CE560 FLT CREW REPORTS UNSAFE GEAR INDICATION AFTER GEAR RETRACTION. FLIGHT DIVERTS AND USES EMERGENCY EXTENSION PROCEDURES TO ENSURE GEAR IS DOWN PRIOR TO UNEVENTFUL LANDING.

Narrative

AFTER INITIATION OF THE AFTER TKOF CHKLIST; IT WAS INDICATED THAT THE L MAIN GEAR LIGHT REMAINED ILLUMINATED AFTER GEAR RETRACTION. THE GEAR WAS CYCLED AND THE SAME RESULT WAS RECEIVED. THE FLT WAS CONTINUED AND WHILE ENRTE; CONTACTED THE COMPANY WHO ASKED IF ENOUGH FUEL TO DIVERT TO ZZZ. WE DID; SO WE DIVERTED. AFTER CONSULTING THE EMER CHKLIST; WE BOTH CAME TO THE CONCLUSION THAT WE WOULD EXECUTE THE 'EMER GEAR WILL NOT EXTEND' CHKLIST TO USE ALL POSSIBLE RESOURCES TO ASSUME THE GEAR WAS DOWN. THIS CHKLIST WAS COMPLETED JUST PRIOR TO LNDG. UPON SWITCHING TO ZZZ TWR; WE DECLARED AN EMER AS A PRECAUTION IN CASE THE GEAR COLLAPSED. WE PERFORMED A FLY-BY AND THE TWR INDICATED TO US THAT THE GEAR APPEARED NORMAL. AFTER THE FLY-BY WE ENTERED A L DOWNWIND PATTERN AND MADE A NORMAL LNDG. WE ELECTED TO LEAVE THE ACFT ON THE RWY AND PERFORMED THE SHUTDOWN CHKLIST AND SET THE PARKING BRAKE. A SVC CTR TECHNICIAN ARRIVED MINS LATER; INSPECTED THE GEAR; AND TOWED THE ACFT OFF THE RWY. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: MAINTENANCE DISCOVERED THAT A MICROSWITCH HAD FAILED ON THE LEFT MAIN GEAR CAUSING A FALSE GEAR INDICATION.