Leading Edge Slats on the Me-109

[*Buzzsaw*]

Originally Posted by Kurfürst

I agree. The hideous stalling characteristics of the 109 are the most important aspect of the 109-FM that needs improved upon. The real 109 was an almost foolproof plane in the air with gentle stall characteristics (and was so in Il-2FB), compared to the thing we have in the sim doing wild things for seemingly no reason.

There are a lot of myths about slats, and a lot of misunderstandings.

The 109's slats do not prevent stalls or automatically give the 109 a stall speed lower than other aircraft. The 109E stalled at speeds higher than the Spitfire I or Hurricane I. A stall is a stall, a loss of effective control of the aircraft by the pilot and a subsequent loss of height.

What the slats do is resist, not prevent the typical right or left wing drop and potential entry into a spin at the stall you see with other non-slat equipped wings, the typical level flight, power off 109 stall is a simple loss of control and gentle nose drop which allows for a quick recovery.

But the pilot still loses control. The aircraft stalls.

And, in accelerated power on stalls under G, the 109 could drop a wing, just like any other aircraft. The chances of this was less, but the slats did not exclude this possibility.

[Kurfürst]

Originally Posted by *Buzzsaw*

And, in accelerated power on stalls under G, the 109 could drop a wing, just like any other aircraft. The chances of this was less, but the slats did not exclude this possibility.

I agree, of course it should stall and yes, the stall speed was a bit higher. The slats practically do the same thing as washout would do on a slat-less aircraft, making the outer wing section stall later (at higher AoA) than the inner wing, thus maintaining aileron control longer.

The problem is how how this stall happens - from everything what I have read I'd expect the 109 to be pushed fairly far in a turn (partly because of the slats, party because of the elevator's characteristics), the ailerons would snatch a bit when the slats are opening (at least on the 109E), and when it would stall, gently start to sink, none of the violent flick overs, flat spins and other rubbish we have the sim.

"When doing tight turns with the Me.109 leading at speeds between 90 m.p.h. and 220 m.p.h. the Spitfires and Hurricanes had little difficult in keeping on the tail of the Me. 109. During these turns the amount of normal g recorded on the Me. 109 was between 2½ and 4 g.[b] The aircraft stalled if the turn was tightened to give more than 4 g at speeds below about 200 m.p.h. The slots opened at about ½ g before the stall, and whilst opening caused the ailerons to snatch ; this upset the pilot's sighting immediately and caused him to lose ground. When the slots were fully open the aircraft could be turned quite steadily until very near the stall. If the stick was then pulled back a little more the aircraft suddenly shuddered, and either tended to come out of the turn or dropped its wing further, oscillating meanwhile in pitch and roll and rapidly losing height ; the aircraft immediately unstalled if the stick was eased forward. Even in a very tight turn the stall was quite gentle, with no tendency for the aircraft to suddenly flick over on to its back and spin. The Spitfires and Hurricanes could follow the Me.109 round during the stalled turns without themselves showing any signs of stalling."

[Robo.]

Kurfurst I suggest you talk to the 109 pilots who are in perfect control of their aircraft and never stall it even in very aggressive maneuveurs (that someone here claimed to be impossible). It is in a good match with real life records - 109 expert can really really push harder and even outturn not so capable RAF pilot.

I also fly the 109 very often and I don't have this problem (unless I make a pilot mistake like too much foot or ). The aircraft is controllable even in very aggressive maneuveurs and last second corrections like full rudder deflection shots. You will get into high speed stall by doing that incorrectly but that's not aircrafts fault. I wonder if FF helps, I am using MSFF2 joystick and I can really 'feel' the aircraft.

Hurricane's stall behaviour is much worse than 109s btw, with droping the wing if you're not careful.

[Kurfürst]

Originally Posted by Robo.

Kurfurst I suggest you talk to the 109 pilots who are in perfect control of their aircraft and never stall it even in very aggressive maneuveurs (that someone here claimed to be impossible).

*sigh* point me in the direction of these experience pilots. Besides you do not seem to get the point - the problem is not that the 109 stalls (it should) neither that it does not outturn RAF planes (it shouldn't though getting near to it's turn limit SHOULD be easier than on those) but HOW it stalls. Stalls are extremely violent on this aircraft and spins occur often.

And apparently it's not just my problem. And dear Sir, I fly the 109 since original Il-2 beta - I have never had the problem with it like it's in Il2, well, except for something was extremely badly sc***d up with the G-6's FM.

"Word came from the Luftwaffe out of Antwerp early in the spring of 1943 that many pilots had experienced spin problems with the Me109 G and had to bail out. Numerous airplanes had been lost. Karl Baur's first reaction: "This is almost a foolproof airplane. How do these guys accomplish that?" The Me 109 had a relatively high wing loading (32.2 lb/sq ft) and therefore stalled readily under heavy G forces but the stall was gentle and the aircraft exhibited good control under G forces. If the stick was eased forward the aircraft immediately unstalled with no tendency to flick over on its back and spin. While not totally spin proof it took a fairly ham fisted pilot to get into trouble in the Me 109.

It took Karl several nerve wracking flights before he was able to get a Me 109 into a spin. Finally, after he had tried every possible dog fight maneuver, he had it figured out. It was during those split seconds before going into a vertical dive that it was possible to get this airplane to spin. Only rough flying inexperienced pilots were able to do it. Karl's solution to the problem was very simple. He advised: "Drop the landing gear boys, and the spin will end immediately." The dropped landing gear would appear to lower the airspeed and reduce the severity of the yaw (the movement around the normal axis of the aircraft, i.e. direction stability). Once the aircraft is not spinning (yawning) around its center of gravity the aircraft being in a nose down attitude accelerates and becomes unstalled.

p.86 of: A Pilot's Pilot, Karl Baur - Chief Test Pilot for Messerschmitt by Isolde Baur

I wonder if FF helps, I am using MSFF2 joystick and I can really 'feel' the aircraft.

Maybe, but I do not have a FFB joystick. I tried it once at a friends, but it behaved very weird in CLOD.

Hurricane's stall behaviour is much worse than 109s btw, with droping the wing if you're not careful.

Yes, the Hurri definietely sucks in this regard - but I do not know how the Hurris stall characteristics were.

[*Buzzsaw*]

Salute

Kurfurst is quite correct in noting the game 109 is quite difficult to recover from spins. I have often seen game 109's spinning to their destruction from considerable heights.

This is quite clearly an incorrect modelling of the real aircraft, which was in fact easy to recover from spins or stalls, one would have to be quite ham handed to maintain a spin in the historical aircraft. Not impossible mind you, given a pilot doing all the wrong things, but given a pilot with the training, recovery should be prompt and with a relatively minor altitude loss.

As far as the historical Spitfire stall characteristics were concerned, there was definitely the possibility of a violent flick and spin if the aircraft was pulled into a high G Stall, however, the Spitfire had a characteristic which allowed experienced pilots to know exactly how far to take it. At a point just before the stall, the aircraft would begin to shudder slightly, this was the warning. Experienced pilots learned to ride this edge, as the shudder happened, and maintain it just at that point.

Unfortunately, this vibration or shudder is not present in the game either.

[JtD]

If the 109 had the elevator authority of a Spitfire, it would certainly be possible to send it into a flick or spin easily as well. Stalling characteristics and control characteristics are related, but still a different pair of shoes.

Hurricane stalls/spins were more problematic than the Spitfires, but it didn't have the sensitive elevator.

Recovery from spins shouldn't be hard in any of the three, but easiest in the 109.

[Glider]

Originally Posted by *Buzzsaw*

Salute

Kurfurst is quite correct in noting the game 109 is quite difficult to recover from spins. I have often seen game 109's spinning to their destruction from considerable heights.

This is quite clearly an incorrect modelling of the real aircraft, which was in fact easy to recover from spins or stalls, one would have to be quite ham handed to maintain a spin in the historical aircraft. Not impossible mind you, given a pilot doing all the wrong things, but given a pilot with the training, recovery should be prompt and with a relatively minor altitude loss.

As far as the historical Spitfire stall characteristics were concerned, there was definitely the possibility of a violent flick and spin if the aircraft was pulled into a high G Stall, however, the Spitfire had a characteristic which allowed experienced pilots to know exactly how far to take it. At a point just before the stall, the aircraft would begin to shudder slightly, this was the warning. Experienced pilots learned to ride this edge, as the shudder happened, and maintain it just at that point.

Unfortunately, this vibration or shudder is not present in the game either.

Can I just say that I found this to be a very good summary of the situation and post 44 is one of the best descriptions I have seen of flying the Me 109.

Thanks for both

[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.