Guest

Kreuger Leading Edge Flaps

Mon Apr 23, 2001 10:52 pm

Hey guys,
Well, this time I just want to know a bit more about Kreuger flaps. How were these different from the norm? It seems they were not too successfull, seeing they are not used anymore on modern jetliners. What were it's pros and cons, and how were they different from normal leading edge flaps? Also, I see that the A300B4 was produced with Kreuger flaps, but the earlier A300B2 did not have them. What kind of flaps did the B2 have?
Thanks,
Tom
 
VC-10
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RE: Kreuger Leading Edge Flaps

Tue Apr 24, 2001 12:03 am

Not too successful ??? The 747 has them inbd of the inbd engines.
 
prebennorholm
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RE: Kreuger Leading Edge Flaps

Tue Apr 24, 2001 5:02 am

The Krueger flaps are simpler, cheaper and less efficient. They basically only extend the cord a little and increase the camber of the wing profile. Their main advantage is that the mechanics behind them take up less space - and that way leaves more room for fuel etc.

The great advantage of the slottes leading edge flaps or slats is found in the slot. By shaping the slot carefully the air passing upward through the slot is accellerated to a speed somewhat higher than the actual airspeed of the plane. The increased airspeed on the uppper surface of the wing increases lift considerably, and therefore slows down take-off and landing speed more than Krueger flaps do.

Best regards, Preben Norholm
Always keep your number of landings equal to your number of take-offs
 
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RE: Kreuger Leading Edge Flaps

Tue Apr 24, 2001 5:10 am

Hey thanks Preben.
I must have been mistaken, I thought that only the Classic 74s had the Kreuger leading edge. Just a quick question, I know the A300B4, 747, 707?, and 727 have the Kreugers, but what aircraft do not? Do 767s etc. have them?
Thanks,
Tom
 
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RE: Kreuger Leading Edge Flaps

Tue Apr 24, 2001 5:26 am

More specifically the slot associated with slats energizes the boundary layer on the upper surface of the wing by accelerating the airflow.

The A300B4 has no krueger flaps.....only slats.

JET
 
prebennorholm
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RE: Kreuger Leading Edge Flaps

Tue Apr 24, 2001 7:55 am

JETPILOT, you are absolutely correct - slats energizes the boundary layer on the upper surface of the wing by accelerating the airflow.

My much longer explanation of the same thing was probably too much "for kids".

Happy landing, Preben Norholm
Always keep your number of landings equal to your number of take-offs
 
Guest

RE: Kreuger Leading Edge Flaps

Tue Apr 24, 2001 9:37 am

"My much longer explanation of the same thing was probably too much "for kids"."

Oh, thanks Preben. Im sure I would be able to understand your explaination given a few read throughs  Wink/being sarcastic.

Can anyone tell me the aircraft which incorporate the Kreuger flaps, or did I list them all above?

-Tom

 
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iahcsr
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RE: Kreuger Leading Edge Flaps

Tue Apr 24, 2001 1:36 pm

I may be mistaken, but I believe the 737 has kreugers inboard of the engines.
Working very hard to Fly Right....
 
dc10hound
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RE: Kreuger Leading Edge Flaps

Tue Apr 24, 2001 3:12 pm

A300-600R, also. Inboard, at the wing root. Only two feet long, though..
"Eagles soar. But weasels never get sucked into jet intakes.."
 
JETPILOT
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RE: Kreuger Leading Edge Flaps

Tue Apr 24, 2001 4:14 pm

I dont think you can classify that as a Krueger flap on the A300....More like a pop out fairing.

JET
 
NKP S2
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RE: Kreuger Leading Edge Flaps

Wed Apr 25, 2001 12:50 am

iahcsr: The 737 absolutely has Krueger flaps...inboard of the engine(s), and with a mechanically linked retractable fairing on the lower edge.
 
Guest

Jetpilot

Wed Apr 25, 2001 7:42 am

The A300s leading edge is classified as a Kreuger flap. I think the 767 has the Kreuger flap?
-Tom
 
Guest

RE: Kreuger Leading Edge Flaps

Wed Apr 25, 2001 7:46 am

Also, just want to know a way to identify Kreugers when they are less obvious for example on an A300. Looking at A300B2 and A300B4 pics, it is very hard to tell the Kreugers on the B4 from the B2. (The B2 does not have Kreuger flaps).

Thanks, Tom
 
Guest

RE: Kreuger Leading Edge Flaps

Wed Apr 25, 2001 7:55 am

Also, just want to know a way how to identify Kreugers when they are less obvious. For example, on the A300, when looking at A300B2 and A300B4 pics, I cannot tell the difference between the Kreugers on the B4 and the standard slots on the B2. I mean, the Kreuger flap is one piece, and so are standard slots, so how could I tell? Anyway, they are obvious on the 727 and 707.

-Tom
 
JT8DJET
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RE: Kreuger Leading Edge Flaps

Wed Apr 25, 2001 7:58 am

King767,

The 767-300 has a small Kreuger, to fill the gap, between the inbd slat and the eng pylon.

I don't know for sure if it is on the other 67 versions.
 
JETPILOT
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RE: Kreuger Leading Edge Flaps

Wed Apr 25, 2001 8:15 am

To clear up the confusion here on the A300 High lift devices I will read from an A300 AOM.

The A300 B2 and B4 have a slat leading edge system and a 2 ft long Krueger flap and a notch. This comprises the high lift leading edge devices on these model.

I was mistaken when I posted that that 2 ft piece of krueger flap wasnt a flap. It is classied as a krueger flap.

But 98 % of the leading edge high lift devices on the A300 are slats.

The leading edge device is known as a slat...not a slot. The slat when extended craetes a slot. THe krueger flap does not.

Krueger flaps deploy from under the wing while slats are compossed of the leading edge of the wing which is moved foward and down opening up a slot between the wing and the slat.

There is such a high lift device know as a slot which is only found on the DC8. If you want me to go into that then I will.

But
 
 
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RE: Kreuger Leading Edge Flaps

Wed Apr 25, 2001 9:19 am

Thanks for clearing that up JETPILOT.
-Tom

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