What happened
During the initial topdressing flight of the day, an aircraft experienced an abnormally long takeoff roll. This performance issue was caused by a blocked injector in the number 8 cylinder, which hindered engine power. As the aircraft accelerated along the downsloping airstrip, the right wing struck a dense, six-foot-tall hedge of thistles located along the edge of the runway. This vegetation had not been present during the pilot's previous operations from this same location.
The investigation
The investigation established that the contact with the thistles led to a critical mechanical failure. Specifically, plant material became trapped between the wingtip and the aerodynamic balance horn. This debris caused the ailerons to deflect and subsequently jam, preventing the pilot from maintaining lateral control. As a result, the aircraft entered an uncontrollable roll to the right, eventually coming to rest at the base of a steep ravine. The accident resulted in one fatality.
Findings
- A blocked injector in the number 8 cylinder caused a loss of power, resulting in an extended takeoff distance.
- The presence of unmanaged, dense thistles along the airstrip boundary created a hazard that was not present during prior flights.
- The jamming of the ailerons by vegetation was the primary factor that led to the loss of control and the subsequent crash.