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Part of the wing AD is to remove ANY sound insulation from the plane. Permanently. They're right. N99387 had some nice, approved, sound insulation. The kind that is some kind of inert synthetic material (fluff) with a laminate of aluminum covered with a laminate of mylar. Should be innocuous, right? Nope. On N99387 it had been there since 1999. Holding moisture. Being a dissimilar metal in places. Result? Surface corrosion, not severe, but it could have got that way, everywhere the stuff touched. It clearly had held moisture. It felt damp to the touch on removal. Highly un-good. Now, where the aluminum and/or fluff was touching the aileron control rod...it made a big rusty hole. So, this quiet little provision of SB31 *may* just be one of the most important provisions. By the way...if I hadn't decided at the last moment to pull wings, rather than making inspection holes, we might not have had the point of view that would let us see an aileron push rod that was going to let go at some point. Okay, I'm a convert. Pull the damned wings off. Look in there. And do whatever you can to let your Ercoupe breathe, from all sides of the skin. Part of me is tempted to never again allow even any kind of cosmetic interior panels to compromise air flow. Sound insulation in an Ercoupe is like wrapping a Harley-Davidson's gas tank in a water-heater blanket to quite the pipes, anyway... ...the only thing that really works is a good headset. Greg ========================================================================== ==== To leave this forum go to: http://ercoupers.com/lists.htm Search the archives on http://escribe.com/aviation/coupers-tech/
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