What was found
AIR RETURN, GROSS NAV ERROR DURING TAKE OFF, NO ECAM. TROUBLESHOT NR 1 FMGC, UNABLE TO DUMP DATA FROM KPBI TO KBOS, EVEN WHEN SWITCHING DATABASES. ATTEMPTED SEVERAL RESETS OF FMGC NR 1 AND NR 2, UNSUCCESSFUL. RELOADED FMS NR 1 WITH CURRENT DATA IAW 22-70-00 AND OPS CHECK SYSTEM, ALL CHECKED NORMAL.