As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING A 500 HR INSPECTION, SUCTION SLEEVE FROM THE ALTERNATE AIR VALVE WAS FOUND INSIDE OF THE AIR FILTER. SUCTION SLEEVE FLANGE AND VALVE BODY GROOVE WERE WORN TO THE POINT WHERE THE SUCTION TUBE WAS ALLOWED TO MIGRATE OUT OF THE ALTERNATE AIR VALVE INTO THE AIR FILTER.