On July 4, 1991, a De Havilland DHC-6 Twin Otter (registration HK-2889X) operated by Helicol Colombia - Helicopteros Nacionales de Colombia was involved in an aviation accident near Yopal, Colombia during landing or approach. 3 people were killed. Investigators recorded the probable cause as: Controlled flight into terrain following a VFR approach in IMC conditions. This summary draws on records from the Bureau of Aircraft Accidents Archives (B3A); 2 related events involving the same aircraft type or operator are linked below.
An aircraft on a VFR approach to Yopal Airport in poor weather deviated left and struck a mountain slope, killing all three occupants. The aircraft was destroyed.
Accident Summary
While conducting a visual flight rules (VFR) approach to Yopal Airport in poor weather conditions, the aircraft collided with the slope of a mountain located approximately 8 km from the airstrip. The impact destroyed the aircraft and resulted in the death of all three occupants. At the time of the accident, the aircraft had deviated 20° to the left of its intended course.
Investigation
Investigators were unable to determine the exact cause of the deviation. Possible explanations considered include strong winds or the crew's decision to avoid adverse weather. The official probable cause was determined to be controlled flight into terrain following a VFR approach in instrument meteorological conditions (IMC).