What was found
DURING A START SEQUENCE FOR A MAINTENANCE/ AIRCRAFT GROUND RUN A COMPLETE #2 HYDRAULIC SYSTEM FAILURE OCCURRED. CREW NOTED AFTER ENGINE MODE SWITCHES WAS PLACED INTO 'FLIGHT' #2 HYDRAULIC PRESSURE DROPPED RAPIDLY, ACCOMPANIED BY CAS MESSAGES ILLUMINATING AND OIL (HYDRAULIC FLUID) WAS OBSERVED EMANATING TO BE SPRAYING OUT FROM THE UPPER DECK. CAS MESSAGES "HYD UTIL PRESS, 2 HYD OIL PRESS, 2-4 HYD PUMP, 2 HYD MIN AND 2 SERVO SEEN ILLUMINATED. AIRCRAFT WAS SHUT DOWN IMMEDIATELY. NR 2 SERVO CONTROL (PRESSURE) LINE WAS SEEN TO BE RUPTURED. NR 2 SERVO CONTROL (RETURN) LINE BECAME DAMAGED AS A RESULT OF THE HIGH-PRESSURE FLUID DISCHARGE FROM THE RUPTURED SERVO CONTROL (PRESSURE) LINE PIERCING THROUGH ITS INSULATION. THE INTERNAL WIRE BRAID COULD BE SEEN. MAINTENANCE CARRIED OUT REPLACEMENT OF ALL DAMAGED LINES. NR 2 POWER CONTROL MODULE WAS SERVICED. NR 2 MAIN HYDRAULIC SYSTEM BLED. OPS CHKS WERE CARRIED OUT TO ASCERTAIN FUNCTIONALITY OF SYS. HYDRAULIC SYS LINES WERE LEAK CHECKED CARRIED OUT VIA GROUND RUN - ALL FOUND TO BE SATISFACTORY. ENVIRONMENTAL CONDITIONS AT THE TIME OF THE OCCURRENCE WERE SUNNY AND CLEAR. OUTSIDE AIR TEMPERATURE WAS QUOTED TO BE 32 DEGREES CELSIUS. A FLEET CHECK WAS CONDUCTED TO ATTEMPT AS BEST TO ASCERTAIN ANY EVIDENCE OF DAMAGES TO OTHER SERVO CONTROL LINES. REF MADE TO PSE/TQ/2026/263265 AND PSE/TQ/2025/191136. NR 1 SERVO CONTROL LINE RUPTURE OCCURRENCES ON 07 OCTOBER 2026 AND 22ND MARCH 2025 RESPECTIVELY. THE OEM WAS INFORMED OF THE INCIDENT BY TECHNICAL QUERY - REPORTING OCCURRENCE. REFERENCE PSE/TQ/2026/265820 FOR FURTHER DETAILS.