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Hi Group. I agree with Paul, that is best to remove the wings AND install the inspection holes to make it possible to detect corrosion in all areas of the center section. The area he refers to is hard to see from either side of the disassembled plane. There are holes in the fuselage giving good view to the small inner ribs ( see the last image from my repair sequence- http://home.pacbell.net/hbeil/ercoupe/corrosion.htm), but only from one side and looking at it from the other side with the wings off, does not let you see much. The best tool to use in that area seems to be a boroscope - any boroscope! - or inspection holes. When I reassembled my plane after replacing such rib in question, I thought that it would be a very good idea to install inspection plates at least in that area. I am planning to do that my next annual. What I will not do is use these flimsy hole covers Univair sells overprized; my A&P mentioned that there are much nicer solutions out there. Hartmut N3330H ----- Original Message ----- From: "Paul M. Anton" <[EMAIL PROTECTED]> To: <[email protected]>; <[email protected]> Sent: Tuesday, September 23, 2003 9:52 AM Subject: [COUPERS-FLYIN] Center section AD revisited > ----[Please read http://ercoupers.com/disclaimer.htm before following any advice in this forum.]---- > > > Some time ago, I advocated using wing removal as the easiest method of > complying with the center section AD. In my own case, I have done a number > of wing removals, and felt that I could spot serious corrosion using this > method. > > I had taken my own wings off for a mini restoration, and was of the opinion > that I was free of all corrosion. Since I had taken the wings off before the > effective date of the AD I didn't sign the AD off. I decided to install the > inspection holes to allow inspection every annual. > > On the pilots side, rear inboard inspection hole I found the inner rib had a > stiffener that was almost powder. The rib itself is fine at this time only > the small stiffener is affected. In addition, there is some surface > corrosion that will progress to pitting in the near future. > This was NOT visible with the wings off. > > Had I not put the inspection holes in, the inner rib would require > replacement in the future, and the surface corrosion would be much more > difficult to control. This was my first installation of the inspection > holes. I wanted to do it to my own plane first before I did it to anyone > else's. I took me 4 hours for the job. This includes some very careful > measuring since I have the ribbed skin and there isn't much room for the > three inch holes. It also includes some OH S--T time spent contemplating the > ugly stiffener. Also this was the first opening I cut, and I was half afraid > to look in the next holes. <G> > > To pull the wings and reinstall them takes me 5 hours with help. The > openings an hour less. > > After this eye opener, I would have to retract any advice I gave about wing > removal, and say scope or openings is the way to go. In fact, if you wanted > to do a really thorough job, wing removal AND openings. You can't get a look > behind the tanks. or at the wing attach fittings with the inspection holes. > > As it stands, I have about 3-4 hours work to remove the corroded stiffener > and make another plus clean up the surface stuff. Perhaps in 3 years I'd > have an inner rib to replace--possibly more. > > If any of you Western Washington Coupers want the inspection holes, I'll be > glad to help very reasonably. > > Cheers: > > Paul > NC2273H > > ========================================================================== == == > To leave this forum go to: http://ercoupers.com/lists.htm > Search the archives on http://escribe.com/aviation/coupers/ > > > ========================================================================== ==== To leave this forum go to: http://ercoupers.com/lists.htm Search the archives on http://escribe.com/aviation/coupers/
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