As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
GEAR DISAGREE AFTER TAKEOFF. (ACFT RETURNED TO IAD AFTER T/O -- EMERGENCY DECLARED) UPON INSP FOUND NLG EXTEND PROX SWITCH OUT OF RIG. CREW STATED RAMP HAD TO ADJUST TOW STOP AND THE HEARD A LOUD "BANG." ADJUSTED NLG PROX SWITCH IAW CRJ-200/32-65-05. OK FOR CONT SERVICE.