What happened
On March 26, 2012, a PA 34-200, registration N4489T, was performing a ferry flight from the United States to Brazil. After completing temporary import procedures in Boa Vista, the aircraft proceeded to Eduardo Gomes Airport (SBEG) in Manaus, Brazil. During the landing roll, the right landing gear collapsed after a critical attachment bolt failed. The collapse caused the right engine propeller to strike the runway, leading to an abrupt engine shutdown, and subsequently caused the right wing to impact the ground. The aircraft came to a stop near the side of the runway. The pilot and the passenger, who was the aircraft owner, were uninjured, but the aircraft sustained severe damage to the right engine, propeller, and right flap.
The investigation
CENIPA investigators examined the wreckage and the aircraft's maintenance history. The investigation focused on the failure of the right landing gear torque link pin. The component was sent to the Department of Science and Technology (DCTA) for metallurgical analysis. Additionally, investigators reviewed the aircraft's recent maintenance records, noting that the aircraft had undergone a full strip-and-paint process in the United States just two weeks prior to the accident. The investigation also identified missing hardware on the rudder trim tab control rod, specifically a missing nut and washer.
Findings
- The failure of the right landing gear torque link pin was caused by alternating bending fatigue originating from corrosion pits.
- The investigation determined that the pin was operating with excessive clearance, likely due to a lack of proper lubrication at the joint.
- Evidence of inadequate maintenance was found, as the missing nut and washer on the rudder trim tab control rod were coated in paint, indicating they were not reinstalled after the recent painting process.
- The investigation concluded that inadequate maintenance contributed to the gear failure.
- An inadequate technical inspection by the FAA during the export certification process allowed the aircraft to be released for ferry flight in an unsafe condition.