As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AN INTENSE IN-FLIGHT FIRE OCCURRED WHEN A CRACK IN THE LEFT ENGINE WYE EXHAUST ASSY DEVELOPED AND ALLOWED HOT EXHAUST GAS TO LEAK THROUGH LOOSE COUPLING INTO ACCESSORY SECTION. THE CRACK IN THE WYE ASSY COULD NOT BE DETECTED UNTIL AIR PRESSURE WAS FORCED INTO EXHAUST SYSTEM BY BLOCKING OFF PORTS. SUBMITTER SUGGESTS THIS PROCEDURE BE ACCOMPLISHED AT LEAST ON ANNUAL INSPECTIONS.