Incident
The aircraft was climbing at 1,000 feet per minute to a cruising altitude of 21,000 feet. Upon passing 19,800 feet, a loud 'bang' was heard. The captain was partially sucked through the broken left side window. After approximately 4 seconds, he was able to pull himself back into the aircraft unassisted. He declared an emergency and landed the aircraft without further incident.
Maintenance Records
A review of the maintenance records revealed that an applicable airworthiness directive (AD) requiring an inspection of the windows was complied with within the last 143.8 flight hours.
Inspection Procedures
The technical representative for Fairchild stated that maintenance personnel who conducted the AD inspection and service bulletin inspections may have failed to detect the crack due to the subtle inspection procedures employed. The approved inspection procedures allow for two methods: (1) removal of the outer frame retainer for direct viewing of the screw holes, and (2) using a 90-degree prism seated in mineral oil for an indirect view of the screw holes. The airline was using the second method.