Substantial items found during annual inspection...

lloydfisher

New member
We found three significant items during my annual inspection which I believe other club members should be aware of. The aircraft is a 2003 7GCAA, purchased new, and it now has 490 hours. One owner, always hangared, in Colorado.

Item 1: On the inside of the shroud around the muffler, there is a stiffener spot welded to the shroud. The stiffener is a piece of stainless, about .025 inch thick, bent into a 90 degree angle, and it's about 3/8 x 3/8 x 6 inches long. It's on the lower, front area of the shroud. The edge of this stiffener had been vibrating against the muffler itself, and had worn two significant grooves into the muffler. Very difficult to estimate the depth of these grooves, but I think they might be legitimate stress risers. I encourage everyone to do a serious "bright light" inspection of this area.

Item 2: On the inside of the duct directly downstream (engine side) of the air filter, there was a substantial "bubble" of paint which had delaminated from the fiberglass of the cowl. Again, this was between the air filter and the rubber duct which connects to the carburetor air box. The bubble of paint had not yet broken free, happily. The bubble was about 1/2 inch by 2.0 inches. It came loose easily when I placed some masking tape on it and pulled it up. Another great place for a diligent inspection. To do that, you'll either need to remove the cowling and look inside the oval-shaped duct, or remove the air filter and look from the front.

Item 3: Related to item 2, there seemed to be significant voids in the fiberglass work inside this air inlet duct, which had been filled with some sort of filler and then painted over. The paint over this area had cracked in sort of a crazing pattern. When it was sanded out to repair, pieces of the filler quite easily flaked out of the voids. Again, this was between the air filter and the carb air box.

Best regards.
 
Thank you Lloyd. My plane has approximately the same number of hours and I will be doing my annual soon. These are things I probably would not have checked otherwise.

Byron
 
These sound like the typical things that can be found during a good annual on just about any airplane....if your mechanic opens his eyes and looks. Yeah, the fiberglass bubble is a bit different, but hand built airplanes can always have defects like this. Most guys would probably have missed that one. The muffler defect is the kind of thing we're always looking for, and more common than you might think. Gotta look real hard at exhaust systems on every brand of airplane. They can be real dangerous. It sounds like you have a mechanic who has learned to look beyond the routine checklist items and find what's what. They are rare. Remember him when somebody tells you he knows where you can get your annual done cheaper!
 
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