As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIR TURNBACK -- AFTER T/O WITH FLAPS UP WHEN LANDING GEAR HANDLE WAS PLACED TO "OFF" POSITION THE RED UNSAFE LIGHT CAME ON FOLLOWED BY GREEN RIGHT GEAR LIGHT ON. ALL HYD PRESSURES AND QUANTITY WERE NORMAL. FOLLOWING QRH WITH GEAR HANDLE IN UP POSITION RIGHT GEAR RETRACTED AND ALL LIGHTS OFF. LANDING WAS NORMAL. REMOVED AND REPLACED RIGHT MAIN GEAR DOWNLOCK SENSOR NR 73 AND PERFORMED LANDING GEAR WARNING SYSTEM TEST IAW M/M.