As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON TRAINING FLIGHT COPILOT NOTICED HOLE IN RIGHT INBOARD COWLING. UPON INSPECTION THE (FREON COMPRESSOR) HAD A SILVER DOLLAR SIZED HOLE IN THE SIDE. IT HAD A FLASH FIRE AND TORCHED A HOLE IN THE SIDE OF THE COWLING. SEVERAL COMPONENTS WERE ALSO DAMAGED.