What was found
ACFT SUFFERED AN EMERGENCY APPROACH & LANDING DUE TO COMPLETE HYD FLUID LOSS. LINE NEAR GROUND TEST PRESSURE COUPLING IN LT OF ACFT BETWEEN LOWER FUSELAGE & CARGO PACK RUPTURED. ALL HYD FLUID LOST, ENTERED COCKPIT THROUGH THE LT AIR CON DUCT, SOAKING CREW & PAX IN HYD FLUID. AFTER A VISUAL INSP, FOUND HYD LINE RESTS IN UPPER PART OF AIR CON DUCT THAT’S AFT OF WATER SEPARATOR. EVEN THOUGHT THE HYD LINE HAD A CLAMP IT STILL IN CONTACT WITH DUCT. WEAR CAUSED BOTH COMPOSITE A/C DUCTS & HYD LINE TO RUPTURE, CAUSING LOSS OF HYD POWER AND DAMAGE OF A/C DUCT IN SAME AREA AS HYD LINE, ALLOWING FLUID TO GET INTO CABIN. HYD LINE REPLACED, A/C DUCT REPAIRED & A/C DUCTS WERE CLEANED. FLT TEST & GROUND TEST OK.