+ Reply to Thread
Page 1 of 2 12 LastLast
Results 1 to 15 of 24
Like Tree2Likes

Thread: Retractable leading edge slats added to an existing wing?

  1. #1
    Registered User cluttonfred's Avatar
    Join Date
    Feb 2010
    Location
    Nairobi, Kenya
    Posts
    1,202

    Retractable leading edge slats added to an existing wing?

    Does anyone know of any designs for or examples of retractable leading edge slats added externally to an existing wing? In other words, the slat would form an external "cuff" changing the wing profile but would expose the original airfoil when deployed? The logic here is that I am looking at ways to make high lift devices like slats, slots and flaps optional--in other words, variations on the same design with and without high lift devices with little or no structural change to the basic design for maximum commonality between the different versions. Cheers, Matthew
    *******
    Matthew Long, Editor
    cluttonfred.info
    A site for builders, owners and fans of Eric Clutton's FRED

    Voici ce que j'ai fait...vous pouvez en faire autant!
    "This is what I have done...you can do the same!"
    --Henri Mignet (1893-1965)

  2. #2
    Registered User wsimpso1's Avatar
    Join Date
    Oct 2003
    Location
    Saline Michigan
    Posts
    2,539

    Re: Retractable leading edge slats added to an existing wing?

    Added to?

    Significant hardware is added forward of the spar and inside the D-tube profile. To do this in an existing wing, would probably require removing wing skin and any support forward of the spar, and rebuilding it with the new hardware, skin, etc. A big job...

    Aerodynamically, the retracted slat also adds wing area forward of the base wing and also changes wing shape. This has got to be done so that the modified foil and base foil both have acceptable stall/spin behaviour, maybe requiring a larger set of tail surfaces too...

    If it were me and I felt that I had to offer it as an option, it would be an option to be chosen at build of the wing, and the foil would be the same either way.

  3. #3
    Registered User Tiger Tim's Avatar
    Join Date
    Apr 2013
    Location
    The Great White North
    Posts
    263

    Re: Retractable leading edge slats added to an existing wing?

    The slats on a Tiger Moth look like an afterthought, but as the Canadian models don't have them I really don't know anything about how they're mounted.

    -Tim

  4. #4
    TFF
    TFF is online now
    Registered User
    Join Date
    Apr 2010
    Location
    Memphis, TN
    Posts
    3,137

    Re: Retractable leading edge slats added to an existing wing?

    Too evasive, be like me taking your appendix out in your kitchen. Doable if you are willing to dissect the wing but not a scab on.

  5. #5
    Registered User cluttonfred's Avatar
    Join Date
    Feb 2010
    Location
    Nairobi, Kenya
    Posts
    1,202

    Re: Retractable leading edge slats added to an existing wing?

    Thanks, guys, I was thinking of easy ways to offer versions of the same aircraft for U.S. LSA regs (51 mph max stall speed clean) and European ultralight regulations (40 mph minimum speed in the landing configuration) other than the obvious options of shorter or longer wings or the same wings with or without flaps. Flaps or a larger span would likely require other design changes due to pitching moment, etc. and I was already trying to keep the horizontal tail small for other reasons. I was thinking that retractable slats might reduce the stall speed enough without other substantial changes. I'd be open to any other suggestions, maybe a fixed leading-edge cuff a forward-mounted split flap?
    *******
    Matthew Long, Editor
    cluttonfred.info
    A site for builders, owners and fans of Eric Clutton's FRED

    Voici ce que j'ai fait...vous pouvez en faire autant!
    "This is what I have done...you can do the same!"
    --Henri Mignet (1893-1965)

  6. #6
    Registered User Tiger Tim's Avatar
    Join Date
    Apr 2013
    Location
    The Great White North
    Posts
    263

    Re: Retractable leading edge slats added to an existing wing?

    Quote Originally Posted by TFF View Post
    Too evasive, be like me taking your appendix out in your kitchen. Doable if you are willing to dissect the wing but not a scab on.
    I'm not 100% certain but I bet installing the slats on a finished Tiger Moth wing would be less invasive than, say, clipping the wings on a J-3 (which is supposed to be doable without a total re-covering).

    Realistically, in answer to the original problem, I suspect a different airfoil or span between the two versions would be far better.

    -Tim

  7. #7
    Registered User dino's Avatar
    Join Date
    Sep 2007
    Location
    florida
    Posts
    264

    Re: Retractable leading edge slats added to an existing wing?

    The Zenair and its Savanah clone have both realized better trade offs by switching to VGs. About 10mph increase in cruise and negligible stall increase.

    Dino

  8. #8
    TFF
    TFF is online now
    Registered User
    Join Date
    Apr 2010
    Location
    Memphis, TN
    Posts
    3,137

    Re: Retractable leading edge slats added to an existing wing?

    I thought all Tiggies had slats when made. Doing aerobatics you bolted them in or removed them. No matter what, the plane was designed to have them originally. I think the original original question means can I walk up to a plane and screw a device on with PK screws into the skin and call it good? No. You have to know how strong the structure is to know where to bolt it on. Spar or substructure.

  9. #9
    Registered User cluttonfred's Avatar
    Join Date
    Feb 2010
    Location
    Nairobi, Kenya
    Posts
    1,202

    Re: Retractable leading edge slats added to an existing wing?

    Quote Originally Posted by TFF View Post
    I think the original original question means can I walk up to a plane and screw a device on with PK screws into the skin and call it good?
    Not quite, TFF, rather I am looking for a way to be able to add or remove the slats according to need--of course, the slats would need to be taken into consideration in the original structural design.
    *******
    Matthew Long, Editor
    cluttonfred.info
    A site for builders, owners and fans of Eric Clutton's FRED

    Voici ce que j'ai fait...vous pouvez en faire autant!
    "This is what I have done...you can do the same!"
    --Henri Mignet (1893-1965)

  10. #10
    Registered User BBerson's Avatar
    Join Date
    Dec 2007
    Location
    Port Townsend WA
    Posts
    4,129

    Re: Retractable leading edge slats added to an existing wing?

    The optimal shape for the wing leading edge with slats is much different than a wing without slats.
    The Helio would not fly well without the slats, I think.

  11. #11
    Registered User Tiger Tim's Avatar
    Join Date
    Apr 2013
    Location
    The Great White North
    Posts
    263

    Re: Retractable leading edge slats added to an existing wing?

    Quote Originally Posted by TFF View Post
    I thought all Tiggies had slats when made.
    Not the C model. Maybe that wasn't the best example to use but to go back a little further in the Moth lineage I wonder if the earliest DH-60s had slats? They seem awfully crude when compared to other retractable slats.

    -Tim

  12. #12
    ARP
    ARP is offline
    Registered User
    Join Date
    Nov 2009
    Location
    Darenth, Kent / England
    Posts
    178

    Re: Retractable leading edge slats added to an existing wing?

    What about leading edge 'turbulators' that you stick on?

  13. #13
    Registered User dino's Avatar
    Join Date
    Sep 2007
    Location
    florida
    Posts
    264

    Re: Retractable leading edge slats added to an existing wing?

    The slats were simply removed from the Savanah and replaced with VGs for those seeking to retrofit.

    Dino

  14. #14
    Registered User
    Join Date
    Jun 2010
    Location
    Palm Bay, Florida
    Posts
    113

    Re: Retractable leading edge slats added to an existing wing?

    Why not design the wing so that the "D" section could be swapped/upgraded to a "slatted" D-section ?
    Maybe offer it as an option.

    John

  15. #15
    Registered User cluttonfred's Avatar
    Join Date
    Feb 2010
    Location
    Nairobi, Kenya
    Posts
    1,202

    Re: Retractable leading edge slats added to an existing wing?

    Thanks, guys, but right now I am thinking that removal leading edge droop cuffs on the outer wing panels like the NASA tests on a Grumman Yankee and/or vortex generators would be the way to go.
    *******
    Matthew Long, Editor
    cluttonfred.info
    A site for builders, owners and fans of Eric Clutton's FRED

    Voici ce que j'ai fait...vous pouvez en faire autant!
    "This is what I have done...you can do the same!"
    --Henri Mignet (1893-1965)

+ Reply to Thread
Page 1 of 2 12 LastLast

Similar Threads

  1. D Leading edge, fabric rear wing
    By billyvray in forum Composites
    Replies: 10
    Last Post: April 22nd, 2013, 12:12 AM
  2. Wing Root Leading Edge Sweep
    By GESchwarz in forum Aircraft Design / Aerodynamics / New Technology
    Replies: 22
    Last Post: July 4th, 2011, 09:54 PM
  3. Super Cub retractable leading edge slat
    By Wrongway John in forum General Experimental Aviation Questions
    Replies: 29
    Last Post: March 27th, 2011, 09:51 AM
  4. Question about Rivets on the Leading Edge of a Wing
    By Tom Kay in forum Aircraft Design / Aerodynamics / New Technology
    Replies: 10
    Last Post: January 5th, 2011, 03:13 PM
  5. Outer Wing Drooped Leading Edge
    By AVI in forum Aircraft Design / Aerodynamics / New Technology
    Replies: 6
    Last Post: June 23rd, 2008, 07:42 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts