The effect of 'clipping' Spitfire wings

[Kev367th]

Kurfurst -
  Prob with clipped wing numbers is the fact that they were removed and refitted as needed. It wasn't as though a standard wing Spit off the production line had to stay like that, or vice versa.
Same goes for extended wing spits.

Thats why I mentioned about the Spit F IX in the tests. I have a sneaky suspicion it's prob an original 1942 or earlier Mk V with a Merlin 61. Hardly the best candidate for any flight test IMO.

I doubt you'll ever get a definate

• number of Spits had clipped wings.

It's hard enough getting ball park figures for the numbers of L.F. Spits. Mostly that has to done by extrapolation.

Thats the one problem with AH - All the planes are PERFECT, 100% examples. Something you'd never find, even in one that just rolled off the production line.

The drawbacks -
Slight increased take off run - Not a problem, in fact they even trialed Seafire III with clipped wings, still had no probs getting off a carrier.
Slight decrease in speed over 20k - Not a problem, clipped wings designed for low alts.
Lowering of service ceiling - See point above.
Loss in climbrate - Yup a prob, but hardly a BIG drawback.
Loss of turn compared to std Spit - Well DUH, the whole point was to increase roll.

The more I read the Boscombe Down writeup the more I realise they completely missed the point of having clipped wings.
Two of the points only valid for high alts, one doesnt matter, the only downside is the loss in climb.
Of course the big question, why the hell were they flying clipped wing Spits 20k and above?
It's known that clipped wing Spits suffered at high alts, so why run tests at 20k+.

Ahhhh ping (lightbulb)-
Merlin 45 fitted to F Vb and F Vc
Merlin 46 fitted to F Vb
Merlin 61 fitted to F IX
Griffon II fitted to XII - can find nothing on this, only Griffon III's, IV's

I'll bet the tests were done at the usual operating alts, all those Merlins are desined for higher alt flying than what would have been normal for L.F. models, which explains test data and comments for 20k and above.

Correct ones would have been (all more powerfull than those above)
45M for the LF Vb LF Vc
50M for the LF Vc
66  for the  LF IX

Yes I know clipped wings were fitted to non LF models, but they were PRIMARLIY for use by LF models

[pasoleati]

Originally posted by Crumpp

Additionally the Spitfire has a sustained turning superiority not an instantaneous turning superiority.  Examining the CLmax and Lift Polars of the FW-190 revels it's turning ability at speed was very good.
Crumpp

But how well could this theoretical high speed turning ability be exploited in practice due to FW´s harsh accelerated stalling characteristics?

[Crumpp]

But how well could this theoretical high speed turning ability be exploited in practice due to FW´s harsh accelerated stalling characteristics?

The "harsh" high-speed stall of the FW-190 existed but is rather exaggerated in Post War literature.  This stems from two allied reports.  Both reports used the same FW-190.

Both Oscar Boesch and Heinz Orlowski have told me you the FW-190 stick burbled before any stall.  If you were paying attention it was easy not to stall it out.

A properly configured FW-190 had two stalls:

It's "normal" stall was gentle and recovered immediately.  At one G in level flight the nose would dip and the wing droop slightly.  

Only when flying at high speed and under extreme G's wing warpage would cause the washout to flatten.  If the aircraft were stalled under this condition it would lose lift along the entire lifting surface of the wing.  The aircraft would then almost invert and left unchecked enters a spin.  Recovery was instantaneous for both the stall and the spin.  Many FW-190 pilots to escape an attacker on their tail used this characteristic.  Talking to the pilots it was not something that surprised you when flying the plane.  In other words, it was not a combat limiting characteristic.  

It was not any different from the P51's.

In fact it was better than the P 51's, as the recovery from any spin that was allowed to develop was instantaneous.  The P51 is almost unrecoverable from a spin.

http://www.google.com/custom?q=stall+&sa=Google+Search&cof=LW%3A450%3BL%3Ahttp%3A%2F%2Fwww.mustangsmustangs.net%2Fp-51%2Favi.images%2F2002-MMlogo450x70.jpg%3BLH%3A70%3BAH%3Acenter%3BS%3Ahttp%3A%2F%2Fwww.mustangsmustangs.com%3BAWFID%3A2c0172bfb87aabde%3B&domains=mustangsmustangs.net&sitesearch=mustangsmustangs.com

For a complete description of the P51's stall behavior pick up copy of AHT.

All the best,

Crumpp

[Karnak]

Your statements here on the 190 seems about right to me Crump, but this thread really didn't have anything to do with the 190 until Kurfurst decided to rewrite whar Dan said so as to be able to say Dan was contradicting himself.

This thread is really only about full winged Spitfires vs clipped wing Spitfires.  Kurfurt's contention, based on one, very brief document from 1941 or 1942, if that the roll rate was not usefully improved, the climb rate was significantly reduced and the turning ability was significantly reduced.

The rest of us contend that the roll rate was significantly improved, though still falling significantly short of the Fw190's, with a small increase in turning radius and reduction of climbrate below 20,000ft.  About that it gets more significant.


You know what it is like to "debate" Kurfurst.  I recall a 109 vs 190 thread in which you went in circles with him contending that the 109 was just outright better than the 190.

[Nashwan]

He still not presents the test (was it a test at all?) conditions of the MkV

Isegrim, read what the image I posted says.

To repeat it:

"The best method of comparison of the rolling performance of different aircraft is based on the steady rate of roll a pilot can generate using a definite stick force, say 50 lb, or full aileron if this requires less than 50 lb. on the stick.  This course has been adopted in Fig.6 which shows the results obtained for the F.W.190, Mustang, Typhoon, and Spitfire V (metal covered ailerons) with both standard and clipped wings.  On all these aircraft instrumental records of rolling performance have been obtained at the R.A.E, similar to those under discussion for the F.W.190.  In this connection it is worth noting that "instrumentation" is essential when obtaining the curves of Fig.6.  Stop-watch measurements of time to bank on fighters are rarely of sufficient accuracy, since the times to be measured are so small."

Crumpp, can you confirm to our suspicious little friend that RAE 1231 is primarily a test of the Fw190, not the Spitfire, that whilst it contains Spitfire, Mustang and Typhoon data in the chart it doesn't go into details of their tests, and that they were tested seperately?

Isegrim thinks it contains some details that contradict the Spitfire roll performance shown in the chart you posted. (Not the Fw190 data, just the Spit data)

[Crumpp]

RAE 1231 is a test of the FW-190's roll rate.

The report is titled:




The graph is a calculation based on inflight measurements of aileron deflection, stick forces, airspeed, and roll rate.  Glauert corrections for compressibility are factored in and the formula used is included in the report.

It was backed up by gun camera observations which estimated the FW-190 could roll at 120 degrees a second at speeds from 170mph to 300mph IAS at 10,000 feet.  The report admits this method is very much a ballpark figure as there is no way to know the stick forces.

With the exception of the FW-190 aileron adjustment it is my opinion that RAE 1231 represents the most accurate roll rate report on the FW-190 I have seen.  I have yet to discover a Focke Wulf or RLM roll rate test.  Evidence suggest's the FW-190 in service could roll better.

All the best,

Crumpp

[pasoleati]

Originally posted by Crumpp
The "harsh" high-speed stall of the FW-190 existed but is rather exaggerated in Post War literature.  This stems from two allied reports.  Both reports used the same FW-190.

Both Oscar Boesch and Heinz Orlowski have told me you the FW-190 stick burbled before any stall.  If you were paying attention it was easy not to stall it out.

A properly configured FW-190 had two stalls:

It's "normal" stall was gentle and recovered immediately.  At one G in level flight the nose would dip and the wing droop slightly.  

Only when flying at high speed and under extreme G's wing warpage would cause the washout to flatten.  If the aircraft were stalled under this condition it would lose lift along the entire lifting surface of the wing.  The aircraft would then almost invert and left unchecked enters a spin.  Recovery was instantaneous for both the stall and the spin.  Many FW-190 pilots to escape an attacker on their tail used this characteristic.  Talking to the pilots it was not something that surprised you when flying the plane.  In other words, it was not a combat limiting characteristic.  

It was not any different from the P51's.

In fact it was better than the P 51's, as the recovery from any spin that was allowed to develop was instantaneous.  The P51 is almost unrecoverable from a spin.

http://www.google.com/custom?q=stall+&sa=Google+Search&cof=LW%3A450%3BL%3Ahttp%3A%2F%2Fwww.mustangsmustangs.net%2Fp-51%2Favi.images%2F2002-MMlogo450x70.jpg%3BLH%3A70%3BAH%3Acenter%3BS%3Ahttp%3A%2F%2Fwww.mustangsmustangs.com%3BAWFID%3A2c0172bfb87aabde%3B&domains=mustangsmustangs.net&sitesearch=mustangsmustangs.com

For a complete description of the P51's stall behavior pick up copy of AHT.

All the best,

Crumpp

Well, I have the AHT. As for the P-51, I just watched a wartime P-51B training film. The pilot giving the commentary was Bob Chilton. He spun the aircraft and described the spin as easy to recover. He also commented on its accelarted stall by saying that elevator buffeting sets in 3-4 mph before the stall and that though the plane flicks out there is no tendency to spin.

As for the 190 stall, at least the accounts given in Herrman&Leverenz´s "FW 190A" book agree with Eric Brown´s account, i.e. the accelerated stall is without warning.

[Crumpp]

As for the 190 stall, at least the accounts given in Herrman&Leverenz´s "FW 190A" book agree with Eric Brown´s account, i.e. the accelerated stall is without warning.

Well when Herrman and Leverenz fly one, let me know and get their opinion.  They wrote an excellent book however it is mostly pictures.  When I examined it looking for your claim the only reference to aggravated stalling in a clean configuration is:





Please point out the page.

I am sure Eric Brown's experience is spot on with the FW-190 he flew.  As I said, the Luftwaffe had a hard time keeping the ailerons adjusted how can one expect the RAE to adjust them properly?

The aileron adjustment blocks are IMHO poorly designed on the FW-190.  They are simply flat smooth blocks of duralumin that fit together.  The aileron attachment screws slide in slots on the adjusting block which mates to the flat smooth duralumin mounting blocks in the wing.

Adding some teeth would have gone along way toward preventing them from loosening and sliding out of adjustment.

Let's look at what Dean says about the P51 in AHT, an extremely detailed fact filled book:





All the best

Crumpp

[Toad]

I've met a lot of guys that flew the P-51 in actual military service.

I've yet to meet one that has anything good to say about spinning it with fuel in the fuselage tank. Mostly their face goes pale at the thought.

However, with the fuselage tank empty, most of them say it would recover from a developed spin IF you had enough altitude. "Enough" comments ranged from "5-6 thousand" to "10-12 thousand" feet.  

[Crumpp]

Your absolutely correct Toad.

All high performance aircraft are capable of inducing an aggravated stall provided they can change the AoA faster than the wing can produce lift at a given speed.

Many aircraft, especially in the early war during WWII where not capable of doing this due to excessive stick forces at high speed.  In later war designs this phenomenon becomes more commonplace and is not quite as surprising as it was when it first appeared in the FW-190A.

It is interesting to note that no test pilots in Germany had ever seen the wings of an aircraft turn white with condensation in a high speed turn or seen it on the propeller tips until the FW-190 appeared.

The light stick forces of the FW-190 could actually be detrimental to its performance if flown by a heavy-handed pilot.

All the best,

Crumpp

[MiloMorai]

Guys, listen up.

Barbarossa Isegrim is absolutely correct in that the Spitfire is the worst piece of garbage ever produced claiming to be a fighter. It is such a crappy piece of machinery that even a Eindecker would have no problem disposing of it in combat. I would even go so far and say the Spitfire would even have trouble besting the Taube.

On the other hand, the 109 was such a superb machine, even the Bf109B would make mincemeat out of the F-23 very quickly.

[Guppy35]

So answer the question then Izzy.

Why did they clip the wings of so many Spit Vs?  Just a quick look through the books shows photos of clipped Spit Vs being operated by the following squadrons.  41, 91, 601, 602, 131, 401, 402, 315, 225, 501.

Even if only those 10 squadrons flew them, that still begs to question why they did it if what you are saying is the final conclusion reached by the RAF.

Why did they clip the wings on the Spit XII if there was no benefit?

Why did they deliver all 1054 Spit LFXVIe's with clipped wings?

Why did they deliver all the Spitfire FRXIVs with clipped wings?  

You are saying that based on the one report you found using an FIX in testing that the RAF decided against the benefits of a clipped wing.

Why were they delivering them in 1943-45 from the factory with clipped wings?

Why did the RAF and other countries that operated the Spit postwar, such as Belgium, operated them with clipped wings if there was no reason?

Is it possible your 1943 report was not the final word?

Quoting the AFDU tactical trial of the Spit XII EN223 in December 1942.

"In the air, the handling of both EN223 and another production Spitfire XII which was made available by Supermarine for one day, were felt to be far superior to the normal Spitfire IX or Vb, being exceptionally good in the lateral control which was crisper and lighter due to the clipped wings.."

Later in the same report:  "It is considered that when used below 20,000 feet it will be able to out pace and out turn the FW190 and roll as well.."

Thier words, not mine.  

Someone in the RAF found something good about clipped wings apparently.

The trial with EN223 is found in Alfred Price's "The Spitfire Story" btw in case you think I'm fabricating it.  Of course I suppose Dr. Price could have too being a Spit dweeb like he is.

The question still remains.  WHY did the RAF operate clipped wing Spits and for such a long period from 42 until well into the postwar period, if what you say is correct?

Dan/CorkyJr

[Guppy35]

Originally posted by Kev367th
Kurfurst -
  Prob with clipped wing numbers is the fact that they were removed and refitted as needed. It wasn't as though a standard wing Spit off the production line had to stay like that, or vice versa.
Same goes for extended wing spits.

Thats why I mentioned about the Spit F IX in the tests. I have a sneaky suspicion it's prob an original 1942 or earlier Mk V with a Merlin 61. Hardly the best candidate for any flight test IMO.

I doubt you'll ever get a definate

• number of Spits had clipped wings.

It's hard enough getting ball park figures for the numbers of L.F. Spits. Mostly that has to done by extrapolation.

Thats the one problem with AH - All the planes are PERFECT, 100% examples. Something you'd never find, even in one that just rolled off the production line.

The drawbacks -
Slight increased take off run - Not a problem, in fact they even trialed Seafire III with clipped wings, still had no probs getting off a carrier.
Slight decrease in speed over 20k - Not a problem, clipped wings designed for low alts.
Lowering of service ceiling - See point above.
Loss in climbrate - Yup a prob, but hardly a BIG drawback.
Loss of turn compared to std Spit - Well DUH, the whole point was to increase roll.

The more I read the Boscombe Down writeup the more I realise they completely missed the point of having clipped wings.
Two of the points only valid for high alts, one doesnt matter, the only downside is the loss in climb.
Of course the big question, why the hell were they flying clipped wing Spits 20k and above?
It's known that clipped wing Spits suffered at high alts, so why run tests at 20k+.

Ahhhh ping (lightbulb)-
Merlin 45 fitted to F Vb and F Vc
Merlin 46 fitted to F Vb
Merlin 61 fitted to F IX
Griffon II fitted to XII - can find nothing on this, only Griffon III's, IV's

I'll bet the tests were done at the usual operating alts, all those Merlins are desined for higher alt flying than what would have been normal for L.F. models, which explains test data and comments for 20k and above.

Correct ones would have been (all more powerfull than those above)
45M for the LF Vb LF Vc
50M for the LF Vc
66  for the  LF IX

Yes I know clipped wings were fitted to non LF models, but they were PRIMARLIY for use by LF models

Quite making sense Kev

Griffon IIb was what was used in the Spit XII prototype DP845.  The production engine was the Griffon III and IV.  Seafire XV, the first Griffon Seafire was the navalized Spit XII and had the Griffon VI.  All were single stage Griffons at that point.  2 stage Griffon 60 series went into the XIV and those following.

Dan/CorkyJr

[Kev367th]

So to sum it up -

The flight test used -

A prototype Spit XII - Although their #s are BN221 and BN222, a mystery?
Mk F V's and an F IX ALL with engines designed for higher alts, flying at their usual alts with a clipped wing.

Add to that the F IX may have been one of the early Spit V airframes with a Merlin 61.

Sorry, I suddenly don't put a lot of credence in that test.

Bit like tuning a cars engine and downforce for sea level, taking it to the top of Kilamanjaro and then saying, 'well it doesn't hold the road as well, or go as fast'.

As I said the more I read it, the more I thought they'd lost the plot.

[pasoleati]

Well, that Beauvois quote was the primary quote I meant. Shouldn´t comments from a test pilot of Beauvois´s  calibre carry more weight than statements from 2 next-to-unkown pilots.

If you check what I wrote, I never mentioned POWER ON spins, and the refernce I gave spoke specifically of the P-51B, not D. And Dean doesn´t say anywhere that P-51D´s power off spin is unrecoverable.