PDA

View Full Version : NACA rate of roll charts



mynameisroland
06-07-2007, 03:25 PM
does anyone have a link where I can find these?

Thanks guys

LEXX_Luthor
06-07-2007, 05:55 PM
SkyChimp's got em. Has to.

Now, does anyone have a link where we can find SkyChimp?

http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif

AKA_TAGERT
06-07-2007, 06:16 PM
Originally posted by mynameisroland:
does anyone have a link where I can find these?

Thanks guys
http://naca.central.cranfield.ac.uk/report.php?NID=2597

Taylortony
06-07-2007, 07:27 PM
Having worked at Cranfield for several years in my past.... I would deem anything that came out of there on paper suitable only for perforating 500 times and rolling onto a cardboard tube

AKA_TAGERT
06-07-2007, 07:32 PM
Originally posted by Taylortony:
Having worked at Cranfield for several years in my past.... I would deem anything that came out of there on paper suitable only for perforating 500 times and rolling onto a cardboard tube That's good to know.. but this document did not 'come out of' Cranfield.. It 'came out of the' NACA. Cranfield simply provided the web space to store the document for others to download.

Xiolablu3
06-08-2007, 01:27 AM
Hmm, so the chart which I have been told is wrong is actually a NACA chart?

SlickStick
06-08-2007, 07:53 AM
Originally posted by Xiolablu3:
Hmm, so the chart which I have been told is wrong is actually a NACA chart?

IIRC, folks say the FW they tested had damaged ailerons or something, I believe. Also, IIRC, the last test performed on in-game planes (somewhere around V4.0X) showed roll rates peaked too soon at lower speeds and were nowhere near correct for the CW Spits or some/all FWs, for example. I'll let Nancy fill in the rest.

luftluuver
06-08-2007, 07:59 AM
Weren't the NACA graphs based on British data?

AKA_TAGERT
06-08-2007, 08:20 AM
Originally posted by luftluuver:
Weren't the NACA graphs based on British data? I seem to recall reading something with regards to that. The NACA 868 is a big document that covers alot of stuff, roll rates being just one of the topics.

AKA_TAGERT
06-08-2007, 08:23 AM
Originally posted by Xiolablu3:
Hmm, so the chart which I have been told is wrong is actually a NACA chart? Not sure.. Who said 'it' was wrong? That and there are a few WWII roll rate charts floating around. This is the one from the NACA 868 doc

Abbuzze
06-08-2007, 08:28 AM
Originally posted by SlickStick:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Xiolablu3:
Hmm, so the chart which I have been told is wrong is actually a NACA chart?

IIRC, folks say the FW they tested had damaged ailerons or something, I believe. Also, IIRC, the last test performed on in-game planes (somewhere around V4.0X) showed roll rates peaked too soon at lower speeds and were nowhere near correct for the CW Spits or some/all FWs, for example. I'll let Nancy fill in the rest. </div></BLOCKQUOTE>

Learnd in this forum that the NACA test of the SpitV in the USA had "wrong" results for roll because they were bad balanced. If it wasn´t possible to ajust such things in an allied plane, how much worse should be the result with a captured plane even if it was in "good" condition.

At the end I don´t real believe in such tests.

AKA_TAGERT
06-08-2007, 08:34 AM
Originally posted by Abbuzze:
At the end I don´t real believe in such tests. LOL! Now that is funny!

Abbuzze
06-08-2007, 08:44 AM
Originally posted by AKA_TAGERT:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Abbuzze:
At the end I don´t real believe in such tests. LOL! Now that is funny! </div></BLOCKQUOTE>

What especially? I don´t believe in german LA5 tests and in US FW tests... (And in US Spitfire test) At least they let a bad taste behind, if the results are very diffent to homeland tests.

Hmm not sure anymore, wasn´t it you, who told me that the Spitfire V was in bad condition, and the testpilot complaind about the sluggish ailerons? http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

SlickStick
06-08-2007, 08:54 AM
Originally posted by Abbuzze:
Hmm not sure anymore, wasn´t it you, who told me that the Spitfire V was in bad condition, and the testpilot complaind about the sluggish ailerons? http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

Cool! You mean "sluggish" ailerons resulted in a roll rate near the FW in that NACA chart?!?!?

Oh my...now how do I make my in-game ailerons for the Mk. VIII CW "sluggish" in that same way? http://forums.ubi.com/images/smilies/winky.gif

Daiichidoku
06-08-2007, 08:55 AM
http://ntrs.nasa.gov/search.jsp

NASAand NACA reports

enjoy

Abbuzze
06-08-2007, 08:59 AM
Originally posted by SlickStick:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Abbuzze:
Hmm not sure anymore, wasn´t it you, who told me that the Spitfire V was in bad condition, and the testpilot complaind about the sluggish ailerons? http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

Cool! You mean "sluggish" ailerons resulted in a roll rate near the FW in that NACA chart?!?!?

Oh my...now how do I make my in-game ailerons for the Mk. VIII CW "sluggish" in that same way? http://forums.ubi.com/images/smilies/winky.gif </div></BLOCKQUOTE>

http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif No, there is a very interesting and long Spitfire V test out there. This spit had metal coverd ailerons, with a roll rate in the range of an Emil IRC - they also mentioned a very sensitive/oversensitive elevator.

This Spit was also the only one ever been tested by the USAF/NACA in the USA.

Daiichidoku
06-08-2007, 09:03 AM
what that about spitfire roll?

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19...90943_1993090943.pdf (http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19930090943_1993090943.pdf)

Page 131 of NACA Report 868, Summary of Lateral-Control Research:
For the P-41C-1-RE at 400 mph IAS, a 31% loss in aileron effectiveness. The aileron reversal speed is about 545 mph IAS.
Spitfire at 400 mph IAS, approx 65% loss in aileron effectiveness


spitfire aileron reversal is at 580 mph....i have no idea if IAS or TAS....and the fact that its in wiki, makes me suspicious...just wish the spitfire aileron reversal value was given in the NACA report

http://en.wikipedia.org/wiki/Control_reversal

"Due to the unusually high speeds that the Supermarine Spitfire could be dived at, this problem of aileron reversal became apparent when it was wished to increase the lateral manouverabilty (rate of roll) by increasing the aileron area. The aircraft had a wing designed originally for an aileron reversal airspeed of 580 mph, and any attempt to increase the aileron area would have resulted in the wing twisting when the larger ailerons were applied at high speed, the aircraft then rolling in the opposite direction to that intended by the pilot. The problem of increasing the rate of roll was temporarily alleviated with the introduction of "clipped" wing tips (to reduce the aerodynamic load on the tip area, allowing larger ailerons to be used) until a new, stiffer wing could be incorporated. This new wing was introduced in the Mark XXI and had a theoretical aileron reversal speed of 825 mph"

AKA_TAGERT
06-08-2007, 09:03 AM
Originally posted by Abbuzze:
What especially?
No big deal.. I just find it funny how folks can pick and choose what they want to belive when they want to belive it. First this side of the fence, than the other side of the fence.

Granted, tests are done by humans, and humans make mistakes.. but to say you don't belive in testing? That just made me smile! No one seems to give them any credit for actually finding their mistake! It is as if they would have been better of not even mentioning it because someone 70 years later is going to give them grief about it. Maybe I am just too much of an engineer that has spent most of his carrier designing and testing weapon systems? In that the way I see it, I would rather have an engineer that can admit a mistake on my team than some engineer that is too full of himself and/or who's ego is so fragile that he can not admit he made a mistake! Because those are the kind of mistakes you will find.. but you wont find them till it is too late. Than everyone has to scramble to try and figure out a work around. After getting burned like that a few times one of the first things I do to a new member of the team is to put him into a situation where his is guaranteed to make a mistake. Than sit back and see how long it takes him to admit it, if ever. If it takes him too long, Ill either get him removed from the team, or give him things to do (unimportant) that don't really mater if they get done or not. Their is a lot of busy work like that in aerospace! http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

Abbuzze
06-08-2007, 09:15 AM
Originally posted by AKA_TAGERT:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Abbuzze:
What especially?
No big deal.. I just find it funny how folks can pick and choose what they want to belive when they want to belive it. First this side of the fence, than the other side of the fence.
</div></BLOCKQUOTE>

I think I´m allways at the same side of the fence. Maybe it´s my bad english.


Originally posted by Abbuzze:
At the end I don´t real believe in such tests.

In my eyes tests of planes in their own country are the most relaiable. And "such" tests are tests of captured planes with unknown condition. They are doubtfull nothing more nothing less.

Beside, was it you, who told me the story of the NACA SpitV?


EDIT:
Here is the test I mentioned:
http://mitglied.lycos.de/luftwaffe1/aircraft/raf/spit_flying.pdf

Irish_Rogues
06-08-2007, 09:15 AM
My take wasn't that you didn't believe in testing, you didn't believe in the results from testing of other country's equipment.

I think it's peoples interpretation, one of the problems discussing in this media.

Daiichidoku
06-08-2007, 09:16 AM
bizarre!

i read this report again only recently, but NOW it ends at pg 80? WTF?

i see in the NACA search TR 868 was updated by someone in apr 07....hmmmmmmmmmmm

still, pg 5 reveals the same thing:

mbfRoy
06-08-2007, 09:40 AM
Originally posted by Abbuzze:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Abbuzze:
At the end I don´t real believe in such tests.

In my eyes tests of planes in their own country are the most relaiable. And "such" tests are tests of captured planes with unknown condition. They are doubtfull nothing more nothing less.
</div></BLOCKQUOTE>
As far as I know these tests were classified back then, no? I ask this because of its relevance back then. I'm positive that, had they been able to capture enemy planes in pristine conditions, with proper fuel and all, they would have tested them to get the most accurate data of all of them.

Now if you don't have a choice and all that's given to you is a plane in not-so-good conditions, and you don't happen to have the fuel the enemy is using, and you don't happen to have a spare fuel processing plant for your needs so you can do several tests, and you don't have the blueprints to repair the...[etc]... then, you have to test that piece of ****, and try to get all the information you can from it.

Doubtfull? I don't think so, unless it's post-war. If I had the chance to test the equipment the enemy is using in the war, I'd test it!!

hop2002
06-08-2007, 09:41 AM
Page 131 of NACA Report 868, Summary of Lateral-Control Research:
For the P-41C-1-RE at 400 mph IAS, a 31% loss in aileron effectiveness. The aileron reversal speed is about 545 mph IAS.
Spitfire at 400 mph IAS, approx 65% loss in aileron effectiveness

An RAE report from April 1941 (about the time they began switching to metal ailerons) says that 65% of aileron effectiveness was lost at 400 mph IAS, and that aileron reversal speed was 477 mph IAS.

Later on, in the report on the Fw 190 roll rate, dated July 1943, they give Spitfire V figures for comparison, both clipped wing and normal wing.

Clipped wing reversal speed is reported as 660 IAS, normal wing as 580 IAS.

The Spitfire wing was strengthened for cannon in the Vc and subsequent variants (and possibly the Vb).

Daiichidoku
06-08-2007, 09:55 AM
Originally posted by hop2002:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Page 131 of NACA Report 868, Summary of Lateral-Control Research:
For the P-41C-1-RE at 400 mph IAS, a 31% loss in aileron effectiveness. The aileron reversal speed is about 545 mph IAS.
Spitfire at 400 mph IAS, approx 65% loss in aileron effectiveness

An RAE report from April 1941 (about the time they began switching to metal ailerons) says that 65% of aileron effectiveness was lost at 400 mph IAS, and that aileron reversal speed was 477 mph IAS.

Later on, in the report on the Fw 190 roll rate, dated July 1943, they give Spitfire V figures for comparison, both clipped wing and normal wing.

Clipped wing reversal speed is reported as 660 IAS, normal wing as 580 IAS.

The Spitfire wing was strengthened for cannon in the Vc and subsequent variants (and possibly the Vb). </div></BLOCKQUOTE>

ty for the aileron reversal value for spits, hop http://forums.ubi.com/images/smilies/25.gif..i KNEW the 580 figure was hogwash


the NACA report does state the aileron results for the spit were taken form a report preparded in england by "Morris and "Morgan"



also found the report i originally quoted (anyone know why these two reports are page numbered differently?) one is UK, the other is USA?

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

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19...90943_1993090943.pdf (http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19930090943_1993090943.pdf)


here is an idex of NACA reports:

http://naca.central.cranfield.ac.uk/citations/cit.html


here is the offical NASA/NACA server:

http://ntrs.nasa.gov/search.jsp

SlickStick
06-08-2007, 09:57 AM
Originally posted by Abbuzze:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by SlickStick:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Abbuzze:
Hmm not sure anymore, wasn´t it you, who told me that the Spitfire V was in bad condition, and the testpilot complaind about the sluggish ailerons? http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

Cool! You mean "sluggish" ailerons resulted in a roll rate near the FW in that NACA chart?!?!?

Oh my...now how do I make my in-game ailerons for the Mk. VIII CW "sluggish" in that same way? http://forums.ubi.com/images/smilies/winky.gif </div></BLOCKQUOTE>

http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif No, there is a very interesting and long Spitfire V test out there. This spit had metal coverd ailerons, with a roll rate in the range of an Emil IRC - they also mentioned a very sensitive/oversensitive elevator.

This Spit was also the only one ever been tested by the USAF/NACA in the USA. </div></BLOCKQUOTE>

Remember, the part of the NACA chart that I refer to is for the Clipped Wing Spitfire, shown on that chart as second only to the FW.

If it wasn't a major improvement to help counter the FW threat back in WWII, then they would not have clipped so many Spitfires to increase their roll rate. Be sure. http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif

Abbuzze
06-08-2007, 10:02 AM
Originally posted by SlickStick:


If it wasn't a major improvement to help counter the FW threat back in WWII, then they would not have clipped so many Spitfires to increase their roll rate. Be sure. http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif

No doubt about this! http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

faustnik
06-08-2007, 10:04 AM
Slick,

The chart doesn't always tell the whole story. Check this out:

http://pages.sbcglobal.net/mdegnan/_images/CliipedSpit_pilotopinions.jpg

There is a discussion of the roll rate questions here:

http://www.acompletewasteofspace.com/modules.php?name=F...le=viewtopic&t=12527 (http://www.acompletewasteofspace.com/modules.php?name=Forums&file=viewtopic&t=12527)

If it wasn't a major improvement to help counter the FW threat back in WWII, then they would not have clipped so many Spitfires to increase their roll rate. Be sure.

Yeah, I agree, there must have been a good reason to do this, or they would not have bothered.

Roll rates are an interesting question because there are some contradictions in the available data. I think the answers to the question might be in the control forces at various speeds, maybe...???

Daiichidoku
06-08-2007, 10:15 AM
Originally posted by SlickStick:
If it wasn't a major improvement to help counter the FW threat back in WWII, then they would not have clipped so many Spitfires to increase their roll rate. Be sure. http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif

clipping helped to evade 190s...as far as shooting them down? well, even quadrupling the spits roll matters not, when you cant catch the 190

which is why they made the "clipped clapped n cropped" V LF, with merlin 50M, to deal with 190s, until the IXs came online...was the engine that made the diff vs 190s, Slick

AKA_TAGERT
06-08-2007, 10:16 AM
Originally posted by Daiichidoku:
also found the report i originally quoted (anyone know why these two reports are page numbered differently?) one is UK, the other is USA?

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

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19...90943_1993090943.pdf (http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19930090943_1993090943.pdf)
WTF?

That is Fing strange.. I never noticed that before! Looks like Taylortony was right about Cranfield? Sorry Taylortony! S! Just a guess.. but it looks like the Cranfiled version was part of a bigger document.. and instead of getting the orginal 868 (stand alone version) they cut this 868 out of the bigger document.. In that the indexs start at around 128 where the US version starts at 2.

I have seen alot of NACA documents that will include other NACA documents.. but.. I have never seen them take that included document and extract it back out and call it the orginal. At a glance, they both look the same, just the page indexing is off.

Daiichidoku
06-08-2007, 10:24 AM
Originally posted by AKA_TAGERT:
WTF?

looking further, this is from the search page RE: tr.868 at the NASA server:

"Also bound with NACA Annual Report 33, p. 125-200.; NACA Technical Report 868."

edit: for interest's sake, here is AR 33
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19...91935_1993091935.pdf (http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19930091935_1993091935.pdf)


this leads me to believe the UK version takes its 868 out of the larger AR 33, and the US/NASA version is the report proper, thus the UK version is number pages 127-195

in fact, i notice now, the UK version's contents page is itself numbered "125"


in any event, the data is there....i wonder if the in game spit actually has 65% or close loss of aileron response @400hpmIAS....hmmmmmmmmm...or, if whatever aileron/roll tate loss it DOES have compare acccuartely to the 31% of a P47(C)

time for a test, TAGERT? http://forums.ubi.com/images/smilies/winky.gif


sigh...edit#3,182

http://img.photobucket.com/albums/v479/Daiichidoku/zar.jpg

edit#3,183
the NASA search page states a publication date of 1950...declassified, perhaps, in '50?

Daiichidoku
06-08-2007, 10:28 AM
mods: please delete TAGERTS edit function http://forums.ubi.com/images/smilies/16x16_smiley-tongue.gif

AKA_TAGERT
06-08-2007, 10:35 AM
Originally posted by Daiichidoku:
mods: please delete TAGERTS edit function http://forums.ubi.com/images/smilies/16x16_smiley-tongue.gif LOL dood great minds thik alike.. and sometimes at the same time!

SlickStick
06-08-2007, 11:13 AM
Originally posted by Daiichidoku:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by SlickStick:
If it wasn't a major improvement to help counter the FW threat back in WWII, then they would not have clipped so many Spitfires to increase their roll rate. Be sure. http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif

clipping helped to evade 190s...as far as shooting them down? well, even quadrupling the spits roll matters not, when you cant catch the 190

which is why they made the "clipped clapped n cropped" V LF, with merlin 50M, to deal with 190s, until the IXs came online...was the engine that made the diff vs 190s, Slick </div></BLOCKQUOTE>

As I did not state that clipped wings were the "only" thing that "helped" in my original post, of course it was also the more powerful Mk. Vs and mainly the stop gap IXs that helped as well with their more powerful Merlin 61s and soon thereafter Merlin 66s.

FW was still faster in a dive and had a faster roll rate than a clipped IX with Merlin 66, but for level speed, depending on the altitude, the regular wing IX and the current FW of the year 1942 were within about 10MPH of each other, although they traded who was faster at different altitudes up to 25,000 feet, IIRC.

Of course, my source may not be "forum or industry" approved, but I think I've read this elsewhere as well.

http://www.odyssey.dircon.co.uk/Spitfire9v190.htm

SlickStick
06-08-2007, 11:22 AM
Originally posted by faustnik:
Slick,

The chart doesn't always tell the whole story. Check this out:

http://pages.sbcglobal.net/mdegnan/_images/CliipedSpit_pilotopinions.jpg

There is a discussion of the roll rate questions here:

http://www.acompletewasteofspace.com/modules.php?name=F...le=viewtopic&t=12527 (http://www.acompletewasteofspace.com/modules.php?name=Forums&file=viewtopic&t=12527)

If it wasn't a major improvement to help counter the FW threat back in WWII, then they would not have clipped so many Spitfires to increase their roll rate. Be sure.

Yeah, I agree, there must have been a good reason to do this, or they would not have bothered.

Roll rates are an interesting question because there are some contradictions in the available data. I think the answers to the question might be in the control forces at various speeds, maybe...???

Oh, I whole-heartedly agree. When they clipped the wings of the early Mk. Vs, the Vs still lacked the power to compete on par with the FW. The clipped IXs with Merlin 66s and XIVs with Merlins and later Griffons were a different story.

Roll rate is definitely linked to speed and control forces on the ailerons. What's strange about this game is that roll rates appear to be faster at slower speeds, when they should increase with speed up to the point of, and I'm guessing here, due to what would be considered compression of the ailerons at high speeds?, as shown on Page 166 (.PDF page 42) of that NACA report?

faustnik
06-08-2007, 11:23 AM
Originally posted by SlickStick:

Of course, my source may not be "forum or industry" approved, but I think I've read this elsewhere as well.

I think you are correct, there was little speed difference between the Spit IX and Fw190. The Fw190 was faster down low, the Spit IX was faster up high, but, the margins were not huge. When you consider a 2%-4% difference in speed of individual a/c, the difference is practically erased. Spit had a turn advantage, Fw190 had roll advantage, a very equal match.

I graphed the Merlin 61 and Merlin 66 Spit IX against the Fw190A5 here:

http://pages.sbcglobal.net/mdegnan/_images/1943_Speed_Compare_II.gif

SlickStick
06-08-2007, 11:30 AM
Originally posted by faustnik:
I graphed the Merlin 61 and Merlin 66 Spit IX against the Fw190A5 here:


Thanks for that .GIF. I squirrelled it away for future reference.

Brain32
06-08-2007, 11:42 AM
*Sniff, sniff* smells like YASC

HellToupee
06-08-2007, 11:58 AM
Originally posted by Daiichidoku:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by SlickStick:
If it wasn't a major improvement to help counter the FW threat back in WWII, then they would not have clipped so many Spitfires to increase their roll rate. Be sure. http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif

clipping helped to evade 190s...as far as shooting them down? well, even quadrupling the spits roll matters not, when you cant catch the 190

which is why they made the "clipped clapped n cropped" V LF, with merlin 50M, to deal with 190s, until the IXs came online...was the engine that made the diff vs 190s, Slick </div></BLOCKQUOTE>

dosnt mean the spitfire never got on a 190s tail, spitfire already could evade 190s easy enough with turn, rolling improvements were more to counter the 190s escape manover of rolling and diving.

!90s were shot down by ur standard spit v, if they couldnt quickly escape bad situations by rolling then diving more would have been.

Xiolablu3
06-08-2007, 12:13 PM
I have seen an RAF test with 4 different pilots giving their opinion on Clipped Spitfire roll rate Vs FW190.

All mentioned explicitly that clipping the Spitfires wing increases roll rate markedly.

However not enough to keep up with the roll of a FW190.

I will see if I can find it.

EDIT : Here it is

http://pages.sbcglobal.net/mdegnan/_images/CliipedSpit_pilotopinions.jpg

Clipping wings on most (I believe there is a report stating that theres not much diference on a Mk XII) SPitfire models increased the roll rate

hop2002
06-08-2007, 12:54 PM
ty for the aileron reversal value for spits, hop Thumbs Up..i KNEW the 580 figure was hogwash

Huh? 580 is one of the correct figures.

The figures according to the RAE are:

480 mph IAS (April 1941)
580 mph IAS (normal wing, July 1943)
660 mph IAS (clipped wing, July 1943)

I'd say the 580 figure is correct for a large majority of Spitfires made. The I, II and early Vs would be 480, the later Vs, VIIIs, IXs, XIVs, XVIs, XVIs etc would be 580, apart from the clipped versions which would be 660 mph IAS.

M_Gunz
06-09-2007, 12:40 AM
Considering that at high speeds those guages read 10+% over, IAS limit is not equal to actual
IAS and not suitable for translating to TAS.

hop2002
06-09-2007, 02:47 AM
The figures I gave from the RAE are corrected air speed, rather than indicated.

Kurfurst__
06-09-2007, 04:55 AM
It's a bit doubtful that the 580 mph IAS figure was ever measured, considering it was waaaaaaay over the Spitfires dive limits.

Probably calculated from test results, as it is the case the of reversal speeds, which is why you have so much scatter beetween the numbers given by one report and another.

Some bits to add to the confusion, these reports generally agree with each other but question the RAE Spit figures in the NACA 868 compilation as well - various reports from AAEE and RAE :

Comparison of Mustand and Spitfire roll characteristics, August 1942
http://i38.photobucket.com/albums/e133/Kurfurst/avia6101262Spit400mphaug42.jpg

Some additional for pilot interviews posted above :
http://i38.photobucket.com/albums/e133/Kurfurst/appendix.jpg

AAEE Report from March 1943 and conclusion and results :

http://i38.photobucket.com/albums/e133/Kurfurst/conclusions.jpg
http://i38.photobucket.com/albums/e133/Kurfurst/clipped_effect.jpg

hop2002
06-09-2007, 06:12 AM
It's a bit doubtful that the 580 mph IAS figure was ever measured, considering it was waaaaaaay over the Spitfires dive limits.

That's true of all of them, of course. No Fw 190 ever flew at a corrected air speed of 760 mph, and no Mustang did 850. Even the 477 mph figure of the April 1941 report was a calculation based on test results.


Comparison of Mustand and Spitfire roll characteristics, August 1942

Interesting that the report notes reversal speed for the Spitfire as 510 mph, compared to the earlier 477 and later 580 mph, which indicates the work that went in to increasing wing stiffness. Sadly it doesn't note what mark of Spitfire this was.

Kurfurst__
06-09-2007, 06:37 AM
Originally posted by hop2002:
Interesting that the report notes reversal speed for the Spitfire as 510 mph, compared to the earlier 477 and later 580 mph, which indicates the work that went in to increasing wing stiffness. Sadly it doesn't note what mark of Spitfire this was.

Can you show us the report which would show 580 mph ?

Interesting though the latest reports done on the XII (which have the stiffest wing of the whole bunch) showed next to no improvement in roll rate if the wings are clipped, and the aircraft have a good pair of ailerons to start with.

The best figure given by the latest report is 1,5 seconds for 60 degree roll using clipped wings (= 40 deg/sec), and about 1.9 secs with normal wings (= 31 deg/sec) at 400 mph.

That's for the better aircraft with the good ailerons, EN 222. The ailerons were often poorly matched on Spitfires, seems like a production problem of the type haunting it through the war. EN 221, with a poor set of ailerons the figures are about 4 secs with normal wings (~ 15 degree/sec), and about 2.2 secs with clipped wing (= ~27 deg/sec) at 400 mph.

It can be seen that clipping the wings help a lot planes with poor ailerons, but even with their wings clipped they can't match the roll of normal winged aircraft with good set of ailerons.

Blutarski2004
06-09-2007, 07:34 AM
The 1946 lecture given by J Smith of Supermarine to the Royal Aeronautical Society ("The Development of the Spitfire and Seafire") states as follows regarding reversal speeds:

quote-

As operational speeds increased ... the effect of torsional stiffness of the wings on aileron effectiveness became a serious factor, and in designing the wing for the Mark 21, a theoretical reversal speed of 825 m.p.h. was catered for as against 580 m.p.h. for earlier types.

-unquote

Kurfurst__
06-09-2007, 08:05 AM
Interesting. So it appears the Mk 21 featured a stronger wing design of greater torsional stiffness.
Can you reproduce the full one if you have it...?

Blutarski2004
06-09-2007, 08:17 AM
The 1946 Royal Aeronautical Society lecture includes as well the following comments on Spitfire aileron effectiveness:

quote-

Careful analysis over a long period on various marks of Spitfire had revealed fairly wide variations in aileron section and in the position of the ailerons relative to the wings. These differences resulted in inconsistent aileron characteristics, and it was felt that ailerons of a type which would be simple to manufacture and which would be less sensitive to manufacturing tolerances were necessary.

Quantitative data obtained from flight trials on a Spitfire Mark V with plain ailerons fitted with a balance tab had previously indicated that aileron properties comparable with those of a metal-covered Frise type could be achieved, with a reduction in drag due to the elimination of the gap. Ailerons of this type with area increased to 6 per cent of the total wing area, as against 5 per cent on earlier marks, were fitted to the stiffer Mark 21 wing and gave a high rate of roll with reasonable stick forces at high speeds.

-unquote


In addition, two graphs were provided.


Graph 1: Spitfire Ailerons. Typical rate of roll curves (Rates of roll for full aileron or 50 lb stick force)

Equivalent Air Speed (mph)_________________________150___170___200___25 0___300___350___380___400

Spitfire Mk V w/ fabric
covered Frise-type ailerons___87____93____75____57____40____27____20_ ___XX (deg/sec)

Spitfire Mk V w/ metal
covered Frise-type ailerons___87____93____104___92____78____60____48_ ___40 (deg/sec)

Spitfire Mk 21 w/ plain
ailerons with tabs___________XX____XX____75____95____118___90___ _75____70 (deg/sec)

- - -

Graph 2: Spitfire Ailerons. Typical stick force versus speed curves (Stick forces to apply 1/4 aileron)

Equivalent Air Speed (mph)____200____250____300____350____400 (mph)

Spitfire Mk V w/ fabric
covered Frise-type ailerons_____8_____15_____26_____43_____70+ (lbs)

Spitfire Mk V w/ metal
covered Frise-type ailerons_____4______5______7______9_____12 (lbs)

Spitfire Mk 21 w/ plain
ailerons with tabs_____________7______9_____13_____18_____23 (lbs)



For whatever it's worth.

Blutarski2004
06-09-2007, 08:31 AM
Originally posted by Kurfurst__:
Interesting. So it appears the Mk 21 featured a stronger wing design of greater torsional stiffness.
Can you reproduce the full one if you have it...?


..... The following is the extent of the detail given in the lecture on the re-design of the Mark 21 wing -

quote-

An increase in wing stiffness of 47 per cent was obtained by ensuring rigid load carrying points at all points of access to the torsion box, and by increasing the gauge of wing plating and modifying the structure at various points on the wing.

-unquote

hop2002
06-09-2007, 08:39 AM
Can you show us the report which would show 580 mph ?

From the RAE report on the Fw 190:
http://www.onpoi.net/ah/pics/users/878_1181399500_roll3s.jpg


The best figure given by the latest report is 1,5 seconds for 60 degree roll using clipped wings (= 40 deg/sec), and about 1.9 secs with normal wings (= 31 deg/sec) at 400 mph.

Those are roll acceleration figures.

Kurfurst__
06-09-2007, 08:49 AM
Originally posted by Blutarski2004:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Kurfurst__:
Interesting. So it appears the Mk 21 featured a stronger wing design of greater torsional stiffness.
Can you reproduce the full one if you have it...?


..... The following is the extent of the detail given in the lecture on the re-design of the Mark 21 wing -

quote-

An increase in wing stiffness of 47 per cent was obtained by ensuring rigid load carrying points at all points of access to the torsion box, and by increasing the gauge of wing plating and modifying the structure at various points on the wing.

-unquote </div></BLOCKQUOTE>

Interesting. So, if I get it right they dropped the D-chamber and went with a box spar ('increasing the gauge of wing plating'), basically ?

Thanks for posting the rest, it's equally interesting stuff... more pieces to the puzzle! http://forums.ubi.com/images/smilies/25.gif

Kettenhunde
06-09-2007, 09:17 AM
Graph 2: Spitfire Ailerons. Typical stick force versus speed curves (Stick forces to apply 1/4 aileron)

Sure that is not stick force per G?

Could you post the chart please?

All the best,

Crumpp

AKA_TAGERT
06-09-2007, 09:20 AM
Maybe in an elevator test.. but aileron?

Daiichidoku
06-09-2007, 11:55 AM
i still wonder if in-game spit will lose 65% of aileron effectiveness(same as "loss of rate of roll?") @ 400mph?

i know its roll is reduced, but to the correct value?

Blutarski2004
06-09-2007, 12:00 PM
Originally posted by Kurfurst__:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Blutarski2004:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Kurfurst__:
Interesting. So it appears the Mk 21 featured a stronger wing design of greater torsional stiffness.
Can you reproduce the full one if you have it...?


..... The following is the extent of the detail given in the lecture on the re-design of the Mark 21 wing -

quote-

An increase in wing stiffness of 47 per cent was obtained by ensuring rigid load carrying points at all points of access to the torsion box, and by increasing the gauge of wing plating and modifying the structure at various points on the wing.

-unquote </div></BLOCKQUOTE>

Interesting. So, if I get it right they dropped the D-chamber and went with a box spar ('increasing the gauge of wing plating'), basically ?

Thanks for posting the rest, it's equally interesting stuff... more pieces to the puzzle! http://forums.ubi.com/images/smilies/25.gif </div></BLOCKQUOTE>



..... K, I'm not certain as to whether or not the "D-Chamber" was replaced by a box spar construction. Actually, I believe that the "D-Chamber" could itself be considered a torsion box.

The more we dig into this stuff, the more complex it proves to be.

Blutarski2004
06-09-2007, 12:04 PM
Originally posted by Kettenhunde:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Graph 2: Spitfire Ailerons. Typical stick force versus speed curves (Stick forces to apply 1/4 aileron)

Sure that is not stick force per G?

Could you post the chart please?

All the best,

Crumpp </div></BLOCKQUOTE>


..... Crumpp, I'm unfortunately not equipped to post the charts themselves. All I can say is that no mention was made concerning G-load, either in the accompanying text or on the charts. When I posted earlier, I reproduced everything which appeared in the original documents related to the charts, including all labels, statements of condition, etc.

My understanding from the document is that the charts relate solely to comparisons of roll rate.