As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
BWI - FLT 1924 - AFTER TAKEOFF FROM BWI, EN ROUTE TO CLT, CAPTAIN REPORTED TO DISPATCH VIA ACARS THAT HE WAS UNABLE TO RETRACT THE LANDING GEAR. FLIGHT RETURNED TO FIELD AT BWI AND LANDED WITHOUT FURTHER INCIDENT. NO EMERGENCY WAS DECLARED. MAINTENANCE RESET THE LANDING GEAR LATCH CIRCUIT BREAKER AND LUBED THE GEAR HANDLE. OPERATIONAL CHECK GOOD WITH AIRCRAFT IN SIMULATED AIR MODE. AIRCRAFT OK FOR SERVICE.