As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER APPROXIMATELY 1 HOUR INTO THE FLIGHT, THE PILOT NOTICED NUMEROUS SMALL CRACKS IN THE LEFT SLIDING WINDOW. CRACKS WERE LOCATED IN THE UPPER LEFT HAND CORNER OF THE SLIDING WINDOW. THE AIRCRAFT RETURNED TO BASE AND AFTER LANDING, CLOSER EXAMINATION REVEALED CRACKS WERE ALSO LOCATED IN THE LOWER FORWARD PORTION OF THE WINDOW. PROBABLE CAUSE: UNKNOWN.