As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
KDEN-KADY - FLT 109 - AFTER TAKEOFF, ON GEAR RETRACTION EXCESSIVE VIBRATION WAS FELT FROM NOSE AREA AND LOUD SOUND HEARD. AIRCRAFT RETURNED TO KDEN. MAINTENANCE FOUND THE NOSE GEAR DOORS DOWN. MAINTENANCE SECURED NOSE GEAR DOORS AND NO DEFECTS NOTED.