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Atlee Dodge lift strut reinforcment bracket install on covered wing

Randy

FOUNDER
S.Dakota
I want to inspect the lift strut attach point on the front spar on a PA-18 project.
As long as I'm doing that I want to install Atlee Dodge's lift strut reinforcement bracket.
The wings are covered.
I'll need to open up the leading edge to do that....
I have a few questions about the size of the hole needed, and how it gets patched again.
The guidance says something about installing a "bullet patch"...and that Stoddards or Univair would have it.
Can't find it in the Univair catalogue.
Also...are the existing bolts going to be long enough..or will I have to get longer ones.
A few pictures would be great if you have some.
Thanks in advance
Randy
 
Don't bother unless it's a rust bucket. If it is, then install new brackets.

Crash
 
Don't bother unless it's a rust bucket. If it is, then install new brackets.

Crash

true,

better to install Atlee's hurricane tie downs.. (eliminates the need for strut attach beef up, since you will not be subjecting that to tie down forces)
http://www.fireweedtech.com/index.p...4:aircrafttiedowns&cid=12:wingparts&Itemid=53

you can inspect existing wing strut attach brackets by just looking up them, and making sure they are strait(and if installed on plane in line with lift strut)
 
The failure of the front spar attach fitting has nothing to do wit rust or age or a deteriorated fitting. When the fitting that connects the strut to the spar attach fitting is use to tie the aircraft down as with the Piper tie down rings, wind gusts that lift the wing with force cause the tie down lines to jerk the fitting perpendicular to the ground and wing, but on an angle to the direction that the attach fitting is designed to take force. The fitting is designed to work in tension between the spar and the strut. Straight line only. When it is pulled on an angle by a lifting gust and the restraining tie down line, the force is at the end of the fitting at an angle to its direction of its designed strength and about 6.5 inches from the bolt through the spar. If nylon line with some stretch capability is used, it isn't as bad as web strap or poly line or worse yet is chain which has vertually no streach and therefore provides a sudden jerk at an angle on the end of the lever of that fitting. Failures can be catistrophic. Atlee's support was an attempt to strengthen this area of the attach fitting.

The other option was to use a bracket or seat belt strap around the spar outboard of the lift strut attach fitting providing for a pull straight down on the spar and not putting any strain on the fitting during high wind conditions while tied down. Both are desirable for aircraft that may be tied down in high wind conditions.

If the fitting has been damaged it pulls the N brace compression member down and can be seen where it makes a greater bulge in the fabric on the bottom of the wing. The inner part of the fitting can be inspected through an inspection cover hole in the bottom of the wing. To inspect the part of the fitting forward of the spar it is necessary to cut a hole in the fabric and leading edge. This was then patched with a bullet patch. I think that was a service buliten but may have been an AD note.

I am aware of one fatality (judge kalimereties) and another wing separation. For aircraft which may ever lbe tied down in high wind conditions these are both desirable mods.
 
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