FIGHTER COMBAT COMPARISON No.2: Bf109E-3 vs Spitfire MkI

[Glider]

I admit this is an interesting thought. Its only a personal thought but the main difference I could think of is the change brought on by technology and the different skills needed.
For instance a modern fighter pilot can more or less do what they want with the controls, the computers will stop the aircraft doing anything dangerous and for a given control input, find the limit of performance for the pilot. An experienced pilot WW2 pilot will be more aware of the edge of the envelope and how to get that last bit of performance out of the design.
A modern pilot has very sophisticated head up display units, helmet dsiplays and audio warnings if anything is amiss. An experienced WW2 pilot would be more aware of what is going on inside the cockpit without spending a lot of time actually looking at the instruments. Scanning is a useful skill.

Keeping a lookout is also a skill. Everyone will agree that its as critical today as ever, but, there is no getting around that radar proximity warnings and other devices tend to ease the load. A ww2 pilot only had the eyes in their head and practice makes perfect.

In the early 70's trainee helicopter pilots at Culdrose were forbidden from joining the gliding club as what we taught, did in some way hinder their learning. To be honest I don't know what and we didn't expect it but it was an issue for the trainees.

As for tactics I doubt if they have changed much.

 

[finnster]

Another error: The idea of a no warning stall in the Spitfire.
All the spits had ample buffet warning of the stall, and NACA reports argue that the Spit V could be flown 'partly stalled'.

 

[Tante Ju]

Yes there was good warning but actual stall in Spitfire was brutal compared to 109. Spitfire had lower stall speed, so the stall happened later though. But when happened, it was very wild.

Both aircraft had good stall charactertics, 109 being more forgiving from what I read. This was one of best selling point for 109 vs. for example 51, Yakovles, Dewo 502 or Fw 190, F4U etc.

After reading it, no wonder he quit writing; he deserved the criticism. All my sources say the RAF lost about 150 planes or so and the Germans lost about 250 planes or so during the BOB. A clear margin regarless of location.

Real sources tell 109s had 2:1 success ratio against British fighters in 1940, increasing to about 4:1 by 1941 when on defense... clearly most of it was down to better tactics and experience, but not all.

 

[Milosh]

And the RAF had ~2:1 ratio vs the Luftwaffe during the BoB.

 

[Glider]

Real sources tell 109s had 2:1 success ratio against British fighters in 1940, increasing to about 4:1 by 1941 when on defense... clearly most of it was down to better tactics and experience, but not all.

Can I ask what the 'real' sources are. For instance I would not be surpised if two RAF fighters were lost to every Me 109. This may well be correct but would ignore that fact that a lot of RAF fighters were shot down by Me110's and the bombers defensive fire. Also when we say RAF fighters are we excluding the Blenhiem and Defiants which were lost. It could be that it might well be 109's vs Hurricanes and Spits but again would this exclude the Hurricanes and Spits shot down while trying to intercept the bombers which were the priority target.

I must emphasise that I am not doubting your figures but am simply trying to show that without understanding how they were compiled, they are interesting but not really gold standard evidence.

 

[Tante Ju]

And the RAF had ~2:1 ratio vs the Luftwaffe during the BoB.

No, it had ~ 1:1. RAF fighters had it worse of course (as did both sides bombers).

 

[Glider]

Statments like this mean nothing unless we know what the source is for any figures quoted by any party

 

[Glider]

Still waiting to see where your tats have come from Tante Ju

 

[Tante Ju]

I am still waiting to see where the other stats come from, too. Perhaps in meantime you should do some research yourself, to see real losses. Search forum for example.

 

[Glider]

I am more than happy to see what I can find but remember I have not been making any claims.

However you are the one quoting loss ratios with nothing to back them up. I pointed out in an earlier posting that without any details the claims being made are usless and now we find you are playing, I will show you mine if I see yours first, which to be honest is pretty pathetic.

Take your posting 46 No, it had ~ 1:1. RAF fighters had it worse of course (as did both sides bombers). What on earth is that trying to say

My guess is that you are saying that the RAF lost as many aircraft as the Luftwaffe, but I don't know what you mean. Are you talking about the whole of the RAF ie including Coastal Command and training aircraft destroyed in the conflict, or are you just talking about fighter and bomber command. Or are you talking about those lost in the daytime fighting excluding night raids on both sides.

All I am asking is that you say on what basis you made the statement

 

[Tante Ju]

Yes all aircraft losses in period.

 

[Glider]

Thanks for the clarification. I admit to waiting with some interest for your sources as I have drawn a complete blank when looking for german losses not part of the fighting over the UK.
Indeed German aircraft that crash landed on return were often not considered to be losses. RAF aircraft in this type of incident were written off as losses as they were not available for service in the short term and when repaired, were included in the new build stats. Which I admit is a pragmatic appraoch with the benefit of simplicity

 

[stona]

If the slats were as bad as some of the allied test pilots seem to say. Why wouldn't some of the Germans wired them shut or deactivated them in some way?
It's seems sort of odd that the one aircraft that shot down by far the most aircraft of any fighter in history was a bad gun platform under some conditions because of slats.

Because amongst other things the Bf 109 would become very difficult to fly slowly or at high angles of attack,there were enough landing accidents as it was.
Cheers
Steve

 

[stona]

Another error: The idea of a no warning stall in the Spitfire.
All the spits had ample buffet warning of the stall, and NACA reports argue that the Spit V could be flown 'partly stalled'.

The Spitfire wing was far more advanced than that of the Bf 109. It had been designed by Beverley Shenstone,who had been involved in the design of the first swept and delta wings in Germany and is credited thus,in print,by Alexander Lippisch.

Shenstone spent hundreds of hours blending the wing's shape and form to create a geometrically and helically twisted wing that was aerodynamically unique in that it balanced wing twist with planform effect and lift distribution needs.It traded pure lifting ability with performance ability. It is not an ellipse like the oft quoted He 70 but a far more complex three dimensional shape,incorporating two different aerofoils,NACA 2213 and 2209.
Have you seen it described mathematically? Shenstone couldn't do the maths himself and was helped by Professor Raymond Howland of University College Southampton. I certainly can't do it!
Howland is one of many,including even Shenstone himself,who have been lost and forgotten in the mythology surrounding the Spitfire. Many made important or vital contributions. The designer watching sea gulls soaring over a cliff top is the stuff of movies and there it should stay.

People still argue about the Spitfire v Bf 109 radius of turn,but the Spitfires rate of turn is demonstrably higher. If you want all the maths then try to find Ackroyd and Lamont's dense "Comparison of turning radii for four Battle of Britain fighter aircraft". One thing is sure,no matter how well flown,slats deployed in a slower speed combat turn,the Bf 109 will stall before the Spitfire.

Shenstone worked hard on the wing/fuselage join area,where on a normally shaped aircraft lift degenerates and speed sapping turbulence and drag occurs,especially under high propeller power effect.Perfecting this area preserved curvilinear lift distribution by continuing the wings lifting effect and lowering fuselage interference drag turbulence to astounding levels. Compared to the Bf 109 the Spitfire delivers the low drag,high speed characteristics desirable in a fighter far better.

This,added to the wings lift coefficient,helping retain vital energy, meant that a pilot could remain on the offensive with a working,energised wing at higher bank angles than a Bf 109 or Hurricane.
Addressing all these factors in one wing was advanced stuff,beyond anything yet seen in the mid 1930s.

Examples.
The ellipsoidal shape of the wing has a narrow tip which might be prone to stall.To cure tip stalling a crude solution would be to put a drag inducing fence along the leading edge near the wing root to trigger an earlier stall at a specific point inboard. This simple solution would have ruined the ellipse's low induced drag benefits.

A similar crude cure seen at the time might be a vertical wing fence chordwise (over the top of the wing) to cure any spanwise airflow problem,but the penalty this time is a loss of lifting area. This was actually done on Spanish built 109s. It did improve the small tapered wing's lift patterns,but with a penalty.

Shenstone worked out how he could twist the wing and vary the twist along it,whilst degrading to a minimum amount the ellipse's low induced drag figure.

By adding twist the ellipse's stalling issue was solved for the smallest of penalties and,in a feature often overlooked,Shenstone added a touch of forward sweep that further benefited the ellipse as it moved the stall forwards and inboard,away from those pointed wing tips. The ailerons kept "working" too,beyond the stall,which is what those US test pilots noticed.
Forward sweep also minimised the washout angle,upsetting the ellipse less,and speeding up the boundary layer.

The word genius is much overused,but Shenstone's work on the Spitfire wing may well be touched with it. A wing designed in 1934/5 was capable of operating at speeds unimaginable at the time,a tactical Mach number of 0.82 is astounding,the P-51 only managed 0.78. The wing is a far more advanced design than any of its production contemporaries.

Alex Henshaw noted that this sharp,responsive,aerobatic,400mph wing was aerodynamically stable at that speed and on the approach at 60mph. In both situations it neither stalled,nor dropped a wing unexpectedly. I don't know where the idea that the Spitfire had a viscious stall came from

Cheers

Steve

 

[krieghund]

Unfortunately an issue from the creation of the Spitfire was corrected with the wing for the Spiteful

 

[Tante Ju]

The Spitfire wing was far more advanced than that of the Bf 109. It had been designed by Beverley Shenstone,who had been involved in the design of the first swept and delta wings in Germany and is credited thus,in print,by Alexander Lippisch.

Shenstone spent hundreds of hours blending the wing's shape and form to create a geometrically and helically twisted wing that was aerodynamically unique in that it balanced wing twist with planform effect and lift distribution needs.It traded pure lifting ability with performance ability.

Its called washout. Its commonly used on all WW2 fighters (that is those without slats which cure the same problem). Washout and washin

It is not an ellipse like the oft quoted He 70 but a far more complex three dimensional shape,incorporating two different aerofoils,NACA 2213 and 2209.

Again, common used on 1930s, 1940 planes. The 3rd and fourth digits simply show the wing thickness percentage (13% at the root, 9% at the tip in the case of the Spitfire). The Fw 190 for example had 15,3% at the root, and 9% at the tip (NACA 23015.3 airfoil at the root and the NACA 23009 airfoil at the tip). The wing was designed using the NACA 23015.3 airfoil at the root and the NACA 23009 airfoil at the tip. The 109 used "2R1" from 14% to 11,35% (NACA 2414 to 2411). 12,9 % was used in the mid-section.

The NACA four-digit wing sections are simply a description of the wing profile and define the profile by:

First digit describing maximum camber as percentage of the chord.
Second digit describing the distance of maximum camber from the airfoil leading edge in tens of percents of the chord.
Last two digits describing maximum thickness of the airfoil as percent of the chord.

So the major difference between the 109 wing and the Spitfire wing apart from relative thickness is that the Spitfire has maximum camber of 20% from the airfoil leading edge while the 109 has 40%.

People still argue about the Spitfire v Bf 109 radius of turn,but the Spitfires rate of turn is demonstrably higher. If you want all the maths then try to find Ackroyd and Lamont's dense "Comparison of turning radii for four Battle of Britain fighter aircraft". One thing is sure,no matter how well flown,slats deployed in a slower speed combat turn,the Bf 109 will stall before the Spitfire.

This has nothing to do with wing shape. The Spitfire simply uses a much larger wing, so its stall speed is much lower. Besides you have it backwards - turn radii is depends on stall speed, in which the lower wing loading plane (Spitfire) will generally have an advantage. Sustained turn rate however is greatly dependant on available power (power vs drag) - this tends to muddy the water since by simply adding power the sustained turn rate will get better and will favour the plane with the higher power loading (109).

Shenstone worked hard on the wing/fuselage join area,where on a normally shaped aircraft lift degenerates and speed sapping turbulence and drag occurs,especially under high propeller power effect.Perfecting this area preserved curvilinear lift distribution by continuing the wings lifting effect and lowering fuselage interference drag turbulence to astounding levels.

Again, nothing special in this. Most designers paid careful attention to this.

Compared to the Bf 109 the Spitfire delivers the low drag,high speed characteristics desirable in a fighter far better.

Demonstrarably untrue since the Spitfire had fairly high drag. Compare the Spitfire to any other first line fighter and its slower on the same power. Again, largely a function of using a very large wing.

This,added to the wings lift coefficient,helping retain vital energy, meant that a pilot could remain on the offensive with a working,energised wing at higher bank angles than a Bf 109 or Hurricane.

Again, you mix thing up. The Spitfire used a relatively thin wing with low lift coefficient. Sq. feet by Sq. feet, it developed less lift than the 109 wing. It just had a lot more wing area to play with.

Addressing all these factors in one wing was advanced stuff,beyond anything yet seen in the mid 1930s.

Hardly. Washout, differing wing profile was common to practically all aircraft of the era.

The wing is a far more advanced design than any of its production contemporaries.

Replace 'advanced' with 'overhyped' and agree with you. It may have been advanced compared to it's British production contemporaries, which is where the hype comes from. This is no degradation to the Hurricane, who's designers aimed for nothing more than an interim type.

I don't know where the idea that the Spitfire had a viscious stall came from

Its described in manuals of Spitfire and even British reports... The aircraft had good stall warning and good near stall characteristics. This was a good thing, but far from unique. It had bad control harmony. When it stalled it had a tendency to flick over its back and violently enter a spin. The 109 had good stall warning and very benign near stall characteristics, ideal control harmony, and no tendency to enter a spin (which was an RLM requirement).

 

[tomo pauk]

Nothing like a good Spitfire vs. Bf-109 debate

<grabs popcorn>

 

[stona]

I'm not going through everything point by point.

Do you believe that the Bf 109 wing was a sophisticated a design as a Spitfires,given the slats and the problems with spanwise flow? What was the tactical Mach number for the 109 wing, does 0.75 ring any bells.

Do you think that the Bf 109 was more slippery than the Spitfire? I'm sure you can look up the figures as easily as I can. The Bf 109 was a very draggy design,it was small and needed a lot of power to overcome this. This got worse through successive versions up to the G-10/K which did achieve better values than earlier Gs. I don't have figures for the F readily to hand.

I've got

Spitfire Mk I A late model Cd 0.0197 Cdo 0.0180 Cdi 0.0010

Bf 109 E Cd 0.0265 Cdo 0.0246 Cdi 0.0018

Lamont and Ackroyd's paper is modern but Vensel and Phillip's war time reports are also of interest,particularly regarding coefficients of lift ( Cl). The Bf 109 must have suffered a loss of wing lift efficiency with its drag creating tapered wing design.They also postulate a de facto reduction of aspect ratio due tip drag in comparison with the Spitfire's elliptical wing tips.

Cheers

Steve

 

[Tante Ju]

Do you believe that the Bf 109 wing was a sophisticated a design as a Spitfires,given the slats and the problems with spanwise flow?

Yes it was half a generation better, especially from the production point of view, since it was designed to tolerate much looser tolerances in production.

Problems with slats and spanwise flow?

What was the tactical Mach number for the 109 wing, does 0.75 ring any bells.

Yes, what was it? What is 'tactical mach number'?

Do you think that the Bf 109 was more slippery than the Spitfire?

Yes.

I'm sure you can look up the figures as easily as I can. The Bf 109 was a very draggy design,it was small and needed a lot of power to overcome this.

No. Figures show that it was one of the fastest on any given power. All versions are faster than the Spitfire on the same power. Only late Yakovlevs better it, which is partially explained by their clean wooden construction and some other compromises. Mustang is slightly better, but not by much.

This got worse through successive versions up to the G-10/K which did achieve better values than earlier Gs. I don't have figures for the F readily to hand.

Again if it was so bad, explain why it was faster. On less power...

I've got

Spitfire Mk I A late model Cd 0.0197 Cdo 0.0180 Cdi 0.0010

Bf 109 E Cd 0.0265 Cdo 0.0246 Cdi 0.0018

I see root of confusion - you believe coefficient of drag is a quality number for aerodynamic cleaness. It really isn't, it just a coefficient comparing total drag of aircraft to wing area. Since wing is only responsible for part of the drag, it doesn't really show much.

Take an example. We have same fuselage, with drag value of 100. We add the same wing to it in two sizes, size is 100, drag value is again 100, one is larger by 40%, size is 140, drag value is 140.

So with small wing of 100 area, we have 100 + 100 = 200 drag. Drag coefficient (wing area is basis) = 200 / 100 = 2.000
With 30% larger wing of 130 area, we have 100 + 140 = 240 drag. Drag coefficient (wing area is basis) = 240 / 140 = 1.710

The larger wing area aircraft, even if nothing was changed just wing area, and even if drag is actually 20% greater, the 'drag coefficent' on wing area basis is 16% lower...

See? Drag coefficient does not tell you how much drag you have.

Lamont and Ackroyd's paper is modern but Vensel and Phillip's war time reports are also of interest,particularly regarding coefficients of lift ( Cl).

It sounds like an interesting study. Can you post this?

The Bf 109 must have suffered a loss of wing lift efficiency with its drag creating tapered wing design.They also postulate a de facto reduction of aspect ratio due tip drag in comparison with the Spitfire's elliptical wing tips.

Yes it's possible, still, everyone acknowledges the higher lift coeffcient of the 109 wing, including the British. There is not much surprise, a thicker wing will develop more lift, and a slats can sustain higher angles of attack (again more lift). Washout compromises wing lift ability. Simple physics.

 

[Glider]

A simple question. If the Me109E was modern and more advanced than the early Spitfires.

Why was the aircraft largely totally redesigned in the Me109F with new engines, wing, slats, and tail?