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-----Original Message-----
From: asw20747@aol.com
To: lml-digest@lancaironline.net
Sent: Tue, 28 Aug 2007 9:18 am
Subject: Ram Air Valve - More Loose Screws!!
Just a heads up the group......
The (2) 6-32 Allen Cap Screws that hold the butterfly ram air valve on the Legacy can and DO come loose!!! (see previous post with an ES also)
This didn't happen to me directly but another Legacy that I'm well aware of. We have been checking these screws, with a small flashlight and a mirror inserted in the tube opening, about every other flight. On this particular Legacy, the screws looked to be fully seated with ALL the threads showing on the back side and then on a subsequent check, 3 days (2 flights) later, we found one screw missing and the other one half way backed out. When they come loose, it apparently happens pretty fast!!!
Borescope inspection revealed that this screw ended up in the number #2 cyl and bounced around a bit without doing much damage before it exited...... LUCKY!!!
The next occurrence may NOT be so lucky.
This is what we did for a fix. NOT a recommendation necessarily..... just what we did.
* Took the inlet tube/valve off the airplane
* Made a long extraction/insertion tool with a 7/64 ball driver and a "T" handle at one end to remove the screws (one at a time if you still have them both!)
* Replace the 6-32 (3/8" long) with high quality 6-32 (1/2") long Allen Cap Screws
* To hold the screws in place on the end of the ball driver we used a small piece of plastic tygon tubing inserted over the end of the ball driver
* Put the new screw in, this can take a while but can be done with patience.
* After the screw is inserted, backed it out so maximum threads were showing
* With a LONG Q-tip inserted down the tube, spread Loctite #267 (EXTRA high strength RED) over the backed-out threads and then immedaitely tightened it down
Notes- we found it was best to get both new screws in place BEFORE tightening with Loctite. The reason we didn't put the Locktite on the threads FIRST, and then insert the screws, is that the Locktite 267 with its integrated primer, was actually starting to dry BEFORE we could get the screw started.
Our test samples showed, one thing. If we EVER need to get those screws out..... WE CAN"T!!!!
I don't know if Lancair has yet come up with a comprehensive list of who has what valve and which were prepared correctly, but I don't think this is anything to fool around with.
Prior to this event, we thought that by keeping an eye on the screws, we would be OK until we heard from Lancair. THAT IS NOT THE CASE!!!
Hope this helps.
Best regards,
Erik Larson
Legacy
N74FX
ASW20747@aol.com
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