Introduction
On January 28, 2016, a Cessna 402B, registration HK-4901-G, operated by Aerollanos del Oriente S.A.S. under General Aviation, was scheduled for a local flight from El Alcaraván Airport (SKYP) in Yopal, Casanare, Colombia. The aircraft carried three occupants: one pilot and two passengers.
Sequence of Events
The aircraft departed at 12:31 local time (17:31 UTC) for a local overflight near the Araguaney area. At 12:34 HL (17:34 UTC), the pilot requested clearance to return to SKYP, which was granted. The aircraft landed on runway 05. During the landing roll, the left main landing gear failed when the upper side link component fractured, causing the gear to retract. The aircraft lost directional control, veered left, and exited the runway onto the safety area between taxiways Alpha and Bravo. The runway excursion occurred at 12:42 HL (17:42 UTC) in visual meteorological conditions. No post-impact fire occurred, and all three occupants evacuated the aircraft uninjured.
Aircraft Information
The aircraft was a 1974 Cessna 402B, serial number 402B0626, with total airframe hours of 14,083.04. It was powered by two Continental TSIO-520-E engines and equipped with McCauley propellers. The last service was a 200-hour inspection on June 24, 2015. The aircraft complied with manufacturer maintenance manuals, Colombian regulations, and applicable airworthiness directives.
Damage
The aircraft sustained substantial structural damage, including fracture of the left main landing gear upper side link, deformation of the left gear doors, sudden stoppage of the left engine, deformation of the left propeller blade tips, dents on the left wing tip and aileron, and blowout of the left tire. Additionally, one runway edge light was dislodged.
Cause and Contributing Factors
The investigation determined the probable cause of the serious incident was the sudden fracture of the upper side link component of the left main landing gear, likely due to material fatigue from stresses experienced during landing, resulting in gear collapse during the landing roll. Contributing factors were deficient maintenance processes that failed to perform special inspections of landing gear components subjected to stress, which could detect material flaws given the aircraft's age and frequent similar failures in this type.