As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ORD - FLT 4094 - DURING CLIMB-OUT, AIRCRAFT LOST GREEN SYSTEM HYD PRESSURE. AIRCRAFT RETURNED TO ORD AND LANDED WITHOUT INCIDENT. MAINTENANCE REMOVED AND REPLACED ACCUMULATOR T-FITTING. SYSTEM OPS CHECKED GOOD AND AIRCRAFT RETURNED TO SERVICE. (M)