As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PIT-SYR - FLT 521 - UPON LANDING GEAR RETRACTION AFTER TAKEOFF THE RIGHT MLG RED LIGHT ILLUMINATED. THE LANDED WAS CYCLED BUT THE RED LIGHT REMAINED ILLUMINATED. THE AIRCRAFT RETURNED TO THE FIELD AND LANDED WITHOUT INCIDENT. MAINTENANCE REPLACED THE PROXIMITY SENSOR CONTROL BOX AND PERFORMED A GEAR SWING. ALL CHECK NORMAL. (M)