As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FORM 337 INSTALLED, STC SA01669CH AIR FILTER ELEMENT BECAME HARDENED AND SHRUNK CONSIDERABLY OVER A SHORT SERVICE LIFE OF 496.6 HOURS. THESE FILTERS HAVE A 2500.0 HOUR SERVICE LIFE. WHEN THESE AIR FILTERS SHRINK THEY PREVENT THE AIR BOX FROM CLOSING PROPERLY, IN RESULT, CRUSHING THE FILTER ELEMENT IF NOT REPLACED. WE INSPECT AND SERVICE THE CPE-1104, AIR FILTER ELEMENT EVERY 100HRS IAW THE ICA DOCUMENT 4003, LATEST REV AS SPECIFIED.