Unpowered Slats

Discussion in 'Aviation' started by GregP, Jan 29, 2014.

  1. GregP

    GregP Well-Known Member

    Joined:
    Jul 28, 2003
    Messages:
    5,905
    Likes Received:
    853
    Trophy Points:
    113
    Occupation:
    Electrical Engineer, Aircraft Restoration
    Location:
    Rancho Cucamonga, California, U.S.A.
    #1 GregP, Jan 29, 2014
    Last edited: Jan 29, 2014
    Sorry, had a great video of F-86 slats deploying in flight during aerobatics and lost the link!

    I'll find it again ...
     
  2. GregP

    GregP Well-Known Member

    Joined:
    Jul 28, 2003
    Messages:
    5,905
    Likes Received:
    853
    Trophy Points:
    113
    Occupation:
    Electrical Engineer, Aircraft Restoration
    Location:
    Rancho Cucamonga, California, U.S.A.
    #2 GregP, Jan 29, 2014
    Last edited: Jan 29, 2014
    Here's a video that shows the slats working. Look at around 42 seconds and also at about 2:01 ... plus other times and you can see them work. You can push them in or out with one finger, there is NO resistance. You have to clevis-pin them in to make them stay up on the ground. Otherwise gavity will make them extend ... unless the bearings are gone ...

    Steve Hinton flying the Sabre.


    View: https://www.youtube.com/watch?v=XPA31R1xifk

    No real reason to post this, just slats working with g-load, speed and angle of attack.
     
    • Like Like x 1
  3. vikingBerserker

    vikingBerserker Well-Known Member

    Joined:
    Apr 10, 2009
    Messages:
    24,064
    Likes Received:
    655
    Trophy Points:
    113
    Occupation:
    Korporate Kontrolleur
    Location:
    South Carolina
    That really is fascinating, thanks for posting that.
     
  4. GregP

    GregP Well-Known Member

    Joined:
    Jul 28, 2003
    Messages:
    5,905
    Likes Received:
    853
    Trophy Points:
    113
    Occupation:
    Electrical Engineer, Aircraft Restoration
    Location:
    Rancho Cucamonga, California, U.S.A.
    You're welcome.

    You can see them creep out as the gusts push the Sabre closer to the stall angle of attack. I believe they deploy some 3 - 4° before the critical ange of attack is reached, just when the airflow around the leading edge starts to burble backwards and hits the slats, pushing them out.
     
  5. Clayton Magnet

    Joined:
    Feb 16, 2013
    Messages:
    145
    Likes Received:
    5
    Trophy Points:
    18
    Correct me if I am wrong, but did they not delete the slats on later Sabre marks?
     
  6. GregP

    GregP Well-Known Member

    Joined:
    Jul 28, 2003
    Messages:
    5,905
    Likes Received:
    853
    Trophy Points:
    113
    Occupation:
    Electrical Engineer, Aircraft Restoration
    Location:
    Rancho Cucamonga, California, U.S.A.
    #6 GregP, Jan 30, 2014
    Last edited: Jun 23, 2016
    The F-86A and a few E's had solid leading edges. So did some of the Canadian Sabres.

    The Sabre we are restoring started life as a Canadair Sabre Mk 6, which is a USAF F-86E with a bigger engine. This one had solid leading edges. We are currently converting it to slats per the new owner's wishes. It hasn't been exactly easy, but is coming along nicely.

    The Sabres had four types of wings. There are long and short, with ans without slats. The short wing is EASY to reecognize. If the ailerons reach the wingtip, it is a short wing. If the wingtip has no ailerons at the tip, it is a long wing. When the F-86F came into service, it introduced the 6-3 wing. It has 6 inches more chord at the root and 3-inches more chord at the tip for improved maneuverabilty.

    From the F-86A to the F-86E, they had conventional elevators and a stabilator. From the F-86F forward it has an all-flying tail. The Canadian Sabre are also easy to recognize externally. Right behind the trailing edge of the wing is an air intake. If it is flush (like an NACA intake), it is a USAF aircraft. If there is a regular airscoop that sticks out, it is a Canadian Sabre.

    The drop tanks on the F-86E and earlier are about 2 feet inboard of where they are on the F-86F and later.

    So, they really are simple to recognize.

    The Canadair Sabre Mk I was essentially an F-86A with 5,200 lbs thrust. The Mk 2 was the same for the first 20 and the rest had the all-flying tail. They only made one Mk. 3 and it has an Orenda engine. The Mk. 4 had a GE engine and was assed to the RAF and later to other nations. The Mk. 5 had an Orenda 10 (6,500 lbs thrust). It had the 6-3 wing. The Mk. 6 had an Orenda 14 (7,440 lbs thrust). Some Sabre Mk. 6's has solid leading edges and some reinstated the slats. The one we are restoring had the solid edges but is being fitted with slats.
     
    • Like Like x 1
  7. Clayton Magnet

    Joined:
    Feb 16, 2013
    Messages:
    145
    Likes Received:
    5
    Trophy Points:
    18
    Was it determined the larger area wing to be just as advantageous as slats, but with less complexity or something?
     
  8. GregP

    GregP Well-Known Member

    Joined:
    Jul 28, 2003
    Messages:
    5,905
    Likes Received:
    853
    Trophy Points:
    113
    Occupation:
    Electrical Engineer, Aircraft Restoration
    Location:
    Rancho Cucamonga, California, U.S.A.
    No.

    The larger wing area was to increase maneuverability of the aircraft at speed and altitude.

    The slats were to make it handle better at low speeds around the taffic pattern and were usually retracted during flight at anything over realtively low speeds unless the pilot was pulling enough g's to make the airflow start to separate around the slats ... then they extended at high speeds, too, to help the Sabre turn better.

    I'd bet they were extended quite often if over 35,000 feet and loading the aircraft significantly in a turn or pull-up ... but I'm also not a Sabre pilot, so I'm supposing that is true from generaly aerodynamic knowledge and some knowledge of the F-86 high-altitude qualities.
     
    • Like Like x 1
Loading...

Share This Page