Leading Edge Slats on the Me-109

[Crumpp]

Then why is washout not automatically considered an anti-spin device?

Washout does not energize the boundary layer....

[taildraggernut]

Originally Posted by Crumpp

Washout does not energize the boundary layer....

neither do slats once they have gone beyond maximum angle of attack and stalled........

[TomcatViP]

Originally Posted by taildraggernut

neither do slats once they have gone beyond maximum angle of attack and stalled........

The section of the wing close to the wing roots have alrdy stalled at that time (pls refer to the diag that has been alrdy posted on another similar topic). Hence the stall has alrdy occured before the slotted portion of the wing has stalled!!!

It's all abt having such device.

Washout is good but produce a lot of drag. Accetable for a GA aircraft but not good for a fighter! It's one of the raison why the Spitty was so slow!

[*Buzzsaw*]

Originally Posted by TomcatViP

Washout is good but produce a lot of drag. Accetable for a GA aircraft but not good for a fighter! It's one of the raison why the Spitty was so slow!

The drag profile for the Spitfire showed the majority of the drag was a function of its radiator placement, not the washout.

And are you suggesting slats don't produce drag? Any device this size extended into the airstream below the wing is obviously going to produce a very large amount of drag.

Even when the slats are not extended there was drag.

And the 109 wing's tendency to early compressibility was partially a function of the slats being present.

If you haven't seen it, then time to look at the following analysis, by an engineer who was on the Messerschmidt design staff:

http://www.wwiiaircraftperformance.o...ner-Me_109.pdf

[TomcatViP]

Originally Posted by *Buzzsaw*

The drag profile for the Spitfire showed the majority of the drag was a function of its radiator placement, not the washout.

And are you suggesting slats don't produce drag? Any device this size extended into the airstream below the wing is obviously going to produce a very large amount of drag.

Even when the slats are not extended there was drag.

And the 109 wing's tendency to early compressibility was partially a function of the slats being present.

If you haven't seen it, then time to look at the following analysis, by an engineer who was on the Messerschmidt design staff:

http://www.wwiiaircraftperformance.o...ner-Me_109.pdf

C'mon a lot of modern fighter use slat and are supersonic. I don't see any link.

More over when you hve 1000hp in front of your airplane you don't care that much abt low speed drag (but to weight).
Washout are draggy during cruise (range) and when you attend your max perf range.

Ok enough of this especially after your argument abt going into the stall after your plane is shaking during a fight (but no mention here from you abt stick travel and af Cg huh).

[Al Schlageter]

Originally Posted by TomcatViP

C'mon a lot of modern fighter use slat and are supersonic. I don't see any link.

Don't you mean drooping leading edges.

[Crumpp]

Heres a really nice and simple way to illustrate this for you...you have pitched up in your 109....inboard section of the wing begins to stall and the lovely slats have deployed keeping you nice and safe....you keep pulling and your angle of attack is still increasing (even for the magic outboard section of the wing).....now you have pitched so much that you have stalled the outboard section of the wing

Let me fix that for you as it the highlighted portion is the source of your confusion on this issue.

Heres a really nice and simple way to illustrate this for you...you have pitched up in your 109....inboard section of the wing IS STALLED and the lovely slats have deployed keeping you nice and safe....

Why don't you schedule some flying lessons and explain to the instructor how the elevator can increase angle of attack AFTER the wing is stalled.

[*Buzzsaw*]

Originally Posted by TomcatViP

C'mon a lot of modern fighter use slat and are supersonic. I don't see any link.

Modern slats may be intended to achieve improvements in lift at low speeds in the same way as the 109's slats, but they are not all the same design as the 109's. Gaps are almost imperceptible in comparison to the 109's when not deployed, when deployed, they move forward almost seamlessly, there is nothing in the way of the large open gaps displayed by the 109's slats when deployed. Modern leading edge flaps are a completely different system. These modern leading edge flaps are also computer controlled, with a degree of sophistication in their deployment which makes the 109's slats appear crude at best.

Slats of the 109 era do confer some benefits, but they also impose penalties.

[Crumpp]

Glider says:

If I ask the flying instructor the following what do you think the reply will be:-

What do leading edge slots do, do they:-

a) Delay the stall or
b) Are they anti spin devices

Just wondering if my flying instructor give the same reply, that you who has told us is a CFI would give.

My money is on (A) what do you think?
Today 05:49 PM

To deliver spark to an engines combustion chamber, we use a "spark plug"! Does it plug up the spark? NO, it is just the name of the device used to provide an ignition source.

When we design a spin resistant airplane, we use anti-spin devices to build that spin resistance.

Because folks do not understand the technical terminology, which I been nice enough to explain which is unfortunately lost in the zeal to prove me wrong by a small select portion, the community ends up with all these pointy-tin foil hat theories that have nothing to do with the spin resistant design of the Bf-109.

[TomcatViP]

Originally Posted by *Buzzsaw*

Modern slats may be intended to achieve improvements in lift at low speeds in the same way as the 109's slats, but they are not all the same design as the 109's. Gaps are almost imperceptible in comparison to the 109's when not deployed, when deployed, they move forward almost seamlessly, there is nothing in the way of the large open gaps displayed by the 109's slats when deployed. Modern leading edge flaps are a completely different system. These modern leading edge flaps are also computer controlled, with a degree of sophistication in their deployment which makes the 109's slats appear crude at best.

Slats of the 109 era do confer some benefits, but they also impose penalties.

I guess you was typing to fast and that charcters outrun your mind.

Hve a look to an F4E wing (or an A4).