As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ACFT WAS DOING A STEADY CLIMB AFTER TAKEOFF WHEN HE HEARD A LOUD BANG AND LOST RPM. PILOT LANDED THE PLANE BACK ON THE RUNWAY. FUND THE CYLINDER HEAD ON NR 4 CYLINDER COMPLETELY BLOWN OFF. PROBABLE CAUSE COULD POSSIBLY BE MORE DEFECTIVE CYL ASSY THAN CALLED OUT IN AD 08-19-05. THIS CYL ASSY IS OUTSIDE THE SN RANGE. RECOMMEND INSTALLING CYL ASSY. (K)