Aircraft and Occupants
The helicopter involved was a Bell 206L-3, registration HK4717. It was configured for non-regular transport. On board were two passengers, one pilot, and one additional occupant, totaling four persons.
Event Sequence
On 5 March 2025, at approximately 08:47 local time (13:47 UTC), the aircraft started its engines without apparent anomalies at Aeropuerto Olaya Herrera in Medellín, Colombia. At 08:48, the pilot initiated a hover and began the takeoff run under visual flight rules. When the helicopter reached an estimated height of one meter above the ground, a sudden loud noise occurred as the covers over the tail rotor drive shaft separated. This was caused by the fracture of the hanger assemblies that support the tail rotor drive shaft bearings. The loss of mechanical connection immediately deprived the aircraft of anti-torque capability, resulting in an uncontrolled yaw to the right. The helicopter then executed a hard landing and came to rest with a heading of 135 degrees.
Damage
The tail boom sustained substantial damage: the drive shaft cover was ruptured and bent, and the skin on the right side was dented between stations 228.79 and 255.77. Damage also occurred to bearing support brackets, pads, one intercostal, and a radius block. The protective cover that dislodged was found on the airport's green area at coordinates 6°12'54.26" N / 75°35'24.80" W.
Occupant Status
All four occupants—the pilot, two passengers, and the additional occupant—were uninjured. They evacuated the helicopter unaided. No injuries were reported.
Post-Event Actions
Ground personnel from the operating company assessed the damage. The event was not immediately recorded in the airport's signal log, and no airport emergency services were requested. The Dirección Técnica de Investigación de Accidentes (DIACC) was notified six days after the occurrence, subsequently assigning investigators to the case.
Investigation
The investigation focused on the fractured hanger assemblies. Fractographic, chemical composition, metallographic, and microhardness tests were performed on the failed components. The source report does not state a probable cause or contributing factors.