As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT PORPOISES VIOLENTLY UPON AUTOPILOT COUPLED APPROACH TO AIRPORT WITH HILLY TERRAIN. TROUBLESHOT SYSTEM AND FOUND OPEN CONNECTION BETWEEN PINS 89 AND 92 ON FLIGHT DIRECTOR COMPUTER PLUG PL67. JUMPERING PINS PER CESSNA DRAWING NR 9419120 CORRECTED PROBLEM, SAW NO EVIDENCE THAT THESE PINS WERE JUMPERED WHEN DELIVERED FROM THE FACTORY. OTHER AIRCRAFT COULD BE MANUFACTURED WITH THIS DEFECT. NOTE: THIS M OR D REPLACES THE M OR D FILED 8-30-95.