As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PHL - FLT1027 - ON CLIMB-OUT FROM PHL, AT 3,000 FEET, THE CAPTAIN'S L1 WINDSHIELD BEGAN TO ARC. FLIGHT RETURNED TO FIELD AT PHL AND LANDED WITHOUT FURTHER INCIDENT. NO EMERGENCY WAS DECLARED. MAINTENANCE REMOVED AND REPLACED THE CAPTAIN'S L1 WINDSHIELD PER JOB CARD J356-11-01. ALSO, REMOVED AND REPLACED THE WINDOW HEAT CONTROL UNIT FOR THE L1 WINDSHIELD. OPERATIONAL CHECK GOOD.