Incident Overview
Approximately 15 minutes after departure, while the aircraft was climbing through an altitude between 12,000 and 12,500 feet, the pilot's flight compartment side 'D' window separated from the aircraft. At the time of separation, the cabin differential pressure was 4.3 psi, resulting in a rapid decompression. The pilot diverted to the intended destination airport and completed a landing without further incident.
Post-Incident Examination
A thorough examination of the failed window was conducted following the event. The inspection revealed evidence of preexisting cracks that originated on the external surface of the window. Specifically, the cracks were located at the transition radius between the window flange and the center portion of the window. The window that failed had accumulated 4,008 hours of service since its replacement and was identified as the latest design of that component.
Inspection Requirements
A review of the scheduled inspection requirements for the window type was performed. These inspections are mandated to occur every 600 hours. The review noted that the inspection procedures do not require the removal of the metal retaining ring to inspect the window.