What happened
On January 10, 2018, a Cessna 414, registration HK4825, was performing a medical transport flight from Arauca to Guaymaral Airport, Colombia. The flight, operated by Colchárter IPS S.A.S., carried a crew of two and four passengers, including a patient and medical personnel.
Upon landing on runway 29, the aircraft initially appeared to touch down normally. However, during the deceleration phase, the landing gear unsecured alarm sounded, and the aircraft began to tilt heavily to the right. The pilot attempted to maintain directional control using differential power, rudder, and braking, but the right wing eventually made contact with the runway. The aircraft continued to slide for approximately 10 meters before losing control and veering off the runway at taxiway Charlie, coming to rest in the safety area. All six occupants escaped without injury, though the aircraft sustained substantial damage, including fractures to the nose and both main landing gears, as well as propeller deformation.
The investigation
The GRIAA investigation focused on the structural integrity of the landing gear components. Investigators examined the aircraft's maintenance records, which showed that a previous inspection in November 2017 had been conducted to check for cracks in the main gear forgings.
Physical examination of the wreckage revealed a catastrophic failure of the trunnion and the separation of the right main gear strut. The investigation established that the intense lateral vibrations and the resulting friction between the tire and the runway created a zigzag pattern on the pavement. This mechanical stress led to the breakage of the actuator's attachment ear and the subsequent failure of the trunnion, which was unable to withstand the extreme loads generated during the loss of control.
Findings
- The primary cause of the incident was the fatigue failure of the bushing in the Link Assy Main Gear Strut at the moment of runway contact.
- The failure of the right gear caused an asymmetric condition that led to the loss of directional control and the subsequent failure of the left main gear and nose gear.
- The operator lacked a comprehensive risk management program to mitigate the impacts of hard landings or operations on deteriorated runway surfaces.
- Maintenance processes were insufficient, specifically regarding the lack of specialized inspections for high-stress landing gear components prone to fatigue in older aircraft.