As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AD 200-18-23 WAS C/W BY INSTALLING NEW GASKET PT 06B23072 UNDER OIL FILTER ADAPTER PLATE. WITHIN 34 HOURS, GASKET BLEW OUT AND ALL THE OIL WAS BLOWN OUT. AIRCRAFT RETURNED TO AIRPORT SAFELY. INSPECTION OF GASKET REVELED THAT THE RUBBER GASKET HAD DISSOLVED AND BECAME VERY SOFT. A NEW GASKET WAS INSTALLED AS PER INSTRUCTIONS IN THE SB 543A, NO FURTHER PROBLEMS HAVE BEEN ENCOUNTERED WITH THIS AIRCRAFT.