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RV 7A Tie Down Ring Question

Tcheairs

Well Known Member
The tie down rings under the wing of my (newly acquired) RV 7A thread into holes in the wing until they hit a "stop" which could be anything and potentially damaging.. They are pretty much all the way in when they hit the "stop" (whatever it is).

What is the proper technique for using these rings and should they have stop nuts on them before bottoming out? If so, how do I protect my wing surface underneath if using a stop nut and washer? and finally,does anyone fly around with them installed?



Thanks
 
The threads in the tie downs are likely longer than the threaded portion that's inside the wing.

Cut a little off the tie down, and then use a common nylon washer to protect the wing skin under the tie down.
 
The ring screws into a long hunk of aluminum thats on the fwd side of the main spar.

The plans have you tap the hole that you screw the ring into an inch deep (I think?) so you're likely just bottoming out on the end of the threaded portion. Even if it was tapped all the way through there's no way your bottoming out on anything else unless the threaded portion of your tie down ring is about 6" long, because the only thing above that is the upper spar cap and skin.

Swiped this picture off the internet so I don't know which model RV it is, but you get the idea.
 

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tie down rings

Tie down loops screw into the wings easily with finger force. Engaging the threads over an inch is plenty strong enough for the loops to do their tie down duties. Caution - there is about 1/8" space between the wing skin and the internal bracket, so if you tighten it too much under the wing, you will bend the wing skin... Don't torque then in there or use a jam nut or you will end up with ugly dints under there.
My practice is to remove them before flight.
 
does anyone fly around with them installed

Know of a couple of guys flying around with them installed. It is an aerodynamic sin. And it hurts my eyes really bad :eek:

Various reasons cited, such as: „too lazy“ or „used as another reference point when flying formation“ or „used to secure the wing when my baby is on the hanger“, etc.

They are a few aircraft out there on which those drag devices wouldn’t be noticed, such as in any of Chris Heintz STOL stuff.
On the other hand, the aerodynamics and the engineering team at Vans have spent dozens of years, countless hours of work, perfecting the shape of our mistresses to a slender, efficient and sexy shape. Flying with rings on is like spitting on their work ;)
 
Know of a couple of guys flying around with them installed. It is an aerodynamic sin. And it hurts my eyes really bad :eek:

Various reasons cited, such as: „too lazy“ or „used as another reference point when flying formation“ or „used to secure the wing when my baby is on the hanger“, etc.

They are a few aircraft out there on which those drag devices wouldn’t be noticed, such as in any of Chris Heintz STOL stuff.
On the other hand, the aerodynamics and the engineering team at Vans have spent dozens of years, countless hours of work, perfecting the shape of our mistresses to a slender, efficient and sexy shape. Flying with rings on is like spitting on their work ;)

Don't hold back, tell us what you really think :)
 
In the spirit of "Total Performance", since my -7A spends over 99% of its time on the ground and tied down, it's tiedown rings are in place all of the time because I want them to be as secure as possible.

I slightly enlarged the hole in the wing skin to allow for a thin 9/16" jam nut secured up against the threaded receptacle. I had them bend when threaded all the way in without a jam nut holding the rope against a strong wind, i.e. 30 kts. or more. It's easier to keep them aligned with the airflow with a jam nut. I also ground down a 9/16" box end wrench to slip between the tiedown ring flange and the skin.

I took them out for flights for awhile, but found the above practice worked better for me.
 
A More Complex Solution

My RV friends were horrified at the thought of leaving the tiedown rings on our RV-6. Another thing, I don’t like how tiedown lines interfere with the pitot tube on the left side. I installed spring loaded, flush, retractable tiedowns on my wingtips and now we’re all happy.
 
Easy fix

Get a hex head set screw for 3/8." This will allow you to adjust the tie down ring for a perfect set for the proper orientation. You can leave a little gap or use a nylon washer. Either way great way to get a perfect set.

BTW, we are coming out with some nice air foiled tie down rings that you won't be ashamed to leave in. And, they might give you a knot of speed!!!

www.jdair.com
 
Yes, they are pricey -- but so what, you can't take it with you.

https://www.cleavelandtool.com/products/stainless-tie-down-ring?_pos=1&_sid=4241dc763&_ss=r

I leave mine in all the time. They are NOT noticeable.

I have those on the wing tie-downs. I had one on the the tail too, but I replaced it with an eyebolt so I could attach a GoPro mount. All three have/had a plastic spring-loaded aerodynamic fairing on them that I think the previous owner had 3-D printed by Steve Melton. They're generally unobtrusive in shape, but the material they're made out of won't support paint so overall they're pretty noticeable...probably more obtrusive than just the Cleveland tie-downs. I have no idea if the fairings add any speed. They're clever, though...
 
The forged tie down on the tail of my -7A makes a pretty darn good tail skid. I crunched my bottom rudder fairing once when I'd just returned from a flight and my passenger and I moved aft of the cg on the wing at the same time. With the tail tiedown ring now secured all of the time, it will keep from banging the rudder on exiting the plane. Of course, now we also exit off of the wing one at a time.
 
BTW, we are coming out with some nice air foiled tie down rings that you won't be ashamed to leave in. And, they might give you a knot of speed!!!

www.jdair.com

Oh, I'm all over this...I love all the little bitty things to fair...fuel tank vents, fuel tank drainks, rudder clevises, etc. :) Gotta get as many 1/10ths of a knot as I can to stay ahead of my buddies LOL!
 
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