As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE A SYSTEM HYDRAULIC FLUID LEVEL DROPPED TO ZERO WHILE ON DESCENT INTO PHL. THE AIRCRAFT LANDED WITHOUT INCIDENT. MAINTENANCE FOUND TWO HYDRAULIC FLEX LINES AT LT ELEVATOR PCU PUNCTURED. THE FLEX LINES WERE REMOVED AND REPLACED. LEAK AND OPERATIONAL CHECKS WERE GOOD.