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  • My first ground loop

    My first ground loop and I wasn't in the plane... :-(

    Gusts of 60 mph, tied down, and she broke the old cotton ropes and flew, sideloaded the gear and collapsed. No visible corrosion on the inside of the tie strut.

    Being experimental, my landing gear diagonal tie struts are welded solid, no bungies, to accomodate the Duane Cole center stick modification. But I'm not really impressed with the solid tie strut. Does anyone have some ideas on putting some suspension back on it?

    Hindsight's 20/20:
    "Stupid is as stupid does."
    Don't get so busy that you don't pay attention to the WX and move your plane.
    Don't trust the ropes just because they are there.
    Our airport receives $10,000 in annual funding from the FAA but has not done any work on the airport in 5 years. (Still not sure what to learn from that one.)
    Attached Files
    Last edited by SpecialT; 01-27-2019, 12:34. Reason: Try to change the title to "Tie down ropes"

  • #2
    You could switch to a Swick style control stick. It allows retention of the original bungees, while retaining the center stick. They do that by running a pushrod inside the torque tube instead of running cables on the outside.

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    • #3
      You were right Tom, the shear bolt is not the weak link in the rigid gear, here's a picture after we got her off her belly. My middle boy was almost in tears when we drove down and saw it on Jan. 8. But I wanted to say congratulations on your Son's solo too.
      Attached Files
      Last edited by SpecialT; 01-23-2019, 13:29.

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      • #4
        Some wrinkles on the wing, I still haven't inspected the wings after taking them off and getting them inside.
        Attached Files

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        • #5
          Bad time there and sorry to see the damage. There are lift spoiler wing covers available that can reduce the likelihood of that happening.

          It looks like that mod removes the upper-A frame from the stock gear I assume for added speed? Without that extra tubing it might be easier to compress that tie strut in a side load. The strut can be cross braced (typically to the lower rear gear leg) in one or two places.

          Being experimental I'd be tempted to install Grove one piece aluminum spring gear. But maybe you just want to replace the bent piece and beef it up.

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

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          • #6
            Grove gear, some new wings with flaps, and 100' riverbed landings. That get's the boys excited. The hard part I guess is making it pencil out. I haven't asked my wife yet, after all the work/money I just spent last year, I might have to wait a while...

            But, I need some pictures and ideas on how to mount some grove gear on these tube frames. 150 or 170/172 gear? And I need to start looking for parts.

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            • #7
              Maybe it's the guys I'm hanging out with? 120 days after my friend took the gear off his Maule up near The Dalles.
              Attached Files

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              • #8
                Might be a good place to ask, what kind of rope is best? Size? Material? Where did you guys buy it? My plane is hangar kept but got to admit when you land at another airport most of us just tie to the ropes that are there. Thinking of some of teh really NASTY ropes I have seen, it seems like a good time to go buy a set of tie down ropes. Lots of sailing around here (SE Virginia on the Chesapeake Bay) but which ropes or whatever have others used and liked? Lets learn from this tragedy!

                Hank

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                • #9
                  Grove would likely be able to offer an adequate mounting scheme. But maybe it's best to step back and think out what plane you'll need or rather have when done. I assume the current configuration had a specific purpose and place in your flying. Now what's left will take repairs and perhaps replacement - time and money. I'd ask if they are worth spending and going back to the original form, or another you'd rather fly. Standard Taylorcrafts are cheap in the market. One can hardly buy a new or used car or truck for what they're offered for and eventually sold.

                  Now if something for a special need is wanted (STOL for example) then real time and money come into play. You usually can't build for what can be bought unless years of deferred flying is ok. I'd run the numbers and then walk away for a few days to think about what's involved. Tough choices.

                  Standard ropes and lines: I use 3/8 to 1/2" twisted or braided nylon to achieve 3-5000# strength (https://www.engineeringtoolbox.com/n...th-d_1513.html). Recently I've tried climbing rope, or I guess marine lines if that's a better local source. I'm not sure the expense of the latter is worth it. They come in metric dimensions and various levels of stretch and tensile strength.

                  Gary


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

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                  • #10
                    Here are some recommendations:

                    I carry lines and use marine dock line, double braided made to Mil Spec 24050E. It has fiber sizing / overlay to protect from moisture, UV damage.
                    1/4" dia break strength is 1785 lbs
                    3/8" dia break strength is 4095 lbs

                    It is soft and has a tight bend radius to coil up nicely and has defined stretch % at load.

                    Attached is the Taylorcraft instructions for tying down the L2. If the tie down kit wasn't available it said to use 3/8 line.

                    Note the instructions to tie it down with the tail INTO THE WIND, very IMPORTANT. There can be no lift generated this way. Even a breeze in the 30's is generating a lot of lift and rope tension and tie down attitude is basically soft field take off attitude. But it requires tying the tail down.

                    I don't use the hand grab but tie the tail down with a loop around the tail wheel spring.

                    The attachment has instructions from the Pilots Manual, Erection Manual, the tie down kit PN list and kit diagram.

                    The FAA's tie down AC is AC20-35 but I agree with Taylorcraft about aircraft orientation not the AC. Line recommendation is 3000 lbs.

                    Recommended knot is Midshipman's Hitch over Tautline hitch for strut and bowline for ground anchor. But the FAA AC says bowline & square knot.

                    Rope is no good if you don't use a proper knot.

                    If you have neighbors that aren't tied down right do it for them or move upwind.

                    Hope it helps, Mark

                    Taylorcraft L2 Tiedown Instructions.pdf
                    Mark
                    1945 BC12-D
                    N39911, #6564

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                    • #11
                      Thought a great idea loaded with common sense, the instructions for the L-2 were probably written prior to there being metal loops cemented into concrete ramps. It would make it difficult unless you had a good selection of tie-down points embedded at the airport ramp pointed in different directions. Even the 1930's era airport 1/2 mile away from me, (no longer operating), didn't have those options, just metal loops set in the ground with concrete and there were only a few. I still have a picture of my mother giving a hand-prop pose with an L-2 during WWII tied-down at that airport at one of the few tie-down points in the grass. I am not sure what the tie-down kit comprised of, never seen one or a picture of one. Was it rope or some type of tie-down rings to be embedded in the ground?
                      Cheers,
                      Marty


                      TF #596
                      1946 BC-12D N95258
                      Former owner of:
                      1946 BC-12D/N95275
                      1943 L-2B/N3113S

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                      • #12
                        Could you be a little more specific on the tie down ropes you use ,does any marine supply store carry these high strength ropes . ? I have been using the 1/2 inch ploy ropes that are rated to about 500 lbs tensile strength available at Tractor Supply , But they have never been tested . Thanks

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                        • #13
                          One consequence of tying down the tail into the wind is potential compression failure of the wing's rear lift strut. I've seen it happen (mainly on Pipers that far outnumber taylorcafts here) several times with factory struts. Replacement struts are heavier duty, at least those sold by Airframes (http://www.airframesalaska.com/Taylo...uts-s/1859.htm). Then there's the potential stress to the rudder, elevators, and ailerons if not properly secured with gust locks. We can't always predict wind direction especially during thunderstorms. But if prevailing winds that break things come from a common direction then we can prepare for that.

                          Spoiler wing covers work very well. They can be made with either raised foam embedded spoiler strips that kill lift, or sewn in mesh air vents parallel and near the leading edge that prevent cover ballooning and break up the laminar flow of air over the wing. I have both and they work.

                          Examples of spoiler strips and covers: http://www.kennoncovers.com/wingcovers.html and http://www.alaskawingcovers.com/WingCovers.html

                          Gary
                          Last edited by PA1195; 01-24-2019, 19:36.
                          N36007 1941 BF12-65 STC'd as BC12D-4-85

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                          • #14
                            The double braid configuration is nicest and most flexible. It is similar to bungee shock cords in construction. Nearly any premium dock/mooring line will work fine for our 12-1300 lb aircraft.

                            Any good Marine store will have proper line, in kit or in bulk. i.e. West Marine is nationwide and inland on lakes and river locations. https://www.westmarine.com/

                            The brick and mortar stores have bulk line reels you can cut to length on your own and in a variety of colors. You just have to heat seal and whip the ends.

                            Same for any good boat sales marina, i.e. Sea Ray, Cobalt, Formula, Meridian. Pick a place that serves larger boats, >6000 lbs, not just small fishing boats.

                            Sailing is a good resource for lines as well but we don't need rigging lines unless you want the color choices.
                            Mark
                            1945 BC12-D
                            N39911, #6564

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                            • #15
                              Gary, totally agree with your points above especially on gust lock, I secure the yoke. I'm in a hangar full time but frequent an airport 15-20 weekends per year with frequent mid-west rain storms and thunderstorms and only those stupid cables to tie down to.

                              The times I'm forced tying down into the wind after a storm it has been physically moved both along the cable and cable stretch aft. I know it has been in the air because my wheel chocks are out of proper position.

                              Its a pick your light plane poison, I'll go with a bit of rudder damage risk vs. whole plane damage risk. A good tight tail-wheel tie down will help reduce the rear strut risk. I go under the steering links and a wrap around the spring.

                              Depending on the ramp mates and tie down type/location I will point it into the wind.

                              In 12 years of going to this airport, it has never been moved after a storm with tail into the wind. Neither has that cable line of multiple aircraft. The whole cable line of aircraft into the wind are generally moved aft, 6"-2 ft. My cabin stays dryer too.

                              I know this isn't fool proof and there are risks both ways (I'm more scared of hail). I'm trying to design a good rudder lock too.

                              Mark
                              Mark
                              1945 BC12-D
                              N39911, #6564

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