As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ORF/DCA - FLT 3144 - LEFT MAIN GEAR DID NOT BEGIN TO EXTEND UNTIL NOSE AND RIGHT MAIN WERE DOWN AND LOCKED. EXTENSION WAS SLOW ONCE STARTED. THE AIRCRAFT CONTINUED INTO DCA AND LANDED WITHOUT INCIDENT. CLEANED RESTRICTOR ON UPLOCK ACTUATOR AND OPERATIONAL CHECK GOOD.