As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(AUS) NO2 CYLINDER INLET VALVE DAMAGED IN THE COLLETT RECESS AREA.VALVE STEM CAP SEPARATED AND ONLY ONE COLLETT HALF WAS RETAININGTHE VALVE SPRING. METAL PARTICLES FROM THE DAMAGED VALVE WERE FOUND IN THE OIL FILTER AND PARTICLES OF THE MISSING COLLETT WERE FOUND IN THE SUCTION FILTER.