As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
IAD-PHF - FLT 6151 - DURING TAKEOFF, AIRCRAFT MADE AN UNSCHEDULED LANDING DUE TO GEAR NOT RETRACTING. AIRCRAFT LANDED AND RETURNED TO GATE WITH NO FURTHER PROBLEMS. MAINTENANCE INSPECTED AND REMOVED AND REPLACED NOSE GEAR AOG SWITCH, OPS CHECK OK. AIRCRAFT WAS RELEASED AND APPROVED FOR RETURN TO SERVICE. (M)