What happened
The aircraft was positioned on the runway for a takeoff roll intended for an aerial application mission. During this phase of ground movement, the left main landing gear suffered a structural failure and collapsed. This sudden loss of support caused the airplane to yaw sharply to the left by approximately 90 degrees. The aircraft then continued to move sideways along the length of the runway. As it slid laterally, the right main landing gear also collapsed under the stress of the abnormal orientation and weight distribution.
The investigation
Investigators examined the wreckage to determine the sequence of mechanical failures. The examination focused on the integrity of the landing gear assembly components. Analysis revealed that the attachment bolt for the left main landing gear had failed. Further technical review could not identify a specific root cause for this failure, leading to a conclusion of undetermined reasons for the initial bolt fracture.
Findings
The primary factor in this incident was the structural integrity of the landing gear system prior to takeoff. The failure of the left main gear attachment bolt initiated the chain of events that led to the secondary collapse of the right main gear. The inability to determine why the bolt failed remains a key finding, highlighting a gap in understanding the specific mechanical or material defect involved.
Safety message
Regular and thorough inspection of landing gear attachment points is critical for aerial application aircraft, which subject their equipment to high stresses during low-altitude operations. Ensuring the integrity of these bolts can prevent catastrophic gear failures during takeoff.