As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE FLAPPER VALVE ON THE PA44180 AIR BOX PIVOTS ON TWO COMBINATION RUBBER GROMMET/NYLON BUSHINGS (MS35189). DURING A 100-HOUR INSPECTION, THIS GROMMET/BUSHNG COMBINATION WAS FOUND MISSING FROM THE BOTTOM OF THE ASSY LEAVING A GAPPING HOLE IN THE BOTTOM OF THE AIR BOX THROUGH WHICH UNFILTERED AIR COULD PASS. IN ADDITION, THE ABSENCE OF THE GROMMET REVEALED THE FLAPPER VALVE SHAFT HAD WORN TO ONE-HALF ITS ORIGINAL DIAMETER.