As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CLIMB, THE CREW RECEIVED A MAIN HYDRAULIC INOP BLUE CAS MESSAGE. THE CREW FOLLOWED THE QUICK REFERENCE HANDBOOK PROCEDURE AND THE MESSAGE DID NOT CLEAR. MAINTENANCE CONTROL WAS CALLED AND FLIGHT 4064 RETURNED TO DCA. MAINTENANCE INSPECTED AND REPLACED THE MAIN HYDRAULIC PUMP IN ACCORDANCE WITH DORNIER MAINTENANCE MANUAL 29-00-00. OPERATIONAL CHECKS WERE PERFORMED AND THE AIRCRAFT WAS RELEASED FOR SERVICE.