Piper PA-28-180 N3470R accident near Three Rivers, Michigan

Probable cause

The pilot's inability to maintain directional control during landing due to the failure of the left main landing gear torque link as a result of fatigue.

NTSB analysis

During a touch-and-go landing, the airplane veered to the left and the flight instructor attempted to correct to the right thinking the student applied the left brake. However, the airplane continued to veer to the left and the right wing struck the terrain. The airplane continued off the runway and came to rest in a field. Examination of the airplane revealed that the left aft spar was bent and fractured, the left main landing gear separated, and the main landing landing gear torque link was fractured. An NTSB Materials Laboratory examination of the torque link revealed the fracture face contained crack arrest marks typical of fatigue cracking that emanated from multiple origins at the surface of the wall on both sides of the link. The fatigue origin areas contained no evidence of gouge damage or corrosion damage. The fatigue cracks were the result of lateral stress produced during landing and taxi operations. Hardness testing of the material produced values greater than the minimum hardness value.

Text from the NTSB. Open the NTSB docket for CEN10LA210 for the full record.