Incident Summary
An air taxi cargo flight concluded with a landing on a hard surfaced runway when the pilot reported a right veer during the landing roll, resulting in a loss of directional control. The right main landing gear subsequently collapsed, causing substantial damage to the right wing spar.
Investigation Findings
Examination by the NTSB investigator-in-charge and company maintenance personnel revealed that the right main landing gear scissor link/strut had become disconnected. This disconnection allowed the right main wheel assembly to turn sideways, overloading the gear leg. Further inspection of the linkage showed that the bolt securing the scissors/linkage had pulled through the washer adjacent to the scissor bushing opening, and subsequently through the bushing itself, disconnecting the linkage.
Manufacturer Recommendation
The airplane manufacturer had issued Service Letter ME-83-37 on November 23, 1983, recommending replacement of the original equipment outer main landing gear scissors link washers with larger, more robust washers for improved service life and main landing gear alignment retention. The operator had not complied with this nonmandatory service letter, and the airplane continued to operate with the smaller washers.