As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING TAKEOFF ROLL IN PHX THE AIRCRAFT HAD A FAST BUT MOMENTARY UNCOMMANDED RUDDER MOVEMENT AT APPROXIMATELY 115 KTS. THE FIRST OFFICER WAS FLYING AND HE THOUGHT IT WAS A NOSE RIGHT MOVEMENT. REMOVED AND REPLACED FAC 1 (FLIGHT AUGMENTATION COMPUTER) AND TESTED WIRING IAW TSM 27-26-00-810-801 AND PERFORMED YAW DAMPER TEST.