Abe's Aviation Tiedowns

Also See Below: Advice for tying down your aircraft

After the awful happenings with the tornado that went through Sun-n-Fun this year, I was keenly aware when I started to see things from Aviation Consumer (I'm a subscriber) regarding the quality of tiedowns, and their analysis of what worked and what didn't, at Sun-N-Fun.  Personally, I have been using "The Claw", for a few years now, having in the past used a few various things:
  1. Dog Screw Anchors
  2. EAA L-shaped rebar
  3. Heavy steel ground anchors
  4. The Claw
The dog screw anchors are clearly too weak to tie an airplane to.  The handle itself will deform under load.   The EAA Rebar would work, but I can't trust any airplane to just one piece of straight rebar for each area of the plane.  The heavy ground anchor screws I used before the RV-10, when I used to fly over to OSH each day, and tie down for the day.  They were pretty darn tough to put in, but with a 4' bar, you could screw them into the ground and they seemed like they'd hold fairly well, although you disturb the soil a lot from installation so there isn't that much solid soil left then to hold the big disc.  That brought me to "The Claw".  The theory seemed good.  3 anchor points, with the pins driven in at an angle.  I was pretty happy with them, and although I didn't realize I needed to install them directly under the aircraft's eye screws, they were and are a pretty good system.  But I wasn't really aware of the shortcomings until after the Sun-N-Fun disaster when I started to hear what worked and what didn't in that storm.  As it turns out, the Claw was a pretty good system, but it did have on weakness...the legs would sometimes break.  After hearing this and thinking about it, it made sense...the legs are made of a cast aluminum, and that just isn't as strong as if they were made by machining them from some good aluminum stock.  So I started to pay a lot of attention as Aviation Consumer did it's review.  In it's first review this year (2011) the claw fared pretty well in the group of things tested, but then they (and consequently I) became aware of a couple of other tiedowns that may offer even better protection.  Among these were the Storm Force Tiedowns, and the Abe's Aviation tiedown system, available in a few different flavors.  With OSH on the horizon, I wasn't going to compromise this year.  EVERY year that I'm at OSH for the week, I spend at least one, if not more than one, night where I'm laying in the camper in fear of what I'll see in the a.m. after the big thunderstorm passes.  It's inevitible, and it happens EVERY year.  It's never been a problem, but I've went through many very windy and gusty storms at OSH.  **Post-OSH-Update: (yes, this year we had more 40mph gusts again, breaking some RV-10 rudder stops off, but mine fared really well)

To see the Aviation Consumer Tiedown Shootout video, watch this link...it's a pretty great test.

I've taken enough engineering and physics courses in my life, and had enough good life experience, to develop a good understanding of what kinds of things would hold well in soil, and after thinking about it, I could see how both the Storm Force and the Abe's system could perhaps be a better system than the claw.  In fact, before I saw the video above, I was even considering the Storm Force Tiedowns.  But once I saw the video and saw what Abe's came up with, I knew that was going to be the superior product..in many ways...it was completely obvious.

Starting right out, the Abe's tiedowns are made of stainless stell...giving them superior strength and life.  I'm sure that adds quite a bit to their cost, which admittedly isn't nearly as cheap as the other systems, but I wasn't looking for the cheapest way to tie down my plane...I wanted the BEST way to prevent my airplane from ending up upside-down at OSH this year.  When you look at how the Abe's system works, there are multiple (5 in my case) flat "spades" that you drive into the ground with a hammer and wood blocks (hammer not included), and then you drive in 2 extra holding pins.  You want to drive them in so that the rope is angled towards the aircraft, not directly below the tiedown rings.  Any fool can see how this would provide a very solid flat surface pushing against the soil, and give a very very strong hold.  In fact, in the Aviation Consumer video, they pulled over 1000lbs and had to pull with a truck to test these, and the tires spun on the grass before the things let go!  So even with only 3 tiedowns, you've got a pretty tough system, but the system I bought from Abe's is the Deluxe 5 system, which comes with 5 spades, each with 2 holding rings.  The way this works is that while the tail only gets one spade, each wing gets two spades, which you orient about 90 degrees from eachother (see the last of the 3 photos), and then you connect them with a piece of cable (included) and then there's a pulley that rides over the cable with a caribiner on it that you tie to the plane.  This allows you to have 2 places that are holding in the soil, spreading the load, and they'll pull very strongly once you tighen up the ropes.  The system also came with some good hi-vis climbing type rope, although as you can see in my photo, I bought some color-matching rope for my set.  With everything in place, you have a very significantly stronger tiedown system than any of the other commercially available models.  It all comes in a nice big red bag, too, and includes everything but the hammer.  Read on below after the pictures.

Click for larger view

The images below came from the Abe's Aviation Site


So now that you know what's all in the system, how is it to install?  Well, I'll give you my experience and my take on how it all is.  First, if I were travelling long distances and only using these for transient 1-night tiedowns in places where I didn't expect bad weather, I'd probably just bring 3 of them.  These things are gonna hold pretty tough, so unless I expected high winds, I wouldn't waste my time hammering them in.  How do they hammer in?  Well, I've got to admit, they aren't nearly as easy to hammer in as the claw or storm force tiedowns would be.  In those, you're only hammering in stakes.  With these, you have to hammer in the whole spade, and in rocky or hard soil, that could get pretty tough.  I initially tried to hammer them in with my little mini hammer that came with "the claw", and although I got them in that way, it took hundreds of hits to get them driven all the way in.  So as you can see in my photo above, I got myself a plastic, shot filled heavier hammer.  This is a much better hammer with about a 2 or 3lb head on it, for pounding these in.  I've only put them into grass thus far, and fairly dry soil at that.  It takes a bit of hammering to get them in.  Once they're hammered, the tying down is quick and painless.  When I first got all 5 in and tied down, I was a bit worried that with all that effort to get them installed, it would be a royal pain removing them.  This turned out not to be the case at all!  With the nice round loops on the stakes, you can just pull on them or easier yet, put one of the ropes through and pull straight up on the rope and they come right out.  Then, since the spades have a lip on the top, you can just hook it under your fingertips and pull straight out.  As long as you pull straight up, they come right out without much effort.  Holding at an angle, pulling against your plane, they'd still have hundreds and hundreds of pounds of holding force.

So after trying these out, and knowing how well they hold, this system is what I'm going to be bringing to all of my longer-term parking destinations with the RV-10 from now on.  I may actually on some trips still bring my "claw" system if I expect rocky or hard soil, because I don't know how I'd get these pounded into anything but grass, but a majority of the places I'd go and stay for more than a day are places like Sun-N-Fun or OSH, and these are ideal for that environment.  The Abes folks tested these things at places such as the grass strips in Idaho, and they worked well there too.

*** Post-OSH Update:  Advice for tying down your aircraft
After reading some articles about tying down aircraft, and seeing things in a local RV group newsletter, and attending OSH, I've got some advice for tying down aircraft that goes beyond what tiedowns you use...

1. Retract the Flaps!  Many RV builders put the flaps down to prevent people from stepping on their flaps.  This is fine for getting in and out when you're with clueless individuals who don't even read your "NO STEP" placard, but if you're leaving the aircraft unattended, retract the flaps.  Flaps will just add drag or enhance lift to the wing, and either way will provide a better frontal surface area to the wind, so if there are large gusts or winds, having the flaps down will magnify the problem.

2. Always use a gust lock!  At OSH this year, people either didn't have strong enough gust locks, or they didn't use them, but after the winds went through one day where it was really blowing dangerously hard, I checked on the RV-10 lot and personally walked by a few RV-10's that had broken rudder stops and slightly damaged rudders.  The ailerons are less often an issue, but having flapping control surfaces is a recipe for disaster and being stranded somewhere.  There are many gust lock options, but USE ONE.

3. Don't use ONLY a seatbelt to secure your elevator!   You can see I figured this one out long ago from my Gust Lock write-up from a while back. On my gust lock, I have something that holds the rudder pedals really securely, and then I attached a strap to it that was cut to the proper length to allow me to use the seat belt to pull back on the stick, but ONLY to the point that the elevator is approximately neutral.  You do not want the elevator fully nose down, nor nose up...either way will just cause the plane to want to react to the winds.  Keep your elevator and other controls neutral, and let the air just flow safely over the plane.

4. Use your tiedown properly.  If you use the claw, tie it directly under the anchor point.  If you use many other types of tiedowns, tie the ropes at an angle of maybe 45 degrees to the wing for best holding.  But follow the manufacturers recommendations for proper use of the diedowns.

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