What happened
On December 29, 2022, a private Cessna 750 Citation X, registration N156VP, was performing a flight from Panama to José María Córdoba Airport in Rionegro, Colombia. The aircraft was carrying 11 occupants, including two crew members and nine passengers.
During the landing on runway 01, the crew successfully touched down on the touchdown zone. Approximately 10 seconds after landing, the crew activated the engine thrust reversers. Upon moving the thrust levers to the deceleration position, the aircraft experienced a sudden and sharp deviation to the left. The pilot attempted to correct the direction using the steering controls and the right brake, and even deactivated the reversers, but the aircraft continued to veer off the runway. The aircraft traveled 185 meters into the safety area before coming to a stop. There were no injuries among the 11 occupants, though the aircraft sustained damage to the left main landing gear door.
The investigation
The GRIAA investigation focused on the mechanical failure of the steering system and the maintenance practices of the operator. Investigators examined the steering control system, specifically the tension between the left and right control cables. The analysis included metallographic and mechanical testing of the 4130 alloy steel cables. The investigation also reviewed the aircraft's approach profile, noting that the aircraft was traveling at approximately 143 KIAS, which was 15 knots above the reference speed, resulting in an unstabilized approach.
Findings
- The primary cause of the runway excursion was the disconnection of the right steering control cable.
- This disconnection was triggered by asymmetrical tension between the left and right steering cables, which caused the nose landing gear to pivot sharply to the left.
- A critical contributing factor was the absence of a locking nut at the steering control cable push rod adjustment point, which allowed the cable to rotate due to operational vibrations.
- The maintenance organization lacked standardized inspection procedures for the steering control system, leading to a failure to identify the aging of the control cables or improper installation.
- The unstabilized approach, characterized by high approach and landing speeds, contributed to the severity of the excursion and hindered the crew's ability to maintain directional control.