109 and compression!!!

[Captain Krunch]

The 109 may or may not have problems maneuvering at speeds above 400IAS but that has NOTHING to do with compression and everything to do with wing design.  Actual "compression" doesn't begin until a plane reaches about 80% the speed of sound and air starts disrupting over the roundish wings.  Some planes like the P-38 compressed earlier because of excessive wing camber but most WW2 aircraft didn't.  Side bar for a second... when your Zeke starts getting stiff at 300ias IT ISN'T COMPRESSING... IT'S BAD WING DESIGN!!!!  

Ok... now all of this assumes flight sims are correctly representing ww2 planes to begin with.  I have no idea how planes really flew at 400ias under differing air density, altitude, temperature, etc.  I don't think anybody really does.  

[Wulf]

I think the high speed maneuvering problems the Bf 109 series suffered from were caused by limited maximum stick forces (caused partly by the cramped cockpit of the Bf 109), as opposed to 'bad wing design'.

[Captain Krunch]

Heck, it might have been the stick.  I should have said bad design, not bad wing design.  

On the flip side...

who really knows?  Ever ridden in a car that you thought was great and your friends said stunk or visa versa?  Fifty year old opinions from pilots are incomplete under the best circumstances not to mention as subjective as they are scientific.  

The only thing we know for certain is that in reality it was a match for any craft it faced.... not to mention the fact it downed more enemy fighter aircraft than any other plane during ww2.  If the Luftwaffe wouldn't have been forced to use trainees on the frontline during the last 2 years the numbers might have been even more favorable.  My guess is that it was kick bellybutton in it's own little way.

[Wulf]

I can't quote where it is from, but I know someone who can find it.

It was an article written by a U.S.A.F. pilot who flew the P-51D, P-38 (J or L, can't remember), Bf 109 (G+), and Fw 190A.

When commenting on the Bf 109, he stated that the stick felt like it was 'mounted in cement' at higher speeds, and that he didn't have enough room in the cockpit to get enough leverage to move the stick at said high speeds...at least not enough movement to actually maneuver.

I'll try and track the article down. The guy who has a copy goes by the handle =jagr= in WB.

[funked]

Wulf, Eric Brown flew all those planes (and more) and he said the same thing about the Me 109G.  It was a 1935 airplane with a 1943 engine.

BTW Eric Brown was a test pilot until the '70s and he has more carrier traps than any pilot in history.  I tend to trust his opinions for two reasons:
1.  He flew every WW2 fighter type I can think of (excepting Soviet types).
2.  He was an engineer and a test pilot.  He knew airplanes.
3.  In his books he is referring to the flight test reports that he wrote for the AFDU.  He is going from his own documentation and adding his personal recollections.

[Kats]

Actually it was a Bf109 G6/U2 that mistakenly landed on the wrong side (heheheheh) July 1944.

And yup, Brown said that the *stick* froze at speeds over 400mph.  That doesn't really mean compression, just that the stick needs alot more force to move it than other planes might have at that speed. Obviously AH models this.

[Captain Krunch]

This is sorta off topic but I remember reading that the Spit did the exact same thing over 400ias.  I wonder if they share design elements?  hmmm  I guess they were both reasonably old designs.

Ya know, maybe in real WW2 combat this wouldn't come into play so much. A lot of action took place in and around bombers at 15,000 to 30,000 feet.  Any time you dropped below 10,000 I bet your mortality rate jumped exponentially. hehe

[wells]

Only the Spitfire's ailerons were a problem.  The elevator was very light.  Pulling out of dives wasn't really a problem as pilots would use that tactic against the 109.

[Captain Krunch]

How the heck can you be so sure? You wrote that like you fly Spit's against 109's on a regular basis. <g>

Although I don't have the Spit book in front of me I SPECIFICALLY remember the author stating it was virtually impossible to pull the stick back over 400ias.  I don't know if that's true or not, I'm just trusting what this guy wrote because I don't have much choice, hehe.

As for the book... I think It's at my buddies house, I'll see if I can get the actual quote out of it.  When it was published in the 80's this guy was a member of The House of Lords or Parliment or Knighted or something.  I can't remember which, but he was some sort of big-wig.  He was a Spit test pilot during the war and helped develop the plane from the very beginning.

[funked]

I've read the same thing as Wells.

Remember that this is all relative.  ALL WW2 fighters (well maybe not the F4U) had greatly increased elevator forces at high speeds.

But the accounts (combat pilots and test pilots) I have read say the Spitfire had a bigger problem with the ailerons than with the elevator.

[Captain Krunch]

I'll see if I can get a copy of the Spit book on Monday.  As for it being heavier on the ailerons than elevator... could be, I have no way to know.  

BUT IN ANY CASE......

This kind of thing isn't terribly important above 15,000 feet where most flying and fighting occured.  It's not until you get down to the lower altitudes that your IAS becomes a problem... and heck, if you are flying at low alt your chances of being shot down go up ASTRONOMICALLY no matter what plane you're in.  You don't have a lot of choices at 5,000 feet when 2 enemies dive onto your 6.... even in a 262.

[Daff]

If you're in a 262 at 5000 feet and have two bandits diving on you..you have fewer chances than in any other plane  ....bad example <G>.
 And yes...the spit had a very light elevator, but suffered from heavy ailerons.

Daff

------------------
CO, 56th Fighter Group

[leonid]

The Spitfire ailerons were quite stiff at speed.  This was the result of the elliptical wing design, not the ailerons per se.  They tried many ways to alleviate this, using non-fabric skins on the ailerons, and even clipping the wings, but the results were never satisfactory.  Further research revealed that the wing design was the result.

One has to remember that when the Brits built the Spitfire, they were mainly focusing on a fighter that performed well in the horizontal plane, not so much the vertical.  I would suppose that WWI and the resultant dominance of aerial dogfights played a large part in this.

[funked]

My understanding is that Spitfire aileron problems were a result of insufficient torsional stiffness in the wing structure.  At high speeds, the aileron forces were enough to twist the wing and counteract the rolling moment of the aileron.

[Captain Krunch]

Ok, I've got a Spit book, but I'm not sure if it's the same one.  It's called, "SPITFIRE" by Alfred Price.  Some of it's really good, other stuff is pure war propoganda trying to be shaped into historical fact.  

One thing I learned was that the Spit had the LEAST "compressable" airframe of any airplane during ww2. It's thin wings allowed air to flow over much faster without causing disruption. I never knew that.

Ok... to the elevator.  According to this book it wasn't what you'd call "light" by any stretch of the imagination.  HOWEVER... it was measurably lighter than the 109's.  By rolling, then diving and then pulling out as sharp as possible a Spit could evade a pursuing 109.  But it went on to say, "Of course these advantages could only be exploited if the Spitfire was flown to her limits."

Later on it compared maneuverability more closely and gave them both poor marks above 400ias.  At the end of the paragraph it stated that... above 400ias, "The Spitfire ceased to have any clear advantage in manoeuverabilty"

That's only one book, and not exactly complete at that, but it's reasonably interesting.  It rated the Spit and 109, "an even match"