As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT 5415 - PHL-LEB - AFTER TAKEOFF FROM BOS, THE CREW NOTED THAT BOTH DIRECTIONAL GYROS WERE DRIFTING AT AN EXTREME RATE. THE CREW NOTIFIED THE TOWER THEY WERE RETURNING TO BOS AND THE AIRCRAFT LANDED WITHOUT FURTHER INCIDENT. MAINTENANCE INSPECTED AND REMOVED AND REPLACED BOTH DIRECTIONAL GYROS. OPS CHECKED GOOD AND THE AIRCRAFT WAS RETURNED TO SERVICE. (M)