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  • Landing Gear questions

    It seems that most Taylorcraft I see have fabric wrapped around the landing gear. Mine has an aluminum skin wrapped around the gear legs (including under the belly). Was that original ('46 BC-12D)? Mine is pretty banged up and cut up due to the previous installation of a wind driven generator. Is it possible to obtain another aluminum one? Or should I just go with fabric?

    And in a related question - I see a lot of the "bush" variants have a small welded tube between the aft gear tube and the smaller link that goes up near the bungees. I assume that keeps the smaller link from bending/breaking. Anybody have any documentation or recommendations regarding this? I've got all the stuff for a Grove conversion and will be running at least 8.50s for some mild off airport stuff (farm pasture, etc).
    Brian Cantrell
    1946 Taylorcraft BC-12D, N96262
    1961 N35 Bonanza, N61GM

  • #2
    I suspect that someone has put the aluminum cover on yours at some point. Most that I have seen are fabric covered, except the few that are leaving them uncovered for back country work.

    The brace you are talking about is a ski brace. Operating on skis can be quite rough on the landing gear. I think you would be just fine on the larger tires without it, but it won't hurt anything if you decide to add it.

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    • #3
      https://www.taylorcraft.org/docs/gea...cement%201.pdf
      https://www.taylorcraft.org/docs/gea...cement%202.pdf

      Click image for larger version

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      Atlee Dodge in Anchorage Ak. does the bracing. http://www.fadodge.com

      Before you reinstall the gear inspect it for internal and external corrosion and make sure the lower drain hole is open.

      Landing gear tie strut SB ce-11-05.pdf

      Gary
      N36007 1941 BF12-65 STC'd as BC12D-4-85

      Comment


      • #4
        Originally posted by cbcfly View Post
        It seems that most Taylorcraft I see have fabric wrapped around the landing gear. Mine has an aluminum skin wrapped around the gear legs (including under the belly). Was that original ('46 BC-12D)? Mine is pretty banged up and cut up due to the previous installation of a wind driven generator. Is it possible to obtain another aluminum one? Or should I just go with fabric?

        And in a related question - I see a lot of the "bush" variants have a small welded tube between the aft gear tube and the smaller link that goes up near the bungees. I assume that keeps the smaller link from bending/breaking. Anybody have any documentation or recommendations regarding this? I've got all the stuff for a Grove conversion and will be running at least 8.50s for some mild off airport stuff (farm pasture, etc).
        I have been running 8.50's for 20 years without problems, only run a single puck caliper, dual is too much. If you have a 70# tail, it does not take much to put it on its back. I can slide my 8.50s on dirt real easy if I am not paying attention. Mud can make things real interesting if you don't maintain directional control. Tim
        N29787
        '41 BC12-65

        Comment


        • #5
          The 337, https://www.taylorcraft.org/docs/gea...cement%202.pdf, states welding the reinforcement tube to "the rear landing gear leg 4" down and to the center streamlined gear leg 12" down."
          Unless my eyeballs are way off, it seems that on the "ski braces" that I've seen, they are welded in at something other than these dimensions.
          What would be the best location to weld these?

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          • #6
            The brace is commonly done to standard PA-12/14, PA-20/22, and of course Taylorcraft. Mine above is about mid-span on the rear gear leg to the diagonal. There's probably some angle that's best from a stress and structural point but I'm not an engineer or experienced welder. Several here are so maybe they can offer a better suggestion. Like on the main airframe tubing the brace creates a strength triangle and supports the diagonal under side loads.

            Gary
            N36007 1941 BF12-65 STC'd as BC12D-4-85

            Comment


            • #7
              I do believe that all B model Taylorcraft had fabric covering on the gear.

              My understanding about the diagonal brace is all about buckling loads under compression (usually for ski-equipped aircraft due to the side-loads during a turn on snow).. I remember studying this in College in the very early eighties.Euler load comes to mind. It's the same reason we have jury struts on the main lift struts. Normally, to reduce the critical Euler load, the "jury" strut is placed half-span of the main member, thus increasing four-fold*, the side-load needed to buckle the main member. In fact, I recall the critical (Euler) load of the bracing member becomes the critical item, rather than that of the main member.

              Structural Engineers such as those designing skyscraper, bridges and multi-storey car parks have to design using the same principles...anything with columns under compressive loads, be they steel, concrete or aluminium.

              But for the Main Landing Gear, (and indeed the Taylorcraft lift struts), there may be a compromise between having the bracing strut at exact the half-way point, and other structural considerations, such as where to attach the other end of the bracing strut!

              *Edited, thanks to an eagle-eyed Taylorcraft owner!
              Last edited by Robert Lees; 06-17-2019, 11:43. Reason: Change "reducing to a quarter" by "increasing four-fold"

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              • #8
                Here's some pics of a right landing gear that failed (likely under side load compression) while on skis. It was previously compromised by internal corrosion in the diagonal strut and upper "A" tubing that connects to the bungee cords. Once the diagonal failed the gear bent outward at the axle and the "A" tubing, restrained by the upper safety cable under the bungees, bent and partially separated from the lower assembly.

                Note in the left pic the magic marker showing that the lower diagonal strut drain hole had been drilled via the factory SB but did not penetrate the tubing. That probably led to the accumulation of water. The failure point was close to where a brace can be added. Water apparently can enter the gear at the open area under the bungees.

                Gary

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                N36007 1941 BF12-65 STC'd as BC12D-4-85

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