As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) OPERATOR IS REPORTING THAT DURING TEST FLIGHT OF AIRCRAFT, AFTER ANNUAL INSPECTION, THERE WAS A LEAKAGE OF THE HYD FLUID. ALL HYD FLUID WAS LOST & A HYD SYSTEM FAILURE OCCURRED. PILOT HAD TO LAND WITHOUT HYDS. NOTE THAT EMER SYSTEM PERMITTED TO LAND WITHOUT ANY CONSEQUENCES. AFTER RETURN TO MX BASE, IT WAS CONFIRMED THAT HYD LOSS WAS DUE TO A RELIEF VALVE FAILURE IN THE RETURN SYSTEM OF NLG HYD SYSTEM. NATURE OF FAILURE TBD CONDITION OF PART TDB.