Online Community of Zenith Builders and Flyers
With Spring in the air, thoughts turn to fly-in's and camping! Most years, I fly down to Sun 'n Fun and camp in the Homebuilt Camping area. I've found that the cheap "dog tether" tie-downs are worthless (they snap or bend too easily) and heavy-duty spiral tethers are difficult to place in hard ground. There are numerous commercially-available tie-downs that all have their pros and cons.
However, being a homebuilder, I naturally wanted to make my own! If you Google "EAA tie down plans," you'll get this link. I really like this design since it involves driving spikes into the ground rather than a spiral tether. I made some modifications that I think make it even better. Here's a pic of the end result:
As you can see, I used an aluminum rather than steel plate since I had that on-hand. I think steel would be better (and heavier!) for long-term durability, but no more than I use them, I think the aluminum will hold up OK. Rather than fabricate the 18" x 1/4" steel spikes called for in the plans, I simply bought some "Yard Tuff" 18" x 3/8" rebar stakes on Amazon - kind of pricey, but they have a welded steel ring (helpful for twisting and pulling) and an anti-corrosion coating (looks like powder coat). Mostly good reviews on Amazon and I lucked-in to finding an "Amazon Warehouse Deal" and got them for a little less. I left one stake high so you could more clearly see the welded ring and spiral fluting - that spiral helps to "unscrew" the stake when you try to pull it out. Since this picture, I cut nearly an inch of the stake off the top just to lighten and shorten it slightly, leaving enough stake I can hit it with the hammer and not hit the ring. Even though the tie-down straps are bright red for visibility, I wouldn't want to think what would happen if someone stepped on those stakes barefoot, so I plan to get some bright orange plastic "caution" tape and flag those steel rings for even more visibility.
I have a lightweight camping hammer that also can be hooked into the welded ring to give leverage to unscrew it and/or pull it. The tie-down straps have a simple latch for quick adjustment. I cut the hook off the end of the strap and replaced it with a carabiner - hooks can slip out of tie-down rings if the wing is rocking up and down. I'll probably wrap the carabiner with some self-fusing "rescue tape" to avoid metal-to-metal contact on the plane's tie down rings. Both the straps and the carabiners are rated higher than the likely tension required to pull out the tie-down. If and when I have to replace the red straps, I'll probably just get a strap twice as long that I can loop through the tie-down plate and the plane's tie-down ring and eliminate the carabiners.
I fully staked one of these and could not get it to budge, even when pulling directly upwards. If placed at an angle to the tie-down ring on the plane, I think it would be extremely difficult to pull out of almost any soil type except loose sand! Rather than make the slightly different plate for the tail as the EAA plans depict, I simply made 3 identical plates of the above design. The whole kit, including a canvas tote bag and the hammer, weighs 8 lb 1 oz.
See you at Sun 'n Fun! ;>)