Leading Edge Slats on the Me-109

[Crumpp]

One wonders what the 109 would have been like to fly without the slats.

It would have been rather bad in the stall characteristics.

The wing would have stalled all at once instead of root first and the tips receiving an energized boundary layer to keep the flow attached.
The entire wing stalling would be violent and uncontrollable.
Same thing the Spitfire would do without the twist. Major difference being twisting the wing does not energize the boundary layer so the ratio of turbulent to laminar flow remains the same.
The slats increase the amount of turbulent flow over the wing. The turbulent flow portion of the boundary layer is the high energy, high lift portion.

[Crumpp]

nothing to do with making it better at turning

Obviously, this comment is an effort to troll because it is contrary to the physics behind the slats.

The slats are a very practical method of allowing the pilot to quickly, precisely, and safely achieve CLmax.

They act as training wheels allowing the pilot to maximize performance of the aircraft without fear of losing control.

[CWMV]

Oberleutnant Erwin Leykauf said, ‘For us, the more experienced pilots, real
manoeuvring only started when the slats were out.'

From Messerschmitt Bf 109 at War. Pretty common statement. Ive seen interviews with Rall where he said the same thing.

[*Buzzsaw*]

Originally Posted by Crumpp

The slats are a very practical method of allowing the pilot to quickly, precisely, and safely achieve CLmax.

Actually your comments are an exaggeration.

What the slats do is allow a pilot the confidence that if he pulls too much G and stalls his aircraft, the likelyhood of a violent spin is diminished and the knowledge he should be able to recover relatively easily.

The slats in themselves do not give any guarantee of a stall not occurring, they merely make the event, when it occurs, less violent.

The pilot still must be able to judge whether or not his aircraft is about to depart, and how many G's he is able to pull before departure may occur.

The slats opened prior to the stall, by RAF estimation, approx. 1/2 a G, and in pulling further G's and in order to avoid a stall, the pilot had to know the further signs of a stall approach, in the same way a Spitfire or Hurricane pilot was required to monitor his aircraft's behaviour.

In addition, the installation of the slats was not without penalty. As noted, the slats by deploying, increased the lift generated by the outer section of the wing, but they also generate more drag and reduce the speed of the aircraft. For earlier models of the 109, in particular the E, the chances of the slats deploying assymetrically in a turn was a factor, which was noted to cause aileron snatching and which could cause the aircraft to change direction without the pilot's intention.

[NZtyphoon]

Originally Posted by *Buzzsaw*

Actually your comments are an exaggeration.

What the slats do is allow a pilot the confidence that if he pulls too much G and stalls his aircraft, the likelyhood of a violent spin is diminished and the knowledge he should be able to recover relatively easily.

The slats in themselves do not give any guarantee of a stall not occurring, they merely make the event, when it occurs, less violent.

The pilot still must be able to judge whether or not his aircraft is about to depart, and how many G's he is able to pull before departure may occur.

The slats opened prior to the stall, by RAF estimation, approx. 1/2 a G, and in pulling further G's and in order to avoid a stall, the pilot had to know the further signs of a stall approach, in the same way a Spitfire or Hurricane pilot was required to monitor his aircraft's behaviour.

In addition, the installation of the slats was not without penalty. As noted, the slats by deploying, increased the lift generated by the outer section of the wing, but they also generate more drag and reduce the speed of the aircraft. For earlier models of the 109, in particular the E, the chances of the slats deploying assymetrically in a turn was a factor, which was noted to cause aileron snatching and which could cause the aircraft to change direction without the pilot's intention.

From what I have read 109 pilots did have concerns about the slats banging open, causing a jolt because of aileron snatching and sometimes upsetting the pilot's aim. Fact is that all designs are a compromise in one way or t'other - like I keep saying slats were no better nor worse at aiding control than other aerodynamic aids. In the end it was the pilot's skills and experience that made a real difference; learning how to get the best out of the aircraft was a great survival technique.

[Crumpp]

Actually your comments are an exaggeration

Let's be specific and point exactly what you think I "exaggerated" otherwise your post is simple trolling and bait attempt to define me as being "red vs blue".

Buzzsaw, you state exactly the same thing I have without any change.

[Crumpp]

4.4. Stalling Tests

We find that under all conditions tested, the Bf-109 has:

no tendency to spin.

http://kurfurst.org/Tactical_trials/...ls/Morgan.html

[Glider]

Originally Posted by CWMV

Oberleutnant Erwin Leykauf said, ‘For us, the more experienced pilots, real
manoeuvring only started when the slats were out.'

From Messerschmitt Bf 109 at War. Pretty common statement. Ive seen interviews with Rall where he said the same thing.

The key of course are the words 'the more experienced pilots'. As the war went on the proportion of experienced pilots fell dramatically.

[CWMV]

With respect that has nothing to do with the purpose/effect of the slats. They did what they did, up to the pilot to exploit it.

[Robo.]

Originally Posted by Crumpp

no tendency to spin.

The in-game 109 has not any unusal tendency to spin - you will stall her of course when you do a mistake and lose control. That is a very good match with the 'us experienced pilots'. I would say that the problem lies in the spin recovery, e.g. once the a/c enters the spin, it is more difficult to recover than it should be.