What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
Prior to entering nat both fmgcs started giving wrong information all lat/ longs were triple checked. Distance information changed from 2000 miles to over 7000 miles with multiple steps in between. An air turnback was conducted to dublin airport. Flight ops alert, 2024-alert-F001, issued for A320/321 fmgc anomalous behavior. These errors occur when a copy active is initially performed, followed by a change of destination in the secondary flight plan
As the FAA filed it
PRIOR TO ENTERING NAT BOTH FMGCS STARTED GIVING WRONG INFORMATION ALL LAT/ LONGS WERE TRIPLE CHECKED. DISTANCE INFORMATION CHANGED FROM 2000 MILES TO OVER 7000 MILES WITH MULTIPLE STEPS IN BETWEEN. AN AIR TURNBACK WAS CONDUCTED TO DUBLIN AIRPORT. FLIGHT OPS ALERT, 2024-ALERT-F001, ISSUED FOR A320/321 FMGC ANOMALOUS BEHAVIOR. THESE ERRORS OCCUR WHEN A COPY ACTIVE IS INITIALLY PERFORMED, FOLLOWED BY A CHANGE OF DESTINATION IN THE SECONDARY FLIGHT PLAN