Bf 109E rate of roll
 

Hello!
The title says it all! I'm looking for the rate of roll of the 109E.
Can aynone help me?
Thanks.

Chris

Re: Bf 109E rate of roll
 

Hi Christian, Butch2K forum: http://www.allaboutwarfare.com is probably the best place to ask about such technical things... You will get the graphic curve...

Re: Bf 109E rate of roll
 

Merci.

CJ

Re: Bf 109E rate of roll
 

here is what i have, cant tell you the original sources indeed... Both state that the 109E got a better roll rate than the Spitfire up to 325 mph indicated airspeed...

Re: Bf 109E rate of roll
 

Arg! Post a wrong one on the previous answer

Re: Bf 109E rate of roll
 

The second one certainly doesn't show the 109 as superior to the Spitfire - quite the reverse. It shows that at lower spreeds the Spitfire is superior to all others, with only the Fw 190 superior until very high speeds are reached.

Are these two graphs showing a difference between the fabric and metal ailerons?

Re: Bf 109E rate of roll
 

Re: Bf 109E rate of roll
 

They look different, Juha, because they were added after the others. As you noted, the original graph does not include the 3 a/c you mentioned.

I find the difference between the roll-rate for the Spitfire 1a and the "Spitfire" very interesting. It's hard to believe it's the same type of aircraft. Would metal ailerons make that great a difference in roll-rate?

Re: Bf 109E rate of roll
 

Hello George
The metal ailerons were a vast improvement. From Quill's Spitfire. A Test Pilot's Story. Arrow Books (1990) p. 182.
When he flew a Spit R6718 with metal skinned ailerons first time on 7 Nov 40 "...they changed the situation in the most spectacular way, being much lighter at the top end of the speed range without any loss of effectiveness at low or medium speeds. The aeroplane was transformed..." at Farnborough "where it was flown by Willy Wilson (OC Aerodynamics Flight) and Roly Falk and they reported a 'vast improvement on anything so far tested'; 'excellent control'..."

What bothers me is the big difference in low and medium speeds on the 3rd graph between the curve of Spitfire (original) and the added curve of Spitfire1a. From Quill and other sources I have gathered that the metal skinned ailerons improved vastly the rate of roll of Spit at high speeds but I cannot remember any reports where there has been claims on vast improvements at low or even medium speeds. I don't have time to check Morgan's & Shacklady's Spit tome.

So I have doubts on the curve of Spitfire 1a and because of that I would not place too much confidence on the curve of Bf 109E4 either. It might be OK but I would like to see some confirmation on its authenticity.

Juha

Re: Bf 109E rate of roll
 

Source is J. Smith:The Developement of the Spitfire and Seafire (Royal Aeronautical Society)

Re: Bf 109E rate of roll
 

Here's a more complete version from niklas's site,showing stick forces as well, it's not quite even playing field.. I wonder if anyone

http://i38.photobucket.com/albums/e1...E_ailerons.jpg

There are some comments of 109E roll rate in the August 1940 Luftwaffe tactical comparison on my site : http://www.kurfurst.bravehost.com/


I've seen an article on a recently restored 109E test flight, the pilot said the ailerons were very impressive, and he compared them to the spit w metal ailerons, but 50% higher roll rate, but nothing more specific. I suppose because of the square wingtips of the 109E..?

Speaking of clipping, I always wondered about that clipped/Unclipped Spit roll rate graph. It seems to originate to RAE, but the trouble with it is that half a dozon reports I have on the same things is just showing it's something alien.

I have ww2 pilot queries, in which they were asked wheter they could compete the 190 in roll - the vast majority said not a chance, ask back for normal wings. I have pilots on restored warbirds, they say the metal ailrons were pretty much the same as the 109s (ie. 80-90 degrees peak), and the clipped at 3 secs for a 360 degree roll. The NACA tests specifically says they can't obtain full deflection over 140 mph ias with 40 lbs, and RAE in comparison with the Mustang notes 45 deg/sec roll rate at 400 mph ias would require 72 lbs stick force on the Spit.

Then there's the British tests on wheter clipping worths it or not, and they say...
http://i38.photobucket.com/albums/e1...it_clipped.jpg

Finally here's some timed roll rate tests on two spit 12s, one was considered having 'poor' ailerons, the other good ones, decribed in the rest of the report. Linked via M williams site : http://www.spitfireperformance.com/mk12roll.gif It agrees well with the findings of RAE posted above.

Compare with the trend on NACA roll chart posted. It just don't agree at all, and I wonder why is this, I tend to b inclined that this is probably showing some MkV experimental aileron type testing, there were quite a few such tests in 1943. Does anyone have a detailed report that the NACA roll chart is originated from?

Re: Bf 109E rate of roll
 

Hello Kurfürst
I expected that You can deliver some facts. Quill also flew a captured Bf 109E in Oct. 40. According to him (Op cit. p. 183) "to my surprise and relief I found the aileron control of the German fighter every bit as bad, if not worse than, at high speed as the Spitfire I and II with fabric-coverred ailerons. It was good at low and medium speed but at 400 mph and above it was almost immovable."

CJE
Best I came across is the following info on Bf 109F-4. Source: Jukka Rautio's Mäntämoottorihävittäjän suorituskyky Osa 6 in Suomen Ilmailuhistoriallinen Lehti pp. 10 - 13. According to it DVL's test results in spring 44 were (flown at 3000m because it was not possible to do the tests at the planned 6000m due "the enemy's air activity")
The fastest roll was made at 500kmh (TAS), time for full roll (360deg)was 4,5 sec. at 600kmh time was 7 sec and at 700kmh 13,5 sec.

Juha

Re: Bf 109E rate of roll
 

Thanks to all for this most interesting discussion.
French also test-flew a captured E-4 but strangely enough they did not bother recording its rate of roll.

Re: Bf 109E rate of roll
 

Hi Juha,

I have that DVL flight test, and it's indeed by far the most detailed roll rate test I have ever seen, probably because it's was done for theoretical research work! I was very impressed with it, though the stick forces appear to be much higher than reported in Finnland tests I am aware of, and Southwood's oral account. These datasets may be incompatible, or maybe it's effected because the testbed aircraft in DVL's tests was Bf 109F, by late 1944, it was quite possibly a bit worn out.

As for J. Quills comments, they seem to be very nicely aligned with British findings, the roll rate at high speed seems equally bad, though the stickforces on the 109 are much lower. I wonder if the full British report on that has more.

Re: Bf 109E rate of roll
 

It's a long time since I read the US report, but on the graph it states "increased wing". As the US received an HF Mk.VII (now in the NASM) this will refer to the high altitude extended tips - not the standard wing. Comments?

I must admit being surprised that the RAE were unable to detect a difference between the standard and clipped roll rate. If it hadn't produced any difference, it would not have passed initial trials and disappointing comments from the service would have prevented it being widely adopted. Perhaps there was some psychological effect? Alternatively, could this have anything to do with differences between the maximum roll rate achievable and the time taken to reach this?

Re: Bf 109E rate of roll
 

Firstly micron468
Thanks for the graph, much appreciated!

Kurfürst
Yes, the test subject was wing twist. On the results, IMHO the roll rate was rather good at 500kmh and at 600kmh. Do You know at what altitude the other tests were made? According to Raunio the problem in the test was that the pilot could not turn the stick greater than 20 kp force at 600kmh because of the narrowness of the cockpit and so was able to use only 6 deg. aileron at that speed. At higher altitude the ailerons should have been lighter. Also in 109G the skin of the wings was thicker so there should have been less aerodynamic twist and a little better rollrate at high speeds.

BTW the Raunio's article was in number 3/2005, I left that out in my earlier message.

On British test on 109E, I cannot remember seeing any graphs of it but in Quill's book pp. 183 - 184 "The A & AEE reported on the Me 109E in Oct. 1941:"The flying controls have excellent response and feel at low speeds but are far too heavy for manoeuvring at high speeds. The extreme heaviness of the ailerons makes rolling almost impossible at speeds obove 400mph."

But if Spit Mk V with metal covered ailerons could achieve only 40 deg/sec at 400mph(640kmh) (at what heigh?) and 109F-4 could made a full roll in 7 sec at 600kmh, was 109 so bad, at least from F onwards?

Juha

Re: Bf 109E rate of roll
 

It'll be IAS, so the height is irrelevant. The Mk.V could only achieve 400mph in a dive, anyway.

Re: Bf 109E rate of roll
 

Thanks Graham, I suspected that, so Smith's graph is identical to that of NACA. Do You Know what was appr. IAS equivalents for 109F 's 500kmh (TAS) and 600 kmh (TAS) at 3000m? Or other way around what were appr. TAS equivalents for Spit V's 310mph (IAS) and 375mph (IAS) at 10000ft?

Also 109E could achieve 400mph only in dive and I think same was true for F-4 at 3000m.

Juha

I should have first look my archives, so for 109F-1 and -2 at 3000m 469kmh (IAS) = 553kmh (TAS) and 486kmh(IAS) = 573kmh (TAS). Source Kennblatt for Bf 109F-1 and F-2. Berlin 1941.

To be honest I was thinking that the difference between IAS and TAS in this case was appr. 50 kmh but it seems to have been appr. 85kmh.

Re: Bf 109E rate of roll
 

And 35mph (56kmh) seems to be rather good appr. for the difference between IAS and TAS for Spit Mk V at around 310mph at 10000ft. This according to some tests shown at www.spitfireperformance.com.

Juha

Re: Bf 109E rate of roll
 

True Air Speed is Equivalent air speed divided by the square root of the relative density (sigma). I think you can assume that for this flight region Equivalent airspeed equals indicated airspeed. This may introduce a few knots difference because of the pressure error on the Spitfire's instruments.

for sealevel root sigma = 1 (by definition)
for 10000ft root sigma is 0.8594
for 20000ft 0.7299
for 30000ft 0.6117

You can interpolate for other heights from that. Values come from the International Standard Atmosphere as tabulated by the Kingston (Hawker) Project Office 1964.

So 310 kts IAS at 10000ft is 361 mph
375 mph at 10000ft is 436 mph

Re: Bf 109E rate of roll
 

Thanks a lot, Graham, greatly appreciated!
I have the formula somewhere but where? Now I'll print a couple copies of Your answer and archive them relevant but different places plus I'll take a couple copies of it on my harddisk. So I probably will be able to find it when the need arise next time.

Thanks again
Juha

Re: Bf 109E rate of roll
 

So, thanks to the conversion formula given by Graham it seems that around 300mph (480kmh)IAS/350mph(560kmh)TAS the rollrate at 10000ft of the Bf 109F-4 used in the DVL's test dropped lower than that of almost all of the fighters used in the NACA’s test shown in the 3rd graph posted by O. Menu. That if I got all right. So not so impressive result after all.

Juha

Re: Bf 109E rate of roll
 

A small point, but I assume you mean mph on both lines, rather than the "310 kts."

Re: Bf 109E rate of roll
 

I refined my rough calculations a bit. The earlier was based only for the time of a full roll of the Bf 109F-4 used in DVL's test but if we suppose that the Bf's rollrate accelerates to full rate during the first 45deg (this is made only because I have info only for time to first 45 deg ,unfortunately for a 109E as shown in the first graph posted by O. Menu but according to Raunio, op. cit, also G-6 took the same time (4sec) at a little over 600kmh to achieve 45deg , (Raunio doesn't give his source) and the time for a full roll for the 109F-4. And also to keep the maths simple). So the according to this refined but still rough calculation it was around 325mph/523kmh(IAS) / 378mph/608kmh(TAS) when the rollrate at 10000ft of the Bf 109F-4 dropped lower than that of almost all of the fighters used in the NACA test and at appr. 375mph/603kmh(IAS) its rollrate is the same as that of Typhoon which had the clearly worst rollrate over 330mph(IAS) among those fighters used in the NACA test (Zero's measurements seemed to stop at 330mph(IAS)).
OK this is my last calculation for a while!!!