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HayateAce
11-20-2008, 09:23 AM
http://forums.ubi.com/images/smilies/heart.gif

http://www.vimeo.com/1405515

Gandy_Katarin
11-20-2008, 09:34 AM
turn you volume up as far as you can and then prepare for the chills to run up your spine http://forums.ubi.com/groupee_common/emoticons/icon_rolleyes.gif

Xiolablu3
11-20-2008, 09:43 AM
Very nice http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

A quick question, does anyone know if it was possible to add and remove the wingtips from Spitfires 'in the field'? Or was it a permanant feature once it was decided?

WOLFMondo
11-20-2008, 10:21 AM
Nice. I need to by a DVD upscaler.

Freiwillige
11-20-2008, 10:21 AM
Originally posted by Xiolablu3:
Very nice http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

A quick question, does anyone know if it was possible to add and remove the wingtips from Spitfires 'in the field'? Or was it a permanant feature once it was decided?

It was decided atthe manufacturer, no choice in the feild. Once it was done it was done.

hop2002
11-20-2008, 11:02 AM
It could be changed in the field pretty easily. There were 2 bolts per wing that needed to be removed, the wing tip taken off, and the new one bolted on.

That's not to say it was changed on a per mission basis, but it's certainly something the mechanics could, and did, do in squadron service.

Divine-Wind
11-20-2008, 11:15 AM
Originally posted by Xiolablu3:
Very nice http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

A quick question, does anyone know if it was possible to add and remove the wingtips from Spitfires 'in the field'? Or was it a permanant feature once it was decided?
I imagine with a good torch it was possible. http://forums.ubi.com/images/smilies/16x16_smiley-tongue.gif

SlickStick
11-20-2008, 11:23 AM
Ooh, yummy Spitfire goodness!!! Thanks for posting that. http://forums.ubi.com/images/smilies/25.gif

The Spitfire is the definitive combination of WWII elegance and lethality. http://forums.ubi.com/images/smilies/heart.gif

Your opinions may vary. http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif

Metatron_123
11-20-2008, 11:37 AM
Nothing less than epic! http://forums.ubi.com/groupee_common/emoticons/icon_cool.gif

general_kalle
11-20-2008, 11:38 AM
arhh i wanna go to flying legends 2009..no...I HAVE TO http://forums.ubi.com/images/smilies/clap.gif

nice video...awesome sound

Xiolablu3
11-20-2008, 02:14 PM
Originally posted by Freiwillige:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Xiolablu3:
Very nice http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

A quick question, does anyone know if it was possible to add and remove the wingtips from Spitfires 'in the field'? Or was it a permanant feature once it was decided?

It was decided atthe manufacturer, no choice in the feild. Once it was done it was done. </div></BLOCKQUOTE>



Originally posted by hop2002:
It could be changed in the field pretty easily. There were 2 bolts per wing that needed to be removed, the wing tip taken off, and the new one bolted on.

That's not to say it was changed on a per mission basis, but it's certainly something the mechanics could, and did, do in squadron service.

So who is correct?

hop2002
11-20-2008, 03:43 PM
I am http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

There's an ongoing discussion along the same lines at the AH board:
http://bbs.hitechcreations.com/smf/index.php/topic,251695.0.html

In particular see Guppy's post towards the bottom of page 3.

Skoshi Tiger
11-20-2008, 06:30 PM
And for a laugh, every so often the ground crew would remove one wing tip, just to see if the pilot would notice it during his pre-flight checks!

jarink
11-20-2008, 07:58 PM
Originally posted by hop2002:
It could be changed in the field pretty easily. There were 2 bolts per wing that needed to be removed, the wing tip taken off, and the new one bolted on.

That's not to say it was changed on a per mission basis, but it's certainly something the mechanics could, and did, do in squadron service.

Considering 8th AF mechanics routinely changed out entire outer wing sections, tails, stabilizers and on a couple occasions even spliced 2 aircraft halves together to make a whole one, I'd say it would be some pretty simple (by comparison) metalwork to remove some wingtips. Replacing them might be another matter.

WTE_Galway
11-20-2008, 08:10 PM
Originally posted by Skoshi Tiger:
And for a laugh, every so often the ground crew would remove one wing tip, just to see if the pilot would notice it during his pre-flight checks!

There was a famous Dakota flying out of New Guinea that was dubbed the DC two and a half.

One damaged wing had been replaced with a slightly shorter one salvaged from a wrecked DC2. The other wing was original.

Waldo.Pepper
11-20-2008, 08:56 PM
Originally posted by Xiolablu3:
A quick question, does anyone know if it was possible to add and remove the wingtips from Spitfires 'in the field'? Or was it a permanent feature once it was decided?

I would think this is the book that would tell you.

Oddly enough I do not own a copy yet.

http://www.haynes.co.uk/Press/HaynesJackets/RGBhr_H4462.jpg

crucislancer
11-20-2008, 08:59 PM
Originally posted by HayateAce:
http://forums.ubi.com/images/smilies/heart.gif

http://www.vimeo.com/1405515

That was awesome. Thank you. http://forums.ubi.com/images/smilies/25.gif

crucislancer
11-20-2008, 09:09 PM
Originally posted by Waldo.Pepper:

I would think this is the book that would tell you.

Oddly enough I do not own a copy yet.



Wow! When did they publish that? I'd love to own a copy.

Waldo.Pepper
11-20-2008, 09:30 PM
Originally posted by crucislancer:
Wow! When did they publish that? I'd love to own a copy.

Then I think you would probably like a copy of this as well. Does Santa think you have been good?

http://www.haynes.co.uk/Press/HaynesJackets/RGBhr_H4463.jpg

crucislancer
11-20-2008, 10:00 PM
Nice! http://forums.ubi.com/images/smilies/25.gif

Not good enough for both, at least according to my wallet. http://forums.ubi.com/groupee_common/emoticons/icon_frown.gif

squareusr
11-22-2008, 07:46 AM
Originally posted by Xiolablu3:

So who is correct?

I guess both are.

Swapping out wingtips certainly would not turn a low-altitude version into a high-altitude version and vice versa, but it could give you a high-altitude version with clipped wings...

Kettenhunde
11-22-2008, 08:28 AM
All airplanes can remove the wingtips rather easily.

That is how you change the position lights, inspect spars, and repair fuel tanks on most aircraft!

Changing wingtip designs however would involve changing the stability and control points. We would have redo the rigging and balance on the ailerons. A much more involved process.

The rigging would not even be close between a normal and a "clipped" wing aircraft:

http://img255.imageshack.us/img255/1986/spitwing1hr1.jpg (http://imageshack.us)
http://img255.imageshack.us/img255/spitwing1hr1.jpg/1/w720.png (http://g.imageshack.us/img255/spitwing1hr1.jpg/1/)

That while the Spitfire manual certainly says the wingtips are removable, it would be unusual that it means they are interchangeable in the field.

Until you find a maintenance manual or document that clearly states the tips are interchangeable I would not put much stock in it.

In none of the restored Spitfires that we have worked was this ever presented as an option either.

All the best,

Crumpp

thefruitbat
11-22-2008, 12:26 PM
Originally posted by HayateAce:
http://forums.ubi.com/images/smilies/heart.gif

http://www.vimeo.com/1405515

Great video, as are his others on that page i've seen, thanks for posting http://forums.ubi.com/images/smilies/25.gif

Spitfire love from Hayate, the world is indeed changing http://forums.ubi.com/images/smilies/crackwhip.gif

fruitbat

HellToupee
11-22-2008, 06:42 PM
Originally posted by Kettenhunde:
That while the Spitfire manual certainly says the wingtips are removable, it would be unusual that it means they are interchangeable in the field.


Everything I've read always indicated it was a trivial process.

Reasons for not being interchangeable would not be technical but practical, changing the handling properties of the plane with any frequency and throwing them into combat would not be smart.

Kettenhunde
11-22-2008, 07:04 PM
Everything I've read always indicated it was a trivial process.


Removing a wingtip is a trivial process. Changinging the wingtip design and flying the aircraft is not!

It is not trivial for very technical reasons, too. When you change the design of the wingtips, you are changing stability and control points. That means the location of the rigging has to change as well as the aerodynamic balance.

http://www.vansairforce.com/community/showthread.php?t=35052

All the best,

Crumpp

HellToupee
11-22-2008, 11:36 PM
various gliders have interchangable wingtips for length or winglets etc that don't require anymore than a few changes in trim.

Kettenhunde
11-23-2008, 05:25 AM
various gliders have interchangable wingtips for length or winglets etc that don't require anymore than a few changes in trim.

I have no doubt Helltroupee what you are saying correct. There are alternate wingtips available for certified designs that require minimual changes.

However each and everyone of these is specifically noted in detailed instructions in the authorized maintenance manuals of these aircraft.

If the Spitfire was able to routinely change wingtips, it would be documented and it would specifically list the alternate wingtips. It would also provide detailed instructions for all the changes required including addressing the rigging. It would say, "no changes required" or issue detailed instructions on how to set the rigging up for test flight and adjustment. Given the aerodynamic details of the Spitfires lateral stability and control, I would be surprised if it said, "no changes required". That does not mean it is not possible but the changes would be published in the authorized maintance instructions.

The Spitfire is a certified design. In a certified design, all the authorized maintenance MUST be documented by a published procedure.

That is just a fact.

Removable does not mean interchangeable by any stretch of the imagination.


Until you find a maintenance manual or document that clearly states the tips are interchangeable I would not put much stock in it.



All the best,

Crumpp

Skoshi Tiger
11-23-2008, 05:40 AM
Just to add fuel to the fire, my text "the Spitfire, Mustang and Kitthawk in Australian" (Stewart Wilson 1988) service has this paragraph in their Spitfire section.

"From 1943 most surviving Spitfire Vs were converted to LF.VA, LF.VB and LF.VC configuration with low altitude Merlin 45M, 50M or 55M engines and clipped wings (by simply removing the detachable wingtips and then covering the gap with a blank) for greater manoueverability at low altitudes the aircraft were now being flown in their daily sweeps across the English Channel and into france. 'Clipped, cropped and clapped' was the possibly unkind description of these Spitfires despite their success against both ground and air targets"

I also found a quote from "Spitfires over the Mediterainian and North Africa" (Osprey press, I know, but http://forums.ubi.com/groupee_common/emoticons/icon_rolleyes.gif)

"The need to halt, or at least hinder the JU86P's Photographicoperations ....
...Engineers at No 103 Maintenance Unit at Aboukir therefore decided to modify a few Mk V's into high altitude interceptors, stripping all unneccesary equipment, including the armour and the four .303-in machine guns, in order to lighten the aircraft. The engines were also modified to give an increased compression ratio, and each fighter was fitted with a four bladed propeller taken from the Spitfire VI. At least three fighters -BP985, BR114 and BR234 - were modified in this way, also being fitted with pointed wing tips and an armament of two .5 in machine guns instead of the 20mm cannon"

There was no talk about where the pointed wing tips come from , but presumably (?) from the Mk VI 's where they got the propellers.

It also goes to show that either "necessity is the mother of invention" or the engineers at Aboukir were animals that had no business being next to an aircraft. I personally think it was the first of the two.

hop2002
11-23-2008, 07:13 AM
Crumpp, if you read the thread I linked to at AH, you'll see several examples of squadrons changing wingtips, eg 131 squadron going from extended to normal, and even individual pilots having different tips fitted to their aircraft, eg Stan Turner having normal tips fitted to his clipped Spitfire XVI.


In none of the restored Spitfires that we have worked was this ever presented as an option either.

Funny you should say that because it's not uncommon for display Spitfires to have their wing tips changed. Take for example the Shuttleworth Collection's AR501. It started life as a standard span Spitfire V. During the war it had clipped wings fitted. It was flown at displays throughout the 90s with clipped wings, before having the standard tips fitted for its role in the film Pearl Harbor.

Last I heard they were debating going back to clipped wings for displays, but they felt the public would rather standard wings.

Kettenhunde
11-23-2008, 04:56 PM
Crumpp, if you read the thread I linked to at AH, you'll see several examples of squadrons changing wingtips, eg 131 squadron going from extended to normal, and even individual pilots having different tips fitted to their aircraft, eg Stan Turner having normal tips fitted to his clipped Spitfire XVI.

I read that whole thread hop2002 and saw nothing that makes me change my mind.

I have see way to many secondary sources that are just plain wrong.


Kettenhunde says:

If the Spitfire was able to routinely change wingtips, it would be documented and it would specifically list the alternate wingtips. It would also provide detailed instructions for all the changes required including addressing the rigging. It would say, "no changes required" or issue detailed instructions on how to set the rigging up for test flight and adjustment. Given the aerodynamic details of the Spitfires lateral stability and control, I would be surprised if it said, "no changes required". That does not mean it is not possible but the changes would be published in the authorized maintainance instructions.


I stand by what I wrote.

The following is a great example of the kind "evidence" being used to make the claim the Spitfire routinely changed wingtip designs:


Take for example the Shuttleworth Collection's AR501.

At no point in this aircraft's history did anyone walk up, unbolt the wingtips, put a different design tip on, and go flying with it.

It received new wingtips ONLY at major overhauls. During reconstitution after the airframe was heavily damaged it was converted and during restoration in civilian hands, it was converted back. This is hardly evidence it was a routine procedure done in the field by operational squadrons..


Its run of good luck came to an end on 9th September, when Cat.B damage was inflicted again. This time Air Service Training Ltd were assigned to repair it and it was with them from 22nd September to 23rd November, being converted to an LFVc with Merlin 45M and clipped wings, together with a variety of other mods and then delivered to No.33 MU on 2nd December. Here it remained in storage until issued to the Central Gunnery School at Catfoss, Yorkshire on 24th April 1945, but its operational life was soon to end and it was delivered to No.29 MU High Ercall for storage on 22nd August 1945.



http://www.sonsofdamien.co.uk/AR501.htm

All the best,

Crumpp

M_Gunz
11-23-2008, 05:20 PM
Originally posted by thefruitbat:
Spitfire love from Hayate, the world is indeed changing http://forums.ubi.com/images/smilies/crackwhip.gif


Time to sell overcoats and mittens in Hades when he praises LW planes!

M_Gunz
11-23-2008, 05:35 PM
I'm pretty sure that some planes did receive instant field mods during the war and actually make it back to land.
Not saying they were going to perform the same after losing some of one wing though, just that they still flew.

Kettenhunde
11-23-2008, 05:43 PM
The Spitfire is easily one of the most published aircraft in History. There is even a Haynes manual on the type.

Surely official instructions on changing to different design wingtips can be located for it!

Once more, for almost every airplane in existence there are much than just "the Manual" on the Spitfire V reference in that thread.

There are Pilot Operating Handbooks, Illustrated parts catalogs, Overhaul manuals, and Maintenance manuals published on most aircraft.

Having an illustrated parts catalog does not tell you how to assemble or service the aircraft.

The idea that the stability and control points do not change is simply ignorant. I am really tired of gamers who do not know the technical details attacking me because they want some gamer piece added. Take that up with the gaming company.

The basic formula for moments about the CG is:

Moment about the CG = coefficient of Moment * dynamic pressure * Reference Area

Your reference area is commonly the wing area. When were remove the wing tips on the Spitfire, the wing area changes.

Guess what happens to all of our moments!

Guess what the basic determination for a CG is in an aircraft?

Moments divided by the weight.

Understand that the forward limit of the CG is determined by the ability of the elevator to produce an upward pitching moment at Vref.

Whoever says that changing the wingtips does not affect the stability and control points does not know what they are talking about.

All the best,

Crumpp

hop2002
11-23-2008, 06:04 PM
Take for example the Shuttleworth Collection's AR501.



At no point in this aircraft's history did anyone walk up, unbolt the wingtips, put a different design tip on, and go flying with it.

It received new wingtips ONLY at major overhauls. During reconstitution after the airframe was heavily damaged it was converted and during restoration in civilian hands, it was converted back. This is hardly evidence it was a routine procedure done in the field by operational squadrons..

AR501 was built with round wings, they were changed to clipped in service, so either are authentic. She also wore round wingtips for the Battle of Britain film in the late 60's.

When she was the only clipped wing Spit on the circuit, it was worth keeping her as such. The pilot's preferred it too as, she was easier to fly, although the stall speed was a few knots faster. Personally I prefer the tips on as she looks more like the classic Spitfire.

The round tips were made up for the Pearl Harbour film (in 2000, I think). It was decided to keep them on in the short term as the general public like the shape better, there was more possibility of film work and there are other clipped wing SPits available if you really wanted to see them.

I liked the old paint job, too, but after the film, and with the new tips, she did need a new coat of paint. Given time, she'll be back to normal in that respect a least.

The Clipped tips are in store and can be fitted very quickly - essentially two screws each, a bit of re-wiring for the nav light, some fabric over the join, followed by several coats of dope and paint. It's only a couple of days in time with not too many man-hours.

The intention was to fly half of each season with them on and half off, changing in August, say, but we've never got round to it. Given enough pressure, it could be done.
http://forum.keypublishing.co.uk/showthread.php?t=22359...t=SPITFIRE+WING+TIPS (http://forum.keypublishing.co.uk/showthread.php?t=22359&highlight=SPITFIRE+WING+TIPS)

That's from one of the Shuttleworth Collection pilots (Andy Sephton, their chief pilot, I believe)

And from further on in the same thread:


With the wingtips in store that have already been fitted to the wings it should be a breeze to change them, it only took two days for us to convert MK732 (Dutch Spitfire IX) & that included drilling & cutting the new wing caps to fit. I don't remember fitting fabric to cover the joints though only to cover the main wingtip bolts (two each side)
I would think though that the pilots notes & operations manual would have to be changed & approved by the CAA due to altered landing speeds etc.

and the reply:


No changes at all are required to the Ops Manual, Permit, Pilot's Notes, speeds, appovals, procedures, or anything else for that matter. Indicated approach and stall speeds are the same - the pressure error change with the tips off cancels the difference (the pitot head is near the wing tip).

Kettenhunde
11-23-2008, 06:53 PM
Hop,


AR501 was built with round wings, they were changed to clipped in service,

Sure, after the airframe was written off and reconstituted by depot level maintenance.

On your BBS posting:

He is not talking about the maintenance manual, he is talking about flight not maintenance!

He is even nice enough to explain why despite the changes the Operations manual stay the same because the pitot static system is self correcting.


No changes at all are required to the Ops Manual, Permit, Pilot's Notes, speeds, appovals, procedures, or anything else for that matter. Indicated approach and stall speeds are the same - the pressure error change with the tips off cancels the difference (the pitot head is near the wing tip).

Not only that you just read into what the guy says!


With the wingtips in store that have already been fitted to the wings it should be a breeze to change them, it only took two days for us to convert MK732 (Dutch Spitfire IX) & that included drilling & cutting the new wing caps to fit. I don't remember fitting fabric to cover the joints though only to cover the main wingtip bolts (two each side)


What else do you think they did for two days after a few minutes drilling, cutting, doping, and painting?

x6BL_Brando
11-23-2008, 07:09 PM
From 'The Spitfire story' by Alfred Price.

".... But there were things that could be done to improve the ability of the Spitfire V against the FW190 particularly at low altitudes. One such move was to 'clip' the wings of the Spitfire by removing the detachable tips, thereby reducing the span to 32 ft 6 in and the wing area by 11 square feet to 231 square feet.
This change reduced the aircraft's inertia moment in the rolling plane and made a noticeable improvement to rolling performance; it also gave a slight improvement to acceleration, diving performance and speed below 10,000 feet."

"A further improvement in speed could also be gained by fitting the Merlin 50M engine; this was similar to the Merlin 45, but, as well as the negative-G carburettor, it had a smaller diameter 'cropped' supercharger impeller which allowed a maximum of +18 pounds boost to be applied at only 5,900 feet and gave a maximum of 350 mph at this altitude, about the same as that of the FW 190"

And finally,

"The combination of clipped wings and the low altitude rated engines resulted in the Spitfire LF V which became known as the 'clipped and cropped' Spitfire. Less reverently, it was known in some squadrons as the 'clipped, cropped and clapped Spitty' because the airframes to which these modifications were applied had in many cases seen better days."

The trials carried out at the Air Fighting Development Unit at Duxford in late 1942 only mention the removal of the wing-tips and their replacement with "thin streamlined fairings". No mention is made of a need to "re-rig" the aircraft beyond this exchange. In fact the official report suggests that these exchanges were made overnight in order to test each of the two Spitfire VBs used in the trial in the different configurations, pitted against each other. So this was not a case of a factory recall or many hours of alteration.
It's not in doubt either to suggest that these improvements could be made in the field, providing that suitable facilities were available. Swapping engines & removing wing-tips is not rocket science after all, needing only spanners, a hoist and a qualified fitter. A roof is preferable but not mandatory. Likewise setting up the stick and rudder is just part of the daily round of a qualified fitter.

None of this suggests that we are talking about a pick n' mix situation however, with some kind of tailoring of the plane on a daily basis for specific missions. The jobs mentioned were inspired by the need to make the existing stock competitive with the FW 190 - and Luftwaffe fans may console themselves with the knowledge that it was the FW 190 that landed in error in Britain, in June 1942, that delivered the opportunity to make the comparative trials that led to these hasty but effective improvements. That they were a stop-gap between the the Mk Vs and the later models is not in doubt.

B

hop2002
11-23-2008, 07:38 PM
Crumpp, what do you read into:


The Clipped tips are in store and can be fitted very quickly - essentially two screws each, a bit of re-wiring for the nav light, some fabric over the join, followed by several coats of dope and paint. It's only a couple of days in time with not too many man-hours.

To me that sounds like very little work and a couple of days for the dope/paint coats to dry. No mention of re-rigging the plane.

Now if there was some evidence that it was a more involved procedure, fair enough, but I haven't seen any such evidence, just supposition. The one direct reference we have is from Sephton, and he seems to think it's a pretty minor job.


it only took two days for us to convert MK732 (Dutch Spitfire IX) & that included drilling & cutting the new wing caps to fit.

It sounds like the second poster is talking about making new wing tip fairings. Just to make it clear, the normal and extended wing tips are small wing sections with a spar etc. The clipped "tips" are simply wooden fairings, basically an end cap, and may well have been made in house.

AWL_Spinner
11-23-2008, 10:33 PM
Nice clip, they practically have a "Big Wing" at the Duxford shows these days.

Kettenhunde
11-24-2008, 01:23 AM
The Clipped tips are in store and can be fitted very quickly - essentially two screws each, a bit of re-wiring for the nav light, some fabric over the join, followed by several coats of dope and paint. It's only a couple of days in time with not too many man-hours.


That comes from the pilot and he appears to be talking about a tips that have already been fitted to the aircraft.

Either way, both say it takes a couple of days at best.

I trust the mechanic more than the pilot when it come to maintenance of the aircraft.


It sounds like the second poster is talking about making new wing tip fairings. Just to make it clear, the normal and extended wing tips are small wing sections with a spar etc. The clipped "tips" are simply wooden fairings, basically an end cap, and may well have been made in house.

Sounds like?? You are speculating.

Speculation as we don't know, because it sounds like the second poster is a mechanic to me! It also sounds like he is talking about just normal fitting of the parts to the individual aircraft, not making new ones. Once again though it must be pointed out that both of them say a couple of days is required. It does not take that long to drill, cut, and fit a part.

That is common, you should have seen all the fitting involved when I replaced my oil cooler, cutting, drilling, and bending metal is normal even in an authorized part specifically made the aircraft.

You shouldn't have to speculate at all. This isn't some unknown or obscure aircraft. It is the Spitfire and a mound of maintenance data should exist.

So it shouldn't be too hard to find the maintenance instructions that specifically state the changes required to mount the tips.

All you have to do is find the maintenance instructions. There is not much else to say on this IMHO.

All the best,

Crumpp

M_Gunz
11-24-2008, 01:33 AM
Changing wingtips doesn't change the center of lift or does it?
When they hang bombs underneath that changes the weight but those were hung under CoG if I have that right?
Did they move the attachment points for bombs between clipped and non-clipped Spitfires?
Or does having bombs not affect the moments but different wingtips does?
Isn't there a region of operation where the pilot can adjust via trim?
I only ask because these things are not making sense to me.

Kettenhunde
11-24-2008, 12:05 PM
Changing wingtips doesn't change the center of lift or does it?
When they hang bombs underneath that changes the weight but those were hung under CoG if I have that right?
Did they move the attachment points for bombs between clipped and non-clipped Spitfires?
Or does having bombs not affect the moments but different wingtips does?
Isn't there a region of operation where the pilot can adjust via trim?
I only ask because these things are not making sense to me.

Hi M_Gunz,

Changing the wing area will alter the Aerodynamic center and change the couples.

The other questions are a resounding "Maybe".

If we had an engineering investigation into the affects of changing wingtips, Operating Instructions addressing the handling differences in swapping wingtips in the same aircraft, and maintenance instructions on how to change the wingtips as well that accounted for the stability and control points then we could say with certainty that you could do it routinely.

With only partial information we are just guessing. It all depends on how comfortable you are in guessing!

All the best,

Crumpp

Skoshi Tiger
11-24-2008, 09:23 PM
I found some pilots notes that talk about handling differences between the cliped wing and rounded wings

This page talks about stall speed
http://www.brenorbrophy.com/Spitfire/spit_IX_XI_XVI/16.jpg

and this one talks about landing and take off

http://www.brenorbrophy.com/Spitfire/spit_IX_XI_XVI/17.jpg

In 'normal winged' version had a slower stall (3-6 mph)and takeoff/langing speed (in the order of 5 mph)

It's interesting to note that they don't state any differences in the acrobatics section that referes to the clipped winged version. Maybe its too hard to quanitify the different 'Feel' of the planes.

None of this goes to show if it was 'routine' to change the wingtips or the issues involved in such a change, but I doubt it that it was. There would have to a fairly good reason to make such a change.

Kettenhunde
11-25-2008, 05:40 AM
None of this goes to show if it was 'routine' to change the wingtips or the issues involved in such a change, but I doubt it that it was. There would have to a fairly good reason to make such a change.

Good find.

Something is fishy with AR501 too. I suspect the aircraft is not close to service standards on the weight and balance. Either that or it is another example of the fallibility of human memory.

Hops Test pilot for AR501 quote:


No changes at all are required to the Ops Manual, Permit, Pilot's Notes, speeds, appovals, procedures, or anything else for that matter. Indicated approach and stall speeds are the same - the pressure error change with the tips off cancels the difference (the pitot head is near the wing tip).

All the best,

Crumpp

Kettenhunde
11-30-2008, 01:03 PM
Further proof that rigging changes are needed in order to change wingtips is found in Guppy35 post. Alex Henshaw's quotes are direct rigging changes. What we don't know is if this is the extent of the changes required.

Flight testing and adjustment of the balance is an intergral part of the process.

Unfortunately it is not from a wartime Spitfire pilot or an operational document. His observations are reflected in the POH and the investigation of the effects of clipping the wings.

I wonder if he is refereing to AR501?


Quoting Charlie Brown, a high time current Spit driver who has flown the V, IX, XIV, XVI and XVIII extensively in both full and clipped wing configuration.

"Clipped wing tips have the following effects:
-Cruise speed increases by approximately 15 mph
-Roll rate is markedly increased
-Slight increase in stall speed (3-5 mph)
-Noticable increase in drag during manouvre-eliptical wing tips really do minimize drag during manouvre
-The aircraft is easier to land because in the three point attitude the aircraft has stopped flying very shortly after touchdown. Eliptical wings require the aircraft to be 'flown' on the ground for a considerable period after touchdown and where any bumps will make the aircraft bounce around like a spring lamb."

Quoting Alex Henshaw regarding the ailerons and the bending of them to adjust.

"After a thorough pre-flight check I would take off and once at circuit height I would trim the aircraft and try to get her to fly straight and level with hands off the stick. The Mark V lacked aileron trim tabs and most of the new ones had a tendency to fly one wing low. When that happened I would land immediately and taxi to one corner of the airfield where a mechanic was waiting. He carried a special tool rather like a tuning fork, on my instructions he would bend the trailing edge of the aileron on his sde once, twice or thrice, up or down. Then he would go around to the other side and similarly bend the opposite aileron in the other direction. That done, I would take off again and trim the aircraft to fly hands off, to see whether the wing dropping had been cleared. Usually it had, but if it had not the process was repeated until trim was acceptable. Sometimes if bending was not sufficiant, it was neccesary to change the ailerons. It was a Heath Robinson system, but it did work."

Hard to argue with Alex Henshaw when it comes to Spitfire flying


http://bbs.hitechcreations.com/smf/index.php/topic,2516...0493.html#msg3120493 (http://bbs.hitechcreations.com/smf/index.php/topic,251695.msg3120493.html#msg3120493)

All the best,

Crumpp

Kurfurst__
11-30-2008, 02:03 PM
http://i38.photobucket.com/albums/e133/Kurfurst/conclusions.jpg

Kettenhunde
11-30-2008, 02:37 PM
Sometimes if bending was not sufficiant, it was neccesary to change the ailerons. It was a Heath Robinson system, but it did work."

Hard to argue with Alex Henshaw when it comes to Spitfire flying



Actually, Alex Henshaw seems to answer the question quite nicely in his own quote.

Some Spitfires most certainly required complete rigging reinstallation of the ailerons even after test flight at least according to Henshaw. I don't think there is any reason not to believe the man.

Question now is was replacing the rigging a required step before the test flight to estabilish the new stability and control points which in some aircraft required further movement or was it a requirement to replace the rigging in only a few aircraft due to high degree of variation in Spitfire aileron balance?

I would suspect the complete rerigging was only needed in some aircraft but I think it would be premature to say for certain without documentation.

Should be a fairly easy question to answer that will be specifically addressed in the Spitfires Maintenance Instructions.

As the report Kurfurst posted points out and the RAE report, "High Speed Tunnel Test on a Spitfire Wing and Aileron" both note a high degree of variation in the Spitfires rigging of the ailerons.

Rigging changes were obviously required due to the stability and control point shifts. Changing wingtips is much more involved than the simple steps needed to access the position lights, tanks, and internal structure of the wing.

All the best,

Crumpp

hop2002
12-01-2008, 09:28 AM
Actually, Alex Henshaw seems to answer the question quite nicely in his own quote.

Some Spitfires most certainly required complete rigging reinstallation of the ailerons even after test flight at least according to Henshaw. I don't think there is any reason not to believe the man.

Crumpp, do you know what Alex Henshaw did?

Every Spitfire produced was test flown at the factory before being handed over. That was Henshaw's job. He flew something over 2,000 new-build Spitfires at Castle Bromwich.

Where does Henshaw say that he's talking about flight tests after clipping wings? Nowhere.

As his job was testing new aircraft prior to delivery, I think it's fairly safe to assume this quote is about new aircraft, not modified ones.

Kettenhunde
12-01-2008, 05:10 PM
That was Henshaw's job. He flew something over 2,000 new-build Spitfires at Castle Bromwich.


So really then this tells us absolutely nothing about whether or not the wing tips could be routinely changed in operational squadrons.

Generally anytime maintenance is performed on an aircraft, it must be test flown and returned to service. The function in question is just checked and the appropriate logbook entry made returning the aircraft to service.

As for new build airframes, they are most definitely test flown for both a minimal engine run in period and to adjust the rigging as Henshaw relates. This quote is relevant then to the factory test flights according to you.

This quote seems to have been taken completely out of context and bears no relevance at all to the question of the maintenance required to change wingtips in operational squadrons.


As his job was testing new aircraft prior to delivery, I think it's fairly safe to assume this quote is about new aircraft, not modified ones.

I think you are right.

All the best,

Crumpp

Kettenhunde
12-02-2008, 03:20 AM
Where does Henshaw say that he's talking about flight tests after clipping wings? Nowhere.


He does not. However Guppy35 uses the quote to illustrate the adjustment procedure of the ailerons.

http://bbs.hitechcreations.com/smf/index.php/topic,2516...0493.html#msg3120493 (http://bbs.hitechcreations.com/smf/index.php/topic,251695.msg3120493.html#msg3120493)

It also also highlights how silly the notion that changing the Spitfire wingtips was a quick and easy procedure. I am at a loss as to the point of posting the quote. It nicely llustrates how little the specific maintenance requirements of actual aircraft are understood by some gamers.

Even new rigs that have been properly set up IAW design stability and control points must be test flown and balanced for the specific aircraft. That fact that some of our Spitfires could not be balanced by the factory is extremely telling on how sensative the type was to rigging.

Why anyone would think that replacing wingtips on the Spitfire does not require rigging changes due to stability and control point shifts is beyond me. It is the realm of gamer fantasy.

All the best,

Crumpp

No41Sqn_Banks
12-02-2008, 05:49 AM
The idea with both clipped and extended wing tips was taken further in Mk. VIII production, when the tips became easily interchangeable and theoretically could be swapped to suit the preferences of an individual pilot or tactical requirement.

Source: http://spitfiresite.com/reference/variants-technology/2...pitfire-wings-02.htm (http://spitfiresite.com/reference/variants-technology/2008/04/spitfire-wings-02.htm)

Unfortunatly, no source is given. Therefore it can't be considered as the final proof but as a small hint.

M_Gunz
12-02-2008, 11:02 AM
Originally posted by Kurfurst__:
http://i38.photobucket.com/albums/e133/Kurfurst/conclusions.jpg

Wherever this came from does not agree with

Shortening the wing span substantially enhanced the roll rate, closing the gap in this respect between the Spitfire and the formidable German Focke-Wulf Fw 190. (http://spitfiresite.com/reference/variants-technology/2008/04/spitfire-wings-02.htm)

which I find the second statement to be somewhat misleading (ie loaded) without actually being completely false.

SlickStick
12-02-2008, 12:48 PM
LOL! This "sword" fight is still going on?!?!

Wow, it's threads like these that remind me of how infinitesimally petty the internet and these forums are. http://forums.ubi.com/images/smilies/88.gif

WTE_Galway
12-02-2008, 04:11 PM
At least they didn't change wingtips during flight.

Aaron_GT
12-02-2008, 04:39 PM
It is not trivial for very technical reasons, too. When you change the design of the wingtips, you are changing stability and control points. That means the location of the rigging has to change as well as the aerodynamic balance.

The physical process of interchanging the wingtips (absent any additional rigging required of other parts as a consequence) was trivial, though, and changing the wingtips, (presumably with rerigging) was possible and was done at times, as evidenced by the service history of some aircraft. Clipping was quite common, but as a rebuild option.

Certainly it gave the option of changing things around (even if it might have taken a few days t rerig) to suit the changes in operations on a longer timescale, hence the clipping of older Vs and IXs in particular.

Few other aircraft in WW2 offered the option of changing wing area in even a few days.

Aaron_GT
12-02-2008, 04:54 PM
In the end the last Spitfires went to a semi-clipped wing with a new internal structure. The stiffer wing meant much less aileron reversal and a high speed roll the same as a P-51 or Tempest. The wing was in development for a long time (from 1942) before finally going into service is the last month of WW2. The new wing required new tail surfaces else it might have been operational 3 or 4 months earlier.

Kettenhunde
12-03-2008, 03:44 AM
The physical process of interchanging the wingtips (absent any additional rigging required of other parts as a consequence) was trivial,

Sure, if you mean changing them out for say static display in a museum.

If you mean to fly the aircraft it is more involved.

All the best,

Crumpp

No41Sqn_Banks
12-03-2008, 04:27 AM
It's not like the Erks were idiots in 1940. Of course they were able to do non-tivial tasks, too. http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

Bremspropeller
12-03-2008, 04:30 AM
The physical process of interchanging the wingtips (absent any additional rigging required of other parts as a consequence) was trivial

NOTHING is trivial in aircraft maintenance. http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif

Aaron_GT
12-03-2008, 05:19 PM
If you mean to fly the aircraft it is more involved.

Which I noted in my post in "additional rigging required of other parts as a consequence", although perhaps my use of 'absent' was a little archaic (probably ok by Fowler) as I used it in the sense of 'apart from'. Apologies if that caused confusion.

Aaron_GT
12-03-2008, 05:34 PM
NOTHING is trivial in aircraft maintenance.

True, but the job of replacing the tips (not including any rerigging, i.e. just the replacement of the tips) would less involved than a lot of battle damage repair jobs. The knock on work is another matter but all I've ever read about the process on unbolting one set of tips and bolting on a different set has emphasised the simplicity of this part of the process.

Again I'd like to mention that very few planes in WW2 had this option.

Crikey2008
12-03-2008, 08:06 PM
Originally posted by SlickStick:
LOL! This "sword" fight is still going on?!?!


Actually, it's possible to see the effects of changing wingtips in flight in-game

Just climb into a navy Zeke with the folding wingtips, takeoff, climb to 500m; fold wings and see if the standard airframe takes the change.

Kettenhunde
12-03-2008, 08:20 PM
These are just the illustrations without the accompanying worded explanation for each procedure. As this is from an actual maintenance instructions for the type a few things should jump out at you. First of all, everything is specified. Right down to the type and nomenclature of the bolts and screws to be used in the repair.

If changing wingtip designs was an authorized user level maintenance procedure, it will be specified in the Spitfires own maintenance instructions.

All aircraft can remove and replace wingtips. Here is the P51. It takes just 3 bolts and 8 screws to remove the wingtip.

However the resulting maintenance for adjusting the ailerons takes a considerable amount of time is a quite complex affair. Rigging usually is that way. This is simply the SAME design wingtip too!

It is very unlikely that the Spitfire can alter physics to avoid the resulting changes in the stability and control points with complete different wingtip designs.

http://img368.imageshack.us/img368/93/p51wingtipsgs6.jpg (http://imageshack.us)
http://img368.imageshack.us/img368/p51wingtipsgs6.jpg/1/w1058.png (http://g.imageshack.us/img368/p51wingtipsgs6.jpg/1/)

http://img229.imageshack.us/img229/8827/p51aileronremovalfg6.jpg (http://imageshack.us)
http://img229.imageshack.us/img229/p51aileronremovalfg6.jpg/1/w1108.png (http://g.imageshack.us/img229/p51aileronremovalfg6.jpg/1/)

http://img407.imageshack.us/img407/3181/p51aileroncontroladjustqs6.jpg (http://imageshack.us)
http://img407.imageshack.us/img407/p51aileroncontroladjustqs6.jpg/1/w1148.png (http://g.imageshack.us/img407/p51aileroncontroladjustqs6.jpg/1/)

http://img229.imageshack.us/img229/7527/p51ailerontrimtabcontroqf6.jpg (http://imageshack.us)
http://img229.imageshack.us/img229/p51ailerontrimtabcontroqf6.jpg/1/w1094.png (http://g.imageshack.us/img229/p51ailerontrimtabcontroqf6.jpg/1/)

Of course this has nothing to do with having to make new control cable if we move our stability and control points. That is another ~8 pages of separate instructions.

We also are not painting the new wingtips or doping new fabric.

Just like the Spitfire, wingtip modifications have been used for many designs to achieve a specific performance goal:


Wingtip mod


http://www.aeroprice.com/aerolibrary/pipermods.htm

Most places estimate ~40 hours to install new wingtips depending on the installation. That does not include test flights and balance adjustments.

IIRC any maintenance that takes more than a day is CRO/ASU level maintenance in the RAF.

All the best,

Crumpp

JSG72
12-03-2008, 08:36 PM
Nice to see the P-51D Mustang getting a mention http://forums.ubi.com/groupee_common/emoticons/icon_rolleyes.gif

Aaron_GT
12-04-2008, 01:14 AM
All aircraft can remove and replace wingtips.

Of course, but I don't recall ever having seen mention of the P51D (as an example) having options for three standard wing tip types for different types of operations. I'm not arguing that it could be done instantly but that the replacement of the tip itself was a straightforward procedure and the choice of different tip types was not generally seen on other types.

Kettenhunde
12-04-2008, 06:55 AM
Of course, but I don't recall ever having seen mention of the P51D (as an example) having options for three standard wing tip types for different types of operations.

Exactly! However like all airplanes, the wingtip was removable in order to conduct maintenance on the aircraft.

It is a dramatic illustration that observing a page from the IPC:

http://img371.imageshack.us/img371/8327/wintipvz4.jpg (http://imageshack.us)
http://img371.imageshack.us/img371/wintipvz4.jpg/1/w900.png (http://g.imageshack.us/img371/wintipvz4.jpg/1/)

Tells the reader absolutely nothing about the complication or time involved in an aircraft repair.


the choice of different tip types was not generally seen on other types.

You say that like the expense, time, and effort required to redesign and change wingtips is a feature?

It is not. It is used as tool to bolster performance to adequate standards for a specific design goal. For example, Piper Cherokee's with Horton STOL kits are not the Bush pilots aircraft of choice. They will however get into a private grass strip that a stock Cherokee cannot thereby significantly lowering the expense of building a private grass strip.

From the AAIA library database:

http://img371.imageshack.us/img371/5463/whythespitswingswerecliyt6.jpg (http://imageshack.us)
http://img371.imageshack.us/img371/whythespitswingswerecliyt6.jpg/1/w728.png (http://g.imageshack.us/img371/whythespitswingswerecliyt6.jpg/1/)

No most WWII fighters did not have interchangable wingtips of different design. It simply was not necessary.

All the best,

Crumpp

Aaron_GT
12-04-2008, 10:57 AM
No most WWII fighters did not have interchangable wingtips of different design. It simply was not necessary.

Given that increased span was proposed for both the 109 and 190 to improve high altitude performance I would disagree. The option of being able to change span and wing area seems to have been something that a number of nations looked at. Being able to make some changes from the same basic airframe would seem to be advantageous.

Naturally, as outlined in your scan, different configurations are going to have different performance values, but that is true if you produce a version of an airframe with different span for a particular task (e.g. high altitude interception in defence of the Reich), so it's not a very persuasive argument regarding the flexibility offered by being able to change tips. If it allows you to reconfigure a basic fighter for high altitude work, or for better speed at low altitude or better roll rate but at a lower manufacturing and material cost then I can't see it being anything other than beneficial to strategic aims.

Xiolablu3
12-04-2008, 12:35 PM
Surely there are enou8gh riggers and fitters around still living for us to get a definitive answer on the 'Spitfire wingtip' debate.

Anyone have a relation or friend who worked on Spitfires in the field?

Kettenhunde
12-05-2008, 03:45 AM
as outlined in your scan,

I think the scan is pretty self explanatory and clearly outlines the reasoning for the clipped wingtip option on the Spitfire.

As for extended wingtips, I don't think the extended wingtips where viewed with any real favoritism from a fighter performance standpoint:


The Mark VIII feels fairly light on the ailerons but at high speeds it becomes very heavy, and so this new combination of extended wing and small aileron cannot be considered satisfactory.


In fact the wingtips did not improve performance enough to rule out simple airframe differences in fit and finish.


There was very little to choose between the performance of the two aircraft which were similarly loaded as regards armament, ammunition and radio, except that at altitude the Mark VIII gave slightly better results than the Mark IX available for the trial. This may be due to the individual engines or airframes of these two aircraft.


http://www.spitfireperformance.com/spit8tac.html

If we examine the size of the performance gains over a properly manufactured Spitfire, there just is not much to choose.


I can't see it being anything other than beneficial to strategic aims.

After examining the details it should be much easier to see that there little actual benefit that existed from changing wingtips. On a strategic level, this diminishes to non-existence.

All the best,

Crumpp

Kettenhunde
12-05-2008, 06:09 AM
Just so the point of the P51 manual does not escape folks who do not have much experience with aircraft maintenance. The manual was just convenient as we own the aircraft.

Changing a wingtip of the same design is generally not a large deal once the initial rigging and balance is set for that wingtip design.

It is when you change designs of the wingtip that it becomes an issue. Hence the average of 40 hours of labor involved if you go buy an aftermarket wingtip design for your GA plane or any aircraft for that matter. Given a basic understanding of the science of aircraft stability and control, this should be a no brainer.

You can see from the P51 manual or ANY aircraft maintenance instructions for that matter, adjust rigging is a major undertaking.

I have removed the wingtips on all of the aircraft I have owned to service various components and replaced them without incident. No rigging adjustment required.

This should be common sense because the topic was changing wingtip designs.

All the best,

Crumpp