What was found
DURING DESCENT NOTICED A SYSTEM HYDRAULIC QUANTITY LEVEL DROPPING . A SYSTEM LOW PRESSURE LIGHT ILLUMINATED. CONFIGURED AC FOR A SYSTEM HYDRAULIC FAILURE CONTINUED FLIGHT WITH B SYSTEM. APPROX 5 MINUTES LATER, LOW PRESSURE WARNING ILLUMINATED ON BOTH B SYSTEM LOW PRESSURE WARNING LIGHTS, FLIGHT CREW OBSERVED A AND B PRESSURE INDICATION DROPPED TO ZERO AT THE SAME TIME B SYSTEM LOW QUANTITY DID NOT ILLUMINATE. CONFIGURED AC FOR MANUAL REVERSION, DIVERTED, MADE UNEVENTFUL LANDING.