As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING TAKEOFF CREW REPORTED THE LANDING GEAR DID NOT RETRACT WHEN SELECTED UP. CREW NOTED A LDG AIR/GRD MESSAGE ON EICAS. CREW RETURNED TO DEPARTURE AIRPORT. MAINTENANCE DOWNLOADED CMC AND FOUND MULTIPLE FAILURES ON THE LT PROXIMITY SWITCH. THE LT WOW PROXIMITY SWITCHES 1 AND 2 WERE REPLACED. OPERATIONAL CHECK WAS GOOD AND AIRCRAFT WAS RETURNED TO SERVICE.