Boyacá

As the accident occurred in an area with hostile rebels, investigators were not able to reach the scene and to access to the wreckage and debris. Thus, the exact cause of the left engine failure could not be determined with certainty.

The probable cause of this accident is the loss of lift, induced by explosions and fire in the left engine, problems that the pilot was unable to overcome because he was flying under VFR mode in IMC conditions.

It was determined that the total weight of the airplane was 6,491 kilos upon takeoff, some 821 kilos above the MTOW. This demonstrates negligence and carelessness in operation, in violation of the airplane's Operation Manual.

Engine failure for unknown reasons.

The accident was the consequence of a controlled flight into terrain caused by the combination of the following factors:
- Decision of the crew to continue the flight under VFR mode in weather conditions below minimums for such visual flight.
- The crew got lost in IMC conditions since the pilot failed to navigate properly, causing the airplane to deviate from the route mentioned in the flight plan.
- Inadequate IFR operation due to the improper use of the aircraft for instrument flight, as it did not have the necessary navigation equipment.
- Inadequate preflight inspection, as the pilot did not inspect the navigation equipment or, aware that it was out of service, began the flight under such conditions.
- Unfavorable wind, cloud cover, lack of visibility and rain in the area of ​​the trajectory followed by the aircraft.
- Deficiencies in maintenance and inspection related to the failure to technically correct the suction to the normal value, which remained very high for more than two months, potentially affecting the readings of the gyroscopic instruments.
- Authorizing the operation of the aircraft with the VOR and ADF systems that were unserviceable.
- Lack of supervision on part of the Operator over the aircraft and crew in the areas of maintenance, dispatch, operation and exploitation, allowing the owner to carry out these activities according to his criteria, which resulted in the aircraft starting the flight with the navigation equipment out of service, in violation of the Aeronautical Regulations Manual.

The primary cause of the accident is an inadequate correction of a previously reported mechanical fault as oil was observed leaking into the left engine turbine section. The appropriate corrective technical action was not taken. The possible contributing factor to this accident was a material failure, consisting of the front bearing of the turbine drive shaft and accessory section failing, causing the shaft to break and therefore the total failure of the left engine immediately after takeoff, causing the loss of control of the aircraft during the turn to return to the runway.