As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CAPTAIN'S SEAT BECAME UNLOCKED DURING ROTATION WHILE CAPTAIN WAS FLYING AND SLIDE TO REAR STOP. SEAT WAS VERIFIED LOCKED DURING PUSHBACK. INSPECTED CAPTAIN'S SEAT IN ALL LOCKING POSITIONS. NO DEFECTS FOUND. MOVED SEAT VIGOROUSLY IN ALL LOCKING POSITIONS AND SEAT REMAINED LOCKED. CAPTAIN'S SEAT FORWARD & AFT LOCKS CHECK GOOD IAW DC9 AMM CHAPTER 25.