Well's Somthings not right in mudsville.

[Karnak]

[sarcasm]But we have to remember that all German tests are 100% accurate, while Aliied tests are always biased against German kites.[/sarcasm]

Sisu

[wells]

F4U,

So what do you make of one person(s) who say the stall speed of an A4/A5 is 110 mph, while Eric Brown says it's 127 mph??  That's quite a difference!  You have the Fighter Conference Report, don't you think those numbers are WAY too scattered to be considered accurate?  Also, don't assume all the pilots involved are combat pilots.  I have a report of a flyoff between a P-47D and a captured 190.  The qualifications of the pilots were this...

 

The pilot of the P-47 had nearly 200 hours in P-40 type airplanes, with seventeen months of combat experience and had flown the test airplane five hours.  The pilot of the Fw-190 had 300 hours in twin-engine aircraft and 500 hours in single engine airplanes, but had no combat experience.  He also had five hours in the test airplane.  Thus the pilots were about evenly matched

NOT!!!  No amount of flying experience can make up for a lack of combat experience!

Also, check this out

 

The FW 190 was very heavy in fore and aft control, vibrated excessively and tended to blackout the pilot

That's what no combat experience does for ya.  Oh yeah, the P-47 easily out-turned the 190 in that flyoff too!  Is there any wonder why??

Sorry, but these type of flyoff reports are absolutely useless and provide no additional information that can't be determined from the physical attributes of the plane and a good physics model.  It's up to the pilot, be in real life or simulation to get the most out of it!

[F4UDOA]

Geez Wells,

A little cranky today? Did you break your favorite calculator or something? The point is Wells that any physics model including yours doesn't mean anything until someone goes out and proves it. In this case we are talking about pilots. Fighter pilots to be specific. Not a bunch of engineers or application developers. I can e-mail you or fax you the Grumman physics model of the F6F-3 before it flew. Those engineers thought they designed the F8F Bearcat except for the fact that they were off by a mile. Has physics changed that much since 1943? I don't think so. The reason you have such a variance in test data is simple. It is also the reason engineers are often wrong and test pilots often die. Because airplanes don't fly in a vacuum. They fly in air with weather and wind and everything else that people forget when designing an aircraft. Do you think that the pilots that flew these test flights lied about their results to impress their superior officers. Marion Carl, Chuck Yeager, Ken Walsh to name a few Americans test pilots. These were tactical evaluations that their friends would rely on in combat against A/C they may or may not be familier with. The fact is that the top speed, stall speed and turning ability may vary from sortie to sortie but they do not vary relative to the A/C sharing the same airspace with it flying side by side. During the test between that FW190A-5 and the F4U-1D their is no doubt that one A/C could out turn the other. Would that vary with different pilots in different conditions, Yes. But not to a degree were you can either reverse the findings or disregard the test. The results were very definitive. And Wells, if my life depended on the result of weather a pilot or an engineer said an airplane could fly. Guess what, if my bellybutton is in the plane I'm listening to the pilot. These test are the single most accurate piece of history you have because the two A/C are in the same area at the same time. Anything else is just speculation.

You are an engineer Wells, explain why the P-47D could climb at less than 3000fpm and the the P-47D25 could climb at almost 3500fpm at the same rated power. Also explain why the Vought engineers went to the trouble of designing an airplane with bent wings and special landing gear just to fit an extra large propeller on it if there was to be no gain in performance? And how does that performance vary with alt. and speed? Is this modeled in the game? Do you have the Max lift coefficient of a Fw-190? What do you think the results should be?

F4UDOA  

[This message has been edited by F4UDOA (edited 06-12-2000).]

[danish]

F4UDOA:
are u arguing or doing the agw-breast-thumbing-thingy.

danish

[funked]

F4UDOA if you are thinking that today's engineers can't predict aircraft performance better than 1940's engineers, you got another think comin'!

[wells]

 

Do you think that the pilots that flew these test
                  flights lied about their results to impress their superior officers.

Not at all!  But I do think that any variance in the results is due to some *reason* that is up to the engineers to find and is irrelevant in a simulation.  These reasons for lack of climb rate or differences in reported stall speeds or whatever, are not given in flight test reports for the most part and unless the person analyzing the report can fill in the holes, it's of little value in designing a simulation which is entirely based on numbers that have to make sense all of the time.

 

I can e-mail you or fax you the Grumman physics
                  model of the F6F-3 before it flew.

Please do!  I would be interested in seeing that.

 

Also explain why the Vought engineers went to the trouble of
                  designing an airplane with bent wings and special landing gear just to fit an
                  extra large propeller on it if there was to be no gain in performance?

Well, to be honest, there was no performance advantage to building it with 'bent wings'.  The P-47 didn't need bent wings nor did the Bearcat or Hellcat.  The wings had to bend that way anyway for carrier ops and forward visibility was slightly improved (they needed all the help in that area they could get).  The wing had 3% more surface area (drag) than it really needed, compared to if it were a straight wing.  In the NACA report, they state that the gaps created between the wing panels had an adverse effect on the max lift coefficient as compared to the Hellcat.

 

A little cranky today? Did you break your favorite calculator or something?

Sorry I may have sounded that way, but really was not attacking you personally, only trying to provide a counterpoint in a hurry!  

I'm pretty happy, I got my DVDrom working smoothly, so now I can watch my Roaring Glory Warbirds videos!!

[F4UDOA]

Wells,

I'm glad to hear your not flaming me too. Got enough people to deal with on these boards. You are always a voice of reason.

I guess the point of my post is to show things that would not be considered in a game design. For instance the F4U and F6F have the same engine and roughly the same drag (.0267 to .0272) but the F4U is significantly faster especially at sea level. Some 30plus knots faster. But there would be no way for a game designer using the AH method to factor that difference in the game using the current physics model. But  the reason in fact is a more efficient low blower stage of the F4U engine. The air intakes are placed to inject air more directly into the engine. It also swings a slightly larger prop. But there is no way to model this without taking the word of people who flew and designed these A/C. I think this is a good example because everyone knows an F4U is faster than a Hellcat. So again when the Hellcat comes to AH will it be just as fast as the F4U or modeled to a historicly slower speed? And if so why??

Also what I meant about the bent wings wasn't that they were an advantage. The large propeller was the advantage and they built the entire A/C around it. The question then is why do it. What is the benifit of the largest propeller available and is this benifit reflected in the flight model? I really think that props in AH are all represented with an 80% efficiency at all speeds and conditions.

I will email you the Grumman report. I just need to scan it. Or I could fax it if you send me your fax #.

Later
F4UDOA

[Jochen]

 

All pilots involved were veteren combat test pilots doing a tactical evaluation. Thier findings are very conclusive based on the fact that the Max speeds for the Fw-190 as well as rated horsepower and boost as well as the weighted condition were all in accordance to the captured manual they were using. In fact the F4U had engine problems during the test which may have slowed it down.

I have news for you... 190 that was tested in RAE test had "rough running" engine which was caused by bad spark plugs. So it's nothing new to have plane performing below itäs par.

 

For anyone on this message board to second guess their report would be a bit silly don't you think?

It's not silly at all! RAE's report which compared captured 190 against Spit V and Spit IX is guestioned no end!

 

As far as the physics of the situation it is relatively simple. The wingloading of the Fw-190A-5 is simply to high to perform tight turns or loops.

Oh yeah? How do you explain P-38 turning so well when it does have much higher wingloading than even 190? There are many more factors affecting turn ability than wingloading alone.

 

The AH FM while it is mostly accurate does not account for prop efficiency.

Ummm... I'm not sure about that one.

That is why actual flight test data is the one truth in flight testing. It is why you play the Super Bowl instead of reading the stats and calculating a score. Just because some very bright people have written a compute simulation does not make it so.

 

My one true facination is with WW2 fighter A/C. Simulators just make it possible to express that feeling. If you modify the truth to fit your hobby then you are just "Gaming the Game" You can't change history.

Yep, I like WW2 fighters too. But if you blindly look historical evicence which is 60 years old without ANY critical attitude and scientific reaosning you will not get accurate results.

 

If you modify the truth to fit your hobby then you are just "Gaming the Game" You can't change history.

Yeah, but you can't change or forgot laws of nature or just forget parameters that surely will affect outcome of tests. Combat veteran of Lufwaffe did fly 190 to it's limits unlike some test pilot that have few hours of experience in 190 and NO combat experience.

------------------
jochen Jagdflieger JG 2 'Richthofen' Aces High
jochen Geschwaderkommodore (on leave) Jagdgeschwader 2 'Richthofen'  Warbirds

Thanks for the Fw 190A-5 HTC!

Ladysmith wants you forthwith to come to her relief
Burn your briefs you leave for France tonight
Carefully cut the straps of the booby-traps and set the captives free
But don't shoot 'til you see her big blue eyes

[-lazs-]

gotta side with F4U on this one.   I will pick a comparisson test over single tests any day and I don't have much faith in engineers predicting the performance of these planes.

Take one test of 190's in Germany in 1942 using a third year combat vet in wintertime running balls out to get to 5k as fast as he can.... Take a 200 hr U.S pilot in the Mojave desert in summer trying to get best climb to 20k and then say "the FW 190 climbs at xxxxfpm at 5k and the p51 climbs at xxxxfpm at 5k" No, I like comparisson tests where the planes are flown on the same day by the same pilots side by side.  

In the 190 test the results were very conclusive... ALL the pilots said they could follow the 190 with ease.... All the pilots said the 190 was very simple to fly but had a vicious stall... If they didn't fly it hard how did they know it had a vicious stall?   the vast weight of anecdotal combat reports and all the comparisson tests all point to the fact that a 190 is easily outturned by a  51 and that a Corsair outurns a 51...  If you read "Soviet Fighters" you will LOL at the "engineers" predictions for soviet planes and their actual performance.   Certainly our modern engineers can do more than they could in '44 but I don't think they can do it with the data they have available for these WWII planes.  How do we know how each prop performed exactly for instance?  It seems here that people want to believe that a 190 will turn with a Corsair or a p51.

joc... I pay my fee just like any one else.  Or does pointing out the emperors lack of clothing make you not one of the community?

 Oh... every test I've seen of a 190 said that it ran rough at low speeds, most say that it cleared out at high speed.  The Brits blamed it on bad plugs,   My guess is that the automatic controls cause this problem and that it is common and not a big deal..  
lazs



[This message has been edited by -lazs- (edited 06-13-2000).]

[F4UDOA]

Jochen,

I am not making a statement about anyone A/C performance as I am asking an open question. I would like to know if the current FM design characteristics take into account things like propeller performance and historic differences that cannot be accounted for with any of the basic criteria for flight performance. I will give two examples.

A. The F4U and F6F. Both had the same rated HP. 2,000HP. Both had approximately the same drag coefficient. F4U=.0267 F6F=.0272 Both had approximately the same wing span, area and Propeller. Then why was there such a disparity in performance and how would this be factored into AH using the current FM design points?

B. The P-47 is on it's way. Well if you get a P-47D5 you will find out that the max rate of climb is aprox. 2700fpm using combat power. If you get a P-47D25 you will get an A/C that climbs at nearly 3400FPM combat power. Why the differance? Because of the change of propeller. Is this accounted for in AH? I have no clue?? Do you Jochen, Funked? Please don't tell me you think so if you don't know for sure. The F4U is faster than the F6F because of a more efficient means of intaking the air into the engine and the turbo but this seemingly cannot be accounted for in the current format. If we are to have a P-47, F6F and F4U in the same simm then we should have three different FM's. It is not as simple as a BF-109F4, G2, G6 and G10 where you have a significant increase in HP to represent the performance increase. The differences are clear but not as easily defined.  

By the way Jochen, the P-38 couldn't turn worth a crap. That's why the Fowler flap installation was installed. It increased the wing area over 30% drastically increasing lift coefficient. That was good enough to turn with German iron but it wasn't anymore effective at dogfighting with Jap A/C as any other Army mount. That is a good example of an easily defined performance feature.

Later
F4UDOA

[This message has been edited by F4UDOA (edited 06-13-2000).]

[funked]

No turbo on F4U or F6F.  I haven't noticed any large disparities between tested top speeds and climb rates for the aircraft in the game, except for the Me 109G-10, which seems to be an Me 109K-4.

[F4UDOA]

Funked,

Ommit the word "turbo" and insert "Low Blower". The PW-R2800 was a Mech two speed two stage 18cylinder engine. It used compressed air in both blower stages to feed the engine.

In any case you didn't answer my question. Why the difference in performance in the F4U/F6F and P-47D5/P-47D25? and are these factors modeled in AH?

F4UDOA  

[This message has been edited by F4UDOA (edited 06-13-2000).]

[funked]

DOA:  I'm sure those differences can be explained by variations in powerplant installation, propeller characteristics, and airframe drag.  You'll have to ask Pyro and Hitech to answer your second question though.

Lazs:  since that USN Fw 190A-5 test was such a good one, you're saying the AH A-5 should be faster than the F4U-1D above 15,000 feet?

[Kats]

 

except for the Me 109G-10, which seems to be an Me 109K-4

What should the difference be between a G10 and a K4?

The reason I ask is because the G10 was produced at the same time as a K4. The G10's were just upgrades of G6's to meet K4 performance specs including (for the most part)the new engine in the K4.

The only difference I can think of without referring to my notes is that the K4 had a smoothed out cowling and some changes in the oil cooling system (or a larger oil capacity - can't remember off hand).

The performance difference should be neglegable, shouldn't it?

[F4UDOA]

Funked,

Your right it is the power plant installation. But how is that modeled in AH.
The same for the P-47d models. How is that to be represented in AH. After the HOG the Thunderbolt and F6F are my favorite mounts you know.

Also the test between the A-5 and F4U did not reach top speed. The speeds were taken after short speed runs. Although the performance advantage over the F6F is notable especially below 10k.

Funked, I did some testing last night with Troxel after our Ladder duel(after he used me like a cheap potato)in a F4U-1C and a
Bf-109G-10. I found that with flaps and WEP in both A/C that in a purely flat turn I could stay on his tail no problem and he could not follow me. However if he used his virtical ability he could make high side runs on me all day and I would have no place to go. The F4U in AH is a complete dog in accelleration at low speed. Due to the fact that the F4U had to qualify for carrier waveoff landings it seems odd. In fact the F4U has lower power loading according to AHT at sea level than a P-38L which has excellent accelleration in AH. In fact the only american A/C that are better are the

FM-2=7487lbs 1260HP HP/LBS=5.94
F6F-3=12213lbs 2000HP HP/LBS=6.11
F4U-1D=12289lbs 2000HP HP/LBS=6.14
P-38L=17699 2850HP HP/LBS=6.21

Not surprisingly the Carrier fighter have a better ratio for carrier takeoff and landing. The F4U and F6F ratio changes with loading but I listed them as they appear in AHT. So I also cannot understand why the F4U accellerates so poorly in AH considering it has better power to weight, an enormous propeller and a lower drag coefficient than the P-38L?? I realize that the G-10 has a large advantage in power loading over the F4U but the difference between the F4U and P-38L seems a bit off. I will do some testing I give you numbers on it. I am starting to believe it is the acceleration and not the turn ability of the F4U that is affecting flight performance.

Thanx F4UDOA

[This message has been edited by F4UDOA (edited 06-13-2000).]