Roll Measurements FW-190 RAE 1231

May 3, 2014

Here is the RAE flight measurements of the FW-190 roll rates.

Frise Ailerons are famous for exhibiting a range of performance. Each one is a little different and proper adjustment has a large effect on performance and handling.

The RAE test pilot who flew the aircraft used to measure roll rates had flown three different captured FW-190's. The one the RAE used had the heaviest ailerons of the three examples.

Data from the manufacturer is far better than using data from a captured aircraft.

Measured Roll Rate at 50lbs stick force input in miles per hour Equivalent Airspeed at a pressure altitude of 10000 ft.

The chart is nice but does not deliver a good mental picture of the rolling capability. The information presented in Chart 6 becomes easier to understand when the relative positions of the aircraft are depicted for comparison. Additionally, the speed in EAS translates well for understanding the aerodynamic forces but does not give the average person a sense of the speed the performance actually occurs at. For example, at 10000 feet, 400mph EAS equals 465 mph TAS! That is mach .72 and only some 60 mph below Vne for the FW-190. At 10000 feet, Vmax for the FW-190A3 is 365 mph TAS or 313 mph EAS.

Graphic depiction of the relative position of a normal wing Spitfire with metal ailerons at 250 mph EAS at 10000 feet after ONE second from Chart 6.

P-51 Mustang at 250 mph EAS at 10000 feet at ONE second

Graphic depiction of the relative position of a normal wing Spitfire with metal ailerons at Vmax (313 mph EAS) at 10000 feet.

The RAE found the Operational Research Section of Fighter Command gave good agreement with their measured results.

Here is Chart 5, Roll position Relative to an attacking Spitfire derived from Combat Film measurements:

Here is a graphic of the relative position of an attacking Spitfire to the FW-190 after ONE second:

May 3, 2014

Here is the relevant portions of the RAE reports from Combat Trials of WNr 313. Note the rolling performance comments in the conclusions:

99. Perhaps the most outstanding characteristic of this aircraft is the remarkable aileron control. It is possible to change from a turn in one direction to a turn in the opposite direction with incredible speed and when viewed from another aircraft the change appears just as if a flick half roll has been made.

What does all this mean to a dogfighter?

Agility.pdf

Edited May 3, 2014 by Crump

May 3, 2014

I think you can do that yourself. Maybe you should check out the Mustang to the Spitfire to see how surprisingly agile the Spitfire was in comparison. That is what I got out of it.

The FW-190 was leaps and bounds ahead of other designs in agility.

Take the Focke Wulf out of the mix and the Spitfire was the leader at low speeds and one of the most agile aircraft designed at the time.

nacaroll.bmp

May 3, 2014

The FW-190 was leaps and bounds ahead of other designs in agility.

Not really, it had the best roll rate, nice for changing direction quickly but it was not leaps and bounds ahead of anything, just another aircraft with it's advantages and disadvantages like all the others.

May 3, 2014

May 3, 2014

Not really, it had the best roll rate, nice for changing direction quickly but it was not leaps and bounds ahead of anything, just another aircraft with it's advantages and disadvantages like all the others.

At the time it was considered leaps and bounds ahead of everything else. It caused a flurry of lateral performance improvement research and is why the Spitfire got clipped wings. Look at the chart. It is 75 degrees ahead of everyone else and is not using all of its potential in the test. I am sure the developers will be able to get the data they need from it.

When the FW-190 was in a turn and attacked by the Spitfire the superior rate of roll allowed it to flick into a diving turn in the opposite direction. The pilot of the Spitfire found great difficulty in following this maneuver and even when prepared for it was seldom able to allow the deflection. A dive from this maneuver allowed the Focke Wulf to draw away from the Spitfire which was then forced to break off the attack.

In other words, When dead on the Focke Wulf's tail the Spitfire pilot was warned when and which direction the FW-190 would roll and the FW-190 rolled only once, he had great difficultly in remaining in an offensive position and almost never got a shot.

Any normal wing Spitfire will encounter the same problem.

The Focke Wulf's agility was able to turn a defensive situation into a neutral situation.

Here is the NACA report on the summary of lateral control research. The chart has been posted twice in the thread.

In a fit of Laziness, the NACA simply transcribed the Equivalent Airspeed (EAS) data from RAE 1231 onto their graph labeled Indicated Airspeed(IAS). Of course, there are steps that have to be taken before one does that and simple comparison of the charts proves they were not done.

I am sure the developers will take note and correct things.

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

Edited May 3, 2014 by Crump

May 5, 2014

In all fairness Crump, we had several instances in the past where you interpreted clear data to win (in your mind) an argument.

What we pretty much all learned in the forum is that there's no arguing with you, you're ALWAYS right. The intelligent ones ignore you, the stupid ones like yours truly here don't, but this is probably because we're usually concerned about how you manipulate info to prove your point, which could potentially lead to wrong information being used in the sim.

This is not a personal attack, I just think you should really try and make an effort and be more reasonable mate, if anything for the sake of your credibility, cos otherwise all your writing, researching and elucubration is a majestic waste of time..

Edited May 5, 2014 by Sternjaeger

May 5, 2014

In which case there's even less reason for this thread. As it is you're wrong, the Fw 190 was used around Stalingrad by I. & III./JG 51; while the Soviets who tested the 190 were impressed by some of its features and characteristics the La-5 and Yak-1 & 9s could outmanoeuvre it below 3,000 metres, so no lessons were needed in agile fighter design...

I'm sorry but this is too much generalized statement. Outmanoeuvre under which circumstances? Are you talking about fight in sustained turns at slow speed? Then you're right. Are you talking about the high speed manoeuvre fight when planes are about or above let's say 450 - 500 km/h? You're probably damn wrong. The biggest problem here is that most people when they're talking about "outmanoeuvred", they're talking about slow speed turning fight only.

Edited May 5, 2014 by II./JG1_Pragr

May 5, 2014

There are tons of threads in this forum part that have nothing to do with the BOS area, where in comparison we have at least an 190, which is discussed here, in the game.

The 190 Data and comparisons are an nice addition to the 190 database (and Spit/P51).

Interestinge infos in your post Crump, thank's a lot for the scans.

Wastel

May 5, 2014

Isn't it easier just to find 190 test data than to try to extract it from combat video when you have no idea what the pilot inputs are or the actual aircraft energy status?

May 5, 2014

There are tons of threads in this forum part that have nothing to do with the BOS area, where in comparison we have at least an 190, which is discussed here, in the game.

The 190 Data and comparisons are an nice addition to the 190 database (and Spit/P51).

Interestinge infos in your post Crump, thank's a lot for the scans.

Wastel

Thanks. I thought it was pretty interesting too. To me it highlighted the previous agility standards of the rest of the world. The information is there in the graph but it just does not allow one to visualize or translate it into useful information until the speed and visual representation of the performance came into play, at least for me.

I was surprised to see just how close to each other and how agile some of the other designs in World War II actually where.

Look at the P40 and the Zeke. At speeds the P-40 fought, it could run circles around the Zeke. At 250mph EAS, in one second the Zeke is 50 degrees behind the P-40!! Everything in the USAAF during World War II had a 30 degrees or more agility advantage over the Zeke. If a USN or USAAF pilot did not join the level turning circle, there just was not much the Zeke could do.

May 5, 2014

Isn't it easier just to find 190 test data than to try to extract it from combat video when you have no idea what the pilot inputs are or the actual aircraft energy status?

RAE 1231 is the flight tested measurements.

The report is not about the combat film investigation. That is a separate test with only the results listed because they agree with the flight tested measurements of the RAE.

There seems to be some confusion on this point about the combat film investigation done by the Operational Research Section of Fighter Command. It is a separate investigation.

That being said, it is a very legitimate technique which is why it was done. Every gun camera film of an FW-190 claim that they knew of was examined. They used films which they could prove the Spitfire was not rolling to measure the roll rate of the Focke Wulf. They then constructed a graph using the known data of the Spitfires roll rate with the measured roll rates they saw on the films of the Focke Wulf.

The graph tells you the relative position over time of Spitfire rolling together with a Focke Wulf.

The RAE captured three FW-190's.

One Fighter variant and two bomber variants fell into British hands. They tested the aircraft and measured the roll rate.

That RAE flight testing confirmed the gun camera film investigation as legitimate and both test's gave good agreement with each other.

Edited May 5, 2014 by SYN_Haashashin
removed unneccesary comment

May 5, 2014

Any ideas about the source test for the Mark Vb roll data - in trials was it a non-standard testbed aircraft or a serial production aircraft tested? I have the referenced (3) papers, but it does not have the often repeated roll curve for the Mark V - I suppose its some sort of derivative/re-calculation of the raw 45 degree bank data collected there. Which is curious, because the "clipping" document seems to state that clipping does not improve aircrafts roll with a "good" match of Frise ailerons and therefore this modification is not recommended, but it improves the aircraft with a "bad/unmatching" set of Frise ailerons (which appears to be a chronic Spit production problem through the war).

May 5, 2014

Guys, keep the personal stuff out. I just cleaned this topic so next offender will meet Mrs ban.

Thanks

May 5, 2014

The RAE captured three FW-190's.

One Fighter variant and two bomber variants fell into British hands.

The RAE didn't capture any Fw190s.

That would be 1 fighter and 3 fighter-bombers at the Royal Aircraft Establishment (RAE) at Farnborough

MP499 - Focke-Wulf Fw190A-3 - W.Nr.313 - single chevron of III./JG2 - SoC September 1943 (landed Pembrey, 23 June 1942)

PM679 - Focke-Wulf Fw190A-4/U8 - W.Nr.5843 - "Red 9" of I./SKG10 - used for spares July 1944 (landed at Manston, 20th May 1943)

PN999 - Focke-Wulf Fw190A-5/U8 - W.Nr.2596 - "White 6" of I./SKG10 - dispatched to unknown destination July 1946 (landed at Manston, 20th June 1943)

PE882 Focke-Wulf 190A-4/U8 - W.Nr.7155 - II/SKG10 (landed at West Malling, April 17, 1943)

There was also NF754 & NF755 captured in Africa. NF754 - Focke-Wulf Fw190A - W.Nr.unknown - unknown unit - fate unknown and NF755 - Focke-Wulf Fw190A - W.Nr.unknown - unknown unit - fate unknown with No. 1426 Flight.

.

May 5, 2014

The RAE didn't capture any Fw190s.

I think Arnim Faber would disagree with you as he was looking down the barrel of Sergeant Jefferies very pistol.

They could have had a million FW-190's on hand but the fact are as stated in the report, the pilot flew three different FW-190's and the RAE measured the roll rate in only one.

So for their comparison purposes in the context of the thread discussing RAE 1231 which you have taken out of context, the RAE had a knowledge base of three aircraft and the Operational Section of Fighter Command experience.

Edited May 5, 2014 by SYN_Haashashin
useless comment. Last warning

May 5, 2014

Faber landed at RAF Pembrey not at Farnborough where the Royal Aircraft Establishment was.

May 5, 2014

Any ideas about the source test for the Mark Vb roll data - in trials was it a non-standard testbed aircraft or a serial production aircraft tested? I have the referenced (3) papers, but it does not have the often repeated roll curve for the Mark V - I suppose its some sort of derivative/re-calculation of the raw 45 degree bank data collected there.

I don't know on the specifics of the Mark Vb roll data, only that it was considered good enough data to be used in the comparison.

Not "lecturing" so please don't be offended, just putting out information to ensure we are all on the same page in the discussion.

You are correct that all of these test's are derived from flight measurements the same way. The flight testing gathers a few data points which are then converted to standard conditions and calculations used to fill in the blanks.

Today and in the United States as well as Germany during the war, aileron sizing in aircraft design is gauged by the criteria of pb/2v. p is the tip velocity, b is wing span, and v is the airplanes flight velocity.

The designer sizes the ailerons to the wing area so that they produce enough moment about the CG to get the tip velocity and value of pb/2v to the required constant.

You calculate Pb/2V which gives you the designs roll capability in radians to complete a 360 degree roll using the NACA stability and control standards in 44.8 wingspans regardless of speed at Pb/2V = .007. That was considered the minimum standard.

Problem is the British did not use this method when they designed airplanes nor did many of the designs in world war II. That is why lateral control dynamics was such a relatively new science.

A guy named Gilruth at the NACA developed it in 1938. The German Aeronautical Science community took note but in England, only a guy named Gates saw it for what it was. Prandtl is considered the father of modern aerodynamics. He was still alive and actually taught a few of the leading aerodynamicist in the United States when they were in school. They all kind of knew each other in the United States and German scientific communities.

The RAE method relied heavily on roll rate measurements from flight testing or wind tunnel investigations. They took the actual measured roll rate and then used it to solve for such things as reversal speed (based on incompressible flow theory without compressibility corrections), torsional losses, etc.

They compared that data to what is called a strip configuration. That is where we assume the wing is a solid rigid structure and using the ratio of aileron area to wing area along with degree of aileron input we calculate a coefficient of rolling moment.

That is used to calculate the moment about the Cg:

Moment about the CG = Coefficient of Rolling moment X Dynamic pressure X wing area X wing span

Wings are not rigid though. So the math gives them the theoretical capability and flight measurements the actual capability. Kind of like shooting in the dark. And that is pretty much what everybody did until Gilruth came along.

The fact dynamic pressure changes means our moment changes and a designer must choose the speed at which he wants to achieve a given design performance is the shortcoming of the strip configuration. That is the magic of Pb/2v, it is independent of velocity and gives a way to maximize performance over the entire envelope.

Which is curious, because the "clipping" document seems to state that clipping does not improve aircrafts roll with a "good" match of Frise ailerons and therefore this modification is not recommended, but it improves the aircraft with a "bad/unmatching" set of Frise ailerons (which appears to be a chronic Spit production problem through the war).

On pages 157 thru 159 in Morgan and Shacklady's The Spitfire, they talk about the problems with the designs ailerons. If you have that book, read it as it pretty good at painting the picture they just did not know what was going on.

Rigging is extremely important in frise type ailerons compared to other aileron designs. The testing surprising showed that rigging was not the issue in the Spitfire.

Reading it reminds me of the duct rumble in the P-51 Mustang. It was a compressible aerodynamics issue that they just were not equipped to solve back then. In the P-51, the cause of the Duct rumble was not known until the stock intake design was examined using modern Computational Fluid Dynamics in the design of the unlimited racer, Strega. It was solved during the war but it was solved almost thru trial and error.

Anybody who knows a thing about this stuff would immediate spot the fact the Spitfire ailerons stick forces diminish with velocity. That is a big red flag something is not right in the lateral control arena.

What you should see is stick forces at a constant input should increase with velocity if everything working as it should.

I have interesting report on the investigating the ailerons on the Spitfire. It notes that flow separation occurs on the ailerons. That means the faster the Spitfire goes, the less aileron surface is effective. They do not come to any solid conclusion as the investigation is one a two dimensional model of the wing/aileron in a high speed wing tunnel. There are some clues presented but the report is more rambling or musing than solid evidence. It is just evidence there was in issue, they were aware of it, but did not have the answer to solve it.

The other factor is the simple fact the Spitfire had a wide chord wing combined with a thin airfoil. The mechanics just do make for torsional stiffness which is key to lateral control. That is why it has such a low reversal speed. It also had cables which were the most common control system used at the time. Cables stretch and diminish control authority with velocity. Production tolerances are going to give you a wide variety of torsional stiffness.

That fact most designs at the time used cables and attached ribs with wider spacing with smaller aileron surface area goes along way towards explaining the agility disparity.

Faber landed at RAF Pembrey not at Farnborough where the Royal Aircraft Establishment was.

Ahh ok.

You think they left it a Pembrey?

May 5, 2014

In all fairness Crump, we had several instances in the past where you interpreted clear data to win (in your mind) an argument.

What we pretty much all learned in the forum is that there's no arguing with you, you're ALWAYS right. The intelligent ones ignore you, the stupid ones like yours truly here don't, but this is probably because we're usually concerned about how you manipulate info to prove your point, which could potentially lead to wrong information being used in the sim.

This is not a personal attack, I just think you should really try and make an effort and be more reasonable mate, if anything for the sake of your credibility, cos otherwise all your writing, researching and elucubration is a majestic waste of time..

+1 Agree 100% with every word.

May 5, 2014

Ahh ok.

You think they left it a Pembrey?

Faber's Fw190 was transferred to Farnborough after Faber landed by mistake at Pembrey. Luftwaffe navigation training must have been lacking with the number of Luftwaffe a/c that landed on the wrong side of the English Channel.

Just correcting your erroneous statements Crump which you have a hard time admitting to.

May 5, 2014

Serious question, nothing personal needing deletion, how exactly is this thread not simply becoming a blatant Spitfire bash?

May 5, 2014

I have interesting report on the investigating the ailerons on the Spitfire. It notes that flow separation occurs on the ailerons. That means the faster the Spitfire goes, the less aileron surface is effective. They do not come to any solid conclusion as the investigation is one a two dimensional model of the wing/aileron in a high speed wing tunnel. There are some clues presented but the report is more rambling or musing than solid evidence. It is just evidence there was in issue, they were aware of it, but did not have the answer to solve it.

it is evidence of an issue that history shows never manifested as any real problem, the Spitfire had one of the best roll rates of any fighter.

May 5, 2014

Faber's Fw190 was transferred to Farnborough after Faber landed by mistake at Pembrey. Luftwaffe navigation training must have been lacking with the number of Luftwaffe a/c that landed on the wrong side of the English Channel.

Just correcting your erroneous statements Crump which you have a hard time admitting to.

You know your point was so obscure, no I did not catch it. Of course the RAE did not physically capture anything. They were a research institute. Do you really think I or anybody else thought they did?

May 5, 2014

You know your point was so obscure, no I did not catch it. Of course the RAE did not physically capture anything. They were a research institute. Do you really think I or anybody else thought they did?

Obscure? Nope, just usual your problem, again.

You definitely did as you said 3 Fw190s were captured by the RAE.

Why don't you just stop the wiggling to get out of admitting you were in error and admit you were in error Crump.

May 5, 2014

The fact dynamic pressure changes means our moment changes and a designer must choose the speed at which he wants to achieve a given design performance is the shortcoming of the strip configuration. That is the magic of Pb/2v, it is independent of velocity and gives a way to maximize performance over the entire envelope.

Here you can see the effect of using Pb/2V and Gilruth's work. The United States did not adopt a stability and control standard until 1942. This resulted in a flurry of flying qualities testing on existing aircraft and work to improve the aircraft handling.

The XP-51 was designed before a standard was in place. Using Gilruth's techniques, design changes were developed that allowed for an increase in agility across the aircraft's envelope.

I do not have the complete report on the clipping of the Spitfires wings. I only have the conclusions and a few cut and pasted selections that were posted on Spitfireperformance.com.

Here is the conclusion:

Spitfire bashing bastards at the RAE published it.......

Kurfurst asked a legitimate question so if we can get a copy of the entire report, it might shed some light on why they made the conclusions they did and how it effects the data used in RAE 1231.

May 5, 2014

interesting document but doesn't say anything not already known about clipped wing spits although there is more evidence (like the graph) that shows the increase in roll rate was significant, the interesting part is the recommendation not to clip them, so does that mean the clipped wing spitfire was an unauthorised modification?

Anyway, completely irrelevant.

May 5, 2014

Kurfurst asked a legitimate question.

Yeah, I'm sure there was no collusion whatsoever that made Kurfurst set this one up for you.

May 5, 2014

above all what's interesting is that despite the conclusion of the document, dated November '44, clipped wing Spits versions were still produced afterwards..

I guess this is testament of the "fighter bias" behind these reports and the danger of misinterpreting this information: the clipped wing is not an intrinsically bad design, it just responds to certain demands, sacrificing some perks in favour of others.

A classic example of the "danger" of giving the wrong value to historical documents is the one of the directives related to the "Dowding Spread": whilst on paper it made sense at the time, in hindsight it turned out to be a complete failure, as it didn't understand the added value of gun convergence.

Edited May 5, 2014 by Sternjaeger

May 6, 2014

Yet despite all the 'negatives' the Spitfire IX/XVI had clipped wing tips.

So did the Spitfire XIV,

May 6, 2014

the clipped wing is not an intrinsically bad design, it just responds to certain demands, sacrificing some perks in favour of others.

Read it....no actually read it.

Agility.pdf

May 6, 2014

..so? What does that document say that we don't already know?

Actually there is something that is not taken into consideration: the fact that they started using the Griffon engine to improve overall performance and reduce the flaws related to the clipped wings solution.

May 6, 2014

Read it, still says nothing to back up your claim, simply goes over the same old ground that the clipped wing spit sacrificed a little bit of high altitude performance in order to gain a significant increase in roll performance, in a way clipping it's wings balanced things, it decreased aspects of its excellent qualities to improve a deficient aspect, isn't that why clipped wing spits got the LF designation?

May 6, 2014

Of far more relevance than clipped wing Spitfires, few of which were flown by the Soviets (some L.F Mk IXs), are the handling qualities of the P-39D:

P-39D_Flying_Qualities.pdf

Edited May 6, 2014 by NZTyphoon

May 6, 2014

Maybe I missed it but were the ailerons in the test Spitfire V, the fabric covered ones or the metal covered ones?

May 6, 2014

If I'm not mistaken the fabric cover was changed to metal during the serial production of Mk.I or Mk.II versions, before the end of 1940.

Edited May 6, 2014 by II./JG1_Pragr

May 6, 2014

above all what's interesting is that despite the conclusion of the document, dated November '44, clipped wing Spits versions were still produced afterwards..

I guess this is testament of the "fighter bias" behind these reports and the danger of misinterpreting this information: the clipped wing is not an intrinsically bad design, it just responds to certain demands, sacrificing some perks in favour of others.

AFAIK the clipped wing versions were a niche used almost exlusively on fighter bomber Spits - the plane had structural issues with wing mounted bombs, especially in diving attacks (skin wrinkling, wing bending) which the clipping alleviated somewhat. Its very rare to see those clipped wings on normal fighter aircraft, and the reason is that tactical experience/conclusion was that even with the clipped wings, the Spit could not roll with the 190, while it sacrificed some of its fortes like turning and climbing. At the same time it had no trouble rolling with a 109 in the normal configuration. In the end, it made little sense to do it - and here I am in complete agreement with your comment on everything being a compromise. Clipped wings were just not a very good tactical choice for fighter pilots, given the tactical enviroment.

If I'm not mistaken the fabric cover was changed to metal during the serial production of Mk.I or Mk.II versions, before the end of 1940.

More like about April 1941, yes they did investigate it in 1940, but production lines had some delays in actually implementing the changes.

May 6, 2014

AFAIK the clipped wing versions were a niche used almost exlusively on fighter bomber Spits - the plane had structural issues with wing mounted bombs, especially in diving attacks (skin wrinkling, wing bending) which the clipping alleviated somewhat. Its very rare to see those clipped wings on normal fighter aircraft, and the reason is that tactical experience/conclusion was that even with the clipped wings, the Spit could not roll with the 190, while it sacrificed some of its fortes like turning and climbing. At the same time it had no trouble rolling with a 109 in the normal configuration. In the end, it made little sense to do it - and here I am in complete agreement with your comment on everything being a compromise. Clipped wings were just not a very good tactical choice for fighter pilots, given the tactical enviroment.

In your opinion, but the reality is somewhat different, the tactical environment suited a clipped wing Spit quite well, as a low level fighter bomber it sounds perfect and by the closing years of the war there wasn't much of the axis left to destroy in the air.

May 6, 2014

Yes, it is indeed curious how this 190 roll rate thread is all about the Spitfire, colour me cynical but I suspect the intention had little to do with simply providing useful suggestions to the developers of a game, a game with absolutely no Spitfires in it.

May 6, 2014

hmm..if i look through this thread, you are the one who brings in the "poor" spitfire, every time.

Without your comments this would still be an 190 thread..and not an spit vs 190 thread.

I would like to get more data on the roll rate and overall agility of the 190 and the RAE conclusions out of their tests.

Please keep your spit whining out of this thread and feel free to open an new, spitfire, thread.

Thank you

May 6, 2014

take every one of my posts out and this is still a Spitfire thread, learn to read.

Roll Measurements FW-190 RAE 1231

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