Paul Thomas Posted June 28 Report Posted June 28 Oshkosh is right around the corner and, if you haven't yet, it's time to think about how to tie down your airplane. EAA publishes one option for a DIY kit (https://www.eaa.org/~/media/files/eaa/homebuilders/5aircraft tiedowns.pdf) and there are commercial units available. The claw is the most popular but past storms have shown too many failures for me to buy it. I decided to roll my own. The spikes hold the steel cable, the washers are not needed if you keep the loop on the spike small enough. The shackle connect the steel cables and the rope. The rope can then be used to tie down the aircraft. I didn't come up with the idea, I saw others use steel cable to a single chain link to modify the EAA idea; I added the shackle to make it more modular. I prefer this design over others because I can easily add ground anchor when I need more strength giving me more versatility. It will also be more compact to pack. The breaking strength is significantly higher than working load but the working load should be plenty for our airplanes. The big unknown comes from is the spikes as that depends on the soil type, moisture content, compaction, load angle, etc but reports from past storms show this system works better than most. The claw claims 3,600 lb combined capacity with the 10 inch spike used in their system. For those wanting higher working loads, it would be easy to add ground anchor points (and then upsize the shackle and rope). If you want to do something similar, here is what I'm using: 18 inch long spike 1/8 steel cable [working load 400lb] 3/8 heavy duty double braided nylon rope [working load is 820lb] 5/16 shakes [working load is 1400lb] Photos don't include it, but I'll be using flat 3/8 washers to prevent the risk of the steel cable coming off the spike.
Yetti Posted June 28 Report Posted June 28 If I was going to do one, I would replace the spikes with 1"x1/8 angle aluminum that was cut and sharpen into a spike. Also using some 1" climbing webbing in a self equalizing anchor set up would reduce the shock loading and anchor failure. Anchoring is more about not creating hard points to fail....
Hank Posted June 29 Report Posted June 29 I bought a set of giant screws from EAA at Sun n Fun, and got rid of my old dog tie-outs; the ones from EAA are much sturdier. In fact, the EAA screws held my Mooney in place during the SnF tornadoes, when planes parked all around me broke loose and blew into each other. Saw many Claw-type that failed, with airplanes sideways if one failed, or upside down, or blown across the way. My Mooney didn't move. The key with the screws is to screw it completely into the ground, all the way to the rope loop at the top. Just use a stick, piece of pipe or screwdriver to get it the last couple of turns. These now live in a stuff bag on my hat rack, with a rope set I made from 3-strand boat rope, with eye splice on one end of each.
PT20J Posted June 29 Report Posted June 29 I have tried a several. A lot depends on the type of soil. Claws work better in rocky soil than screws which work better in sandy soil.
BDPetersen Posted June 29 Report Posted June 29 And if it happens to be a dry year, the “screws” become a verb rather than a noun. 1
midlifeflyer Posted June 29 Report Posted June 29 I still have mine. 12” yellow ABS tent stakes and tie down rope. Have not used the at OSH, but they did hold a high wing securely in place overnight in western Kansas with 60 KT winds and a dirt storm.
Pinecone Posted June 30 Report Posted June 30 And a few more. I just Googled "Best Aircraft Tiedown."
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