As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT 41437 - CLT-LAX - AIR TURNBACK - THE FLIGHT CREW EXPERIENCED A LOUD, CONSTANT NOISE WITH EXCESSIVE VIBRATION AFTER TAKEOFF. THE AIRCRAFT WAS UNABLE TO CLIMB MORE THAN 500 FEET PER MINUTE AND UNABLE TO REACH SPEEDS BEYOND 280 KTS. AFTER A FLY-BY, IT WAS DETERMINED THAT THE NOSE GEAR DOORS HAD NOT RETRACTED. THE CREW DECLARED AN EMERGENCY AND RETURNED TO CLT. MAINTENANCE REMOVED AND REPLACED THE LANDING GEAR CONTROL INTERFACE UNIT. OPERATIONAL CHECK WAS GOOD. (S)