As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
MEM INFLIGHT T383/17APR DURING GEAR RETRACTION CREW REPORTED EXTREME AIRFRAME VIBRATION. RETURNED TO MEM AND LANDED WITHOUT INCIDENT. WHEN LOWERED GEAR FOR LANDING VIBRATION DIMINISHED. NO UNSAFE GEAR INDICATIONS. UPON INSPECTION IT APPEARED ONE NOSE GEAR DOOR HAD NOT BEEN CLOSED. INSPECTED NOSE GEAR DOORS. SYSTEM GROUND CHECKED NORMAL OPERATION. (CLOSED)