What was found
DURING CRUISE CREW RECEIVED GSD FAIL #2 CAS MESSAGE (GARMIN DATA CONCENTRATOR UNIT),CHECKLIST REQUIRED USE OF EMERGENCY GEAR EXTENSION DUE TO ANNUNCIATIONS BEING INOPERATIVE. GEAR DOWN WAS CONFIRMED BY GROUND DURING APPROACH. CHECKLIST FOLLOWED, EMERGENCY DECLARED, AND UNEVENTFUL LANDING PERFORMED. MAINTENANCE REPLACED FAILED GSD2 UNIT, P/N 011-01457-01 S/N 2JH007972