Bf-109 vs Spitfire vs Fw-190 vs P-51

[Milosh]

Hi Glider

This sbook about the 2 TAF sounds like an excellent reference, can you post the bibliographic details....I would like to track down a copy.

parsifal, if these aren't the books Glider was referring to, I highly recommend.

- 2nd Tactical Air Force: v.1: Spartan to Normandy June 1943 to June 1944: Vol 1 by Christopher Shores
- 2nd Tactical Air Force: Breakout to Bodenplatte v. 2 by Christopher Shores
- 2nd Tactical Air Force: Volume 4: Squadrons, Camouflage Markings, Weapons and Tactics 1943-45 by Christopher Shores
- 2nd Tactical Air Force: Volume 4: Squadrons, Camouflage Markings, Weapons and Tactics 1943-45 by Christopher

Amazon has them starting around $40.

 

[parsifal]

thanks, I will see if I can get copies here in Australia

 

[claidemore]

you say south england is 700 billion square feet then say 1 piece of debris every 466 billion square feet
that is 2 pieces on the whole of south england (presumably the balance of the 1.5 million are embeded in the bomber you mentioned) oh and I did read your signature quote.

The fact is people were hit by falling rounds and casings and when they were it wasnt a round falling on its own.

I did say I wasn't a math wizard! I believe the number should be one piece of debris for every 466 "thousand" sq feet. Musta forgot to drop a half dozen zeros. (no pun about hypothtical Zeros during BoB intended!)

Really the most pertinent part of my post was the bit about the shovels and rakes, which tools are useful for shovelling various substances.

All kidding aside, you look at the return fire from bombers, 109 fighters, Hurricanes, Spitfires, it adds up to quite bit of metal falling down, though of course it is spread out over the several weeks of the battle.

 

[drgondog]

If John comes back under a different nom d'plume here are some data of twist.

First the Spit:
2 degrees positive for ~ .2 Span, then start constant degreesm(negative) to the tip for approx zero incidence at the tip. The Spit had a near elliptical planform wing and this twist had the effect of significantly increasing the induced drag due to the twist effect

Fw 190
2 degrees positive at root, then 2 degree (negative) from root to .85 span, then zero for remainining .15 span to approx zero incidence at the tip.

P-51B ~ 0 at root increasing along strake 1 degree (positive) to about .18 span, then start constant 1 degree (negative) washout to tip resulting in zero degree washout at tip.

P-51D ~.2 degrees at root increasing to 1 degree (positive) at strake/wing intersection at ~ . 2 span, then 1 degree negative until zero incidence at the tip

Both the 51 and the 190 improved their lift distribution profiles to approximate (but not equal the Spit) lift distribution - but the 51 Twist was more of a straight line, whereas both the Fw190 and Spit twist was not constant...

The Fw 190 had probably the most violent departure at stall in a turning manuever, reversing to the oppsite wing.
I don't have the 109 data - hopefully Kurfurst or VG33 have the information - but I doubt that that 109 had no washout..

 

[drgondog]

Claidemore - where did you find this quote?

"The trouble with most people isn't what they don't know....it's what they do know that simply isn't so"

 

[parsifal]

If John comes back under a different nom d'plume here are some data of twist.

First the Spit:
2 degrees positive for ~ .2 Span, then start constant degreesm(negative) to the tip for approx zero incidence at the tip. The Spit had a near elliptical planform wing and this twist had the effect of significantly increasing the induced drag due to the twist effect

Fw 190
2 degrees positive at root, then 2 degree (negative) from root to .85 span, then zero for remainining .15 span to approx zero incidence at the tip.

P-51B ~ 0 at root increasing along strake 1 degree (positive) to about .18 span, then start constant 1 degree (negative) washout to tip resulting in zero degree washout at tip.

P-51D ~.2 degrees at root increasing to 1 degree (positive) at strake/wing intersection at ~ . 2 span, then 1 degree negative until zero incidence at the tip

Both the 51 and the 190 improved their lift distribution profiles to approximate (but not equal the Spit) lift distribution - but the 51 was more of a straight line.

The Fw 190 had probably the most violent departure at stall in a turning manuever, reversing to the oppsite wing.
I don't have the 109 data - hopefully Kurfurst or VG33 have the information - but I doubt that that 109 had no washout..

can you explain what this means...eg, the FW190 with its 2 degrees. What angle is that, and what does it do in laymans terms to the flying/aerobatic qualities of the aircraft?

 

[banned man]

I just never learn.

 

[Njaco]

Just for sh!ts and giggles....

Show me a squadron record that has any mention of friendly fire that is a pilot saying" I shot down one of our own" by your own standards you must be able to find 2% (good luck on that one) and then look at the claims which on both sides overestimated by at least 100%, it is that discrepancy that provides the logic for 10% that is 10% of enemy claimed shot down and wernt were actually FF.

24 August 1940
RAF No. 235 Sqdrn log: P/O D.N.Woodger of No 235 Squadron and his gunner D.L.Wright were shot down and killed in error by a Hurricane of RCAF No 1 Squadron at 16:45hrs. Their Blenheim IV (T1804) crashed at Bracklesham Bay.

"The most poignant incidents involved Allied aircraft shooting down other Allied aircraft. A well-known case was on Aug. 24, 1940. No. 1 (Canadian) Sqdn., flying Hawker Hurricanes, newly declared operational, was about to enter the Battle of Britain. Only the commanding officer, Squadron Leader Ernest A. "Ernie" McNab, had seen combat a few days before, attached to a British unit.

The squadron scrambled 12 fighters, led by McNab, to patrol at 10,000 feet. Having observed one combat in progress, they spotted three twin-engined aircraft approaching below. McNab started to attack, then recognized the machines as Blenheims–a British type. He and his section broke away, but two following sections, each of three Hurricanes, pressed on, shooting down one Blenheim in flames and heavily damaging a second. Returning to base, the Canadians claimed to have destroyed one Junkers 88 and "probably destroyed" a second.

The Blenheims had taken off from Thorney Island to avoid being bombed by an approaching German raid. Surviving crewmen stated they had fired recognition signals; the Canadians apparently confused these with return fire. Yellow Section (Flt. Lt. Gordon R. McGregor, FO Jean-Paul Desloges, FO Arthur D. Nesbitt) carried out the most telling attack; only inexperience and bad shooting by other pilots prevented greater losses. Fighter Command investigated the incident but did not pull No. 1 (Canadian) Sqdn. from the line."

 

[B-17engineer]

With a username like that I wouldn't of guessed who he was! Good catch.

As for the Blenheims, how were the signals fired?

 

[claidemore]

Claidemore - where did you find this quote?

"The trouble with most people isn't what they don't know....it's what they do know that simply isn't so"

Paul Harvey

 

[Njaco]

....and thats the rest of the story!

 

[parsifal]

Nj you sh*tstirrer

 

[DerAdlerIstGelandet]

Do they really think we are that stupid and can't tell when someone opens another account?

 

[Glider]

parsifal, if these aren't the books Glider was referring to, I highly recommend.

- 2nd Tactical Air Force: v.1: Spartan to Normandy June 1943 to June 1944: Vol 1 by Christopher Shores
- 2nd Tactical Air Force: Breakout to Bodenplatte v. 2 by Christopher Shores
- 2nd Tactical Air Force: Volume 4: Squadrons, Camouflage Markings, Weapons and Tactics 1943-45 by Christopher Shores
- 2nd Tactical Air Force: Volume 4: Squadrons, Camouflage Markings, Weapons and Tactics 1943-45 by Christopher

Amazon has them starting around $40.

Those are the ones.

 

[The Basket]

Washout means that the wing doesn't stall altogether.

The wing tips stall before the wing roots.

Giving a stall warning and allowing the pilot control even when the wing is starting to stall. Greater resistant to spinning or departing controlled flight.

I would be surprised if the 109 had no washout.

That's my understanding anyway.

 

[drgondog]

can you explain what this means...eg, the FW190 with its 2 degrees. What angle is that, and what does it do in laymans terms to the flying/aerobatic qualities of the aircraft?

There are several things to consider on a wing. First the angle of incidenceof the airfoil relative to the zero lift angle where it joins the fuselage. In the case of the Fw190 and Spit, both started with a 'positive' 2 degree angle. In the case of the 51B and D the angle of incidence was near zero at the root, but INCREASED to 1 degree "positive' at the point where the relative strakes intersected the rest of the straight line leading edge,

Second - the twist. Twist is the amount of change of angle of incidence of the airfoil, varying spanwise along the leading edge. Both the Spit and Fw 190 have interesting concepts. They both start with a positive 2 Degrees but the Spit has no twist for about 20% of the span, then it deceases non-linearly until it reaches zero incidence at the tip. The Fw190 starts negative twist from 2 degrees immediatley but also varies non linearly until it reaches .85 span where it has reduced to zero degree incidence also - then has no twist for the remaining .15 span.

The Mustang INCREASES angle of incidence from the root to about .18 span where it reached the one degree positive angle of incidence, then decreases angle of incidence linearly until it reaches minus 1 degree at the tip.

Third - the aeordynamic effects of twist. First - Twist along the leading edge, varying the angle of incidence from free stream velocity vector for a given flight condition has the effect of changing the lift distribution of the wing spanwise (moving the center of lift inboard)- and up to a point, usually around 1 degree, improves (reduces) induced drag due to the spanwise vortices created by the lifting line. (.i.e. Lift). Essentially it has the effect of approximating an elliptical lift distribution, and moves the lift distribution - from an untwisted wing of same properties - inbourd.

The second effect of twist, when increasing twist more than optimal, is to provide less angle of attack to the freestream out near the wing tip, thereby reducing the stall poiint when the inboard angle of attack (incidence) to the freestream has exceeded maximum lift.

Simply, inboard wing is stalling faster then the tip and at the ragged edge of stall there is some remaining laminar flow around the ailerons to provide some roll stability.

Visually, take a plastic ruler, hold one end (wing/fuselage) fixed apply torque to the other end (tip).

The relative angle change along the ruler edge from one end to the other is 'twist' in the context of what we have been talking about.

I hope that was clear - and not too verbose.











then both decreased linearly to zero angle of incidence at the tip.

 

[Timppa]

Just as a matter of interest AFAIK - and I could be well wrong in this! - the 109 didn't have washout at all, as it had leading edge slats to perform the same function instead.

Hoerner agrees:
"There is no twist built into the wing of the Me-109"

 

[parsifal]

Thanks guys (I think)

I will go and try and learn a bit more I guess, but for now, if I can indulge your patience. Your saying that wings have an angle (of incidence?) that can vary along the wing edge, and this angle has an effect on the stall characteristics of the aircraft. Correct (or partially correct)????

Is this also related to the inherent flex that most wing designs have....you know, when you look out the window of a 747 you see the wing is not straight....it tends to curve upward at the edges. I always thought that sort of thing added strength to the wing, and also tended to improve stability, as air under the wing was allowed to escape more smoothly....or is that completely bollocks? I also have read somewhere that the 109 had a much more rigid, unflexing wing, but I didnt know if that was a good thing or a bad thing compared to the "flexing" wing concept.


Our recently departed friend also spokje about how prohibitively expensive the rounded wings of the Spit were to construct. I knew that they were expensive, but ridiculously so??? does not seem plausible...


And how does wing flex, stall characteristics, wing angle have anything to do with FF?????

 

[drgondog]

Thanks guys (I think)

I will go and try and learn a bit more I guess, but for now, if I can indulge your patience. Your saying that wings have an angle (of incidence?) that can vary along the wing edge, and this angle has an effect on the stall characteristics of the aircraft. Correct (or partially correct)????

Yes to enhancing airflow over the tip region when the inboard sections are stalling... giving ailerons something to work with rather than being immersed in totally separated flow. Of course, it is also Near stall as the inboard sections are In stall.. Twist also yields aerodynamic benifts by altering the lift distribution toward the elliptical.

Is this also related to the inherent flex that most wing designs have....you know, when you look out the window of a 747 you see the wing is not straight....it tends to curve upward at the edges.

No. The flex is an aeroelastic effect caused by the bending loads (lift) along the span. A stffer wing will flex less but also have a higher natural frequency - the latter, when approximating the frequency of say a prop/engine combination or turbine blade rpms, could cause resonance, fatigue - and ultimately structural failure - (i.e. Comet)

I always thought that sort of thing added strength to the wing, and also tended to improve stability, as air under the wing was allowed to escape more smoothly....or is that completely bollocks?

Yes... other than the discussion of providing last minute aileron effective when all else was lost due to stall.

I also have read somewhere that the 109 had a much more rigid, unflexing wing, but I didnt know if that was a good thing or a bad thing compared to the "flexing" wing concept.

I have not seen any sound data to suggest that the 109 wing was 'stiffer' or not. I suspect 'not' as Willy was notorious for stripping all unnecessary weight. The 109 theoretically required more than average beam/skin combinations due to the placement of the wheel well - forcing the main spar behind the primary aerodynamic center. I would like to see the actual anaysis details but suspect a leading edge 'spar type' stiffener, as well as the use of an aft spr type beam along the flap intersection of the wing.


Our recently departed friend also spokje about how prohibitively expensive the rounded wings of the Spit were to construct. I knew that they were expensive, but ridiculously so??? does not seem plausible...

Once tooling/jigs are put into play the wing was slightly more difficult to QA but should not have been more difficult to build in the twist. Aside from that, the Spit wing probably was more labor and materials intensive tha say a 109 or Mustang wing because the plan form geometry was more complicated.


And how does wing flex, stall characteristics, wing angle have anything to do with FF?????

doesn't. he was rambling about Spit wings, twist, etc in one of his intellectual 'walk abouts' and I decided to look it up..

The stall characteristics were a natural follow on to 'why have twist' and wing incidence to clarify a basis to discuss what twist 'is'

And finally, apparently Timppa and Kurfurst are correct that the 109 has no twist. In chapter 14-4 Hoerner states that the 109 has no twist in the wing. I find it surprising but accept that Hoerner has knowledge on this subject.

When I finally looked at a planview of the 109G and spotted the location of the slats I understand why the twist was not necessary for aileron control as the slats cover the leading edge on the outboard half of the wing.

Having noted this, I wonder if Willy tested wing twist as a mechanism to improve lift distribution and found no benefits

 

[davparlr]

Hoerner agrees:
"There is no twist built into the wing of the Me-109"

Which means the entire wing would stall at he same time. That could be sporting, slats or no slats. However, the slats extending would certainly give warning to the nearness to stall, however, after slat extension, aircraft could uncontrollably depart at any time.