What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
(-23) The pilot privacy data omitted states he was descending at 180MPH into portland, Oregon (pdx) airspace at 8000' AGL when he experienced a sudden and violent shaking of the aircraft. The pilot privacy data omitted put positive force on the rudder pedals and pulled back on the yoke and the shaking stopped. Controllability did not change so he continued his flight landing without incident in Eugene, Oregon (eug). Investigation revealed an unknown event in smooth air that caused substantial empennage structural overload and subsequent damage aft of the 256.9 bulkhead.
As the FAA filed it
(-23) THE PILOT ^PRIVACY DATA O^ STATES HE WAS DESCENDING AT 180MPH INTO PORTLAND, OREGON (PDX) AIRSPACE AT 8000' AGL WHEN HE EXPERIENCED A SUDDEN AND VIOLENT SHAKING OF THE AIRCRAFT. THE PILOT ^PRIVACY DA^ PUT POSITIVE FORCE ON THE RUDDER PEDALS AND PULLED BACK ON THE YOKE AND THE SHAKING STOPPED. CONTROLLABILITY DID NOT CHANGE SO HE CONTINUED HIS FLIGHT LANDING WITHOUT INCIDENT IN EUGENE, OREGON (EUG). INVESTIGATION REVEALED AN UNKNOWN EVENT IN SMOOTH AIR THAT CAUSED SUBSTANTIAL EMPENNAGE STRUCTURAL OVERLOAD AND SUBSEQUENT DAMAGE AFT OF THE 256.9 BULKHEAD.
NTSB investigation
The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.
Other reports on N4647D · 3
Matched to the same aircraft by N-number and date.