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-   -   Leading Edge Slats on the Me-109 (http://forum.fulqrumpublishing.com/showthread.php?t=35549)

Crumpp 12-09-2012 11:33 PM

Quote:

Let's call them fish blankets instead, that should avoid any confusion
It is not my confusion, Taildragger.

Like I said, it is not the first time that terminology has been explained in this thread.

Crumpp 12-09-2012 11:41 PM

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I do not say the 109 era slats were equivalent to modern era LE flaps, that claim was put forward by Tomcat. In fact I was pointing out the big differences.
He is right, many modern fighters do use automatic slats. What is the issue??

Crumpp 12-10-2012 12:02 AM

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Buzzsasw says:

It's clear your insistence, against all the evidence presented, that the 109's slats made the aircraft "spin proof", is simply not factual.
Look Buzzsaw, the act of spin proofing an airplane by the application of anti-spin devices builds a spin resistant design. Are you confused by the terminology??

Quote:

Crumpp says:

The Bf-109 exhibits the same normal behavior for LE Slats. It is difficult at best to get it to spin under normal operating conditions
http://forum.1cpublishing.eu/showpos...2&postcount=67

That was page 6 and you never answered my question on why you leaped in spouting the same exact thing I said!!

Quote:

We are now in the usual counterproductive and meaningless back and forth which always seems to occur when you enter a thread.
I asked you in your first post Buzzsaw to clarify what you think I exaggerated which is your claim and to point out exactly your point of contention.

I have asked you several times. Do that and we will clear it up.

There won't be any conflict just be honest and let's get the facts out.

It is pretty obvious most posters in this thread do not know the terms and confused them.

taildraggernut 12-10-2012 12:10 AM

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Originally Posted by Crumpp (Post 486325)
Taildragger can you explain what reducing the angle of attack to prevent a stall has to do with your claim of raising the nose on the BF-109 with the elevator to completely stall the energized boundary layer of the tips while the rest of the wing is stalled?

I don't see the connection.

Do you actually read the posts people respond to you with? It is apparent you have great difficulty grasping the context of many of them, so I will need to explain my perfectly clear and highlighted in bold quote was saying the elevators remain effective in the stall, did you get that? The elevators remain effective in the stall......now if you have effective elevators you have the ability to pitch beyond critical angle of attack, now are going to stick with the theory that the 109 had some form of pitch inhibition?

Crumpp 12-10-2012 12:20 AM

1 Attachment(s)
Quote:

I should remind you that slats deploy before the main wing has actually stalled which makes my original text quite correct thanks.


Ok taildragger,

Do you understand that the basic effect of the slats is to add energy to the boundary layer and delay seperation?

On the lift polar, the slats have the effect of extending the lift polar increasing both maximum co-efficient of lift tied to that, available angle of attack. This is a completely different effect from increasing camber, btw.

The wing stalls at a higher angle of attack with the slats deployed.

The plain airfoil cannot reach that same angle of attack and is stalled while the tips continue to fly. When the plain airfoil, which makes up the majority of the Bf-109's wing is stalled, the pilot does not have enough control to raise the nose and stall the tips which do gain the benefit of the slats.

Study the diagram below and explain to me how the plain airfoil can continue to fly and reach the slated portion CLmax??

taildraggernut 12-10-2012 12:20 AM

Quote:

Crumpp says:

The Bf-109 exhibits the same normal behavior for LE Slats. It is difficult at best to get it to spin under normal operating conditions
Under normal operating conditions

Now is pulling hard turns in combat 'normal operating conditions'?

Crumpp 12-10-2012 12:21 AM

Quote:

so I will need to explain my perfectly clear and highlighted in bold quote was saying the elevators remain effective in the stall, did you get that?
OK....:confused:

Come on and let's do some stalls.

You try to keep the nose up with elevator!!!

:-P

You understand the aerodynamic center in a normal stable airplane is behind the Center of Gravity. When our wing produces less lift, the reduction in aerodynamic force on the aerodynamic center causes the nose to drop. It is not hard to size the elevator appropriately. In fact, the forward CG limit is defined by our inability to raise the nose at landing velocity (not Vref, flare).

taildraggernut 12-10-2012 12:23 AM

Quote:

Originally Posted by Crumpp (Post 486333)
Ok taildragger,


Study the diagram below and explain to me how the plain airfoil can continue to fly and reach the slated portion CLmax??

No, you explain to me what the phenomenon is that prevents the still effective elevator from allowing you to pitch beyond the slatted portion of the wings maximum angle of attack.

Crumpp 12-10-2012 12:26 AM

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Now is pulling hard turns in combat 'normal operating conditions'?
:confused:

For a fighter, yes!!

Read the RAE report, guy!

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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.

Crumpp 12-10-2012 12:28 AM

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No, you explain to me what the phenomenon is that prevents the still effective elevator from allowing you to pitch beyond the slatted portion of the wings maximum angle of attack.
I have explained three times already. It just does not sink in!

Quote:

Crumpps says:

The plain airfoil cannot reach that same angle of attack and is stalled while the tips continue to fly. When the plain airfoil, which makes up the majority of the Bf-109's wing is stalled, the pilot does not have enough control to raise the nose and stall the tips which do gain the benefit of the slats.


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