Accident Overview
The airplane was destroyed when it impacted terrain after the pilot lost control during the takeoff and initial climb phase.
Structural Examination
Investigators found severe corrosion at two structural tube clusters located directly below the right wing's forward and aft attach fittings. One of these clusters included a windshield pillar. The forward structure available for carrying loads before the accident was less than 30% of the pillar tube's original circumference. Deformation observed at the separation point of the pillar tube indicated that the pillar failed under compression loads.
Manufacturer Insights
A representative from the aircraft manufacturer stated that the windshield pillar is normally subjected to tensile loads during flight. It is possible that compression loads generated during the takeoff roll led to a compression failure of the pillar. Such a failure would have altered the lift characteristics of the wing because the separation point was directly below the right wing forward attach fitting.
Maintenance History
The most recent annual inspection of the airplane was performed in January 1999. The maintenance entry for that inspection stated, in part, "treated steel tubing as required." In June 1999, a major repair was made to a tube cluster in the aft fuselage area, which was noted as being "due to external rust through from past acid spill."