As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WITH CENTRE AUTO-PILOT IN CMD IN CLEAR AND SMOOTH AIR AIRCRAFT ABRUPTLY PITCHED NOSE DOWN, A-C LOST 30 FEET AND IMMEDIATELY HARSHLY PITCHED UP THEN BEGAN TO PORPOISE. [SUP 05-18-07] REPLACED CTR FLIGHT CONTROL COMPUTER. REF SMC3, NEEDS CAT 3. PERFORMED CAT III PER MMM 22-10-00 AND 34-61-00 CMC GRD CHECKED NORMAL.