What happened
On April 15, 2018, a Bell 206 L4 helicopter, registration HK 4484, was engaged in an external load recovery operation at Cerro El Pinche, in the Argelia municipality of Cauca, Colombia. The mission, operated by Helifly Colombia, involved removing the wreckage of another Bell 206 aircraft from a mountainous area.
During the final phase of the operation, the pilot was attempting to hook a large component—the fuselage of the wrecked aircraft—to the sling. As a ground technician was securing the attachment devices, the right skid of the helicopter made contact with the wreckage. This contact created a pivot point that caused the aircraft to tilt and capsize onto its right side, ultimately impacting the ground in an inverted position.
As the aircraft rolled, the main rotor blades struck a ground technician acting as the signalman, causing one fatality. The pilot, who sustained minor injuries, was able to shut off the fuel valve from the inverted position and evacuate the aircraft safely. The helicopter sustained major structural damage, including a fractured tailboom, broken rotor blades, and a fractured mast.
The investigation
The GRIAA investigation examined the sequence of events, the technical state of the Bell 206 L4, and the coordination between the flight crew and ground personnel. Investigators reviewed the flight history, noting that while previous loads had been successfully transported that day, the weight and complexity of the fuselage required a reorganized approach. The investigation also analyzed the meteorological conditions, which were found to be favorable, and the communication protocols used during the external load maneuver.