As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SJC INFLIGHT T1174/17DEC - NOSE LANDING GEAR UNSAFE INDICATION. ABNORMAL LOUD NOISE IN COCKPIT. NOSE GEAR DID NOT RETRACT. RETURNED TO SJC AND LANDED WITHOUT INCIDENT. FOUND NOSE LANDING GEAR STRUT SHOCK CYLINDER FLAT. REPACKED NOSE LANDING GEAR STRUT AND SERVICED. SYSTEM GROUND CHECKED NORMAL OPERATION.