What was found
(CAN) DURING CLIMB OUT, THE CREW WITNESSED THE RT COCKPIT HEATED WINDSHIELD CRACK. THE CRACK SLOWLY KEPT PROGRESSING TO A LENGTH OF ABOUT 5 INCHES. THE CREW INITIATED A RETURN TO BASE AND LANDED WITHOUT FURTHER INCIDENT. MX R&R THE WINDSHIELD. NO CAUSE AS TO THE FAILURE COULD BE DETERMINED, OTHER THAN IT APPEARS TO HAVE ORIGINATED AT THE EDGE OF THE WINDOW AT A HEATING ELEMENT. THE TOTAL TIME ON THIS WINDSHIELD COULD NOT BE DETERMINED.