As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) CREW ON LANDING DECLARED AN EMERGENCY DUE TO RED LIGHT ON RT MAIN GEAR. INVESTIGATION AFTER LANDING REVEALED THAT TRIP BOLT OPERATING MICROSWITCH ON DOWNLOCK WAS BROKEN P/N 100021303 LEADING TO FALSE INDICATION. TRIP BOLT P/N 100021303 WAS REPLACED AND RETRACTION TEST COMPLETED.AIRCRAFT RETURNED TO SERVICE.