What was found
(CAN) AT FLIGHT LEVEL 370, THE COCKPIT LT SIDE WINDOW OUTER PANE CRACKED. THE CRACK WAS A 7 INCH CRACK ON THE FWD LWR CORNER. THE ACFT THEN RETURNED TO BASE WITH NO FURTHER INCIDENT. UPON REMOVAL OF THE LT SIDE WINDOW IT WAS FOUND THAT SEVERAL OF THE FASTENERS WERE CORRODED. IT WAS ALSO FOUND THAT AT 2 OTHER LOCATIONS AROUND THE WINDOW, CRACKS HAD DEVELOPED FROM OTHER SCREW HOLES. THE MX PROGRAM HAS A COCKPIT SIDE WINDOW INSP USING A PRISM METHOD EVERY 300 HRS OR 12 MONTHS. THE LAST INSP WAS COMPLETED 171 FLIGHT HOURS PRIOR TO THE EVENT.