Compression Member Insert Torque Value

[PA18project]

Does anyone know the torque value for the cast piper compression member inserts. I cant seem to locate it and I sure don't want to strip out those fragile piper threads if at all possible. Thanks.

 

[Fabman]

I always use a 1/4" drive ratchet when tightening them so I don't get carried away.

 

[bob turner]

Put helicoil inserts in, even if threads are not stripped. Takes a special tool to insert them.

 

[mike mcs repair]

Just barley snug...

i thought helicoils were a no-no in them...?? hmm not sure why though..... too short threaded area, or corrosion, don't remember why... anyone?

 

[bob turner]

Nothing could be weaker than that soft casting.

 

[mike mcs repair]

Nothing could be weaker than that soft casting.

not trying to be disagreeable...

just had suggested helicoils many many years ago for that and been turned down... but I don't remember "the why" behind it.....

but there are so many logical things dealing with real planes that are a "sin" because we lack an approval piece of paper to do it....

doesn't mean it will not work, and is not better than original.....

take for example this topic on the shorter sister site..
http://www.shortwingpipers.org/phpbb3/viewtopic.php?p=7583

I assumed bushing a flap or aileron hanger a no brainier... but someone just got a STC to do it and will sell you 2 tiny bushings and a piece of paper for $140

After 3 years of work with the FAA, I now have an STC'd (SA02128LA) and PMA'd kit available for an easy repair of worn aileron and flap hinges. All the Piper models discussed on this website are on the Approved Model List. There is an article and ad upcoming in the SWPN describing the repair. Please contact me at fabricdoctorLLC@aol.com if you would like more information.

-------------------------------- response from Bob---------------
As far as the hinge repair itself is concerned, a number of years ago I noticed a loose hinge on one of the flaps on my PA-22/20. Discovering that there really was no legal fix other than replacing the entire hinge (which is a difficult and time consuming job, to say nothing of the cost of the hinge and the associated fabric work), I began working with the FAA and a DER (Designated Engineering Representative) to come up with a solution. Three years later and after a great deal of documentation, I obtained an STC. In a nutshell the repair consists of using a custom reamer to ream the affected hinge slightly oversize in order to accommodate a thin bushing. Since the bushing is very thin, we decided to use an epoxy adhesive to hold it in place rather than use an interference fit that might result in distortion of the bushing during placement. Including the removal of the aileron or flap, the whole procedure can be done in less than an hour of work. (The epoxy, however, must cure for 24 hours before reinstalling.)
I now have complete PMA'd kits available that include everything you need for the repair, including new clevis pins. The kit costs $139.00 and includes bushings for two hinges along with installation instructions and all the necessary STC documentation. If you need additional bushings they are available for $8.00 each. Shipping is included.
I can accept credit cards as well as a check by mail if you are interested.
As I said in my posting, an article and ad is upcoming in the next issue of the SWPN.

Bob Andrews
The Fabric Doctor LLC
147 Woodstock Ct.
Claremont, CA 91711
909-621-2859
909-946-1081

that's weird....... have seen many bushed, never thought it was an issue, just very common maintenance item.... must depend on your fsdo??.... and I thought the $3.00 5/16 bushings were expensive....... Oh I see $8 now gets an extra bushing

 

[bob turner]

A little known fact I found out from this site: NAS bolts can be obtained in oversizes up to 1/32, and all you do is ream the hole and insert the bolt. I do not know if clevis pins can be obtained like that.

"Genuine" in Paso Robles is the place to go . . .

If there were any load at all on those compression struts, those threads would pull out in flight. When you very carefully insert a bolt on reassembly, the chances are about 20% that it will keep on turning. At that point, a Helicoil makes a whole lot of sense.

Some common repairs are covered in 43-13, which is approved data. I think I would interpret that document broadly - but then, I am also in favor of keeping light aviation aloft. We can shut it down by writing complex rules and slavishly adhering to them.

 

[luvcubs]

A repair or modification such as this to a control surface hinge is considered a major repair according to Part 43 and the ACO (Aircraft Certification Office) which, incidentally, trumps any FSDO info. Therefore some type of approved data is required along with a 337 for the repair to be legal. Since no approved data exists for any type of sleeve or bushing repair on the flap and aileron hinges, the STC was granted in order to provide approved data . Furthermore, the FAA will not issue an STC for a minor repair.