Why do Spitfires turn better than Hurricanes?!

[ICDP]

The quote is from the "Complete and Unabridged" version of the Big Show, published in 2004. Clostermann had many notes and diary entries that were not used in the original version.

See page 42, "My first big show over France". Clostermann was flying a Spitfire Mk IX against most likely 109Gs

[Kurfurst]

Originally Posted by Viper2000

the Spitfire had the highest tactical Mach number of any WWII fighter, and could not be out-dived by any aircraft under control until the advent of the XP-86 in 1947.

'Fighter' seems to make the sentence untrue, given that the supposed .89 Mach figure was measured on an unarmed photo recce aircraft (ie. aerodynamic windshield, no cannons stubs, no MG ports ruining the flow over the wing); besides the fact that the said report of the PR XI dive measured does not mention a thing about control behaviour..

I have a report of a proper Mark IX (ie. Fighter) dive trial, and it shows exactly the same symptoms of loosing control as any other fighter above 0.80 Mach. Add to that the instruments were also inaccurate at these speeds, and you have a myth liked by fans, but with very little root in reality.

[justme262]

For what it's worth... here is an interview with a Battle of Britain Ju87 pilot in which he says a Hurricane could hang on the tail of a Stuka in a sustained turn but a Spitfire was too fast.

http://www.youtube.com/watch?v=McloM9Es3oM

[Sternjaeger II]

Originally Posted by 41Sqn_Stormcrow

Walking to the wingtip without making move the plane (Mustang) is barely an indicator of the wing strength. I'd say it didn't move because the landing gear is set so much more apart from each other in a P51 than in a Spit that made the difference here.

If you ever get a chance get to the wingtip of a Spit, rock its wing and see what happens, then do the same on a Mustang (if you can grab the tip that is, it's SO thick!). The whole impression you get from being around a Spitfire that it was designed with (mostly wrong) performance in mind, not with sturdiness as main concern.

One thing is fact which in turn is exploited today on purpose for modern fighter design but which also extends to other domains:

The less stable a device is the more prone is it to change its state. This principle can be exploited in a beneficial way. If you make something instable it is more easier to move around. For instance designs like the Eurofighter is instable and only kept on course because of computer software. This inherent instability allows to be more manoeuverable than a stable plane because anythings stable will tend to maintain its current status and is highly unwilling to assume another state (that is another attitude or flight direction).

So if the Spit is as manoeuverable it is likely on the edge of stability and thus somewhat nerveous.

that is true with designs which are designed to behave as such. The Spit wing was designed in a time when transonic and supersonic envelopes hadn't been fully explored yet, and its flexibility could prove fatal if stressed under sustained heavy G loads.

Some years ago I had the chance to speak to a gentleman who fought first with Macchi 202 and then with Bf109s for the Regia Aeronautica. He met Spitfires over Northern Africa and he said that in two separate occasions saw two Spits diving to chase Macchis only to lose controls under what seemed to be compressibility issues of the tail surfaces.

[TomcatViP]

Compressibility is not really affecting the tail surface (even if it does). In fact most comments on this phenomena are describing the formation of shocks waves on the wing surface that affect the pitching moment. The pitching moment is so great that the tail surface can't compensate for it... Hence the horrific impression to pull the stick without effect. The immediate solution is to lower the Mach number.

yeah yeah ... I know I am "marking" the wall myself here too but ... this thread is full of info for anyone (e.g : a reminder is a valid info)... Let's step fowrd pass that ugly wall

Note :
1. the Stuka's pilot impression is really good add.
2. Closterman's feelings abt the Spit as one of the top scoring ace of the ETO shld be taken into account more seriously. And even if it does not affect the Spitfire MkI it's an important point of view regarding the Spitfire capabilities vs vs the assumptions made here that tends to extrapolate perfs out from charts of latter variants.
3.the pitching moment is negative on most airfoil section

[Viper2000]

Originally Posted by Kurfurst

'Fighter' seems to make the sentence untrue, given that the supposed .89 Mach figure was measured on an unarmed photo recce aircraft (ie. aerodynamic windshield, no cannons stubs, no MG ports ruining the flow over the wing); besides the fact that the said report of the PR XI dive measured does not mention a thing about control behaviour..

I have a report of a proper Mark IX (ie. Fighter) dive trial, and it shows exactly the same symptoms of loosing control as any other fighter above 0.80 Mach. Add to that the instruments were also inaccurate at these speeds, and you have a myth liked by fans, but with very little root in reality.

I didn't claim that a Spitfire fighter was capable of Mach 0.89 in a controlled dive. You seem to have set the PR.XI Mach number up as a straw-man.

The Spitfire Pilots Notes put the dive limit at 450 mph IAS (after position error; so really it's more like CAS but without the modern compressibility correction) or what was effectively Mach 0.85, the limit being defined by a lookup table due to the absence of a Mach meter.

I would suggest that Eric Brown is probably the best reference for relative performance of fighter aeroplanes because he flew so many types.

It's fine to argue instrument error when you're talking about squadron pilots diving in the heat of battle and seeing fantastic numbers on their ASI. Indeed, I'm more than happy to offer up the alleged Mach 0.92 dive by a Griffon Spitfire in the vicinity of Hong Kong post war as likely erroneous.

However, RAE were a competent flight test organisation, and they were perfectly capable of correcting for compressibility. The same goes for NACA, though it is notable that the USAAF went to RAE for an assessment of the high speed handling characteristics of their fighter aeroplanes (See Wings on my Sleeve).

Compressibility correction for a pitot tube really isn't that hard, especially subsonic when you can just say that gamma = 1.4.

Therefore I have considerable confidence in the Spitfire PR.XI dive data showing Mach 0.89; if you look at Morgan & Shacklady you'll see that the aeroplane was rather impressively instrumented for these high speed dives. I also note that this tended to break engines due to overspeeding, resulting in several serious accidents, despite the fact that the propeller was modified to feather in an attempt to contain rpm.

So I wouldn't claim that a Spitfire fighter could be safely operated by a squadron pilot at such a high Mach number.

But I have no reason to believe that it was unsafe to operate the aeroplane within its published envelope (i.e. the lower of 450 mph after position error correction, or Mach 0.85), not least because pilots tend to get quite vocal if aeroplanes scare them within the published envelope, and I also have no reason to disbelieve the tactical Mach numbers quoted by Eric Brown in his various books.

IIRC there may be some dive test data from a Spitfire IX showing a tactical limit of about Mach 0.83 out there somewhere. This would be fairly reasonable.

AFAIK the tactical limit for the Mustang is about 0.80, Thunderbolt about 0.72, Bf-109 and Fw-190A 0.75, whilst the P-38 was only ok to about 0.68. However, my books are at home; the numbers can be cross-checked in Wings on my Sleeve, Wings of the Luftwaffe, and Wings of the Weird & Wonderful.

[Sternjaeger II]

Originally Posted by TomcatViP

Compressibility is not really affecting the tail surface (even if it does).

LOL I love you man

In fact most comments on this phenomena are describing the formation of shocks waves on the wing surface that affect the pitching moment. The pitching moment is so great that the tail surface can't compensate for it... Hence the horrific impression to pull the stick without effect. The immediate solution is to lower the Mach number.

yeah yeah ... I know I am "marking" the wall myself here too but ... this thread is full of info for anyone (e.g : a reminder is a valid info)... Let's step fowrd pass that ugly wall

I always dozed during my theory lessons, but if memory serves compressibility on tail surfaces is the creation of shock waves on the leading edge, which creates a void that makes the control surfaces ineffective because they're outside of the airstream (Viper might give a more educated explanation of it).

[Sternjaeger II]

Originally Posted by Viper2000

I would suggest that Eric Brown is probably the best reference for relative performance of fighter aeroplanes because he flew so many types.

Brown's accounts are a good read but hardly of any serious value man.. I think this is the biggest mistake: always looking for a source of comparison, but looking only into English literature on the subject.

The Germans had a lot of planes to play with, and I believe they might have produced an extensive literature on the subject, it would be interesting to hear from our German speaking friends on the matter.

[Viper2000]

Brown was at the RAE high speed flight; decision makers acted upon his views at the time. I don't think that you'll find a substantially better source.

The Germans didn't have the opportunity to test war trophies after VE day, so their literature is unlikely to be anything like as broad as that produced by the Allies, especially at the RAE; don't forget that the RAE were the world-leaders in high speed flight until the idiotic cancellation of the Miles M.52...

[Sternjaeger II]

Originally Posted by Viper2000

Brown was at the RAE high speed flight; decision makers acted upon his views at the time. I don't think that you'll find a substantially better source.

questionable.. he wasn't the only pilot, only the one that bothered writing a somehow interesting (albeit incomplete and biased) text on his experience. RAE had to make a lot of compromises in their testings, so if you're looking for an accurate testing, look somewhere else.

The Germans didn't have the opportunity to test war trophies after VE day, so their literature is unlikely to be anything like as broad as that produced by the Allies, especially at the RAE; don't forget that the RAE were the world-leaders in high speed flight until the idiotic cancellation of the Miles M.52...

Brown's tests of our interest were mainly made during war years, the postwar years were more devoted to jet planes (he's claimed as the only Allied pilot who flew a Komet, but in fact he only glided in it).

The Luftwaffe had an extensive testing of captured planes (they even bothered to install a DB601 on a Spitfire to check its performance!).

I found some literature of interest:

"Luftwaffe Test Pilot, Flying captured Allied Aircraft of World War 2" Published in German in 1977 and English in 1980. Author: Hans-Werner
Lerche.

1. Strangers in a Strange Land Vol. 1 (Squadron Signal pub) by Hans Heiri Stapfer. Usually available on the web for
$ 10 - $ 15 used condition. A number of photos and color drawings are included as well as interesting discussions on specific aircraft that were captured.

2. Fremde Vogel unterm Balkenkreuz I have scanned photos from this book, but haven't been able to find a copy for sale.....it contains a number of photos of captured
aircraft in Luftwaffe service organized by country of origin. This book was published in the early 1980s I think.

3. Il Ricco Bottino (The Rich Booty) by Hans Werner Neulen. Excellent book on captured Italian aircraft in Luftwaffe service. around $ 18.

4. The Luftwaffe from Training School to the Front (Chapter 10) by Meyer and Stipdonk. Chapter 10 provides a number of photos of captured aircraft.

5. Foto Archiv Band 8. Although several Band in this excellent publication include at least one or two photos of captured aircraft..Band 8 includes by far the most with
several types I not seen elsewhere. You can order this one online at the following site:
www.stormbirds.com/flugzeug/ (http://www.stormbirds.com/flugzeug/)

Flugzeug magazine and Jet & Prop magazine, also available at this web address, have published excellent articles on this subject. Included are: Fiat G-12; Bloch SO 161;
Hopfner Ha 11/33; Brequet Br 521 Bizerte (2 parts); SM-75/SM 82; Rechlin September 1943 display; SE 200 etc.

6. Luftwaffe Fledglings 1935 - 1945. by Ketley and Rolfe. Although not exclusively about captured aircraft, this book nevertheless contains quite a bit of interesting
information, photos and drawings concerning captured aircraft used as trainers.

7. Modell Fan magazine ran a series of articles in the late 1970s and early 1980s entitled 'Sie Flogen mit dem Balkenkreuz' there were at least 13 or 14 articles in this
series, maybe more.

8. The Czech magazine REVI has published comprehensive articles by Igor Mrkvanek on captured Czech aircraft in Luftwaffe service. Very informative.

9. Flypast has published at least two very interesting articles on captured British aircraft in Luftwaffe Service.

10. Luftwaffe Codes, Markings and Units (Barry Rosch) contains quite a bit of information on captured aircraft organized by Luftwaffe unit. Some photos and drawings of
captured aircraft are included throughout the book.

11. The Luftwaffe Verband Journal has published several articles on aircraft evaluated at Rechlin or operated by Versuchsverband.