As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
GEAR DISAGREE ON LANDING NOSE DIDNT COME DOWN TURNED ON 3B CYCLED GEAR HANDLE BOTH MAINS CONFIRMED DOWN NOSE NOT DOWN HEARD BANG. AFTER CYCLING GEAR ALL 3 GEAR DOWN. EMERGENCY WAS DECLARED. / REMOVED AND REPLACED LANDING GEAR SELECTOR VALVE IAW CRJ 900 AMM 32€“32€“000-400-801-A01 ALL OPS CHECKS & LEAK CHECK GOOD. COULD NOT REDUPLICATE FAULT. NO DEFECTS NOTED AT THIS TIME.