Summary
On September 1, 2015, a Bell 206 L3 helicopter, registration HK3311, operated by Sociedad Aérea de Ibagué S.A. (SADI S.A.) and tasked with transporting cash, experienced a loss of control after encountering severe turbulence. The accident occurred near Boavita, Boyacá, Colombia, at approximately 19:10 UTC. The aircraft suffered major structural damage and both occupants were injured.
Flight History
The helicopter had been performing multiple cash-transport flights that day, departing from Guaymaral at 14:30 UTC and completing three routine flights. After a fuel stop in Tunja, it departed at 17:33 UTC with two individuals on board—a pilot and a passenger from the security company Prosegur. The flight proceeded through several towns before departing Guicán at 18:57 UTC en route to Chita.
During the climb, the aircraft reached an altitude of about 13,000 feet. As it began its descent and entered the Chicamocha River canyon, the pilot reported a sudden onset of severe turbulence that affected the flight profile and trajectory, causing a rapid descent. The pilot attempted to regain control using the flight controls but was unsuccessful. The helicopter struck terrain on a mountainside at coordinates N 06 11 16.38 W 72 28 16.00 at an elevation of approximately 4,800 feet.
Aircraft and Crew Information
The aircraft was a Bell 206 L3, serial number 51195, manufactured in 1987. It had accumulated 6,597.7 hours of flight time. The engine was a Rolls-Royce 250-C30P with 5,458.1 hours. The helicopter was equipped with a main rotor and tail rotor, both with substantial service hours.
The pilot, aged 43, held a commercial helicopter license (PCH) and a valid medical certificate. He had 3,691.9 total flight hours, with 634.96 hours on the Bell 206. His most recent checkride on the type was on August 31, 2015.
Meteorological Conditions
Weather conditions at the time were generally favorable, with satellite imagery showing no significant storm development in the area. However, analysis of the geography, topography, and time of day indicated the presence of downdrafts and updrafts that generated strong mechanical turbulence along the mountainside where the aircraft entered. The turbulence was consistent with mountain wind patterns, where air flowing over obstacles creates turbulent eddies on the lee side and within canyons. During the afternoon, upslope winds reach peak intensity, making turbulence more pronounced.
Impact and Wreckage
The helicopter impacted terrain at a high angle and low forward speed, as evidenced by ground marks and vegetation cuts. The main rotor assembly remained attached to the mast, but blades showed evidence of striking the ground and the fuselage at low RPM. The tail boom was separated and found forward of the fuselage, with paint transfer between the vertical stabilizers and main rotor blades. The landing gear was fully collapsed with sudden tensile and compressive failures, indicating a high-impact force. The wreckage was concentrated within a 20-meter radius.
Injuries and Damage
Both occupants evacuated the wreckage: the pilot sustained minor injuries and exited unassisted, while the passenger sustained serious injuries and was rescued by local residents. The aircraft was destroyed, with major damage to its entire structure and all primary components. No damage to third parties or property occurred.
Investigation
The accident investigation was conducted by the Grupo de Investigación de Accidentes e Incidentes de Aviación (GRIAA) of Colombia. The NTSB was notified as the authority of the state of manufacture per ICAO Annex 13. Investigators arrived on September 3 due to adverse weather at the site. The helicopter was not equipped with flight data or cockpit voice recorders, which were not required by regulations.