FW-190A vs Spitfire, Me-109G, P-47D in dogfights

[David603]

I was intrigued by your description of the Anton as a low speed turner, so I decided to try some rough tests in Il2 to see if this supported the idea.

They are by no means perfect, but I did my best to keep conditions the same throughout the test and the results are averages of the good turns (ie if I stalled the aircraft or found myself more than 100m above or below my starting altitude I discarded the results).

I used the Fw109A-5 and the Spitfire LF MkIXc for the tests.

Technique used was a flat turn, using rudder where needed to keep the aircraft's nose up, and just trying to see the tightest turn that I could produce, regardless of speed.

Full throttle @ 500m (left turn)
MkIX 17.1 sec
A-5 22.4 sec

80% throttle @ 500m (left turn)
MkIX 16.0 sec
A-5 18.7sec

As you can see, while the Spitfire only gains 1.1 sec by downthrottling, the A-5 gains 3.7 sec, halving the gap from 5.3 sec to 2.7 sec, and the difference between a down-throttled A5 and a full throttle MkIX is only 1.6 sec.

The A-5 turns on a similar radius but at a lower speed, and is noticeably easier to stall, especially if you try to change direction once you have slowed down in the turn. Since both aircraft have props that rotate to the right, I didn't try repeating the tests with right turns.

[Ernst]

Originally Posted by David603

I was intrigued by your description of the Anton as a low speed turner, so I decided to try some rough tests in Il2 to see if this supported the idea.

They are by no means perfect, but I did my best to keep conditions the same throughout the test and the results are averages of the good turns (ie if I stalled the aircraft or found myself more than 100m above or below my starting altitude I discarded the results).

I used the Fw109A-5 and the Spitfire LF MkIXc for the tests.

Technique used was a flat turn, using rudder where needed to keep the aircraft's nose up, and just trying to see the tightest turn that I could produce, regardless of speed.

Full throttle @ 500m (left turn)
MkIX 17.1 sec
A-5 22.4 sec

80% throttle @ 500m (left turn)
MkIX 16.0 sec
A-5 18.7sec

As you can see, while the Spitfire only gains 1.1 sec by downthrottling, the A-5 gains 3.7 sec, halving the gap from 5.3 sec to 2.7 sec, and the difference between a down-throttled A5 and a full throttle MkIX is only 1.6 sec.

The A-5 turns on a similar radius but at a lower speed, and is noticeably easier to stall, especially if you try to change direction once you have slowed down in the turn. Since both aircraft have props that rotate to the right, I didn't try repeating the tests with right turns.

Nice. Do you have the track? How about using flaps combat in FW190? This is a nice test to do. May your FW turn was not sustained, but spitfire one did?

[AndyJWest]

Two questions, David603:

Were you trying to do a minimum-radius turn, or a best-rate turn? The results would be different. In combat, rate is usually more important than radius.

Are these sustained turn rates? Unless you can maintain speed, altitude and turn rate continuously, the results may be misleading. Even a loss of height of a few meters can make a noticable difference to results.

EDIT ---
I've been doing a bit of experimenting, using my prototype autopilot application (see http://forums.ubi.com/eve/forums/a/t...097#4121016097), and though I need to investigate further, I find it very difficult to believe a Fw 190 A5 will do a 360 degree sustained turn in 18.7 seconds, regardless of throttle settings. IL-2 compare suggests the best turn time will be around 24s, which is much more consistent with the results I'm getting at full throttle, and trying to turn at that sort of rate at 80 % throttle results in a rapid decay in airspeed. My autopilot is struggling to hold a smooth turn in these conditions (it was never designed to do this), but I'd be surprised if a human pilot could do much better - the plane is right on the edge of the stall.

As Ernst says, we need to see a track.

[Gaston]

The Spitfire Mk IX at full throttle is still 1.6 seconds faster than a FW-190A-5 at 80% throttle: This could be plausible if the FW-190A-5 does not use an optimal flap setting: The flap setting was critical to low-speed performance.

The Spitfire IX could not use a combat flap setting: 2 position only...

Soviet tests of a FW-190A-4 did show about 19 seconds in turn times, but it was displayed as 19-23 seconds, implying the difference in side of the turn(?).

Note the best Soviet Gustav time for that test, for a clean Me-109G-2, WAS 22 seconds, so right there you have the FW-190A out-turning the Me-109G to one side at least...

Me-109F was 20 seconds.

Note that the longer-nose A-5 was said by the Soviets to shave a second off these figures, which would give about 18-22 seconds.

I assume these real-life tests were all done at full power without flaps...

At partial power it could be all these aircrafts do not do much better in sustained turn TIME, but much better in RADIUS, which gives some advantage in sight lead also...

A FW-190A-8 in sustained low-speed level turns, flaps down, at 70% power(?), can gain nearly 180° per 360° on a P-51D at full power riding on the edge of a stall: If flaps up full power for the P-51D means 23-24 seconds, then the FW-190A-8 with the broad-blade prop could be as low as 16-17 seconds to one side (it was the right side with flaps down), to reverse a tail position in 2.? X 360° turns... The A-8 was said to be better than all previous FW-190As in low-speed maneuverability, especially with the broad-blade prop.

Of note is that the FW-190A riding on the edge of a stall requires the use of the ailerons to catch the stall's wing drop: At low speeds this favoured the choice of the longest chord of three different types of ailerons that could be used. The FW-190A Western ace in AH's forum described adding "spacers" to the hinges of his longest-chord aileron choice, to increase low-speed wing-drop "catch" performance further, this of course at the expense of aileron leverage and performance at high speed...

This choice of his was specifically described by him as being exclusively aimed at low-speed turn performance...

These aileron hinge modifications could explain the out-of-the-ordinary low-speed turn performance he mentions for his P-51D shootdown: 2.? X 360 to reverse a tail position on the deck, the P-51D almost stalling in front of him...

Not clear if the aileron hinge extensions were a field modification, or availabe as a kit...

Interesting tests for the in-game figures... Thanks!

Gaston

[AndyJWest]

Soviet tests of a FW-190A-4 did show about 19 seconds in turn times, but it was displayed as 19-23 seconds, implying the difference in side of the turn(?).

Nope 19-23 seconds means exactly what any engineer/test pilot would expect it to mean - somewhere between the upper and lower limit, but not accurately measured. Or if it doesn't, it is down to you to provide evidence why, not just assume it means what you want it to.

And as for 'catching the stall's wing drop' with aileron, this is nonsense if you are talking about a sustained turn (along with airspeed, turn rate and altitude, AoA must be constant so either the wing is stalled or it isn't), and dubious as a means to recover from a stall anyway. If a wing is stalled, down aileron is going to make it worse.

Even with the luxury of an autopilot, and no worries about structural/engine failure, fatigue from G forces, instrumentation errors and the rest, practical experience with the few tests I've run tells me that any measurements of turn rates need to be taken with some scepticism. Out of curiosity, does anyone actually know how turn rate was measured? The compass would be useless, and I'm not sure a gyro would be much better - they tended to tumble with extreme manouvering.

[JtD]

Originally Posted by AndyJWest

Nope 19-23 seconds means exactly what any engineer/test pilot would expect it to mean - somewhere between the upper and lower limit, but not accurately measured. Or if it doesn't, it is down to you to provide evidence why, not just assume it means what you want it to.

Actually the numbers are 22-23 seconds. So 19-23 means the author has manipulated original data to prove his point, nothing else. Don't blame the engineers / test pilots.

[AndyJWest]

Originally Posted by JtD

Actually the numbers are 22-23 seconds. So 19-23 means the author has manipulated original data to prove his point, nothing else. Don't blame the engineers / test pilots.

Interesting. So where did the '19 seconds' come from? Of course, if Gaston can provide a verifiable primary source to validate his figures (does he know what this is?), there might be room for debate.

Actually, I'd still like to know how turn rates were actually measured. With figures being bandied about supposedly accurate to 1/10th of a second per 360 degrees, it would be nice to know how they were arrived at.

And I'm still waiting for a track that can show a sustained turn in a Fw 190 A5 anywhere near 18.7s per 360 degrees. then again, I'd be surprised if you could do that in any true horizontal turn, sustained or not...

[JtD]

Originally Posted by AndyJWest

And I'm still waiting for a track that can show a sustained turn in a Fw 190 A5 anywhere near 18.7s per 360 degrees. then again, I'd be surprised if you could do that in any true horizontal turn, sustained or not...

Not that hard, with 25% fuel and without ammo you can easily sustain 18s/360 at sea level, tested on the Moscow map (winter). It's just about how much apple the oranges are. Or vice versa.

Real life testing consisted of a number of 360° turns at 1000m altitude, observed and timed from the ground. At least in the SU. Variances of the results were due to aircraft conditions, atmospheric conditions, flying conditions and piloting skills. While an individual test would give you results with as many digits as one liked, these were rarely used for practical purposes. Usually, as with the Fw 190A-4, there'd be a range of numbers given in whole seconds. The more testing had been done, the better the engineers and pilots knew the plane, the more constant the plane performance was, the smaller the range would be.

[Ernst]

Reducing powe can or not to help increase turn rate. If you are above your corner speed so reducing power ll help.

In il2 in particular i feel that reduce power to 80 percent in the middle of turn help a little to increase your turn rate for a moment. I am not certain but i feel the aircraft turning faster at cost of some airspeed.

Someway torque of the engine works against your turn, the plane wants to go out and drifts. This way may be setting engine in 80 per cent helps a more stable turn.

[JtD]

That's true Ernst, above corner speed, if you reduce you speed, you'll turn faster.

But Gaston is focusing on sustained turning and the mechanics behind it, so my reply was directed at that. I should have made that clear.