As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE AIRCRAFT RETURNED FROM A FLIGHT WITH NO DEFECTS NOTED. AIRCRAFT WAS MOVED INTO THE HANGAR AND APPROXIMATELY 20 MINUTES LATER A LOUD BANG WAS HERD. THE AIRCRAFT WAS STATIC WITH THE DOOR CLOSED. THE LOUD BANG WAS THE CABIN ENTRY DOOR FORWARD COUNTERBALANCE SPRING BREAKING IN THE SECOND COIL.