What happened
On September 8, 2021, a Bell 206B3 helicopter, registration HK4404, was performing a non-scheduled passenger and cargo flight (air taxi) from Medellín to a landing site in Cañas Gordas, Antioquia. The mission involved transporting two passengers and high-value cargo for a security transport company.
During the final approach to the designated helipoint, the main rotor blades struck an electrical cable. This impact caused severe vibrations and a loss of engine power due to damage to the accessory gearbox. The pilot initiated an emergency landing procedure in a nearby field. During this emergency descent, the aircraft struck additional low-tension wires and subsequently collided with a utility pole. The impact with the pole caused the main rotor to disintegrate and resulted in a hard landing. The force of the impact caused the tail rotor section to detach from the tail cone. Despite the substantial structural damage to the airframe, skids, and rotor system, all three occupants evacuated the aircraft safely without injuries.
The investigation
The GRIAA investigation focused on the sequence of events leading to the loss of control and the operational environment of the landing site. Investigators established that the pilot was technically proficient and the aircraft was airworthy. However, the investigation revealed that the landing site had been changed by the client at the last minute, meaning the pilot was operating at an unfamiliar location.
Investigators examined the lack of prior risk assessment for the new landing site and the failure to perform adequate reconnaissance to identify obstacles such as the power lines and poles. The investigation also reviewed the operator's safety management processes regarding the acceptance of unverified landing sites.