On August 14, 1999, a Cessna 210B (registration N9588X) was involved in an aviation accident near Port Angeles, WA. Investigators recorded the probable cause as: The failure of maintenance personnel to detect cracked main landing gear saddles during required inspection, and subsequent fatigue fracture of the left main landing gear saddle resulting in separation of the saddle and disabling of the left main gear. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
After takeoff, the left main landing gear failed to lock up. Despite efforts, the gear remained unlocked. The pilot burned fuel and landed in grass with minor additional damage. Post-accident inspection revealed fatigue fractures in both main gear saddles.
Event Description
After takeoff, the left main landing gear would not lock in the 'up' position. The pilot subsequently was unable to get the left main gear into either the up-and-locked or down-and-locked positions, despite repeated efforts to do so. After burning down fuel, the pilot performed a successful landing in grass next to the runway at his destination with the left main gear unlocked, sustaining only slight additional damage in the landing.
Post-Accident Examination
Post-accident examinations disclosed a fatigue fracture with at least three separate origins in the left main landing gear saddle, a structural component that mounts the gear strut to the airframe. Fatigue cracks were also found in the right main gear saddle. Both main gear saddles had been dye-penetrant inspected for cracks in accordance with AD 76-14-07R2 approximately 3 weeks and 30 flight hours before the accident, with no defects found.