As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
COMPLETE LOSS OF SYS A HYD AFTER 30 MINUTES OF FLIGHT, ALTITUDE 370, SPEED MACH .78 & QTY PERCENT & PRESS SHOWED O. THE FLIGHT DECLARED AN EMER & RETURNED WITHOUT INCIDENT. R & R PRESS SWITCH TRANSDUCER ON THE PRESS MODULE IAW AMM 29-31-12. OPERATIONAL & LEAK CHECKED OK IAW AMM 29-11-00, NO LEAKS NOTED. THE ACFT WAS GNDED.