As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ENG 2 WITH REPORTED THICK SMOKE, AND HYDRAULIC QUANTITY ON SYS 2 ZEROED OUT. POSSIBLE WITH HYDRAULIC LEAK ON ENGINE. CREW DECIDED TO SHUTDOWN BOTH ENGINES FOR SAFETY PRECAUTION. ACFT NOW AWAITING TOW TRUCK. IDENTIFIED HYDRAULIC LEAK ON LT MLG HYDRAULIC HOSE ASSY GOING TO THE NR 2 BRAKE ASSY. REPLACED BRAKES HOSE ASSY AS PER Q400 AMM: 29-00-00-000-802/29-00-00-400-802.