Something I recently read about Bf-109E series

[gripen]

HoHun,
The RAE tests were made at 12k and at full throttle (Spitfire 6000lbs, Bf 109 5600lbs). We also know that the Spitfire had higher critical mach number so it could sustain more Gs troughout hole altitude range. In the case of the sustained turning the Spitfire could allways turn smaller circles than the Bf 109 despite what ever power ratings were used. Generally the energy level of the plane is not a big issue if the controll forces are not the limiting factor, as an example we can compare these planes:

Spitfire
3g turn, V~170mph R=688ft, about 17s
5g turn, V~225mph R=678ft, about 14,5s

Bf 109
3g turn, V~190mph R=870ft, about 20s
5g turn, V~250mph R=855ft, about 15,5s

So we can see that energy gives better turning times but not much better turning circles.
I believe that main reason for these Bf 109 out turning Spitfire cases is skill of the pilots; same thing happened when experienced RAE test pilots flew mock combats against Spitfires piloted by normal squadron pilots.

gripen

[HoHun]

Hi Gripen,

>So we can see that energy gives better turning times but not much better turning circles.

12000 ft is still lower than the typical engagement altitude during the Battle of Britain, which I'd say probably ranged from 20000 ft to 30000 ft.

The G-rates you quote are non-sustainable, and while you're right on turning circles, we're talking about turn rates here.

To illustrate my point: At its service ceiling (about 32000 ft), the turn rate of the Spitfire I is (close to) zero. The Me 109E has a higher ceiling (37500 ft), so that at the 32000 ft, it has much more energy left for turning than the Spitfire.

If this seems somewhat academic: It shows that even if the Spitfire I turns better at 12000 ft, there'll be some altitude between 12000 ft and 32000 ft where both aircraft have the same sustained turn rate, and above that altitude, the Me 109E is able to beat the Spitfire I in sustained turns.

Whether that is tactically meaningful depends (among other factors) on the exact break-even altitude, but Leykauf at least attributed several of his kills to superior turning of the Messerschmitt.

Regards,

Henning (HoHun)

[gripen]

HoHun,
I generally agree your point ie. plane with higher ceiling (depending how we define service ceiling) will reach better turn rates at high altitude. But AFAIK typical fighting altitudes during the BoB were a lot below 30k (less than 10k during early stages of the BoB and around 20k later), did Leykauf claim the altitude?

Also the pursuing plane must turn inside other planes circle to reach firing position despite what ever sustained or momentary turn rate it does.

gripen

[Bombjack]

The speed at which max sustained turnrate is achieved in a Spit is considerably higher than that of the 109. If Leykauf's victims were pulling sustained turns at or around the stall, I would expect him to outturn them.

[Daff]

I agree with Gripen here.
AFAIK, Bombers flew fairly low in BoB (From 10-20k) and the LW was ordered to fly close escort, so they had to be at roughly the same altitude.

Daff

[mw]

hmmm...  Just a thought, 109's slots decreased stall speed but the increased drag with the slots out outweighed any benefit in getting around the circle.

[Badboy]

Originally posted by HoHun:


In short, there are many reasons why apparently contradicting accounts and reports could be all true, and one shouldn't dismiss any of them prematurely :-)

Regards,

Henning (HoHun)

Wise words indeed!

You just reminded me of some of the lengthy debates we used to have way back when, seems like an eternity ago!

How long have you been flying AH?

Nice to see you buddy!!

Badboy

[gripen]

Originally posted by Bombjack:
The speed at which max sustained turnrate is achieved in a Spit is considerably higher than that of the 109. If Leykauf's victims were pulling sustained turns at or around the stall, I would expect him to outturn them.

Well, actually exact numbers for max sustained turn rate at 12k and full throttle are:
Spitfire: R=696ft Vi=133 2,65g 19s
Bf 109: R=885ft Vi=129 2,1g 25s

So there is not much difference in speeds at max sustained turn rate and the Spitfire has a clear advantage as numbers show. And the elevator control forces are not the limiting factor for the Spitfire, so more speed means just a bit more advantage for the Spitfire.

gripen

[Angus]

Just read this old and excellent thread, so I thought I's breathe some life into it again:)
Here is some additional test pilot comparison of the Spitfire and the Me109E:

I have mentioned how badly I felt about the ailerons of the Spitfire at the time of the Battle of Britain. In October 1940 I flew a captured Me109E; to my surprise and relief I found the aileron control of the German fighter every bit as bad - if not worse - at high speed as that of the Spitfire I and II with fabric-covered ailerons. They were good at low and medium speed, but at 400mph and above they were almost immovable. I thought the Me 109E performed well, particularly on the climb at altitude. and it had good stalling characteristics under g except that the leading-edge slats kept snapping in and out. But it had no rudder trimmer - which gave it a heavy footload at high speed - while the cockpit, the canopy and the rearward vision were much worse than the Spitfire. Had I flown the Me 109 earlier, I would have treated the aeroplane with less respect in combat.
Jeffrey Quill

How about that!