Prototype, Production, or Captured War Booty?

[Vermillion]

Ok gonna open up a can o' worms here  

I wanted to ask a question here and see what everyone's opinon is.

Where should the data come from that is used to build our Flight Models? Prototypes, and aircraft used for acceptance testing (pristine, highly maintained "optimum" aircraft)? Production, or an "average" aircraft (average joe's plane sitting on the front)? Captured War Booty which may or may not have been tested to its fullest?

Now of course if its the only source of data available, thats what we should use. But if multiple sources are available, which should take preference?

The reason I ask, is that right now, most of our American and British aircraft FM's are built with prototype/specially prepared test aircraft data.

Our single Russian aircraft is built with "production" data. Which is quite a disparity with the "prototype" data.

My opinon, is that regardless of which way you go, all aircraft should be modeled on an even basis. My preference would be prototype/acceptance aircraft, in optimum condition, flying on 100 octane fuel. But thats just my opinon.

Whats yours?

PS: This could make for some really scary aircraft, for instance the Ki-84 that did 427mph after the war during official US flight testing.

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Vermillion
**MOL**, Men of Leisure
Carpe Jugulum
"Real Men fly Radials, Nancy Boys fly Spitfires"

[Rocket]

Ya know the only way to get true data would be to have a plane configured just as it was in the war and fly it for test data.  Problem I see is who in their right mind would allow wieghts to be added in place of the long removed guns and pilot armour and then let the plane be pushed through test that could possible destroy the airframe and with the # of planes being added the cost would be staggering.
You could take the manufacturer's flight data since we all know they didn't use it for propaganda  
You could take pilot data like they are able to remember that long ago correctly and not taint up the data with love of their plane.
You could take data from the many books out there that seem to have different numbers for each plane.
Or you could try to balance data from all these sources and come up with what we have.  I think that there will ALWAYS be someone to say "hey this plane is hosed" because it doesn't match their favorite reading material.  

You have brought up a very valid point Verm.  How do you get ACCURATE flight data when you can't recreate EXACT flight conditions.

Anyone have any real ideas how it could be done better?


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The Red Dragons
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_______________________

 www.reddragons.de

[This message has been edited by Rocket (edited 04-24-2000).]

[juzz]

It's not where to get data, but which source to use. You missed the point.

You see, Verm's not happy flying his 2nd hand, clapped out old La-5FN while all the Mustang boys zip past in their factory-fresh P-51D's that are still under the manufacturer's 30 days/30 bullets(whichever comes first) warranty.  

I say make them all fly like a real, everyday operational aircraft did so we at least have a "level playing field" on which to base historical events.

[This message has been edited by juzz (edited 04-24-2000).]

[indian]

Or you could get test info off the NASA web site and simulate the best you can with a mix of everyday data and factory specs.

[Vermillion]

That would be my preference too Juzz, except that most countries didn't keep records or test fly operational aircraft. Only for specially prepared aircraft.

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Vermillion
**MOL**, Men of Leisure
Carpe Jugulum
"Real Men fly Radials, Nancy Boys fly Spitfires"

[Westy]

A)  Prototypes, and aircraft used or acceptance testing (pristine, highly maintained "optimum" aircraft)?
 
    No effing way. totally unrealistic unless you're going to enter the aircraft in the Bendix races..

B) Production?

     This should be the high water mark for the actual performance figures ot be used.

C) or an "average" aircraft (average joe's plane sitting on the front)? Captured War Booty which may or may not have been tested to its fullest?

   This should be the lowest the set of figures or measurements that should be.   Except in the cases of locally altered aircraft (more guns, less guns, added boost, altered boost)  this would be the lowest setting because other than being shot down or an out right wreck these would perform a bit less than those right off the assembly line aircraft but more to true life..

 So my answer? Aircraft performance settings here should be in between the figures for aircraft right off the production lline with aircraft having been flying in combat at the lines. With a lean towards aircraft with time on the frame and engine.

 -Westy

[Vermillion]

 

A) Prototypes, and aircraft used or acceptance testing (pristine, highly maintained "optimum" aircraft)?

No effing way. totally unrealistic unless you're going to enter the aircraft in the Bendix races..

So does that mean you expect to see the P-51, P-38, B-17, Spitfire Mk V, Spitfire Mk IX, and several other of our most popular aircraft totally detuned in the next revision?

Because thats where most of the data used to build the FM's for those aircraft come from. Special designated test aircraft that were much more highly maintained than a normal frontline aircraft.

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Vermillion
**MOL**, Men of Leisure
Carpe Jugulum
"Real Men fly Radials, Nancy Boys fly Spitfires"

[F4UDOA]

Vermillion,

Good question! And one of my favorite topics as well. I think you really picked a touchy subject though. I say this because a lot of people may get a little upset if their favorite A/C gets toned down a bit or doesn't get the extra 25mph with the special rocket boost his A/C was supposed to have. However I am looking at this from a different point of view. I think the only somewhat accurate data that is available today is from comparitive flight test performed during wartime. I say this not because I don't belive that the services kept certain A/C in test condition but because I know there was a lot of exagerated claims on both sides as to the performance of their A/C. Also the fact that if you read the opinions of historians directly after the war as compared to 30yrs later you'll find that opions change and certain A/C are disregarded completely. It is a widely held belief now by many that the P-51D was the Uber plane of WW2. But why is this opinion held? Was it the opinion of the top Aircorps people of the time? Or was it range? Anyway you understand were I'm going.

My point is that manufactures specs tend to be exagerated. Axis data largely came from three countries who not only thought they had uber planes but that they were the uber race as well. Much of it is based on proto-type equipment that never had a prayer to enter combat. So is there data to be considered accurate? Which brings us back to flight test data. It is at least an accurate representation of the real combat A/C in some condition that was representitive of a the actual airframe and engine. I personally have test data on the FW-190A3 and A5-U8 vrs almost every allied fighter in service during WW2. I also have F4U vrs P-51B as well as A6M-2 and -5 vrs almost all allied A/C. If more of this data can be collected along with fighter conferance data I think we can get a better idea of actual A/C performance.

Here is a brief test of fact and fiction Vermillion. Have everybody that replies to this post list in order of best to worst flat turning radius of fighter A/C in AH. Not as modeled but as flown in real combat condition. Then compare it to what is modeled in AH. Then check the flight test data. Just a test of WW2 IQ.

You also mentioned that you had Ki-84 data. Anything you can share with the crowd?

Thanks
F4UDOA

[juzz]

 

So does that mean you expect to see the P-51, P-38, B-17, Spitfire Mk V, Spitfire Mk IX, and several other of our most popular aircraft totally detuned in the next revision?

Only if they need it.

[wells]

The first and foremost important piece of data is level speed, both at sea level and at critical height.  You need corresponding power outputs for both altitudes so you can see if they make any sense.  The problem with that is generally, power outputs given are sea level figures, while speed is at critical height.  Once you decide on which set of data to use for this area, then I would say nail down the weight.  Find as much data as you can on gun weights, fuel weight, ammo weight (bombs, rockets etc), pilot weight and empty weight.  Add em all up and see if it comes close to the normal loaded weight (if given) or max take-off weight.  If it does, then it looks like you have a reasonable set of data.  Let every other performance attribute 'fall out' of the model.  Sure, compare to RL tests to see if it's close, but don't take it as gospel, especially climb rates.  

[Westy]

"So does that mean you expect to see the P-51, P-38, B-17, Spitfire Mk V, Spitfire Mk IX, and several other of our most popular aircraft totally detuned in the next revision?"

 If it meant a level playing field ? Yes.  If, for example, the P-51-D numbers were for an optimum aircraft being tested right out the factory door with less than a regular combat load then so should the 109, 190 Zeke or Yak-9.

 On the other hand if (for the sake of this discussion)  there were only a handful of aircraft that this info could not be retrieved for, then I trust Pyro and HTC to model it the best that they could - without having to subject all  the other aircraft, that they have good documentation on, to a detuning for the sake of supporting a fair and socialistic process.

 I personally woul'd love a P-47-D, but not one with a FM based on a test mule that was unarmed and only filled with 25 gallons of avgass and then fly against folks who pilot a 190-D9 who's flight model is based on possibly a war weary Patuxent River war booty test plane. Although I'm sure that those aircraft tested after the war had better octane fule in them, had no bullets either either and had less than a full load of avgas in case the pilot encoutnered problems so he didn't go up like a BIC lighter scraped along the runway.

BTW,  I'm only offering a laymen/sim user type of opinion aka .02. I cannot duplicate nor do I  even know how to utilise the formulae HTC uses and I cannot compete with you or any of the other engineers who are able to present facts into the discussions at that level.

 -Westy

[This message has been edited by Westy (edited 04-24-2000).]

[Vermillion]

Now your starting to see my point Westy  

Actually, the most prevalent data available is either manufacturers data (prototype/test aircraft), or data gathered when the military acceptance tested the aircraft to see if they met the performance specs. And you can believe these aircraft were of a very high quality of finish and maintenance.

Its my understanding that this is where the data that we use for most of our Allied aircraft came from. So I have no problem using this data.

My point is that you shouldn't penalize countries that have aircraft data from tests other than under optimum conditions.

For instances, the Russians Aircraft design bureau, pulled "average" aircraft from the production line, and tested them. This was so they could compare them to the prototypes to do quality assurance testing, and to look for ways to increase quality assurance. And if you look at the performance specs of our La5fn, its obvious that the numbers come from one of these "production" aircraft tests.

Likewise much of the data available for German aircraft is obviously from the "war booty" class. Planes from after the war, or aircraft that were captured in various locations or ways, by the Allies. In my opinon, if manufacturer's data or the Luftwaffe's data is available it should certainly take precedence over any captured aircraft test data.

I'm kind of strange in our hobby. I have no "preferred" historical country, or aircraft type. I like them all. US, German, Japanse, British, and Russian. I see very interesting aircraft from each and every country, but I just want them on a level playing field in our game. All of them.

Edit: F4UDOA, no I don't have the data from the Ki-84 test. But I do know it existed at one time, where and when it was tested, what aircraft it was and what serial number it was, who in the US owned it for a while, and that it eventually was sold back to a Japanese owner. According to US Air Force Musuem, the data was destroyed and no longer exists, at least in their archives. I am still trying to track down anyone who might have copies of this data.

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Vermillion
**MOL**, Men of Leisure
Carpe Jugulum
"Real Men fly Radials, Nancy Boys fly Spitfires"

[This message has been edited by Vermillion (edited 04-24-2000).]

[F4UDOA]

Westy,

Do you have any information that would make you believe that the A/C tested at Patuxant or Wright AFB were detuned or inoperable other than what is stated in the reports? The test data I have on the FW-190A-3 and A5 coresponds directly to stated performance by the Luftwaffe. I have never seen a capture report on a D9 however. The test data I have is the original intelligence report with the classified stamp right on the cover. It list weight's, HP, altitudes and wing loading conditions. As a matter of fact the only A/C not working properly was the F4U being tested. It was overheating due to too lean a mixture. In fact the numbers for the test I have seen are almost always in line with performance stated with the exception of characteristics that require head to head testing like accelleration, turning radius, rate of roll ect. Email me your fax and you will have it today.

Anyway I understand your point but what figures would you change if you could? Do you think the LA-5 should be faster? The Mustang slower? I have always read that a Mustang can out turn a Bf-109 of any varient. But is this the case in AH? Should it be, what would you change? I have asked for weight tables for various AH A/C so we can determine wing loading but I have never seen the figures being used. What do you think needs to be looked at?

F4UDOA

[Vermillion]

F4UDOA, look up the max speed in most reference books for the La5fn. My books (notice plural) say 402 or 403 mph, which incidentally is the prototype speed.

--------------La5FN ---------La5FN ----------
-------------Prototype------Production -----

Power at ---- 1,470 hp ------ 1,470 hp ---
altitude

Speed at ----- 370 mph ------- 356 mph ---
SL

Speed at ----- 403 mph ------- 385 mph ---
altitude ---- 20,750 ft ----- 20,000 ft ---

Climb to ------ 4.7 min ----- 4.7 min ---
5,000m (16,400ft)

Turn time ----- 18.5 secs ---- 19 secs ---
seconds

The physical specifications are also exactly the same, except for empty weights (2,582lbs vs 2,678lbs) and loaded weights (6,984lbs vs 7,323 lbs). But both aircraft were similarly equiped armament wise.

Now look at the AH performance specs for the La5fn, and tell me which we have.


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Vermillion
**MOL**, Men of Leisure
Carpe Jugulum
"Real Men fly Radials, Nancy Boys fly Spitfires"

[F4UDOA]

Vermillion,

That's why I ask which one?
Based on the A/C mentioned in the thread I can't tell what you think is undermodeled or overmodeled. Is this the only A/C?
 
I don't care what source AH basis it's data on as long as they share their source material so I can compare it to what I have.
I am not going to pretend to be an expert in russian A/C considering I do not have a lot of data on them. I would just ask to see what you are using so I know were to find it.
By the way what is turn time a measure of?

Also take a look at your empty weight again.
2,700lbs? Are you sure. My Jetta weights more than that. Especially with a 1400HP radial in it (I mean the La-5, not the VW)????

Thanks F4UDOA

[This message has been edited by F4UDOA (edited 04-24-2000).]