As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN)AFTER LANDING GEAR RETRACTION CONTINUOUS THUMPING HEARD AND FELT UNDER THE COCKPIT FLOOR. THUMPING OCCURRED ON ONE SECOND INTERVALS AND CONTINUED UNTIL LANDING GEAR SELECTED DOWN NINE MINUTES LATER. BOTH NOSE WHEEL ASSEMBLIES CHANGED.