What was found
ON A DESCENT, AND AT APPROX 270 KEAS, BOTH MLG INDICATIONS INDICATED "UNSAFE" AND RECEIVED LANDING GEAR FAIL CAS. REDUCED AIRSPEED AND CAS MESSAGE DISAPPEARED. FURTHER INVESTIGATION SHOWED THAT ANY TIME A SMALL LOAD WAS PUT ON THE ACFT, LANDING GEAR FAIL CAS MESSAGE WOULD POST AND BOTH MLG INDICATED "UNSAFE." PREPARED THE EMERGENCY GEAR EXTENSION CHECKLIST, BUT AT THE LOWER AIRSPEEDS THE GEAR OPERATED AND LOCKED APPROPRIATELY, A NORMAL LANDING WAS MADE AND THE ACFT WAS PUT INTO MX. THIS ACFT ALSO HAD A SUBSTANTIAL AIRFRAME VIBRATION AT HIGHER AIRSPEEDS THAT MAY BE RELATED.