Accident Details
On July 22, 2019, at approximately 1147 mountain daylight time, a Cessna 402B airplane, registration N7947Q, sustained substantial damage when it was involved in an accident near Boise, Idaho. The airplane was occupied by two pilots and an FAA observer, none of whom were injured. The flight was conducted under Title 14 Code of Federal Regulations (CFR) Part 91, in accordance with a Part 135.297 instrument proficiency check and a Part 135.399 check airman observation flight.
Sequence of Events
The first pilot, who served as the operator's director of operations, reported that he was receiving an instrument proficiency check from the second pilot, the operator's chief pilot. An FAA aviation safety inspector was seated in the passenger cabin to observe the check ride for the purposes of a check airman observation flight.
After completing a series of required flight maneuvers, the crew returned to the departure airport, where the airplane was cleared to land. During the landing approach, the first pilot selected the landing gear selector switch to the down position. This action was followed by the illumination of three green indicator lights, confirming that the landing gear was down, locked, and safe for landing. All three occupants verified and verbally confirmed that the landing gear was “down and locked.”
The landing was uneventful, and the airplane continued down the runway while decelerating. When the pilot initiated a left turn to exit the runway, the right main landing gear collapsed. Subsequently, the right wing impacted the ground, resulting in substantial damage.
Postaccident Examination
A postaccident examination of the landing gear system revealed that the right main landing gear assembly bell crank pivot bolt (part number NAS464P4-26) had sheared. The fracture features were consistent with a ductile overstress failure. An illustration from the applicable parts catalogue, labeled as Figure 1, depicted the main landing gear retraction linkage, with the affected bolt from the accident airplane identified as item #29.