What was found
AFTER 1 MINUTE INTO A FLIGHT, A LOUD BANG WAS HEARD FROM THE REAR OF THE AIRCRAFT WITH A RIGHT YAW AND NOSE DOWN PITCH. PILOT HAD NO PEDAL CONTROL. THE PILOT PERFORMED A RUN-ON LANDING WITH NO DAMAGE TO AIRCRAFT. THE TAIL ROTOR GEARBOX DEPARTED THE AIRCRAFT. NO CAUSE HAS BEEN DETERMINED. THE FAA, NTSB, AND BELL HELICOPTER ARE INVESTIGATING. A DAILY INSPECTION OF THE T/R DRIVE SYSTEM HAS BEEN IMPLEMENTED UNTIL FURTHER NOTICE.