be taken at face value. It matters under what circumstances they were obtained and who the audience was. For example, if a particular manufacturer wanted to push a particular prototype, they might have "adjusted" the data accordingly. On the other hand, evaluations of captured enemy aircraft were usually much more critical and unfavourable than those coming from the manufacturer; perhaps to some extent for propaganda reasons. Finally, there must have been great discrepancies between the performance of brand-new machines and those that had been used under combat conditions for a while. Some aircraft may have been damaged, resulting in a somewhat lower performance, while others may have been "tuned-up" in the field for higher output. There would also have been differences between individual machines of the same type, depending on usage and differences in wear and tear. So, unless there is a wide range of data for any particular type and model of aircraft, it would be extremely difficult to make an assessment that would accurately reflect the performance characteristics and capabilities of each individual plane of a certain make.

Please don't get me wrong; I appreciate the acribic work that is done in regard to perfrmance data and evaluation. However, I believe that there needs to be some room for variation, though I don't know how this can be accurately modeled in IL-2. Apparently, SOW is supposed to have it. To me, and this may well reflect my skill level, or lack thereof, it's always my opponent's plane that I feel is the "Ueber-Plane," no matter what we're flying at the moment. If I am in La-7, I still get shot down by Bf-109Fs, if I am in a FW-190D-11, the P-51Ds still get me. If I switch to the Allied side, it's similar in reverse. Perhaps, any of this would be more apparent in online-play, which I don't do.
So, if the flight model of the Bf-109K will be adjusted in a new slot, does that then mean, that all sorts of other aircraft need to be adjusted, too?
Anyway, end of rant for now.

Regards,

RB

[ACE-OF-ACES]

First off, a big thank you to ACE OF ACES for the work on performance data. I appreciate this attention to detail,

Thank you

even though I have to admit that for the most part, I don't even know how to read all these charts.

It's easy

Take the following P-47 top speed graph



Well say you want to know what the top speed is at 15kft..

Place your finger on the LHS where it says 1.5 (that is 15,000ft), ie the Y axis (Altitude)

Than drag your finger to the RIGHT until it intersects one of the lines

For example the green one (P-47D-27)

Once your finger intersects the green line

Start moving your finger DOWN until you hit the X axis (TAS)

Under your finger is the SPEED at that alt, ie 15kft

Which looking at the graph is ~395mph

When it comes to comparing flight data, I am rather sceptical to begin with.

Really?

Now let me get this straight

You admit your experience is such that you don't understand the charts enough to even read them

Yet you feel your experience is such that you can be sceptical of the results

The results that you don't understand how to even read

Is that right?

I have to admit, I find that very strange

In another thread with a similar discussion topic, somebody mentioned that the stock flight models for IL-2 were designed in such a way that their in-game performance is balanced to that of other aircraft. Sometimes, compromises in regard to the representation of actual flight data had to be made, so that aircraft would still retain a semblance of their actual, historical traits compared to each other, while still fitting into the performance parameters that the game engine allows.

Well one thing is for sure

You can find people who feel that way

But you can also find people who don't feel that way

All I know is that when Oleg was asked if he adjusted the flight models for 'game' balance he said no

That is the thing about peoples 'feelings'

They are based on nothing but a 'feeling'

They can not be proven wrong or right, because it is just a 'feeling'

Where as on the other hand, given real world data, you can compare it to the in-game results and get the same results each time you do it

Because the math is not based on how someone 'feels'

With all these discussions about flight data, the first thing that comes to my mind is how and for whom these data were obtained. I don't think that any particular set of performance data can be taken at face value.

And what is that 'feeling' of yours based on?

This 'feeling' you have about the data that you yourself said you don't fully understand

It matters under what circumstances they were obtained and who the audience was. For example, if a particular manufacturer wanted to push a particular prototype, they might have "adjusted" the data accordingly.

I have never bought into the notion that the ethics of the manufactures were such that they would fake such things. Especially when you consider the fact that the air forces they build the planes re-did each test to ensure the plane could do what the manufacturer said it could do as part of the acceptance testing. So it would be silly to lie knowing that the min they turned the plane over to the air force their lie wold be reviled. The only case I can think of someone doing that is someone who knew the plane would never make it to production, Than they could say just about anything they wanted to say about it in that they knew their lie would never be discovered. As was the case for many German engineers late in the war that were being pressured to come up with some super weapon to save their skins

On the other hand, evaluations of captured enemy aircraft were usually much more critical and unfavourable than those coming from the manufacturer; perhaps to some extent for propaganda reasons.

I have never bought into the notion that the ethics of these test pilots was such that they would be charged with testing an airplane to find it's weakness for their pilots to take advantage of only to lie about the result. In that they knew what they said was going to be used by pilots in the field and thus their pilots in the fields life depended on them being truthful.

Finally, there must have been great discrepancies between the performance of brand-new machines and those that had been used under combat conditions for a while. Some aircraft may have been damaged, resulting in a somewhat lower performance, while others may have been "tuned-up" in the field for higher output.

Be sure, but this sim like most does not attempt to model wear and fatigue.

There would also have been differences between individual machines of the same type, depending on usage and differences in wear and tear. So, unless there is a wide range of data for any particular type and model of aircraft, it would be extremely difficult to make an assessment that would accurately reflect the performance characteristics and capabilities of each individual plane of a certain make.

Which is why most real world data consisted of testing more than one plane. Take the P51 and P38 testing done, the USAAR pulled several planes from the assembly line 'at random' to preform acceptance testing on.

Please don't get me wrong; I appreciate the acribic work that is done in regard to performance data and evaluation. However, I believe that there needs to be some room for variation,

For a guy who admits he does not understand the data, you sure have a lot of opinions on how valid it is!

But I digress!

Just so you know it is generally accepted that +/- 5% error is acceptable in a simulation. A few years back some add ons for the Microsoft's Combat Simulator claimed to have 1% error but to be honest they never really provided any proof of it. It was just something they claimed to have, much like UltraPack claims to have more accurate flight models than HSFX. Maybe they do, maybe they don't all I know is the few I have looked at don't. That is the neat thing about comparing to the real world data. It removes all the 'feelings' and all that is left is the 'facts'.

though I don't know how this can be accurately modeled in IL-2. Apparently, SOW is supposed to have it. To me, and this may well reflect my skill level, or lack thereof, it's always my opponent's plane that I feel is the "Ueber-Plane," no matter what we're flying at the moment. If I am in La-7, I still get shot down by Bf-109Fs, if I am in a FW-190D-11, the P-51Ds still get me. If I switch to the Allied side, it's similar in reverse. Perhaps, any of this would be more apparent in online-play, which I don't do.

There is a lot of truth in that

You unlike most are willing to admit they have been bested by a better pilot

In your case AI

But that kind of honesty while looking in the mirror is the exception to the rule

A lot of folks here will blame it all on the flight model without even taking pause to consider that what they saw was not an over molded plane but a better pilot

So, if the flight model of the Bf-109K will be adjusted in a new slot, does that then mean, that all sorts of other aircraft need to be adjusted, too?

Nope because like I pointed out

Oleg never adjusted for balance

And none of the mod makers I have spoke to adjust for balance sake, except one, Freddy and his HISTOMOD KOREAN mod. Freddy 'feels' he provides a better 'game' by ignoring real world data when developing his flight modles and prefers to base them on.. on.. on.. Hmmm actually he has never really explain just what it is he does base his flight models on.

[bohr-r]

Hi Ace of Aces,

You wrote: "That is the neat thing about comparing to the real world data. It removes all the 'feelings' and all that is left is the 'facts'." See, that's where I respectfully disagree with you. What exactly is the "real world data"? What are the "facts"? Performance data for aircraft were rarely, if ever recorded only for the purpose of documenting the performance of an aircraft. There are almost always other factors and agendas to be taken into consideration. There is no such thing as "objective," or "un-biased" recoding of data. The desired results will influence the findings. That's why I think that one should not take any set of data at face value, but critically evaluate them. That is why I think that studying performance data can only go so far and should ideally be combined with other avenues of research.
For example, when flying an early-model A6M-Zero in the IL-2 game, I find that the performance of the aircraft in relation to other contemporary planes is very undermodeled in regard to speed. Why do I think that? From reading accounts of Japanese and Allied pilots who flew the Zero, or who fought against it, I am under the impression that the early-model Zeros were not only better armed and more agile, but also considerably faster than the contemporary P-39s, P-40s, and F-4 Wildcats. In contrast, performance data seem to indicate that the early Zeros were actually slower than their American contemporaries. What does this mean? Does it mean that the veterans who flew these planes, or who fought against them, all have inaccurate memory? How were the performance data obtained? As far as I know, the US tested at least one captured Zero during the war and several others after the end of World War II. Let's imagine for a second that the captured Zeros tested by the Allies were actually faster than most contemporary Allied fighters. Would such information have been published or forwarded to the troops? Probably not, because it could have damaged morale considerably. Instead, what was published may well have been an "adjusted" version of the performance data that made Allied aircraft look better by portraying the Zero as slower than it actually was.
I don't know whether this really took place, but the scenario seems pretty likely to me. The same would go for Axis powers testing captured Allied aircraft. In order to arrive at a reasonable average, one would have to have performance data for dozens, if not hundreds of aircraft of the same type that could be compared with each other. But that is rarely the case. That's why I think that any isolated set of performance data, especially the ones still recorded during the war, are suggestions at best. Besides performance data, I think it is important to also draw on qualitative, if sometimes anecdotal evidence, such as accounts of test pilots, front-line combat pilots and ground crew in order to obtain a more even perspective on the performance of particular aircraft. I don't think that performance data alone can tell the whole story.

Regards,

RB

[ACE-OF-ACES]

You wrote: "That is the neat thing about comparing to the real world data. It removes all the 'feelings' and all that is left is the 'facts'." See, that's where I respectfully disagree with you. What exactly is the "real world data"? What are the "facts"?

Real world data is data that is not simulated data
Facts are something that actually exists; reality; truth, something known to exist or to have happened, a truth known by actual experience or observation; something known to be true.

Performance data for aircraft were rarely, if ever recorded only for the purpose of documenting the performance of an aircraft.

Disagree 100%

There are almost always other factors and agendas to be taken into consideration.

I have never bought into the notion that the ethics of the manufactures were such that they would fake such things. Especially when you consider the fact that the air forces they build the planes re-did each test to ensure the plane could do what the manufacturer said it could do as part of the acceptance testing. So it would be silly to lie knowing that the min they turned the plane over to the air force their lie wold be reviled. The only case I can think of someone doing that is someone who knew the plane would never make it to production, Than they could say just about anything they wanted to say about it in that they knew their lie would never be discovered. As was the case for many German engineers late in the war that were being pressured to come up with some super weapon to save their skins

There is no such thing as "objective," or "un-biased" recording of data. The desired results will influence the findings.

Wrong

The interpretation of the data can be biased, but the data itself is not. Unless you think you can apply pear pressure to an altimeter gauge to make it report incorrect values

That's why I think that one should not take any set of data at face value, but critically evaluate them.

The number 5 is the number 5 no mater how you spin it. Now one might try and interpret the number 5 to be the color blue, but in doing so such a person would expose themselves as biased or a fool

That is why I think that studying performance data can only go so far and should ideally be combined with other avenues of research.

Really?

Now let me get this straight

You admit your experience is such that you don't understand the charts enough to even read them

Yet you feel your experience is such that you can be skeptical of the results

The results that you don't understand how to even read

Is that right?

I have to admit, I find that very strange

For example, when flying an early-model A6M-Zero in the IL-2 game, I find that the performance of the aircraft in relation to other contemporary planes is very undermodeled in regard to speed. Why do I think that? From reading accounts of Japanese and Allied pilots who flew the Zero, or who fought against it, I am under the impression that the early-model Zeros were not only better armed and more agile, but also considerably faster than the contemporary P-39s, P-40s, and F-4 Wildcats.

That is easy to explain

You yourself admit you don't know how to read the graphs

Based on that there is a good chance you don't know the difference between TAS and IAS

Which is the mistake most people make when commenting on speed

Than there is the test method itself

I can not tell you how many people have sent me track files of their 'tests' claiming this or that only to find the only error in the sim is in the way they did the 'test'

In contrast, performance data seem to indicate that the early Zeros were actually slower than their American contemporaries. What does this mean? Does it mean that the veterans who flew these planes, or who fought against them, all have inaccurate memory? How were the performance data obtained?

That is why combat reports are useless

The story is one sided

You don't know the state of mind or the sate of the other plane

That is to say for everyone 109 pilot that says he could out turn a Spitfire there is a Spitfire pilot that says he could out turn a 109

Which is why real world data collected under controlled test conditions is the only way to fly

Pun intended

As far as I know, the US tested at least one captured Zero during the war and several others after the end of World War II. Let's imagine for a second that the captured Zeros tested by the Allies were actually faster than most contemporary Allied fighters. Would such information have been published or forwarded to the troops? Probably not, because it could have damaged morale considerably. Instead, what was published may well have been an "adjusted" version of the performance data that made Allied aircraft look better by portraying the Zero as slower than it actually was.

I have never bought into the notion that the ethics of these test pilots was such that they would be charged with testing an airplane to find it's weakness for their pilots to take advantage of only to lie about the result. In that they knew what they said was going to be used by pilots in the field and thus their pilots in the fields life depended on them being truthful.

I don't know whether this really took place, but the scenario seems pretty likely to me. The same would go for Axis powers testing captured Allied aircraft. In order to arrive at a reasonable average, one would have to have performance data for dozens, if not hundreds of aircraft of the same type that could be compared with each other. But that is rarely the case. That's why I think that any isolated set of performance data, especially the ones still recorded during the war, are suggestions at best.

That is your 'feeling' and your welcome to it

I just don't agree with it

Which is not to say or imply that I think every detail of the higher brass on the enemy strengths and weaknesses in all aspects of war was passed down to every private in the field.

All I know is what I have read, and from that I have yet to see where some weakness let alone strengths of the enemy aircraft was withheld from the pilots. In that it would just be silly. Take the Thach Weave, based on knowing the zero could out turn the F4F they developed tactics to deal with that 'strength' of the zero. That is just one example of why such info should not be held back

Besides performance data, I think it is important to also draw on qualitative, if sometimes anecdotal evidence, such as accounts of test pilots, front-line combat pilots and ground crew in order to obtain a more even perspective on the performance of particular aircraft. I don't think that performance data alone can tell the whole story.

Combat reports are neat in that they tell you about the pilot and his tactics, but they tell you very little about a match between two planes. As noted above it is a one sided story, you don't know if the other plane had engine troubles or if the pilot even knew he was being chanced when the guy chasing him said he caught up to him. Do you really want a flight model based on one sided story that don't contain enough information to even begin to reproduce the test in the game to see if you get the same results?

[LuckyOne]

A way to go ACE-OF-ACES,you have a very professional approach,as a professor I can say that... :wink:

[ACE-OF-ACES]

A way to go ACE-OF-ACES,you have a very professional approach,as a professor I can say that... :wink:

Thanks LuckyOne!

Working in the aerospace industry for 15+ years I kind of figured out how to write things up!

I just thank god for spell and gramer checkers!

[TheGrunch]

Well, Oleg always has said that the Bf-109 is his favourite aircraft.

[bohr-r]

Hello Ace of Aces, hello Lucky One,

Thanks for your comments. 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. 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, though. I just don't think that the data alone can tell the whole story. The context in which the data were gathered and published or disseminated is important, too. Based on my experience in the work that I do, I think that "truth" is always relative and not absolute, even when it comes to the collection of "hard" data. It is very difficult, if not impossible to separate "hard data" from their interpretation.
However, I do have a few more questions for Ace. From your experience as an engineer, how great do you think the discrepancies between factory-fresh aircraft and combat-used planes of the same type would have been in regard to performance? Was this perhaps something that the game developers of IL-2 were trying to build into the game (hence some of the inconsistencies in regard to actual flight data)? Is it something that could/should be reflected in how the fms of in-game planes? Are these differences reflected in the graphs you have presented? These are just comprehension questions, not criticism.
My example of the Zero, was just that, an example. I am aware of the difference between True Airspeed and Indicated Airspeed. I was not referring to speed values indicated on any gauge or display in the game, but to the fact that in-game, the AI can outrun me in their P-40s, or Wildcats when I am flying an early version of the Zero. When they chase me, they always catch up, when I and my AI-wingmen chase them, they always get away.
Ace, you wrote:

"That is why combat reports are useless

The story is one sided

You don't know the state of mind or the sate of the other plane

That is to say for everyone 109 pilot that says he could out turn a Spitfire there is a Spitfire pilot that says he could out turn a 109

Which is why real world data collected under controlled test conditions is the only way to fly

Pun intended Wink"

I think, this is exactly the point we seem to disagree on. I do think that the "state of mind" or the "state of the other plane" are important. I believe, there is validity to the statements of combat pilots, even though they are subjective, especially if there are several such reports indicating similarities. If one discovers a discrepancy between the recorded flight data and the statements of pilots who flew, or who fought these planes, shouldn't one ask why that is? Is it really only a matter of perception, or perhaps of differences in pilot skill? Would those not also have to be factored into considerations of performance differences? Or is this the point where we reach the limitations of the IL-2 game engine?

Anyway, your thoughts on this are much appreciated.

Regards,

RB