Me 109 leading edge slats

Discussion in 'Other Mechanical Systems Tech.' started by zetland76, Apr 2, 2010.

  1. zetland76

    zetland76 New Member

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    Hi,
    Can anyone give me any info on this. I believe they were deployed automatically. When and what controlled this. I heard they were a bit of a problem in dog-fights.
    The more info the better!

    Thanks in advance

    Mike
     
  2. Kurfürst

    Kurfürst Banned

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    Simply air pressure / angle of attack of the aircraft.
     
  3. Trebor

    Trebor Well-Known Member

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    I noticed that when I downloaded a payware BF-109E (that a buddy of mine gave me for no charge) and whenever I'd pull back on the stick, those slats would expand, and I always wondered what they were for. but thanks for clearing that up!
     
  4. Kurfürst

    Kurfürst Banned

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    They are high lift devices. The amiunt of lift a wing would generate increases with the angle of attack. After a certain AoA however, the airflow becomes turbulent and ultimately separates, at which point the lift produced actually decreases and the aircraft will stall.

    Leading edge slat, when they open at high AoA increase that critical AoA when all this happens (and this way, by definition the maximum lift), therefore they help stall characteristics at say, landing or allow the plane to be pulled harder in turn, ie during turns.

    Its also very practical since they only operate when they are actually needed.
     
  5. billswagger

    billswagger Member

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    Its not so much that they were a problem in dog-fights, they were actually meant to help the plane in turning but some observations do mention minor aileron snatch and buffeting at lower speeds. They could also be a problem if one slat opened more than the other, but i'm not sure that is possible with out mechanical failure.

    Bill
     
  6. beaupower32

    beaupower32 Well-Known Member

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    The 109 Lair- The Online Source for Messerschmitt 109 information


    This was off the 109 Lair website. Hopefully this will help. The pictures are on the website, if you want to check them out. Go to Technical Reference, then structures, then wings, then slats.

     
  7. davebender

    davebender Well-Known Member

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    Most modern fighter aircraft like the F-22 and Eurofighter Typhoon utilize leading edge slats. That tells me leading edge slats are a good feature on fighter aircraft. They were probably cutting edge technology when introduced on the mass production Me-109.
     
  8. schwarzpanzer

    schwarzpanzer Member

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  9. VALENGO

    VALENGO Member

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    There is an old training film about Me 262 (not Me 109, but take for sure is the same functionality of the slats) where you can see a man that raises a slat and leaves it fall again. This test was a routine check to be sure that the device was not jammed and could freely move.
     
  10. zetland76

    zetland76 New Member

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    This web site is great!

    Thanks for all the replies. I'll be reading them for some time I guess

    Thanks

    Mike
     
  11. vanir

    vanir Banned

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    Hiya davebender, on modern fighters the items you're referring to are leading edge flaps rather than slats, more about stall speed at low AoA. They're actively controlled by the flight computer along with a small amount of rear flaps and change the shape of the airfoil, unlike slats which are a boundary layer control used for achieving high AoA.

    The whip thin airfoil of supersonic a/c gives them very high stall speeds, up around 300kmIAS or more and that was a problem in the old 2nd generation days. Even if you could raise the AoA safely it's not going to bring such a figure down significantly enough to be very useful. Swing wing was one solution but even these generally have a leading edge flap system to get reasonable landing speeds out of a supersonic fighter. The modern approach is double deltas and body lift with the system, flight processors have changed the game a bit so a modern warplane is probably easier to fly through normal manoeuvres than anything from WW2.



    zetland, I remember Gen.Rall mentioning he had troubles with the Emil in tight turns, with one slat snapping open through the turn and inducing a stall if you weren't ready for it. Someone else told me the rail system in Gustavs onwards fixed this, I think it was Kurfürst actually.
     
  12. Milosh

    Milosh Well-Known Member

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    The Ol' Stringbag, the Fairey Swordfish, had leading edge slats on the upper wing.
     
  13. ppopsie

    ppopsie Member

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    Swordfish! Patent for the automatic slats still held by Handley Page. Was the Bf109 affected by this patent? or was it expired?

    One more question; did the Swordfish have slat locking mechanisms like the one in the Tigermoth?
     
  14. billswagger

    billswagger Member

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    I've had a question about the rate of roll for the various 109s, particularly since its been said that high speeds the Emil was too stable, difficult to roll, yaw or pitch.

    I wondered what sort of improvements were made to help deal with those issues, particularly in the F and G series. Being they improved wings, i would think they also had improved aileron effectiveness, but the information on roll rates is cloudy.


    Bill
     
  15. FLYBOYJ

    FLYBOYJ "THE GREAT GAZOO"
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    The F-86 had L/E as did the Lysander...

    To claim patent rights I believe the system has to be built exactly like the patent holder. If there are different components and the basis of operation of slightly different, there's no basis for patent infringement.
     
  16. Shortround6

    Shortround6 Well-Known Member

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    there was an German WW I pilot who was a co-holder of the patent with Handley-Page and they wound up being good friends. These slats were fitted to quite a number of aircraft during the 30's but experience showed that they were only useful at rather high angles of attack and a lot of later aircraft dropped them and the related letter box slots. As a for instance it is reported that only the first 50 Handley-Page Halifaxes were fitted with slats.
     
  17. Milosh

    Milosh Well-Known Member

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    Were not the slats eliminated with the 6-3 wing?
     
  18. FLYBOYJ

    FLYBOYJ "THE GREAT GAZOO"
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    Yes
     
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