As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT 1421 - DTW - DURING CLIMB CONFIGURATION WITH THE AUTO PILOT ENGAGED EXPERIENCED A VIOLENT PITCH DOWN CONDITION, AUTO PILOT DISENGAGED. REMOVED AND REPLACED NR 2 VERTICAL GYRO. SYSTEM OP CHECK GOOD ON GROUND IAW DC-9 MM 34-27-0 AND 22-10-0. (M)