Spitfire wing..a new view

It is all in the mathematics. Prandtl and Lanchester both came up with the circulationary theory in Edwardian era and Prandtl published a diagram of a ‘Spitfire’ wing planform in 1918. Lanchester’s model aeroplanes had elliptical wings… here is a glider model from the 1890s which is preserved at NAL.
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There are interesting aerodynamic analyses of several WW” fighters carried out by David Lednicer that shows the superiority of Spitfire aerodynamics… it may not be much but it enabled the pilots of the Spitfire to survive and conquer when an odd percent or two meant the difference between life and death. The Sport Aviation ref is on the net somewhere but I could not find it again.
•Lednicer, David A. “Technical Note: A CFD Evaluation of Three Prominent World War II Fighter Aircraft.” Aeronautical Journal, Royal Aeronautical Society, June/July 1995.
•Lednicer, David A. “World War II Fighter Aerodynamics.” EAA Sport Aviation, January 1999.

And for the penultimate word on the subject try reading this!

His (auto)biography was unpublished, which sort of suggests that whatever his achievements, he didn’t feel the need to tell the world of them; I’m not sure we’ll ever know exactly how much input there was from others.

I also think that for a man who apparently didn’t care for asthetics, Mitchell designed some beautiful aeroplanes.

My own thoughts are that he did care, very much, but in an enviroment where funtional A/C were all that was required, it is very hard to justify (as any designer working for a large company, on military contracts must) any unnecessary flourishes,I think he deliberately down played that side of hi designing; afterall the Spitfire doesn’t really need the wing tips to perform its role, but there they are, on K5054.

Depends on which reality you rely.
I got the book (didn’t know it was published until Mark mentioned it) and just finished it. Good read and very interesting to learn about the genesis of the Spitfire design.
Then again, whatever books or documents are unearthed or published, the myths or follies still persist.

Cees

A book about it here, published this year.

An interesting read.

Mark

Beverley Shenstone may well have perfected the elliptical wing, but it wasn’t used on the Spitfire.

There is a lot in the first few pages of this thread, but it isn’t very structured. Lance Cole has had access to Shenstone’s unpublished autobiography and other papers, it is definitively worth a read if you’re interested in this subject.

I would suggest pretty much all you need to know about this subject, is contained in the first few pages of this thread.

A book about it here, published this year.

An interesting read.

Mark

It wasn’t elliptical

In fact it was basically a rough drawing.:confused:

The Spitfire Wing – A Mathematical Model

The only recorded account of Mitchell’s choice of an elliptical wing for the Spitfire, according to an autobiography by his Canadian aerodynamicist, Beverly Shenstone, is “I don’t care a damn what shape it is as long as we can get the guns in!” According to Mitchell’s Deputy Designer, Joseph Smith, Mitchell had a thick pencil and drew freehand large-scale curves, softly at first, then repeatedly over, harder and thicker until he got a fair curve. This was a practical and overworked man who had no time for aesthetics or analytical design. In November 1934 Shenstone went to the Paris Air Show where the Germans had unveiled their Heinkel 70 aircraft with elliptical wings. On November the 16th the RAF published the requirement for eight guns. It is believed that the decision for an elliptical wing on the Spitfire was made in the second half of that month.

http://thoughtality.com/the-spitfire-wing?showall=1

The design similarity of the empennage is clearer here. Even to the original rudder and elevator horn balances, as on the proto Spitfire, both substantially changed later.

http://www.scaleworkshop.com/workshop/he5148bg_1.htm

Fascinating. Clearly the Heinkels were a very strong design influence.

In my view this is not surprising considering the small scale and numbers of the design staff.

Mark

I would like to add my thoughts here, though I have to admit that I didn’t read the whole threat, so I might be repeating what has already been said. Early on it was suggested that someone might come up with the construction of the He 70s wing so see if RJ copied the wing or not. The wings of the Heinkel 70 were made of wood. I’m not sure if these wings had a negative incidence (the upper wing of the Heinkel 51 did – of 1°) but I can check that. When we were designing the wings of our He 51 replica we came across a side profile of the aircraft in which the airfoil sections are included. This drawing is in 1:40th scale. We blew it up to 1:5th scale and carefully redrew the sections. The wing of the He 51 has a length to height ration of 1:0,13. I don’t know what the He 70s ratio is and also not that of the Spitfire but on the He 51 it was a pretty thick wing for a biplane. Perhaps the airfoils on the He 51 / He 70 were similar.

No doubt someone at Supermarine’s design office was inspired by what was done at Heinkel’s. Note the tailplanes of these He 51s. Aren’t they a familiar sight?

Peter

Awsome

Lost for words mate.Really starting to fill her in.Can,t wait till next year…Some of our work…:D

‘Just updated http://spitfire3d.com/

There will be some more interesting stuff next year when I will be able to measure parts from disassembled wings. The wings are the priority for a while, but I will return to the rest of the aircraft.

I’m really not sure where you’re going with this, but let’s not get too over sensitive about it. 😉
However, you’re wrong on the timing of the conversion to metal ailerons. The first test aircraft and the decision to factory fit metal ailerons came in November 1940, but aircraft with fabric covered ailerons were still coming off the line well into early 1941.
I note that you’ve been in aviation all your life, as I have also and a pilot since the age of 18 (many years ago!) I would consider that this leaves us pretty much even. We are in basic agreement, just a slight difference on semantics.

I was not going anywhere with it 😀 just fighting my corner 😀
Yes I was probably wrong about the metal ailerons,whatever you may think..I am not a spitfire enthusiast and do not have any text books about it.
I never said she was perfect,when i said impeccable stall spin etc we were discussing the wing at that time and not the whole aircraft and always (from me) relative to the 109 and specifically slow speed and landing manners.
Glad to hear you are a real pilot,with your username,you could have been a virtual pilot.:D
If i knew what a semantic is…I might agree with you !! 😀

regards baz

another bit you missed in one of my posts,i was not talking about the later marks and specified my comments were up to mk 9/16.

edit… post 124 refers !!

cheers baz

Fair point. I didn’t check back…

It was sensitive but not oversensitive you seem to have ignored my posts where i said all a/c are compromises (eg post 64),the heavy ailerons were corrected during the BoB,I would say its flying qualities were excellent…esp for 1936,I have worked in aviation all my life and usually write and say things very carefully,you have to read my posts carefully before being picky and pedantic.

regards baz

I’m really not sure where you’re going with this, but let’s not get too over sensitive about it. 😉 I’ve not ignored your posts or your careful wording as you’ll have seen I’ve made the point all along that all aircraft are compromises. Yes, I agree the Spitfire had excellent flying qualities, particularly for 1936. The point being made is that excellent though it was, it was not perfect although modifications did remove or reduce some of the foibles.

However, you’re wrong on the timing of the conversion to metal ailerons. The first test aircraft and the decision to factory fit metal ailerons came in November 1940, but aircraft with fabric covered ailerons were still coming off the line well into early 1941. The aircraft remained sensitive in pitch right though, however. The point was made that this sensitivity could lead the aircraft into high speed stall for novice pilots, which was the case and remained so, and was commented on by pilots such as Ritchie.

I note that you’ve been in aviation all your life, as I have also and a pilot since the age of 18 (many years ago!) I would consider that this leaves us pretty much even. We are in basic agreement, just a slight difference on semantics.

Going back a bit, there was one other variant that had problems that needed a lot of attention – the 21 which was initially rejected for service.

another bit you missed in one of my posts,i was not talking about the later marks and specified my comments were up to mk 9/16.

edit… post 124 refers !!

cheers baz

This is true and obvious however the Spitfire _was_ sensitive in pitch and heavy on the ailerons so Ritchie wasn’t incorrect in his assessment which was written some time later. One adapts but ultimately the point remains that the Spit was a compromise, like all aircraft, and while on the whole its flying qualities were very good there was the odd foible.

Going back a bit, there was one other variant that had problems that needed a lot of attention – the 21 which was initially rejected for service.

It was sensitive but not oversensitive you seem to have ignored my posts where i said all a/c are compromises (eg post 64),the heavy ailerons were corrected during the BoB,I would say its flying qualities were excellent…esp for 1936,I have worked in aviation all my life and usually write and say things very carefully,you have to read my posts carefully before being picky and pedantic.

regards baz

First impressions are not always correct,if you fly a different type of aircraft for the first time then your control inputs are still going to be instinctive for your previous type,if you had been flying an aircraft that was very stable longitudinally then a spit might seem at first to be more sensitive than it really was,one adapts very quickly to a new a/c.Same as getting in a new car,for a short while some things seem really strange but after a day or two…bingo !! everything becomes normal again.Was it RRS Tuck who got back into a Gladiator after flying a spitfire for the first time…he thought it was like a rheumatic old goose…and yet before he had been quite happy with a Glad .

regards baz

This is true and obvious however the Spitfire _was_ sensitive in pitch and heavy on the ailerons so Ritchie wasn’t incorrect in his assessment which was written some time later. One adapts but ultimately the point remains that the Spit was a compromise, like all aircraft, and while on the whole its flying qualities were very good there was the odd foible.

Going back a bit, there was one other variant that had problems that needed a lot of attention – the 21 which was initially rejected for service.

No, but that wasn’t the qustion being answered. The question was ‘have I heard any ex spit pilots say a bad word about the a/c’s handling’. To which the answer as can be seen is yes, I have.

First impressions are not always correct,if you fly a different type of aircraft for the first time then your control inputs are still going to be instinctive for your previous type,if you had been flying an aircraft that was very stable longitudinally then a spit might seem at first to be more sensitive than it really was,one adapts very quickly to a new a/c.Same as getting in a new car,for a short while some things seem really strange but after a day or two…bingo !! everything becomes normal again.Was it RRS Tuck who got back into a Gladiator after flying a spitfire for the first time…he thought it was like a rheumatic old goose…and yet before he had been quite happy with a Glad .

regards baz

Hardly a really serious control problem,the comment about sensitivity in pitch might depend on what you had flown before,one soon gets used to different control feel,once the a/c were modded to metal ailerons the roll control at higher speed was much better…fine tuning…all a/c go through a rolling modification programme and gradually improve capability and safety through its service life…same for cars !!
The spitfires 2 weaknesses surely were its sensitivity to c of g change and relative lack of fuel (fuel compared to P51…not 109 or hurri !!)

cheers baz

No, but that wasn’t the qustion being answered. The question was ‘have I heard any ex spit pilots say a bad word about the a/c’s handling’. To which the answer as can be seen is yes, I have.