What happened
On November 3, 2013, a Cessna 414, registration HK4714, operated by Aerolíneas Alas de Colombia S.A., was performing a taxi flight from Guaymaral to Quibdó. During the landing phase on runway 31 at El Caraño Airport (SKUI), the aircraft was in the deceleration phase of the landing roll when the right main landing gear unexpectedly retracted.
This mechanical failure caused the aircraft to tilt sharply to the right, resulting in the right wing's lower surface scraping the runway pavement. The impact caused the sudden stoppage of the right engine and subsequent damage to the propeller blades. The aircraft continued to travel approximately 50 meters along the runway before veering off the paved surface and coming to a stop 15 meters into the safety area. All four occupants (two crew members and two passengers) evacuated the aircraft on their own and were uninjured.
The investigation
The GRIAA investigation focused on the mechanical failure of the landing gear system. Investigators examined the aircraft on jacks and inspected the right main gear and its associated components. The examination revealed that several components of the right main gear had suffered breakage due to overload. Specifically, the investigation identified a fracture in one of the trunnion mount lobes and a fracture in the adjusting screw.
Maintenance records were reviewed, showing that the landing gear system had undergone service on October 18, 2013, which included non-destructive testing of the nose gear and trunnion. Since that service, the aircraft had flown approximately 18.55 hours and completed 12 landings. The investigation noted that the pivot bolt (NAS464P4-26) showed signs of plastic deformation and a smooth surface, with the fracture exhibiting ductile characteristics consistent with static shear loads.
Findings
- The primary cause of the incident was the overload failure of the pivot bolt and adjusting screw in the right main landing gear, which triggered the inadvertent retraction of the gear during the landing roll.
- The investigation concluded that the failure was likely linked to imprecise adjustments or improper assembly during the last maintenance service.
- The complex mechanical design of the Cessna 414 landing gear system can induce maintenance errors if service instructions are not followed with extreme precision.
- The aircraft sustained damage to the right wing lower skin, the right aileron, and the right engine propeller blades.