As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING GEAR RETRACTION, RECEIVED A GEAR DISAGREE NLG CAS MESSAGE AND DETECTED AN ABNORMAL AIR SLIPSTREAM NOISE LEVEL. CONDUCTED QRH ABNORMAL PROCEDURES AND EXTENDED THE GEAR. NORMAL THREE GREEN EXTENSION. RETURNED TO DEPARTURE AIRPORT AND LANDED. REMOVED AND REPLACED UPLOCK SWITCH IAW 680A MM CH 32-32-00. ALSO REMOVED AND REPLACED RT NLG DOOR UPLOCK ROLLER AND LOWER BRACKET AND HARDWARE.