What happened
The incident began during taxi operations at Greensboro Regional Airport in North Carolina. The captain observed that the aircraft was pulling toward the right side of the taxiway. This issue temporarily resolved itself when the pilot applied pressure to the right brake pedal. Following a standard takeoff sequence, the copilot noticed an anomaly while retracting the landing gear: the right main wheel appeared to be canted out of its normal alignment. After the gear retraction cycle completed, the in-transit indicator light for that gear remained illuminated. Consequently, the crew decided to divert to their operator's base at Clarksburg, West Virginia.
After burning off excess fuel to reduce landing weight, the crew lowered the landing gear for approach. Upon inspection during the precautionary landing, it was confirmed that the right main wheel had rotated 90 degrees from its normal position. The landing itself proceeded normally without any structural damage to the airframe or injuries to the occupants.
The investigation
A thorough examination of the aircraft revealed that the right gear torque link assembly had failed. Specifically, the failure was caused by stripped threads on several of the bolts securing the assembly. These stripped threads permitted a side load to shear the locking plate during routine ground operations. A review of the relevant maintenance manual showed that specific torque values for these bolts were not listed, which likely contributed to the bolts being under-torqued during previous maintenance.
Findings
The primary contributing factor was the improper installation of the torque link assembly bolts. The lack of explicit torque specifications in the maintenance documentation allowed mechanics to install the fasteners with insufficient clamping force. This led to thread stripping and subsequent failure of the locking mechanism, causing the gear wheel to rotate out of position during retraction.
Safety message
This incident highlights the critical importance of precise torque application in landing gear maintenance. Maintenance procedures must ensure that all fasteners are installed within specified limits to prevent structural failures that can compromise flight safety.