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lbhskier37
06-16-2005, 08:46 AM
I was just wondering if too slow high speed rolling in the P51 and FW, and the too fast high speed rolling of the P38L have been changed since 4.0?

lbhskier37
06-16-2005, 08:46 AM
I was just wondering if too slow high speed rolling in the P51 and FW, and the too fast high speed rolling of the P38L have been changed since 4.0?

lbhskier37
06-16-2005, 02:37 PM
I'm gonna bump this, but it looks like everyone is too busy crying for beta04 to care.

new-fherathras
06-16-2005, 02:37 PM
do you have something to back up your claims about to slow/fast rollrates?



and no, nothing else then SBD tourqe and FW-190 fuelbug was fixed in 4.01 from 4.00

ICDP
06-16-2005, 03:04 PM
Fw190A8 rollrate in degrees per second (DPS) at 10000 feet
(speeds are in IAS)

I completed 3 rolls and averaged the results.

180MPH = 126DPS (matches chart)
220MPH = 149DPS (matches chart)
260MPH = 101DPS (155 in NACA chart)
300MPH = 79DPS (130 in NACA chart)
340MPH = 62DPS (103 in NACA chart)
380MPH = 59DPS (82 in NACA chart)

So the lower speed rollrate is fine but since the Fw190 needs to be flown at higher speeds (250MPH+) this is not a good thing. In my findings the rollrate at the Fw190's ideal speeds is out by quite a margin.

I also tested the P51B/C and found the rollrate also suffers at higher speeds but not by as high a margin as the Fw190A. So I find this problem is not limited to the Fw190.

P51B
180MPH = 78DPS (63 in NACA chart)
220MPH = 92DPS (78 in NACA chart)
260MPH = 106DPS (90 in NACA chart)
300MPH = 100DPS (94 in NACA chart) <- close
340MPH = 82DPS (93 in NACA chart)
380MPH = 66DPS (88 in NACA chart)

So as we can see the P51B rollrate is out at very high speed but at low speeds it is better in the sim. The P51B doesn't suffer nearly as bad as the Fw190A, in fact it comes out quite well over the NACA numbers apart from very high speeds.

bolillo_loco
06-16-2005, 04:04 PM
In game P-38: 75% fuel 10,000 ft above sea level all speeds in IAS no rudder imput was used to assist roll rates, both engines were operated at the same power rating, and I used air starts at 3,000 meters. *Note: above 150 mph IAS it was easy to maintain my IAS and altitude during the roll, but at 100 - 150 mph IAS it was very difficult to maintain speed and altitude. During the rolls at speeds of 100 - 150 the 38 kept diving when I got inverted and picked up 30 - 70 mph IAS, 150 was not too bad, but at 100 mph ias it was very pronounced. due to this I would condisder my results at 150 mph IAS inaccurate and my results at 100 mph IAS to be very inaccurate.

P-38J

100 8.5 seconds - 42 DPS
150 7 seconds 51 DPS
200 6 seconds 60 DPS + 13 DPS
250 6 seconds 60 DPS - 3 DPS
300 8 seconds 45 DPS - 35 DPS
350 10 seconds 36 DPS -17 DPS
400 12 seconds 30 DPS

P-38L-1-LO

100 10 seconds 36 DPS
150 7 seconds 51 DPS
200 6 seconds 60 DPS +7DPS
250 5.5 seconds 65 DPS -6 DPS
300 4.5 seconds 80 DPS -3 DPS
350 4 seconds 90 DPS +3 DPS
400 4 seconds 90 DPS

P-38L-5-LO

100 8 seconds 45 DPS
150 8 seconds 45 DPS
200 7 seconds 51 DPS - 2 DPS
250 5.5 seconds 65 DPS -6 DPS
275 5 seconds 72 DPS -7 DPS
300 4.5 seconds 80 DPS -3 DPS
325 4 seconds 90 DPS -3 DPS
350 4 seconds 90 DPS -5 DPS
400 4 seconds 90 DPS



http://pages.sbcglobal.net/mdegnan/_images/RollChartClr2.jpg

faustnik
06-16-2005, 04:14 PM
Bolillo,

Could you run the same test on the P-38J please?

I got a chance to test the L (late) a little and it seemed that even a little initial lag was modeled into the roll.

lbhskier37
06-16-2005, 04:31 PM
I was going off a thread posted when 4.0 was out. I'm at work and havent had a chance to check.

bolillo_loco
06-16-2005, 05:23 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by faustnik:
Bolillo,

Could you run the same test on the P-38J please?

I got a chance to test the L (late) a little and it seemed that even a little initial lag was modeled into the roll. </div></BLOCKQUOTE>

sure thing I have revised my original post to include all P-38s. anybody feel free to try my results under the same testing proceedures and compair it to my data to either confirm or find in-accuracies.

Buzzsaw-
06-16-2005, 05:35 PM
Salute

Looks like the 190 needs to be adjusted. Having a good rollrate across the speed range is very important to this aircraft being able to be flown to its historical advantages.

What is the rollrates for the Spits and 109's?

Sorry, haven't had a chance to test the planes myself and won't get a chance till this weekend.

Vrabac
06-16-2005, 05:49 PM
Can anyone imagine a day when FW190 won't be crippled? But we can hope... http://forums.ubi.com/images/smilies/35.gif

I'm glad to see I'm not mad, it seemed to me that it's roll was way to slow.

Hunde_3.JG51
06-16-2005, 06:24 PM
Since we are talking about roll rates, I found this in a book called Supermarine Spitfire by Chaz Bowyer. It talks about just how much the Spitifre improved over the course of its life and I noticed this:

Rate of roll (at 400mph):

Spitfire I: 14 degrees/sec (ouch, imagine that on the chart above)
Seafire 47: 68 degrees/sec

Does anyone know where the Spitfire V, IX, XIV, etc. would be? This is a drastic improvement and I was wondering how steadily it increased or if it was a huge jump somewhere?

Oh, and someone should send their roll test results to Oleg and crew.

bolillo_loco
06-17-2005, 01:44 AM
the 38J rolls 45-30% too slow at speeds above 250 mph IAS and at 200 mph IAS it is about 30% too fast. I could not get accurate measurements below 200 mph IAS

ICDP
06-17-2005, 02:19 AM
The fact that the P51B does have a historical advantage at higher speeds is good. It is the fact that at medium speeds it is the equal of the Fw190 that is wrong.

Can anyone else please test the Spitfire rollrate? I tested the Spitfire MkIXe standard and elipitcal wing versions and the rollrate is still identical. This has been the case since the Spitfire was introduced to FB, the clipped wing version should have a distinctly superior rollrate. At the moment there is no discernable difference in performance betwee standard and clipped wing Spits.

ImpStarDuece
06-17-2005, 02:27 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Hunde_3.JG51:
Since we are talking about roll rates, I found this in a book called Supermarine Spitfire by Chaz Bowyer. It talks about just how much the Spitifre improved over the course of its life and I noticed this:

Rate of roll (at 400mph):

Spitfire I: 14 degrees/sec (ouch, imagine that on the chart above)
Seafire 47: 68 degrees/sec

Does anyone know where the Spitfire V, IX, XIV, etc. would be? This is a drastic improvement and I was wondering how steadily it increased or if it was a huge jump somewhere?

Oh, and someone should send their roll test results to Oleg and crew. </div></BLOCKQUOTE>

The effect on the improvement in Spitfire roll rate was incremental but quite a bit of it was fixed very early on in the piece, 1939-1941 ish.

In the Spitfire II they refined the control linkages and alieron balance to improve the rate of roll. There was a really interesting report done of a comparison between the P-36 (H-75), Spitfire I, Hurricane II and Gladiator. The Spitfire I needed 57 1/2 pounds of pressure to get 1/4 alieron deflection at 400mph while the P-36 only needed about 23 lbs and the Gladiator about 24 lbs. The P-36 was rated as a much better bird above 250 mph! The roll rate of the Hurricane was also mentioned; at 400 mph the Hurricane took 2 seconds to roll 90 degrees whilt the Spitfire took a massive 8 seconds and the pilot could only produce 1/5 alieron deflection.

The problem was traced back to to several areas; the alieron type (being a Frise type alieron), alieron distortion and ballooning of the alieron fabric, incorrect trimming and improper gearing of the control linkage.

The Spitfire II got better linkages in late 1939/ early 1940, reducing the pilots workload in the cockpit by about half. However, there wasn't a great improvement in rate of roll. Mostly this was because of slight alieron snatching due to the badly balance of the alierons, poor high speed trim and massive (i.e. visible to the pilot) ballooning of the alieron fabric.

To prevent balooning the RAF begun fitting Spitfire IIs and Is with metal alierons in Spetember/October 1940, even though tests had been complete by early 1940. It wasn't until 1941 that all units had been converted. I think that Hurricane squadrons also underwent conversion, but the Hurri is prennially underreported so I can't find any sources apart form references to tests made.

The Frise balance was also reweighted and the alieron linkage reset closer to the wing in a mod in 1940 which helped the Spitfire IIs rate of roll. At one point the A.A.& E.E reported that in early Spitfires the alierons were "almost immovable at speeds above 300 mph".

Later Spits also played with the alieron structure a little, reworked the linkages as well as some other mods.

I'd say though that the biggest improvements would of been due to the reworked linkages in 1940 and the introduction of metal alierons in 1940/41. Paraphrasing a test pilot he siad that the difference between a Spitfire with metal alierons and one without had to be flown to be believed.

Kurfurst__
06-17-2005, 05:55 AM
Spit I roll rate :

http://www.onpoi.net/ah/pics/users/715_1102086136_spitihighspeedroll.jpg
http://www.onpoi.net/ah/pics/users/715_1095082092_spiti_109e_ailerons.jpg


There were 3 major problems with the Spit`s roll rate :

a, Excessive control forces making deflecting the controls impossible at high speeds
b, Aileron ballooning, reducing aileron effectiveness at high speed
c, Relatively high wing twist and flexing, accounting for 65% reduction of roll rate at high speeds as per the NACA

Only the ballooning was solved by replacing it with metal covered ailerons in 1941, the rest of the problems persisted through the war, appearantly.

They tried clipping the wings, but it was not much of a help, appearantly, from the PRO :

http://www.onpoi.net/ah/pics/users/715_1119007854_rolltestonspit5-9-12_conclusions.jpg


And this by NACA on Mk V`s roll rate :

"Measurements of the flying qualities of a Supermarine Sptitife VA airplane." NACA Advanced Confidental Report, by William H. Phillips and Joseph R. Vensel.

The tests were conducted at Langley field, Va., during the period from December 30, 1941 to January 29, 1942. Sixteen flights and apprx. 18 hours flying time were required to complete the tests.

[...]

Desription of the the Supermarine Spitfire airplane

Name and Type : Supermarine Spitfire VA (Air Mininstry No. W3119).
Engine : R-R Merlin XLV
Weight, empty : 4960 lbs
Normal gross weight : 6237 lbs
Weight as flown for tests : 6184 lbs

Ailerons (metal-covered)
Lenght (each) : 6 feet, 10 1/2 inches
Area (total area, each) : 9.45 sq. feet
Balance area (each) : 2.45 square feet

[...]

A stick force of 2 lbs to the right and 3 lbs to the left was required to overcome aileron friction.

[...]

Lateral Stability and Control

Aileron-control characteristics : The effectiveness of the ailerons of the Supermarine Spitfire airplane was determined by recording the rolling velocity produced by abrubtly deflecting the ailerons at various speeds. The aileron angles and stick forces were measured. It should be noted that the airplane tested was equipeed with metal covered ailerons.

[...]

The ailerons were sufficiently effective at low speeds, and were relatively light at small deflections in high speed flight. The forces required to obtain high rolling velocities in high-speed flight were considered excessive.
With a stick force of 30 lbs, full deflection of the ailerons could be obtained at speeds lower than 110 miles per hour. A value of pb/2V of 0.09 radian in left rolls and 0.08 radian in right rolls were obtained with full deflection.

Rolling velocity (at 6000 ft altitude) of about 59 degrees per second could be obtained with 30 lbs stick force at 230 miles per hour indicated speed.

The ailerons were relatively light for small deflections, but the slope of the curve of stick force against deflection increased progressively with deflection, so that about five times as much force was required to fully deflect the ailerons as was needed to reach one-half of the maximum travel. The effectiveness of the ailerons increased almost linearly with deflection all the way up to maximum position. The value of pb/2V obtained for a given ailerons deflection was nearly the same in speeds and conditions tested. It may be concluded, therefore, that there was very little reduction in aileron effectiveness either by separation of flow near minimum speeds or by wing twist at high speed.

Fig 27 shows the aileron deflection, stick force, and helix angle obtained in a series of roll at various speeds intended to represent the maximum rolling velocity that could be readily obtained.

The pilot was able to exert a maximum of about 40 lbs on the stick. With this force, full deflection could be attained only up to about 130 miles per hour. Beyond this speed, the rapid increase in stick force near maximum deflection prevented full motion of the control stick. Only one-half of the available deflection was reached with a 40 lbs stick force at 300 miles per hour, with the result that the pb/2V obtainable at this speed was reduced to 0.04 radian, or one-half that reached at low speeds.

Another method of presenting the results of the aileron-roll measurements is that given in figure 28, where the force for different rolling velocities is plotted as a function of speed. The relatively light forces required to reach small rolling velocities are readily seen from this figure. The excessive forces required to reach high rolling velocities and the impossibility of obtaining maximum aileron deflection much above 140 miles per hour are also illustrated.


From :

STABILITY AND CONTROL SUB-COMMITEE. AERONAUTICAL RESEARCH COMMITEE
Comparision of aileron control charactheristics as determined in Flight Tests of P-36, P-40, 'Spitfire' and 'Hurricane' Pursuit airplanes.

By William H. Philps. N.A.C.A. Confidental Bulletin. 16th November, 1942

[..]

The aileron effectiveness of the various airplanes is compared in the following table on the basis of the response obtained with stick forces of 30 and 5 pounds. A force of 30 lbs is somewhat less than the greatest stick force exerted by the pilot. Repeated flight measurements have shown, however, that this forcer is a reasonable upper limit for manouvering at high speeds. A comparision at a stick force of 5 lbs are also included to bring out a rather interesting fact regarding the order of merit of aileron effectiveness for the various airplanes when very light forces are used :

Rolling velocities obtained with 30 lbs stick force at 230 mph indicated airspeed at 10 000 ft. (deg/sec)

P-36 : 43
P-40 : 90
Hurricane : 64
Spitfire : 63

Rolling velocities obtained with 5 lbs stick force at 230 mph indicated airspeed at 10 000 ft (deg/sec)

P-36 : 9
P-40 : 8
Hurricane : 19
Spitfire : 15



A further comparision of the aileron performance of the four airplanes is given in figure 2, which shows how the control force characteristics influence the rolling velocities obtained through the speed range.



This if form Alex Heshaw, the Chief pilot of the Castle Bromwhich Spitfire plant. He basically flew hundreds of Spitfires after they left the factory and were tested for airworthyness.


"I loved the Spit, every Marks of it. But I must admit, that altough later Marks were much faster, they were also progressively inferior to previous Marks in manouveribility. When we checked how a Spit behaves during roll, we counted how many complete rolls we could do under a given time. With the Mark II and V, we did 2 1/2 rolls, but the Mark IX was heavier, and only capable of 1 1/2 rolls. The later, more heavier versions could do even less. Designing an aircraft is about finding balance. It`s hardly possible to improve performance without degrading other properties of the aircraft. "

And this from Jeff Ethell:

"The elevator is very light, while the rudder is stiff and the ailerons even more so. Every Spitfire I have flown take more muscle to roll than most other fighters. As speed increases, both rudder and ailerons get heavier, creating a curious mismatch at high speeds... on has to handle the almost oversensitive elevators with a light fingertip touch while arm-wrestling the stiff ailerons."

Blutarski2004
06-17-2005, 08:43 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Hunde_3.JG51:
Since we are talking about roll rates, I found this in a book called Supermarine Spitfire by Chaz Bowyer. It talks about just how much the Spitifre improved over the course of its life and I noticed this:

Rate of roll (at 400mph):

Spitfire I: 14 degrees/sec (ouch, imagine that on the chart above)
Seafire 47: 68 degrees/sec

Does anyone know where the Spitfire V, IX, XIV, etc. would be? This is a drastic improvement and I was wondering how steadily it increased or if it was a huge jump somewhere?

Oh, and someone should send their roll test results to Oleg and crew. </div></BLOCKQUOTE>


..... Hunde, I believe that Bowyer got his roll rate info from the same RAS lecture transcript from which I quote below. These Spitfire roll rate data were taken from THE DEVELOPMENT OF THE SPITFIRE AND SEAFIRE - 706th lecture delivered before the Royal Aeronautical Society (19 Dec 1946) by J. Smith (chief designer for Supermarine during the war).

Herewith follows the roll rate graph values, as closely as I can approximate them:

All data are give for "full aileron or 50 lb stick force" - I suppose whichever limit was achieved first.

All air speeds are given as "equivalent air speed". Not sure what is meant by this term; I'm guessing that it means indicated airspeed.

Spitfire V / fabric covered frise ailerons:
90 deg/sec @ 170 mph (lowest speed graphed)
75 deg/sec @ 200 mph
55 deg/sec @ 250 mph
40 deg/sec @ 300 mph
27 deg/sec @ 350 mph
20 deg/sec @ 380 mph (end of graphed values)

Spitfire Mk V / metal covered frise ailerons
85 deg/sec @ 150 mph
105 deg/sec @ 200 mph
90 deg/sec @ 250 mph
75 deg/sec @ 300 mph
60 deg/sec @ 350 mph
40 deg/sec @ 400 mph

Spitfire Mk V / plain ailerons with tabs
65 deg/sec @ 180 mph
75 deg/sec @ 200 mph
95 deg/sec @ 250 mph
118 deg/sec @ 300 mph
90 deg/sec @ 350 mph
70 deg/sec @ 400 mph

The explanatory text which accompanied the graphs follows:

QUOTE -
Careful analysis over a long period of time 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

Smith then goes on to show a graph of stick efforts required to "apply 1/4 aileron at various speeds.

Spitfire V / fabric covered frise ailerons
8 lbs @ 200 mph
16 lbs @ 250 mph
27 lbs @ 300 mph
43 lbs @ 350 mph
57 lbs @ 375 mph (end of graphed values)

Spitfire V / plain ailerons with tabs
7 lbs @ 200 mph
9 lbs @ 250 mph
13 lbs @ 300 mph
18 lbs @ 350 mph
24 lbs @ 400 mph

Spitfire V / metal covered frise ailerons
4 lbs @ 200 mph
5 lbs @ 250 mph
7 lbs @ 300 mph
9 lbs @ 350 mph
12 lbs @ 400 mph

Smith elsewhere mentions in passing some roll rate values for other Spitfire Marks, to wit -

Spitfire I - 14 deg/sec @ 400 mph
Seafire 47 - 68 deg/sec @ 400 mph


Hope this helps.

Blutarski2004
06-17-2005, 08:46 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by ICDP:
The fact that the P51B does have a historical advantage at higher speeds is good. It is the fact that at medium speeds it is the equal of the Fw190 that is wrong. </div></BLOCKQUOTE>

..... Agree.



<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Can anyone else please test the Spitfire rollrate? I tested the Spitfire MkIXe standard and elipitcal wing versions and the rollrate is still identical. This has been the case since the Spitfire was introduced to FB, the clipped wing version should have a distinctly superior rollrate. At the moment there is no discernable difference in performance betwee standard and clipped wing Spits. </div></BLOCKQUOTE>

..... True, especially as roll rate broadly varies as the 4th power of the wingspan.

Blutarski2004
06-17-2005, 08:54 AM
Nice post Kurfurst. I have not seen this particular information on Spitfire roll performance before.

hop2002
06-17-2005, 01:23 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Nice post Kurfurst. I have not seen this particular information on Spitfire roll performance before.

</div></BLOCKQUOTE>

The NACA data Isegrim is quoting comes from their test of a Spitfire Va, sent to the US in April 1941. Robert Stanford Tuck flew it in late 1941, and described it thus:

"It happened that Wright Field had the only Spitfire in America-a Mark V. Unfortunately almost every pilot in the Air Corps had had a go on her and like a car that had too many drivers, she was the worse for wear...'She was very tired, very sloppy-she'd had the guts caned out of her all right."

NACA tested it after that, in other words it was a "very sloppy", "very tired" Va that had had "the guts caned out of it".

NACA also only tested at 30 lbs stick force.

You might like to look at http://www.1jma.dk/topic.asp?TOPIC_ID=3624&whichpage=2 (http://www.1jma.dk/topic.asp?TOPIC_ID=3624&amp;whichpage=2)

where Isegrim and I went over Spitfire roll rates (he still hasn't given me the apology he owes me from that thread), and at this current thread on the AH board on the same topic
http://www.hitechcreations.com/forums/showthread.php?s=&threadid=153240 (http://www.hitechcreations.com/forums/showthread.php?s=&amp;threadid=153240)

faustnik
06-17-2005, 01:29 PM
Here's an RAAF chart that I've been colorizing:

http://pages.sbcglobal.net/mdegnan/_images/RAF%20roll%20testCLR.jpg

Blutarski2004
06-17-2005, 03:08 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by hop2002:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Nice post Kurfurst. I have not seen this particular information on Spitfire roll performance before.

</div></BLOCKQUOTE>

The NACA data Isegrim is quoting comes from their test of a Spitfire Va, sent to the US in April 1941. Robert Stanford Tuck flew it in late 1941, and described it thus:

"It happened that Wright Field had the only Spitfire in America-a Mark V. Unfortunately almost every pilot in the Air Corps had had a go on her and like a car that had too many drivers, she was the worse for wear...'She was very tired, very sloppy-she'd had the guts caned out of her all right."

NACA tested it after that, in other words it was a "very sloppy", "very tired" Va that had had "the guts caned out of it".

NACA also only tested at 30 lbs stick force.

You might like to look at http://www.1jma.dk/topic.asp?TOPIC_ID=3624&whichpage=2 (http://www.1jma.dk/topic.asp?TOPIC_ID=3624&amp;whichpage=2)

where Isegrim and I went over Spitfire roll rates (he still hasn't given me the apology he owes me from that thread), and at this current thread on the AH board on the same topic
http://www.hitechcreations.com/forums/showthread.php?s=&threadid=153240 (http://www.hitechcreations.com/forums/showthread.php?s=&amp;threadid=153240) </div></BLOCKQUOTE>


..... Hop, thanks for YOUR info, which I also was unaware of. It does place matters in a rather different light.

Kurfurst__
06-17-2005, 04:16 PM
NACA definietely tested the plane at more than 30 lbs; Hop doesn`t tell the truth (quite unsurprising, knowing his record)

ie. :

"The pilot was able to exert a maximum of about 40 lbs on the stick. With this force, full deflection could be attained only up to about 130 miles per hour. Beyond this speed, the rapid increase in stick force near maximum deflection prevented full motion of the control stick. Only one-half of the available deflection was reached with a 40 lbs stick force at 300 miles per hour, with the result that the pb/2V obtainable at this speed was reduced to 0.04 radian, or one-half that reached at low speeds. "


Hop is propagating a sinlge 'MkV' test which has a strange spike on it (it was repeated in NACA report 868).
He claims it to be a flight test, however every time I ask him to post the ENTIRE document, he refuses it... strange!

Moreso, None of the other Spitfire roll rate tests show similiar spike, which is rather abnormal. It seems to indicate the uniquely high roll curve Hop is showing is a result of calculations, or, simple extrapolation of aileron effectiveness and stickforce, and was not actually measured.

Interestinly enough, Dave Southwood who flew the clipped Spitfire, claims 3 seconds (=120 deg/sec) for the plane as peak roll rate.

I wonder if Hop will deny again to provide to complete document and cherry-pick from it while dismissing half a dozen contradictionary test results, or just skip the whole and leave us with his claims unsupported, as usual.

To me the paper he presented looks like a calculated/extrapolated performance probably from a experimatal plane used to evaluate new types of ailerons on the Spit, and these facts are pointed out in the rest of the report Hop denies us to see.

hop2002
06-17-2005, 04:50 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Hop is propagating a sinlge 'MkV' test which has a strange spike on it (it was repeated in NACA report 868). </div></BLOCKQUOTE>
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Moreso, None of the other Spitfire roll rate tests show similiar spike, which is rather abnormal. It seems to indicate the uniquely high roll curve Hop is showing is a result of calculations, or, simple extrapolation of aileron effectiveness and stickforce, and was not actually measured. </div></BLOCKQUOTE>

Look at the chart Faustnik posted. It shows spikes for almos every aircraft, including the Spitfire. Such a spike is normal for most aircraft, inclduing the Spitfire.

So it's not "a single MK V test", the Australian figures are different, and therefore come from a different source.

The reason the NACA test you are refering to doesn't show such a spike, is, I suspect, because of the state of the Spitfire they tested.

We've seen Tuck's description of the condition of the aircraft as very tired, very sloppy. In fact, it's hard to imagine that the only Spitfire in America at the time wouldn't be rather tired, as I should think everyone and his dog went for a test flight in it.

I suspect the more tired and sloppy it became, the more the spike in the roll rate evened out, due to slop in the aileron control cables.

Exactly how many Spitfire tests don't show such a spike, and are they all of the same Wright Field Spitfire?

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">To me the paper he presented looks like a calculated/extrapolated performance probably from a experimatal plane used to evaluate new types of ailerons on the Spit, and these facts are pointed out in the rest of the report Hop denies us to see. </div></BLOCKQUOTE>

I don't have the full report, but it does say that the figures are tested at the RAE, and stresses the need for accurate instrumentation for such tests, disparaging roll rate figures obtained just with a stopwatch as hopelessly innacurate because of the times involved.
http://www.onpoi.net/ah/pics/users/282_1119048787_roll2m.jpg

Skyraider3D
06-17-2005, 05:21 PM
I'm with you on the rollrate issue concerning the Fw 190. Earlier this evening I made this post...
http://forums.ubi.com/eve/forums/a/tpc/f/26310365/m/1561092133


I believe the true maximum rollrate for the Fw 190 at 400 kph/250 mph should be in excess of 190 deg/s. The NACA report shows 155 deg/s but the example they tested had unusually heavy ailerons and underperformed.

Hunde_3.JG51
06-18-2005, 12:07 AM
You guys are ridiculous (in a good way). I asked one question and got all this great stuff, thanks alot guys, it is much appreciated.

Hunde_3.JG51
06-18-2005, 12:19 AM
Oh btw, did anyone send their FW-190 roll-rate findings to Oleg and crew? I haven't tested, but *IF* there is something wrong could someone please report it.

ICDP
06-18-2005, 02:20 AM
I reported my findings from 1st page on this thread. I hope this gets fixed as the historical rollrate of the Fw190 was one of its advatages.

ImpStarDuece
06-18-2005, 02:53 AM
Some more charts, just to confuse everyone http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

http://i7.photobucket.com/albums/y290/ImpStarDuece/Fw190_rollrate_01.jpg

CUJO_1970
06-18-2005, 11:49 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Hunde_3.JG51:
Oh btw, did anyone send their FW-190 roll-rate findings to Oleg and crew? I haven't tested, but *IF* there is something wrong could someone please report it. </div></BLOCKQUOTE>


This issue was known, confirmed and reported long before 4.01m was ever released.

Be sure.

Hunde_3.JG51
06-18-2005, 11:55 AM
Thanks ICDP and FW-190fan. Its good to hear that it was confirmed, not so good to see that it wasn't fixed in 4.01. Thanks again.

MAILMAN------
06-21-2005, 05:44 PM
The one thing that I have noticed is how poorly the Corsair (all versions) roll in the clean condition above 200 KIAS. Besides energy retention one of its best attributes was its roll rate. It was supposed to be close to the FW, but nothing rolls as good as the FW except at ultra hi speeds. I find that above 200 MPH the P-40 rolls faster than the F4U Corsair. Anyone have the information on this. I have read pilots accounts and seen data, but wasn't smart enough to save it.

hop2002
06-22-2005, 09:10 AM
http://www.onpoi.net/ah/pics/users/282_1119452800_f4uroll.jpg

I don't know how the Corsair roll rate changed between versions, so bear in mind this might not be representative of most, or even many, Corsairs.

SlickStick
06-22-2005, 02:54 PM
Hmmm...notice in those charts how the Spitfire with clipped wings rolls second only to the FW?!? The Spit CW roll rate has changed in V4.01m.

The CW Spits roll much slower than they did before, as well as the Ki-84s. I haven't done the comparison testing yet, but all planes seem to have decreased roll rate to me in V4.01m, including the FW-A9. Just my .02βΆ to add another opinion to the facts presented here.