As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT 8657, ENROUTE SEA-CLM AIR TURNBACK/DISCREPANCY: RIGHT COWLING OPENED IN FLIGHT RIGHT AFTER TAKEOFF. AIRCRAFT WAS RETURNED TO SEA. NO EMERGENCY DECLARED. LANDED WITHOUT FURTHER INCIDENT. CORRECTIVE ACTION: MAINTENANCE FOUND R/H UPPER ENGINE LATCH UNLATCHED. PERFORMED INSPECTIONS OF ENGINE AND COWLING, NO DEFECTS FOUND. SECURED COWLING. AIRCRAFT RETURNED TO SERVICE.