Spitfire IX v. FW 190A

[Gaston]

I have to find the time to make the graphics, and real busy otherwise...

At 3 Gs sustained, the Spitfire's wings bear about twice the load aero-engineers think it does...

Aero-engineers assume around 22 500 lbs at 3 Gs (aircraft's weight at 7500 lbs X 3): It's likely in reality around 45-48 000 lbs...

So where does the extra wing lift, for the extra 24 000 lbs, come from?

Read what I wrote here (minus a few minor mistakes) and assume wind tunnel tests gave them a perfectly accurate assessment of a wing's lifting abilities: The lift values are confirmed: It was all there right under their noses...

Let's see if you can find why they didn't know about half the lift force effectively borne by the wings at 3 Gs...

The bottom line is, even if the Spit does beat the FW-190A in turns (which it does do by a wide margin above 4 Gs unsustained) there is no reason, according to them, why the two should be so close at low sustained speeds...

Even Russian TsAGI tests show the FW-190A-5 beating, in right turns, all the Bf-109Gs except one: A Bf-109G-4 that barely matches it at 21 seconds for a sustained 360...

Where the hell is the math that accounts for this match?

There is plenty of evidence engineer calculations predict nothing when it comes to heavy, powerful nose traction types...

I think it's about time they noticed how an aircraft flies...

Let's see if you can find the mystery of the missing 24 000 lbs...

Gaston

 

[Glider]

Let's see if you can find the mystery of the missing 24 000 lbs...

Gaston

All this time I didn't realise that a Spit could carry a Grand Slam, how foolish of me.

 

[parsifal]

I am underwhelmed by this argument. And in fact we dont have to prove anything. The accepted theory is on our side, you are the one promoting a view outside the accepted norms and trying to dispute the universally accepted theory, and that means its up to you to present the supporting facts and arguments, and then even explain it to technophobes like me. Youve done none of that I submit. just a bunch of unsupported statements, expressed in ever more frantic terms and making ever more fantastic and unbelievable positions. Then you get upset that we dont follow you into this descent into madness.

If you want us to treat you seriously, go away find the supporting argument, present it and then explain it in a way that people can understand. Until then, be a bit more respectful, and learn a little humility

 

[Gaston]

I am underwhelmed by this argument. And in fact we dont have to prove anything. The accepted theory is on our side, you are the one promoting a view outside the accepted norms and trying to dispute the universally accepted theory, and that means its up to you to present the supporting facts and arguments, and then even explain it to technophobes like me. Youve done none of that I submit.

Fair enough Parsifal: I'll write the text and do the graphics.

You still do have to explain discrepancies in your "facts", if you claim to be open-minded about the subject being discussed...

But I still think it should be noted that the accepted theories that are on "your side" do little to predict what is actually observed to occur: Where does your math predict an observed sustained turn parity between the Bf-109G and the FW-190A at 21 seconds in right turns?

How does it arrive at such a result? I've yet to see the math demonstrated in any coherent way...

Also at least one very experienced Fin ace quotes the "optimal" sustained turn rate for the Bf-109G-6 as being at 160 MPH.

"Accepted math" puts it around 220-240 MPH at least...

6G unsustained "Corner Speed" on the P-51D Mustang is tested as being at a minimal speed of 320 MPH... Your math? 250-260 MPH...

Even if my theory is completely wrong, at least it attempts to explain all of the above in spades, while "your side" accepted math theories explains nothing of it...

It would be more encouraging if you at least recognized the failings of accepted theory to match observed reality... I am still waiting for that kind of open-mindedness to be on display, even if my theories turn out to be nonsense...

I mean, if you can't predict the most basic data that the "Society of Experimental Test Pilots" found in 1989 with real aircrafts, just exactly what can you predict with "your" math?

Gaston

P.S. By the way, for those treating the P-51's Pilot's flight manual figures as gospel, note that the B-29's flight manual was said to be the very first to have, by a very wide margin, serious and complete flight data gathered in a serious scientific way... The P-51, pre-dating the B-29, was obviously not included in that...

G.

 

[parsifal]

gaston

As I said, I cannot respond, this will have to wait for the pilots and the engineers in this place to review your submission. in the meantime you should do just as you say, post your calculations and your figures to support your theory.

Becaus this is such a drawn out thread, perhaps we should summarise wehat is your position. I am given to believe you are of the opinion that the Spitfire IX could not out turn an FW 190???/ Or is your supposition something else again?

 

[Glider]

Being serious for a moment I am looking forward to your maths and graphs, but can I also ask you to put any sources down for your comments.

For instance the statement note that the B-29's flight manual was said to be the very first to have, by a very wide margin, serious and complete flight data gathered in a serious scientific way

This looks at first glance like a big assumption without foundation. However if it was a recognised expert then more authority would be given to the statement, so the who said it and when, is pretty important.

 

[drgondog]

I have to find the time to make the graphics, and real busy otherwise...

At 3 Gs sustained, the Spitfire's wings bear about twice the load aero-engineers think it does...

At 3G the Lift = SQRT[(G)>>2 - 1]*W = Sqrt(8)*W=2.83*7500=21,213 pounds At 8G the Lift=sqrt[(8)>>2-1]*W= 7.937*7500=59,529 pounds for turns in which the a/c is in a steep bank. For a dive pullout the applied forces are a direct multiple of the Gross Weight of the airframe times the 'G' load

Aero-engineers assume around 22 500 lbs at 3 Gs (aircraft's weight at 7500 lbs X 3): It's likely in reality around 45-48 000 lbs...

Nope - see above - but at an 8G Corner Velocity (much faster than the 3G sustained turn velocity) the Normal' vector of Lift is 7.937*Weight. see above for formula.

BTW - this is near the limit load for stress for the Spit and the region in which it starts to 'bend'

So where does the extra wing lift, for the extra 24 000 lbs, come from?

From pulling higher G's at CLmax. For a Gross Weight=7500 pounds (heavy for a Spit), pulling 8G's would equate to 60,000 pounds of lift on the wing and very likely be at the limit design stress for the spars... and not sustainable for maintaining a stable altitude

Read what I wrote here (minus a few minor mistakes) and assume wind tunnel tests gave them a perfectly accurate assessment of a wing's lifting abilities: The lift values are confirmed: It was all there right under their noses...

The Maximum Lift = CLmax*Wing Area*1/2*rho*(Vel)>>2

Let's see if you can find why they didn't know about half the lift force effectively borne by the wings at 3 Gs...

Lets see you place lucid and constructive math on your posts and maybe you can figure it out

The bottom line is, even if the Spit does beat the FW-190A in turns (which it does do by a wide margin above 4 Gs unsustained) there is no reason, according to them, why the two should be so close at low sustained speeds...

Speeds near stall (at CLmax) are in the domain of the fearless (and competent) pilot flying in an imperfect fluid with an imperfect aircraft. The a/c with the best tip control (i.e. positive aileron authority) throughout and a slightly better wing loading and enough power available is liable to 'win'

Even Russian TsAGI tests show the FW-190A-5 beating, in right turns, all the Bf-109Gs except one: A Bf-109G-4 that barely matches it at 21 seconds for a sustained 360...

Where the hell is the math that accounts for this match?

Where in the hell is the match that is perfectly flown, with specified weights, perfectly conditioned airframe and engine flown in exactly the same conditions? The math is all over the forum - look for both max sustained turn and rate of turn equations - they are close so long as you have a reasonable CLmax, GW, BHp, and flight test data to derive parasite drag from high speed runs and published, Hp/Altitude and GW

There is plenty of evidence engineer calculations predict nothing when it comes to heavy, powerful nose traction types...

So, trot out your evidence - oh I forgot you don't do math, or engineering, or physics, or wind tunnel tests, or fly..

I think it's about time they noticed how an aircraft flies...

Let's see if you can find the mystery of the missing 24 000 lbs...

Gaston

"Don't feed the trolls" - my last intersection of your endless bloviating.

 

[drgondog]

How does it arrive at such a result? I've yet to see the math demonstrated in any coherent way...

We have yet, here or HiTech or every site you have trolled, to see you coherent in any demonstarble way.

Also at least one very experienced Fin ace quotes the "optimal" sustained turn rate for the Bf-109G-6 as being at 160 MPH.

He is quite correct - that is the speed at which the 109 may be flown (in perfect condition and pilot skill) in a sustained, near 3G turn, with no excess power.

"Accepted math" puts it around 220-240 MPH at least...

Demonstrate your math and prove that it is 'acceptable'

6G unsustained "Corner Speed" on the P-51D Mustang is tested as being at a minimal speed of 320 MPH... Your math? 250-260 MPH...

6.33 G corner speed for a 10,000 pound P-51D is approximately 259mph.


P.S. By the way, for those treating the P-51's Pilot's flight manual figures as gospel, note that the B-29's flight manual was said to be the very first to have, by a very wide margin, serious and complete flight data gathered in a serious scientific way... The P-51, pre-dating the B-29, was obviously not included in that...

G.

The P-51 Flight Manual was complied with theory accepted in 1940, in 1940, in 1960,, etc all the way to this date - and set limit loads, operations planning, cruise settings, etc that are 'guidelines' for the prudent pilot to observe.

The tools are more sophisticated, assumptions to simplify the solution of non-linear differential equations are no longer necessary to predict complex flight conditions - but neither the engineering mathmatics nor the underlying physics have changed.

Gastion - you are not being rejected because your theories are beyond anyone's level of comprehension - they are rejected because your levels of comprehension are below expectations to carry a serious discussion regarding physics of motion, fluid mechanics or structures.

 

[parsifal]

I am not even going to attempt the engineering argument. I am not an engineer, dont fly, and and was never much chop at maths. But I do understand the history, and history is the big brother of operational research. Understanding the history allows you to put all the other bits into perspective.

This is my basic take on the history.

Throughout 1941, the RAF mounted a very costly, but ultimately successful campaign to push the defending LW away from the channel coast in the vicinity of the channel ports (Dunkerque, Calais, Boulogne). The exchange rate in that campaign was heavily in favour of the LW...around 3 RAF fighters lost for every 1 LW fighter. Main types involved were Spit IIs and Hurri IIs on the RAF side, and Me 109 Es and Fs for the LW.

In 1942 the RAF began to deploy Spit Vs in substantial numbers which appear to have added range. The LW began to deploy FW 190s, which also had additional range. the LW and the RAF traded blows throughout 1942, with the LW able to undertake tip and run raids across the channel with small groups of FW190s. I dont have figures on the exchange rates but over Dieppe, the RAF deployed mostly Spit Vs at long range. This long range hampered the numbers they could maintain over the invasion fleet, and meant that the LW was able redress the numbers imbalance to a large degree. An exchange rate between the Spit Vs and the FWs was roughly 110 Allied aircraft lost to about 35 LW machines. The ratio of losses RAF:LW remained the same as it had been the previous year, but qualitatively the RAF had to be improving, as it was a battle fought by the RAF at considerable tactical disadvantage. I am led to believe that at other times the exchange rate between the RAF and the LW was much closer, which is corroborated by the fact that soon after the battle at Dieppe, the LW pulled back from the channel coast pretty much completely. The RAF had won.

The Spit IX was developed specifically to counter the high speed low level attacks into British controlled airspace by the FW JGs. Unless a range of general histories are wrong, I am of the opinion that in this capacity the Spit IX was superior to the FW190. These Fws were not Jabos, they were operating as Fighters....the Spit IX was developed to restore qualitative parity between the LW and RAF, and in this it was successful.

So, to try and argue that a Spit IX was inferior and somehow outclassed by a FW is a nonsense to me...clearly the operational results show that the Spit IX was at least competitive to the FW, and IMO was in fact superior in some respects.

These are the basic facts as I see them. Perhaps people can post corrections to that understanding, I am happy for that to occur, but once we arrive at an agreed set of basic facts, we then need to go after the reasons why those basic facts are as they are. If I am right, and the Spit IX bested the FW in the battles over the channel, then why is that so.......its no good accepting the basic facts and then skipping off into lala land trying to prove that the FW was superior, or that they somehow won their battle. there are other factors of course, but the writings of the time dont suggest to me that the Allies were flying inferior machines by the time they were using the Spit IX....quite the opposite.....

 

[drgondog]

In my opinion the Spit IX was a superior dogfighter to enemy oppostion throughout its prime deployment subject to comments below. When the 109K and the 190D were introduced they were faster and had more options to engage/withdraw against the MK IX than in 1943 and 1944.

During the time the A5-A7 were in play along the coast against the RAF (or Med) I suspect the outcome was dictated by the pilot that saw the other one first and pilots skill to capitilize on a tactical advantage - as the Fw 190 was terrific in a high energy manuever fight, giving sustained turn and climb to the Spit as well as slower than the Spit > 25000 feet, but faster at low altitudes, much better roll/reverse to neutralize the Spit turn advantage, and very good in dive and initial turn.

I'm less inclined to think that the 109G could compete as well as the 190A5-A7 but the fight would be close in both the vertical and horizontal with the edge (period to period engine variants) going to the MK IX.

 

[renrich]

According to the USN reports published by Williams where an FW190 was compared to the F6F3 and F4U1, the Navy fighters were both judged to be superior in a turning fight to the FW to the point that Navy pilots were advised to only fight the FW by closing with it. My strong impression is that the Spitfire IX would be superior to the F6F and F4U in a turning fight (dogfight) so it would have to have a substantial advantge over the FW in that type of action. For what it is worth, Eric Brown also says that the Seafire LIIC had a better turning circle than the FW190A-4.

 

[parsifal]

well now i am confused. If we are all in agreement about the basic historical facts (or are we???), which is that the Spit IX was more manouverable than the FW 190A in the horizontal plane, then what on earth has all this bitter recrimination been about this last 10 pages of this thread. What exactly is the divisive issue here????

 

[Glider]

Personally I agree with you and am waiting for Gastons evidence, which might be a long wait.

 

[drgondog]

Parsifal - only one entitiy was invloved in 'bitter disagreement' relative to the Spit IX overall manuever superiority to the Fw 190 series.. and the Troll will be back. I haven't seen him return to the other sites but he trashed their tranquility with absurdities (piled very high) with equal zeal

 

[parsifal]

and the Troll will be back.

Thats just downright funny DG. i like it......

 

[renrich]

To add to the William's published report, the Navy fighters were said to be able to follow the FW in all maneuvers whereas the FW could not follow the Navy fighters in those same maneuvers. Something I did not understand since the FW had a better rate of climb than the Navy planes was that the FW could not follow the two other fighters in a loop. If it tried to it would stall out. ???

 

[Altea]

Even Russian TsAGI tests show the FW-190A-5 beating, in right turns, all the Bf-109Gs except one: A Bf-109G-4 that barely matches it at 21 seconds for a sustained 360...

A rather unsustainted assesment.
The TsAGI tests "Samoletostroenie p. 95" are clearly showing that soviet FW-190 A-5 is turning a sustainted 360°, in 22-23 secunds, the 109 F4 in 19.8-20.6s, the 109 G-4 in 21s (that means it's might be a best or a middle value).
In case that you have two different values in soviet tests, one is for the left turn, the other one for the right.

The Spit IX beats them all, due to low wing loading, high power to weight ratio.
Ñïèòôàéð Mk.IX â ÖÀÃÈ.
No mystery in physics

Where the hell is the math that accounts for this match?

? Either a type mismatch from your sources, or your own error.

Regards

 

[parsifal]

and still we wait.........

 

[Njaco]

Now, now, .... research takes time.

 

[Gaston]

A rather unsustainted assesment.
The TsAGI tests "Samoletostroenie p. 95" are clearly showing that soviet FW-190 A-5 is turning a sustainted 360°, in 22-23 secunds, the 109 F4 in 19.8-20.6s, the 109 G-4 in 21s (that means it's might be a best or a middle value).
In case that you have two different values in soviet tests, one is for the left turn, the other one for the right.

The Spit IX beats them all, due to low wing loading, high power to weight ratio.
Ñïèòôàéð Mk.IX â ÖÀÃÈ.
No mystery in physics


? Either a type mismatch from your sources, or your own error.

Regards

No. I had the scans from the original documents: It showed the following: Best Bf-109G turn time, to right: G-4: 21 seconds (This G-4 bested all the other Gustavs, including the G-2, by a small margin. 21 seconds was the very best a Gustav ever did in those tests.)

The FW-190A-5 had TWO sets of values: Flaps down and flaps up: Flaps up: 22 seconds to right, 23 seconds to left.
Flaps down: 21 seconds to right, 22 seconds to left.

If you don't want to believe, don't, but that was from an original scan, and it was clear to the right NO Me-109G bested the best the FW-190A-5 did...

So you have a significant difference in wingloading that is ignored in real-life, by a lower power-to-weight ratio aircraft, in a way you can't explain...

Furthermore, the TsAGI tests found the FW-190A-8 to be slightly slower turning, but I know from combat reports this was unlikely to be a valid comparison (in this case the likely explanation is the A-8 had four wing guns while the A-5 had two): The FW-190A-8 is in fact capable of being at least as good or better, but probably only by using downthrottling, and it was likely worse than the A-5 at high Gs...

If the Spitfire did 17.5 seconds in these test (which did not occur on the same day, so are worthless for comparisons: They are not comparative data at all), then I would think a downthrottled FW-190A-8 with broad ailerons and broad wood prop can do at least 17.5 seconds to the right...

I do find the methodology of these Russian tests suspicious: 17.5 seconds is better than most Russian types, yet the Russians in combat were never impressed by the Spitfire's maneuverability, and even tried to lighten the weight by removing the outer machine guns... They found the Spitfire unsuccessful in combat in horizontal maneuvers, but superior in vertical maneuvers, and changed their way of flying accordingly (source: Le FANA de L'Aviation)...

Once again, tests and reality seem irretrievably divorced...

Many or even most British pilots knew the Hurricane turned much better in sustained turns than the Spitfire... If so, does that mean 16.5 seconds for a Hurricane?

If entry speed and exit speed were the same, did they use a sustained G load during the turn? I doubt the Spitfire would shine so much if they did... My guess is they made the first 90° a very high G turn, bleeding speed, then relaxed it on the remaining 270° to regain some of the speed using the power available to keep speed constant... The British in fact found NO differences in truly sustained turns between the Spitfire Mk V and the Spitfire Mk IX, even at 30 000ft(!), and this has been borne out numerous times by numerous tests: The Russians have this one Mk IX at quite a lower value than the Mk V at 18.8 seconds with 17.5 seconds, then another Mk IX at a more reasonable 18.5 seconds...

To me 18.5 is a more plausible Mk IX time. We'll probably never know the real downthrottled, flaps down, broad wood prop turn times of a FW-190A-8, but it was lower than that, while at high Gs the FW-190A probably could not even carve above a real 5 Gs without mushing...

The Me-109G had no hope whatsoever in sustained turns against a P-47D, even at 140 MPH, yet the wingloading of the P-47D was much higher than the FW-190A!: 50% greater than the Me-109G!

I have all the elements of my wingloading theory written down in a comprehensible format, but have to put them into a graphic form... I am sorry this took so long but there were many problems I had to solve to understand all the implications of how the forces balanced each other out to produce a neutral result that was hard to detect (unless in actual combat!).

This is some of the data I am working with: A P-51's Merlin at Full WEP at 72" I will assume puts out a force of 1800 lbs on the entire surface of the prop disc. The tilted back surface I will assume amounts to 60% of that, so we are back to an easy to calculate 1000 lbs...

There were a lot of problems to solve to understand all the implications of the theory: I have the diagrams on paper, and will now reproduce those on computer to post them here.

My theory has to do with leverages, and if it is wrong, then there is the simple possiblity that some aircraft simply generate a lot more drag at higher angles of attack than others, leading to unpredictable disparities... I doubt it, because I can't see such large differences in drag arising out of details in the shape from aircrafts that are all basically similar in drag...

Also my theory explains why heavy wingloading does much better at low Gs but more poorly at high Gs, which angled drag disparities alone would not...

Sorry again for the wait, but it won't be too long now... About one week, not much more...

Gaston