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Thread: Aerobatic sighting device

  1. #1

    Join Date
    Nov 2011
    Posts
    11

    Aerobatic sighting device

    Right now my sighting device is tape on my canopy marking 90 and 45 degrees but I'd really like to get one for my wing tip.. I have low wing aerobatic mono-plane..is it possible to buy a pre-built adjustable sighting device for my wing tip.. Or does anyone know of any plans I can use to design and build my own..

    Thanks for the help

  2. #2

    Join Date
    Nov 2011
    Location
    Orange County California
    Posts
    2
    I'm loooking for the same thing for the wing tips on my Pilatus Aerobatic Glider.

  3. #3

    Join Date
    Oct 2011
    Location
    New Hampshire
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    1,300
    I once had Dennis Sawyer, a master mechanic on aerobatic airplanes, explain how he was constructing a sighting device for a monoplane in his shop. You start with a carbon fiber hockey stick. Cut off the curving part. Set up a jig to hold the stick and a balsa extension that you wrap in more carbon fiber cloth to get the length that you need. Epoxy carbon fiber rods to the aft end of the stick to create the angles that you can use for 45 references. Drill two holes in the forward end for -3 bolts that will hold the finished sighting device onto end of the wing.

    Obviously you need to determine that the end rib of the wing is strong enough or you need to beef it up with glass or carbon fiber cloth.

    Mounting on a sailplane is a more interesting issue as the pilot sits forward of the wing and the wing flexes. So the question is whether you could mount it maybe 10' out from the cockpit, projecting forward. Would look like a big pitot boom. Don't know what the structure is there.

    If you are in Florida, Dennis can be found at Spruce Creek.

    Best of luck,

    Wes
    N78PS

  4. #4

    Join Date
    Nov 2011
    Posts
    11
    Does it matter what shape/design I use for the sight? for example I see a lot of monoplanes like extra and edge using a triangle shape but they seem to be more mid wing not sure if it would make a difference, where as my planes a low wing. there are many other designs out there, just not sure what to go with and there doesn't seem to be much information out there on designing these.. also and ideas how I can make it adjustable? obviously it will have to be adjusted depending on the pilots seating position. are the angles normally adjustable as well?

  5. #5

    Join Date
    Oct 2011
    Location
    New Hampshire
    Posts
    1,300
    There are multiple schools of thought on what little sticks you put on the end of your aerobatic sighting device.

    First, please understand that in level flight across the box the stick will NOT be parallel to the horizon. As your speed changes, your angle of attack changes, and the relationship of the stick to the horizon changes.

    The stick is most useful setting your vertical up or down lines. You should be flying zero lift and the stick should look perpendicular to the horizon.

    45 lines, up and down, are problematical. Gluing a little stick 45 to the main stick and laying that little stick on the horizon may not get your airplane into the attitude that the Judges see as 45. And your ship will look a little different on inverted 45's vs upright 45's. So you can make yourself crazy regluing the little sticks at slightly different angles to try to set them so that the Judges tell you that you present a good 45. So no one does that. What you will see is that folks make a star or a triangle or a diamond, and then fly some fudge factor different than what the little sticks say. The sight looks cool but you don't actually fly what it says for 45's.

    I understand that the Russians believe that all you need is the stick and all of the angled stuff added is a waste of time. So you can choose to just have a naked stick.

    I have seen an aircraft that had a naked stick with colored stripes that I think are used by the pilot to confirm that the wing tips are even when in the vertical. I think that the pilot must have painted the colored stripes, then pulled to the vertical, looked left and right to set the wingtips are the same relation to the horizon, and then memorized that the say blue strip on the horizon when looking at the stick meant no need to look the other way to check. This may be useful when initiating a roll in the vertical.

    Some folks have a stick on each wingtip, some just put one out to the left. I see no difference in the scores of those two groups of pilots.

    I will note that putting a little star on the end of your sighting device gives folks walking by something to be impaled by or to damage. Some folks put covers on them when parked.

    So your sighting device can have any feature that you think that you need to better check your aircraft attitude. A friend's sighting device has a rabbit's foot attached to it. You may choose your own talisman.

    Best of luck,

    Wes
    N78PS

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