As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
D: PHX - AIR TURNBACK - 3/31/01 - EN ROUTE FROM PHX TO BOS THE AIRCRAFT LOST GREEN HYDRAULIC SYSTEM QUANTITY AND RETURNED TO PHX MAKING AN UNEVENTFUL LANDING. MAINTENANCE FOUND THE LT YAW DAMP SERVO ACTUATOR LEAKING AT THE OUTPUT SHAFT; THE SERVO ACTUATOR WAS REPLACED; LEAK CHECKS AND OPERATIONAL CHECKS WERE GOOD.