Clipped wing variant?

Edit @Krupi, sniped by the man himself ;)

Well, to be fair those reports were not done like flight testing is done today. IIRC those weren't test pilots but regular ones that had to fill out a survey sheet after flights. So if they weren't happy with it it wasn't necessarily the plane's fault.

Not sure where I read those reports though. Perhaps they were mentioned in one of my books. Could have been "Wings on my Sleeve".

But one thing is clear: Those cut wings will have advantages, but also disadvantages. I am almost sure that if we get both there will be some nice discussions here as well on that topic. :)

Indeed! :huh:

Certainly goes against some of the things I have read from the actual test pilots! :music_whistling:

I recall a report from a test carried out at various altitudes which stated that up to ~25000ft the manoeuvrability increased, due to the roll rate presumably, and that the clipped spitfire was able to shake off the normal spitfire up to that altitude.

Yes slightly slower climb rate and improved dives, I imagine the dive was only an initial improvement.

@Sith

We will never see a IX with HF wings it had a different engine Merlin 70 IIRC and given the things I read from Jeffery Quill bemoaning about the extended wing tips we are not missing anything! :D

Found this in some folder on my PC. Sorry don't know the source anymore, perhaps a similar thread on a forum about another WW2 sim.

This is one of the pages I had in mind. I don't know which exact version was tested though, and I am not an expert for aircraft performance.

Indeed! :huh:

 

Certainly goes against some of the things I have read from the actual test pilots! :music_whistling:

 

I recall a report from a test carried out at various altitudes which stated that up to ~25000ft the manoeuvrability increased, due to the roll rate presumably, and that the clipped spitfire was able to shake off the normal spitfire up to that altitude.

 

Yes slightly slower climb rate and improved dives, I imagine the dive was only an initial improvement.

There were conflicting opinions and conflicting flight test results - mainly on Mk Vs - as to how effective the clipped wings were: in some cases, it was down to the personal preferences of the pilots.

AFAIK, for 2 TAF Spitfires especially, the clipped wings helped relieve some of the bending stresses incurred on the outer wings during dive/glide bombing attacks. Most of the Mk XVIs had clipped wingtips, as did many XIVs; not sure of the ratio of L.F. Mk. IXs with clipped wings cf normal wings.

@Sith

We will never see a IX with HF wings it had a different engine Merlin 70 IIRC and given the things I read from Jeffery Quill moaning about the extended wing tips we are not missing anything! :D

Yep, those extended wingtips were hardly worthwhile, considering their disadvantages outweighed whatever small advantage they offered in climb rate at altitude and any possible increase in service ceiling.

Found this in some folder on my PC. Sorry don't know the source anymore, perhaps a similar thread on a forum about another WW2 sim.

 

This is one of the pages I had in mind. I don't know which exact version was tested though, and I am not an expert for aircraft performance.

I would take the word of engineers and test pilots over that of a Wing commander :D

Never was shown in tests

Lower acceleration because of lower rate of climb

Negligible effect, because the wingtips have low loadings comparing the main parts of the wing. In vain

Doesn't sound to me like the clip wing had any real advantages. If this is the case, I'm not really in any hurry to try it out.

Never was shown in tests

Lower acceleration because of lower rate of climb

Negligible effect, because the wingtips have low loadings comparing the main parts of the wing. In vain

So there is no advantage due to lower drag? Not even in level flight? No higher top speed? No higher acceleration in level flight, or better performance in a dive? No better roll rate?

Well, as the english say, my hopes are dashed...:(

According to what I read the roll rate was higher. Just not as much higher as expected.

@Krupi: Me too! This is only an example. There are other documents that seem to come to the same conclusions though.

Doing some more searching around I think there may be some misunderstanding about the data sources.

For example there is an often quoted report it seems that says the clipped wings were better in many regards, but that one was about a Mk.V Spitfire. IIRC that one had other ailerons, so the modification might have been good for the Mk.V but didn't prove advantageous on later models.

Here it is:

Quote from Alfred Price (can't check validity, I got it from the net somewhere) "The Spitfire Story":

The account below is taken from the report on the comparative trial of clipped wing and standard wing Spitfire VBs, flown by the Air Fighting Development Unit at Duxford towards the end of 1942. The sole difference in the case of the former was that the wing tips had been removed and thin streamlined fairings fitted in their place. Thus wing span was reduced from 36 ft 10 in to 32 ft 6 ins, and wing area from the normal 242 square feet to 231. The removal of the wing tips reduced the fully loaded weight by 30 pounds; wing loading was increased by about one pound per square foot.

 

Method of Test

Two Spitfire VB aircraft were selected with a performance which was almost identical, the loading and equipment carried were standard in each, and the propeller, engine and finish of each aircraft were similar. A test flight was made under maximum cruising conditions and no differences could be determined. The wing tips were then removed from one aircraft and trials were carried out, each trial being performed twice to enable the pilots to be changed. The wing tips were then replaced on one aircraft and removed on the other and similar tests carried out. Differences in speed were taken as relative increases or decreases owing to possible instrument inaccuracies, and position error differences with and without tips. Readings for level speeds were taken at 10,000,15,000, 20,000 and 25,000 feet; zoom climbs were made 10,000-15,000 ft and 20,000-25,000 ft; dives were made with similar engine settings.

 

Results of Comparative Tests

 

Level Speed 10.000 feet.

In each case the clipped wing Spitfire proved the faster by a small margin estimated in the nature of 5 mph.

15,000 and 20,000 feet. The average results at these two heights showed that the difference in speed is not measurable.

25.000 feet. The standard Spitfire is very slightly faster than the clipped wing Spitfire.

In all level speed runs the clipped wing Spitfire accelerated rather better than the standard Spitfire.

 

Climb

The average difference in time during zoom climbs from 20,000 to 25,000 feet was 15 seconds in favour of the standard Spitfire.

From 10,000 to 15,000 feet no differences were indicated.

 

Dive

In all diving tests the clipped wing Spitfire drew away from the standard Spitfire.

 

Manoeuvrability

At all heights to 25.000 feet the rate of roll is considerably improved by removal of the wing tips. The response to aileron movements is very quick and very crisp. Four dog-fights were carried out, starting with the standard Spitfire on the tail of the clipped wing Spitfire. On two occasions the clipped wing Spitfire evaded so rapidly in the rolling plane that it was able to lose the standard Spitfire and reverse the positions in about 20 seconds. On the third occasion the clipped wing Spitfire was also able to lose the standard Spitfire. The fourth occasion was at 25,000 feet and the standard Spitfire was able to keep the clipped wing Spitfire in sight.

The minimum turning circle of the clipped wing Spitfire at 20.000 ft has been increased by 55 feet at 1,025 feet compared with the FW 190 turning circle of 1,450 feet (RAE Farnborough figures). This slight increase does not therefore detract from the fighting qualities of the aeroplane in any way. since the clipped wing version is unlikely to be in combat with the standard Spitfire.

 

Take-off

The take-off run must theoretically be slightly longer, but in taking off with the clipped wing Spitfire in close formation behind the standard Spitfire, no difference was detected.

 

Landing

No difference detected.

 

General

The view downwards over the wing tips, for what it is worth, is improved by a not inconsiderable amount. The strengthening of the wing by removal of the wing tips may permit higher maximum IAS to be used.

 

Conclusions

The trials have shown that;

 

Speed

Below 1,000 ft Clipped wings give an increase

15 - 20,000ft No difference

Above 20,0000ft Standard wings are slightly faster

 

Climb

Below 1,000 ft Differences hardly measurable

15 - 20,000ft Differences hardly measurable

Above 20,0000ft In zoom climb from 20 - 25,000ft from level flight at full throttle, standard wings about 15 seconds faster

 

Rate of Roll

Below 1,000 ft Clipped wings superior

15 - 20,000ft Clipped wings superior

Above 20,0000ft Clipped wings superior

 

Acceleration

Below 1,000 ft Clipped wings superior

15 - 20,000ft Clipped wings superior

Above 20,0000ft Clipped wings superior

 

Dive

Below 1,000 ft Clipped wings superior

15 - 20,000ft Clipped wings superior

Above 20,0000ft Clipped wings superior

 

Turning circle

Slight increase for clipped wings, amounting to 55 feet at 20,000ft.

EDIT: then there's those two as well, but ALSO about the Mk.V, and the pilots seem to like it but still say it isn't as good as expected. (more attachments).

I've got to say,and personally speaking here,I am I no hurry to try this,if it ever does come to fruition.

I've always thought that the clipped wing variant of the Spit looks an aesthetically big mess,it just doesn't look right does it ?.......and I'm sure Mr Mitchell would've hated what they did to his beautiful creation.

I find it very disappointing when his name is the only one attached to the spitfire there were many who developed the aircraft and Joe Smith who continued the development from 1936 onwards is forgotten.

No disrespect to Mitchell, engineering a aircraft is not a one man job it requires a team of highly resourceful and skilled individuals with a plethora of skills.

Clipped Wing is ok for MK14 the Bird is overall looking like a bodybuilder on steroids..

But doesn't like it on early Spit..

@Krupi Most time in History great engineering is sadly linked only to one Person that could be never archive this on his own was only the lead of development Team and the names was used as Propaganda and get connected to the specific Aircraft til present day, or can you tell out of the Mind how is working with Kurt Tank and Willy Messerschmitt or Mikojan for the MIG Series as Hero of the Soviet Union.

Doing some more searching around I think there may be some misunderstanding about the data sources.

 

For example there is an often quoted report it seems that says the clipped wings were better in many regards, but that one was about a Mk.V Spitfire. IIRC that one had other ailerons, so the modification might have been good for the Mk.V but didn't prove advantageous on later models.

Here it is:

 

Quote from Alfred Price (can't check validity, I got it from the net somewhere) "The Spitfire Story":

Then there's the chart (see attachment) that shows a nice big difference in roll rate. But that one is from a Mk.XII

 

EDIT: then there's those two as well, but ALSO about the Mk.V, and the pilots seem to like it but still say it isn't as good as expected. (more attachments).

The comparative trials of the 2 Mk V Spits appears to show a clear advantage to the clip wing. Additionally, the combat trial between the same spec 2 Spitfires Mk V show that the clip wing comes up trumps in all cases. I have a copy of this report too in my copy of the Alfred Price book named 'The Spitfire Story' (IBSN 1-85409-305-3).

Moreover, it is worth noting that it was not for nothing that the clip wing was part of the natural evolution of the Spitfire. Spitfires were eventually produced with clip wings at the factory and eventually the Spitfire evolved to designed squared off wing tips on faster later marks of Spitfire too. This takes nothing away from the success of the early 1940 Battle of Britain era design with standard wing tips, but the need for speed and manoeuvrability was constantly changing as the war moved on and the Spitfire wing changed to meet the new needs of air combat as it developed over the period of the WWII. At the end of its development to Spitfires wing was squared off. So, the squared off wing actually ended up as the standard wing. That should tell us something about the advantages of changing design to meet changing requirements.

Happy landings,

56RAF_Talisman

Talisman, I am a bit surprised by this however I was aware that there was some contention as to the benefits of clipped wing.

I do wonder if the benefit was none existent why did supermarine continue to produce it, it must have had some benefit.

Regarding the mk24 wing, you cannot use it as evidence of the benefit of clipped wing, yes it was squared off however crucially it was longer IIRC as the standard wing.

Talisman, I am a bit surprised by this however I was aware that there was some contention as to the benefits of clipped wing.

 

I do wonder if the benefit was none existent why did supermarine continue to produce it, it must have had some benefit.

 

Regarding the mk24 wing, you cannot use it as evidence of the benefit of clipped wing, yes it was squared off however crucially it was longer IIRC as the standard wing.

I am just pointing out that the direction of travel in the development of the wing was away from the initial type of wing tip shape and that there was good reason. Prior to the Mk24 plenty of other Spitfire types continued to move away from the initial type of wing tip.

The comparison trial between the two Mk V Spits of the same specification and the dog fight trial appear pretty conclusive to me. For my money, that is the best information I have seen. I don't see how other tests/charts between Spitfires that were not the same specification can be relevant. For me it is the test between the two Mk V Spits that is most useful; also, the clip wing Spit having the better of 4 dog-fight tests says to me that the clip wing was king for a low fighter.

Happy landings,

56RAF_Talisman

Just as a point of interest, I read that the Spitfire with the most kills that is still flying is a Mk V with, yes, you guessed it, clipped wings. :thumbup:

This specific Mk. VC, EP120, is the Spitfire with most kills still flying - 7 German aircraft.

Happy landings,

56RAF_Talisman

I just remembered about this report NACA 868...

http://naca.central.cranfield.ac.uk/reports/1947/naca-report-868.pdf

In particular page 165 & 166... it makes me wonder which spitfire they tested a Mk V?

Looking forward to the Clip variant - should be fun!

I fail to see why this is such a point of contention- can someone please provide me some insight? why were the wings even clipped? seems like the defacement of a perfectly good aircraft. :huh:

It was thought to improve the roll rate of the aircraft drastically, reduce the drag slightly however it did have a negative effect on the climb rate and stall speed.

There are documents which seems to indicate that the removal was not beneficial so really the point of contention is whether or not they did improve all these areas or was it simply that metal ailerons required tweaking to individual aircraft to give the same benefits.

According to YoYo without a complete wing redisign, clipping the "E" type wing didn't do much of anything positive.

I assume that the later versions of the Spit, such as the XIV which featured the clip wing also had a completely diffferent wing design.

No the XI and XIV had the same wing essentially.

It was deemed too disruptive to redesign the wing so it wasn't until the mk21 that a completely redesigned wing was introduced.

Interesting. I thought that it featured a different wing. So all of its performance comes from the improved engine, propeller and fuselage?

Furthermore, the wing on the XIV had the tendency to wrinkle at pressure points. To offset some of the load, the clipped wing negated at least some of the stress off the wing.

You are correct to suggest that engine and propeller provided most of the performance gains. However, they weighed 1000's of lbs more than early-war Spitfires, so the performance gains in one area led to performance losses in other areas.

I can fully recommend Morgan & Shacklady's Spitfire - The history for more info about Spitfire evolution. It is considered The Bible of Spitfire reading. :thumbup: