As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WITH AUTOPILOT IN AUTO G/S MODE, AND GLIDE SLOPE CAPTURED, THE AIRCRAFT PITCHES UP AND DOWN AND MAY OR MAY NOT RECOVER TO GLIDE PATH. REPLACED PITCH CHANNEL COMPUTER WITH A SERVICABLE UNIT IAW B727 M/M 22-11-121. CHECKS GOOD AT THIS TIME IAW B727 M/M 22-11-01.