Today I pulled the lower cowling on my RV-3B (Rusty's, bought from Richard Nadig) for the first time.

I didn't like the air spaces between the air duct and the oil cooler and wanted to get it ready for warmer days. When I removed the duct (piano hinge on top, nothing on button) I was stunned by discovering that the fiber duct had worked its way though some weather stripping on the left side and had been rubbing on one of the oil channels in the oil cooler. I think I have less than 20 hours on it since I bought it from Richard who supposedly did an annual just before I bought it. Just what I need: another oil fire. I had already lost the muffler on my way back from Shady Bend to Clearwater (was clamped on the front end and hung in a piece of rubber from a tire in the back). Needless to say, the new HushPower II muffler is welded to the exhaust header ball joint now, and hung from a more substantial piece in the back. I guess the lesson is: just because it's signed off by and A&P it doesn't mean it's safe. Do your own thorough inspection.

Specifically be aware of the potential danger of fiberglass ducting rubbing on water and oil coolers. Fiberglass is a great abrasive.

Finn