As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
#5 CYLINDER HEAD SEPARATED FROM THE CYLINDER BETWEEN THE 5TH AND 10TH COOLING FINS ON CLIMB OUT. THERE WAS EVIDENCE OF EXHAUST BLOWBY ON APPROXIMATELY 1/3 OF THE CIRCUMFERENCE OF THE CRACKED CASTING, PRIOR TO THE COMPLETE FAILURE OF THE CYLINDER. THE AIRCRAFT PERFORMED AN EMERGENCY LANDING. LAST ENGINE INSPECTION 7/7/2021 ETT 2261.1 COMPRESSION OF CYLINDER #5 76/80.