As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
VERTICAL NAVIGATION CAPTURED ALTITUDE CONSTRAINT AT FLIGHT LEVEL 240 NORMALLY. UPON PATH RECAPTURE AIRCRAFT BEGAN DESCENT BELOW VERTICAL NAVIGATION PATH. SELECTED VERTICAL SPEED AND SPEED 280 TO REGAIN PATH. AIRCRAFT ACCELERATED RAPIDLY TO 300KT PLUS 450 FEET, PER MINUTE DOWN. UNRESPONSIVE TO FLIGHT CONTROL UNIT INPUT. FLIGHT MODE ANNUNCIATOR INDICATIONS NORMAL. PERFORMED AUTO FLIGHT SYSTEM TEST. LAND CATEGORY 3 CAPABILITY, PER AMM 22-97-00. TEST PASS GOOD.