---------------------------------------------------------- Zenith601-List Digest Archive --- Total Messages Posted Mon 10/08/12: 2 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 06:50 AM - Wing attach bolts (BobbyPaulk@comcast.net) 2. 02:30 PM - Re: Wing attach bolts (Larry McFarland) ________________________________ Message 1 _____________________________________ Time: 06:50:13 AM PST US From: BobbyPaulk@comcast.net Subject: Zenith601-List: Wing attach bolts List While finishing up my "Conditional" last Sat. I checked the 12 wing attach bolts for the proper torque. I found the pilots side top two inside bolts to take a good 1/4 to nearly 1/2 turn to get back to 144 inch pounds of torque. I could see that the nuts had not moved because I had the orange inspection lacquer on the threads. They were not loose on the last inspection ( 35 hrs. ago ) and I have not been rough or pulling high G's. The rest of the bolts were in spec and did not turn. Has anyone else experienced this? What caused it and is it unsafe? I would appreciate your input. Bobby ( age 74 ) Zodiac 601 XL "B" Jabiru 3300 S/N 1141 Sensenich 64" x 51" Prop Bing Carb 260 Main & 285 Needle Jet Status - Flying 160 hrs. ________________________________ Message 2 _____________________________________ Time: 02:30:57 PM PST US From: "Larry McFarland" Subject: RE: Zenith601-List: Wing attach bolts Hi Bob, The stretch during torqueing would be slight, but thermal effects, a couple of .0002 seasonal material shrinkage and/or thread climb within the fastener threads could have allowed conditions to require more tightening. Or you might have gotten Chinese counterfeits that have a compromised material strength. There are lots of reasons, but you=99d be more certain if you replaced the bolts and tightened those two questionable bolts to failure to find out how much safety you have in excess of the specified 144 inch-pounds. The test might be enlightening and give you some comfort in having looked at it closer. It might just save your skin too. Fly safe, Larry McFarland From: owner-zenith601-list-server@matronics.com [mailto:owner-zenith601-list-server@matronics.com] On Behalf Of BobbyPaulk@comcast.net Sent: Monday, October 08, 2012 8:50 AM Subject: Zenith601-List: Wing attach bolts List While finishing up my "Conditional" last Sat. I checked the 12 wing attach bolts for the proper torque. I found the pilots side top two inside bolts to take a good 1/4 to nearly 1/2 turn to get back to 144 inch pounds of torque. I could see that the nuts had not moved because I had the orange inspection lacquer on the threads. They were not loose on the last inspection ( 35 hrs. ago ) and I have not been rough or pulling high G's. The rest of the bolts were in spec and did not turn. Has anyone else experienced this? What caused it and is it unsafe? I would appreciate your input. Bobby ( age 74 ) Zodiac 601 XL "B" Jabiru 3300 S/N 1141 Sensenich 64" x 51" Prop Bing Carb 260 Main & 285 Needle Jet Status - Flying 160 hrs. ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message zenith601-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/Zenith601-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/zenith601-list Browse Digests http://www.matronics.com/digest/zenith601-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.