Are slats shy ?

[Crumpp]

I suggest AOA changes would generally result in the slats being either in or out ... hence the pilots description of them "banging" in or out.

Look at the Bf-109E polar I posted, it is only ~2.5 degrees of AoA between the slats beginning to open and fully deployed. That is not much to work with.

I did not say it was easy or did not take practice to control them. You are right in that it is not something a pilot is likely to master in his first few hours. They take some getting used too. The airplane will shift when they deploy. If you watch the video, you can see some of the changes in radius in that turn. The slats can make loud startling noises.

In a fighter equipped with them, that shifting would make aiming more difficult. Once you learn what they can do though, the low speed maneuvering is fantastic. I won an ultralight Short Landing contest with a 4000lb airplane because of those slats. I could hang that airplane on the propeller all day long. In fact, clean, it would not break in the stall. With full length LE slats, the plane would nose up, hang on the propeller, and gradually enter a 900 fpm descent. You were stalled when the airplane was nose up and descending. The stall angle was so steep, I used to put a pencil on the glare shield to impress FAA examiners and it would fall straight back to the luggage compartment over the top of all the seats without hitting them.

The real maneuvering fight would not begin for a Bf-109 pilot until those slats where out. That is exactly how I felt about my aircraft. Once those slats deployed, it was time get busy if I wanted to maneuver.

"The Bf 109s also had leading edge slats. When the 109 was flown, advertently or inadvertently, too slow, the slats shot forward out of the wing, sometimes with a loud bang which could be heard above the noise of the engine. Many times the slats coming out frightenened young pilots when they flew the Bf 109 for the first time in combat. One often flew near the stalling speed in combat, not only when flying straight and level but especially when turning and climbing. Sometimes the slats would suddenly fly out with a bang as if one had been hit, especially when one had throttled back to bank steeply. Indeed many fresh young pilots thought they were pulling very tight turns even when the slats were still closed against the wing. For us, the more experienced pilots, real manoeuvring only started when the slats were out. For this reason it is possible to find pilots from that period (1940) who will tell you that the Spitfire turned better than the Bf 109. That is not true. I myself had many dogfights with Spitfires and I could always out-turn them.
One had to enter the turn correctly, then open up the engine. It was a matter of feel. When one noticed the speed becoming critical - the aircraft vibrated - one had to ease up a bit, then pull back again, so that in plan the best turn would have looked like an egg or a horizontal ellipse rather than a circle. In this way one could out-turn the Spitfire - and I shot down six of them doing it. This advantage to the Bf 109 soon changed when improved Spitfires were delivered."
- Erwin Leykauf, German fighter pilot, 33 victories. Source: Messerschmitt Bf109 ja Saksan Sotatalous by Hannu Valtonen; Hurricane & Messerschmitt, Chaz Bowyer and Armand Van Ishoven.

http://www.virtualpilots.fi/feature/...09myths/#slats

As I see it based on my experience and knowledge:

Slats Pro's

- Low speed handling / maneuvering improvement
- very benign stall
- immune to spinning (read the RAE trials)

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

Slat Con's
- Opening moment reduces effectiveness as a gun platform.
- Asymmetric deployment is normal. A mechanical malfunction is not. If a slat becomes stuck due to mechanism failure, the pilot has a real control problem if the other deploys.
- noise form a hard opening is startling.