Leading Edge Slats on the Me-109

[Kurfürst]

Originally Posted by IIIJG52_Otto_+

I agree with you on that first .. but I'm sure that with a Bf-109E in the CloD, you can not do some maneuvers as in reality, (such as, closed scissors, or Immelmann turn) at speeds flight from reality, because the aircraft enters itself in a spin unreal and unrecoverable.
We need to improve the Bf-109 FM more accurately.

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.

[Redroach]

Originally Posted by Kurfürst

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.

And this, I think, after recently testing in an E-4, has improved somewhat, with the slats actually working now. But, still, this is a highly subjective point of view and probably still doesn't compare favourably to RL.

[Crumpp]

slats don't prevent spins

No, they only make it exponentially harder to enter a spin

[Crumpp]

The hideous stalling characteristics of the 109 are the most important aspect of the 109-FM that needs improved upon.

After that, the stability and control. The Bf-109 was one of the best shooting platforms of the war.

[*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.

[Varrattu]

Just out of curiosity ... ...

Has anyone of you experience flying a real BF109E?

Regards

[bongodriver]

Originally Posted by Kurfürst

Care to expand on that?

Not really, it's pretty self explanatory.

[Crumpp]

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.

Right.

Obviously folks do not understand how the LE devices work. Many people would benefit from reading chapter 19 of a book called "Stick and Rudder" by Wolfgang Langewiesche.

It would eliminate all the stupid arguments on these boards.

http://www.amazon.com/Stick-Rudder-E.../dp/0070362408

Handley Page automatic slats equipped aircraft have unique and non-traditional stall characteristics as a result.

The stall was quite gentle because of the LE Slats. The effect of the slats is to increase the angle of attack the stall occurs at by energizing the boundary layer behind the slat.

The slats on the outboard and the inboard wing is not slotted. This means the inboard portion will ALWAYS stall at a lower Angle of Attack. With the inboard wing stalled, it no longer produces the lift required to raise the nose and increase the outboard portion of the wing that is slotted to the stall Angle of Attack.

It acts like training wheels, automatically countering an asymmetrical stall so that depending on the CG location, no amount of rudder input at the stall point will cause a spin.

Today, slats for spin proofing have fallen out of favor and given way to cuffed wing designs. The aerodynamic effect is the same but the cuffs offer the advantage of a constant drag picture without the complexity of the automatic slat. Drag forces increase with the slat deployment as lift and drag are connected linked by a fixed relationship.