Spitfire XIV vs Bf-109 K-4 vs La-7 vs Yak-3

[Mitya]

Congratulations on Russia win!

Thank You very much!

 

[Glider]

Why not the Mk.XIV? In the comparison listed the Spit is 3km/h faster.

Mainly because of the timeline. The 109K4 with the 1.98 boost was only available inearly 1945 which is roughly when the Mk 21 came out.

To compare the K4 1.98 against a standard Mk XIV which was 12 months older isn't a fair comparison.

 

[Kruska]

Hello Soren and drgondog,

As a new fellow on this forum, may I ask politely what problem you guy's have with each other?

I surely do not know as much as many others on this Forum do, yet I will still post my opinion or perceptions – regardless of true or false – It will then be a "hopefully" good discussion that will come up with reasonable proof in order to contribute to each others existing knowledge.

Drgondog,

Hitler for sure couldn't show up with academic degrees or a Staff officer training course, still (don't ask me how ) he became leader of a thousand years empire and commanded the entire Wehrmacht.

Soren,

Why do you answer to a person in such a manner as below?

Quote: You're truely the most clueless member of this forum glen.
Quote: glen come back when you actually know what the MW-50 system is, and when you have learned to read properly as-well!

Come on Soren, not everybody is an "expert", means I can't state something wrong without getting "screwed up" straight away? Isn't it possible to indicate to someone else in an orderly fashion that he is wrong or misread something?

Well maybe you just had a bad day or week

And fellows, I am not trying to play moderator or to act as such, I was just putting a question to the two of you.

Regards
Kruska

 

[Soren]

Ok Bill, lets solve this;

I know the purpose of downward wing twist (washout), I've explained it on here various times before; it is for preventing tip stall, or to put it more thuroughly keeping the outboard wing section from stalling before the inboard section, making sure the a/c doesn't suddenly enter an uncontrollable spin without warning as-well as keeping the ailerons effective up until the stall. The 109's slats were positioned the way they were for the very same reason.

However in the case of the 190 you will note that the wing twist was applied to such a degree as to provide elliptical lift distribution under G's (which btw is the reason for the violent departure), it was purposely done so to achieve the maximum 'e' factor and therefore L/D ratio in turns. Now ofcourse you wont see that on Lednicer's comparison as his simulation was done under 1 G, something you seem unable to grasp.

And as for the P-51 turning as well as the 109, wake up Bill! The Bf-109 throughout its versions has a lower wing power loading and it features slats + a high lift airfoil, leading to a MUCH lower lift-loading which is comparable to that of the Spitfire. On the other hand the P-51 features a laminar type airfoil which is known for low Cl low critical AoA! Now supposing you're as much into aerodynamics as you claim then how can that stray past your nose ??

And as if that wasn't enough I've presented the qoutes from ALL modern Bf109 pilots plus many vets, which all make it clear that the P-51 is a pig in a turn compared to the Bf109! You've got it presented in both black white as well as orally! When is enough Enough ?

Infact reading you're view on the situation Bill it seems like you've mistaken the Bf-109 as the Fw-190A, the reason being that the Fw190A P-51 are close when it comes to turn performance, the Fw-190A being slightly better at low to medium alt while the P-51 is slightly better at high alt. Exactly as how you seem to think it would be against the 109, well let me let you in on a little secret: The Bf-109 is a much better turnfighter than both, easily outturning the Fw-190 in German comparative test flights.

Now moving on..

Later you went on to claim that the P-51 could take a 30mm high explosive round to the wing, exploding, and still continue to fight on let alone fly! And to prove your point you started babbling on about -51's hit by flak shells, oddly presenting pics of rudder elevator hits (By 37mm Flak presumably) eventhough you were well aware we were talking about the wing!

Christ you're so obsessed with the P-51 that you think it's some sort of supermachine! Get over it, AND yourself!

And as for my tone against glen, well Bill if you knew him you would have the very same tone; He has on multiple occasions lied in the WW2 general subforum, claiming to have pictures info that doesn't exist. He thinks the Germans Americans, and let me qoute: Cheated with the results of their gun trials!

Now as for you Bill, I hope your bad habbit of sidetracking threads has ended, and not for my sake, for everyone elses.

 

[KrazyKraut]

Mainly because of the timeline. The 109K4 with the 1.98 boost was only available inearly 1945 which is roughly when the Mk 21 came out.

To compare the K4 1.98 against a standard Mk XIV which was 12 months older isn't a fair comparison.

Total delivery of K-4s is estimated at around 1,500. By early '45 about every fourth 109 was a K-4. How many of these used 1.98 ata i don't know, but only around 120 Mk.21s were completed total before V-E and most were not yet with operational squadrons. Mk.21 would be better compared against Ta-152s, I think.

 

[starling]

my name is not bill.anyway,did the 109 not have a tendancy to crash on take off or landing.perhaps only aces could handle this problem.there is no need to get narky if one believes or not whether the said a/c had these inherent design faults.yours,preacher.

 

[Glider]

Total delivery of K-4s is estimated at around 1,500. By early '45 about every fourth 109 was a K-4. How many of these used 1.98 ata i don't know, but only around 120 Mk.21s were completed total before V-E and most were not yet with operational squadrons. Mk.21 would be better compared against Ta-152s, I think.

The point was they came into service at basically the same time and its that which makes it a fair comparison.
No doubt had the British been the ones with their backs against the wall it would have come out a lot sooner and in greater numbers.

 

[KrazyKraut]

I would compare those to eachother that were likely to encounter eachother, regardless of when they first saw sunlight.

1.98 ata K-4s were likely to encounter Mk.IVXs. Mk.21s? Not likely, with so few in service. For comparison: the first Ta-152s entered service as soon as octobre '44, but they were never significant, just like the Mk.21.

 

[starling]

i hope you are not refering 2 me soren,i have never knowingly lied on other forums and i now have a camera.i have photos of my grandad sitting in the cockpit of a very late me-109,i do not know if is possible to put a picture on here as i do not have a scanner,it is a digital camera however.starling.

 

[Soren]

No starling I was not writing to you I was writing to Drgondog, and no I was not refering to you either, I was refering to glen.

 

[drgondog]

Hello Soren and drgondog,

As a new fellow on this forum, may I ask politely what problem you guy's have with each other?

I surely do not know as much as many others on this Forum do, yet I will still post my opinion or perceptions – regardless of true or false – It will then be a "hopefully" good discussion that will come up with reasonable proof in order to contribute to each others existing knowledge.

Drgondog,

Hitler for sure couldn't show up with academic degrees or a Staff officer training course, still (don't ask me how ) he became leader of a thousand years empire and commanded the entire Wehrmacht.

Soren,

Why do you answer to a person in such a manner as below?

Quote: You're truely the most clueless member of this forum glen.
Quote: glen come back when you actually know what the MW-50 system is, and when you have learned to read properly as-well!

Come on Soren, not everybody is an "expert", means I can't state something wrong without getting "screwed up" straight away? Isn't it possible to indicate to someone else in an orderly fashion that he is wrong or misread something?

Well maybe you just had a bad day or week

And fellows, I am not trying to play moderator or to act as such, I was just putting a question to the two of you.

Regards
Kruska

Kruska - as you witnessing what appears to be a hissing contest - at least from one source - there is a history.

The latest is all about Mr. Soren casting doubts about my academic background when I contradicted some of his more foolish ventures into aero theory. If you wish to dig, look into the threads about Spirfire vs 109, Best Variant, etc.

Briefly, when you catch the rascal sticking his snout in aero theory and thump his nose.. there is a huge outcry and we end up taking threads in a tangent, or someone else incurs his sarcastiv 'wit' (I'll have to look that word up again)

After I had had enough of his 'stuff' on qualifications (or lack therein) I simply said put up or shut up and posted my MS Aerospace Engineering from Univ Texas -1972.. and have been hounding him to do the same. He won't because he can't.

He is self taught on the subject and his teacher failed him miserably. I KNOW there is a lot I don't know maybe in spite of my education.. but he doesn't know what he doesn't know and makes some truly 'interesting' statements - and NEVER produces facts, in complete context of the issue, or simply moves on.

See my next post - and I apologise for this.. and I promise I won't ever call you clueless.

Regards,

Bill

 

[parsifal]

Starling

Hohun has put up a post somewhere that shows the accident rate for Me109s due to thenarrow tracked landing gear as being only a very small increase, compared to the wide tracked FW 190. It seems pretty claear from that evidence that the claims about high accident rates is a furphy

 

[Glider]

I would compare those to eachother that were likely to encounter eachother, regardless of when they first saw sunlight.

1.98 ata K-4s were likely to encounter Mk.IVXs. Mk.21s? Not likely, with so few in service. For comparison: the first Ta-152s entered service as soon as octobre '44, but they were never significant, just like the Mk.21.

You could always look at it the other way. What was the Mk21 most likely to encounter? the 109K

 

[Soren]

Bill you might have an education within the aero industry but in that case you're refusing to use it, cause otherwise us two would agree allot. And your refusal to support your claims and answer my direct questions only supports that.

I've explained from the beginning that I'm an educated engineer with an interest within aerodynamics and that what I know about aerodynamics comes from the books I've read about it and from the limited knowledge you get when you fly yourself. I've never worked with any of those fancy lift distribution programs which cost a fortune. I've used programs for estimating wing Cl, Cd0, Cdp, 'e', critical AoA etc etc..

I tried being nice towards you Bill but that went right out the window when YOU starting throwing mud into my face because I misunderstood a computer generated pressure distribution illustration. You were the one who insisted on being rude and calling names, which in my book is childish prick like behavior - I thought you were smarter than that.

 

[Soren]

and I promise I won't ever call you clueless.

No but you'll probably call him a bonehead sometime as you seem to love to call people names..

 

[Hunter368]

He is self taught on the subject and his teacher failed him miserably. I KNOW there is a lot I don't know maybe in spite of my education.. but he doesn't know what he doesn't know and makes some truly 'interesting' statements - and NEVER produces facts, in complete context of the issue, or simply moves on.

Bill,

While watching you two (Soren and you) argue everyday does get old.............
I had to LMFAO while reading this little barb. That is a good one though.

 

[drgondog]

Ok Bill, lets solve this;

I know the purpose of downward wing twist (washout), I've explained it on here various times before; it is for preventing tip stall, or to put it more thuroughly keeping the outboard wing section from stalling before the inboard section, making sure the a/c doesn't suddenly enter an uncontrollable spin without warning as-well as keeping the ailerons effective up until the stall. The 109's slats were positioned the way they were for the very same reason.

Actually not quite right. The purpose of twist was in fact to wash out the stall angle of attack to keep aileron control - but the pupose is to maintain control in the roll axis - not to prevent 'entering an uncontrollable spin'. It certainly was nice if the aircraft gave an indication of stall, but a.) not all aircraft entered a violent and uncontrollable spin, and b.) that characteristic was not pre-determined by analytical methods - otherwise Tank would have foreseen this in the design of the 190 wing

However in the case of the 190 you will note that the wing twist was applied to such a degree as to provide elliptical lift distribution under G's (which btw is the reason for the violent departure), it was purposely done so to achieve the maximum 'e' factor and therefore L/D ratio in turns. Now ofcourse you wont see that on Lednicer's comparison as his simulation was done under 1 G, something you seem unable to grasp.

Something you have repeatedly 'missed' Soren is that Lednicer plots the twist as a function of semispan for the Spit, the 190, the 51B and D and quite clearly states that the 190 went from +2 at root to 0 at 81% then NO twist from 81.5% to tip... are we in a 'grasping' contest? Minus one for you.

You can recover if you prove Lednicer wrong in his grasp of Fw 190 twist vs semi span plot on page 86.


.

Let's take these one at a time

From pages 550-551 - chapter Elements of Finite wing theory, "Principles of Ideal-Fluid Aerodynamics", Krishnamurty Karamcheti, Professor of Aeronautics and Astronautics- Stanford Univesity.. Published by John Wiley and Sons -1966

"To obtain an elliptic lift distribution on a (geometrically and aerodynamically) untwisted wing, the spanwise distribution of the chord should be elliptic"

Point 1. Elliptical Wing is the optimal planform for minimum Induced Drag
Point 2. Varying the tip ratio to approximately .4 will closely approach an Elliptical Wing as far as reducing the induced drag at the sacrifice of adding more weght (for same aspect ratio)
Point 3. The downwash corresponding to an elliptic lift distribution is a constant all along the span, further the rolling and yawing moments on such a wing are zero no matter how the chord, the angle of attack and the wing section are arranged.

Further, from 12:8-9 Spanwise Lift Distribution under Load "Supersonic and Subsonic Airplane Design" by Gerald Corning Professor Aeronautical Engineering Department - University of Maryland 1960

Point 4. The downwash corresponding to a trapezoidal wing planform varies along the span
Point 5. The spanwise lift coefficient for a trapezoidal wing planform changes with the downwash along the span.
Point 6. The G forces have bearing only on the elastic properties of the wing - and have nothing to do with lift distribution Unless and Until the wing twists or bends to change the relative angle of attack from 'no load' angle.
Point 7. The changes which tend to throw lift load Outboard are a function of bending rigidity, while the changes which tend to throw lift load Inboard are a function of torsional rigidity.

Therefore - pulling high G's seemed to affect the Fw 190 for two reasons (not known when designed) a.) aeroelastic bending of the Fw190 wing, moving the lift distribution outboard, and b.) not having twist in the outboard 20% of the span. As Lednicer quotes the LW report dated January 1944 you may presume he knows more about the German explanation than you do.

Page 89 of Lednicer's Report.

Now - it is your turn to present facts and references to support all of your points... but you 'skip' your turn usually so I'm holding my breath.

Education - Experience - and now References.

 

[drgondog]

Bill,

While watching you two (Soren and you) argue everyday does get old.............
I had to LMFAO while reading this little barb. That is a good one though.

Hunter - if it is 'old' for you, think about me! Lol.

I just will not let him skate on this subject of aero/structres when he makes so damn many mistakes - then insults the guy that disagrees with him - 'for not grasping the obvious'.

have a great day and put this battle on 'ignore'

 

[Soren]

Oh no you don't Bill, answer my questions first!

The below just proves what I've been saying all along:

From pages 550-551 - chapter Elements of Finite wing theory, "Principles of Ideal-Fluid Aerodynamics", Krishnamurty Karamcheti, Professor of Aeronautics and Astronautics- Stanford Univesity.. Published by John Wiley and Sons -1966

"To obtain an elliptic lift distribution on a (geometrically and aerodynamically) untwisted wing, the spanwise distribution of the chord should be elliptic"

Point 1. Elliptical Wing is the optimal planform for minimum Induced Drag
Point 2. Varying the tip ratio to approximately .4 will closely approach an Elliptical Wing as far as reducing the induced drag at the sacrifice of adding more weght (for same aspect ratio)
Point 3. The downwash corresponding to an elliptic lift distribution is a constant all along the span, further the rolling and yawing moments on such a wing are zero no matter how the chord, the angle of attack and the wing section are arranged.

Further, from 12:8-9 Spanwise Lift Distribution under Load "Supersonic and Subsonic Airplane Design" by Gerald Corning Professor Aeronautical Engineering Department - University of Maryland 1960

Point 4. The downwash corresponding to a trapezoidal wing planform varies along the span
Point 5. The spanwise lift coefficient for a trapezoidal wing planform changes with the downwash along the span.
Point 6. The G forces have bearing only on the elastic properties of the wing - and have nothing to do with lift distribution Unless and Until the wing twists or bends to change the relative angle of attack from 'no load' angle.
Point 7. The changes which tend to throw lift load Outboard are a function of bending rigidity, while the changes which tend to throw lift load Inboard are a function of torsional rigidity.

 

[Soren]

Oh and next time read all of what Lednicer says in his article:

Lednicer:
"A wartime Focke Wulf report (Ref. 14) indicates that at higher loading conditions (i.e. when pulling more gs) elastic deformation of the Fw 190 out wing shifts the load distribution outboard [elliptical effect = entire wing generates lift at the same angle of attack]. This would cause even more of the wing to reach its stalling lift coefficient simultaneous. Combined with the sharp stalling features of NACA 23000 airfoils, this would produce the harsh stall found in by Capt. Brown. A gentle stall would be evidenced by a more gradual progression of the 2D stall spanwise. "

Hmmm.. you turn Bill!