Antioquia

The accident was the consequence of the combination of the following factors:
- A loss of control in flight as a result of a decrease in minimum control speed and drag, caused by a loss of power on the left engine (n°1);
- A failure of the propeller feathering system on engine n°1, caused by an excessive amount of grease accumulated in the blade coupling section, which prevented the propeller from being feathered quickly (or feathering at all) when the crew attempted to do so. The uncontrolled rotation of the propeller (spinning) created significant drag and made it more difficult to control the aircraft.
- The confirmed loss of power on the left engine, of undetermined origin, was probably caused by a turbocharger malfunction;
- An excess aircraft weight (approximately 770 lb or 349 kg above the MTOW), contributed to the aircraft's inability to accelerate and climb.
The following contributing factors were identified:
- Deficient operator processes in the preventive maintenance of the propellers, failing to detect and allowing the accumulation of grease in the blade coupling section, a circumstance that delayed or prevented the propeller from feathering in a critical phase of flight.
- Failure by the operator to comply with the requirements established by Supplement Type STC SA00192SE in order to operate aircraft HK-5121 with an increased MTOW of 7,352 lb, consisting of:
• Incorporating an FMS (flight manual supplement) into the operation to ensure that no more than four vortex-generating flaps (or blades) were missing.
• Not extending the length of the aircraft's wings or installing winglets.
- Failure by the Operator to comply with the procedures for preparing the Weight and Balance form, by not recording the exact weight of each of the occupants and, instead, using average weights that led to a Takeoff Weight (TOW) lower than the actual weight.
- The operator's lack of knowledge of the impact on the aircraft's MTOW, the altitude of the aerodrome, and the ambient temperature, which at Olaya Herrera aerodrome is lower than the operating MTOW of 7,000 lb corresponding to operation in standard atmosphere.
- The operator did not have a risk analysis for each of the company's operating aerodromes, establishing weight limits for takeoff, taking into account the aircraft's performance charts, the specific operating conditions, and the possible failure of an engine during takeoff or initial climb.

It was determined that the accident was the consequence of an inappropriate planning and execution of the flight, since the amount of fuel required to fly from the airport of destination to an alternate airport was not considered, nor was the amount of reserve fuel, nor the contingency fuel, nor the minimum landing fuel, quantities of fuel required by aeronautical regulations for the execution of the type of international flight that the aircraft CP-2339 was performing. The following factors were considered as contributing:
- Loss of situational awareness,
– Premature configuration of the aircraft for landing,
– Latent deficiencies,
– Lack of operational supervision and control of part of Operator,
– Organizational and operational deviation on the part of the Operator (non compliant to standard procedures).

The following findings were identified:
- Execution of a take-off with a weight approximately 17% higher than the maximum gross operating weight (MTOW) established for the C208B aircraft.
- Limited climb rate with signs of lift loss due to the low performance given by the overweight during the initial climb phase.
- Forced landing in mountainous terrain due to loss of lift caused by overweight during the initial climb.
- Absence in the identification of the risks associated to an overweight operation of the aircraft.
- Lack of supervision by the Aircraft Operator in relation to the dispatch of aircraft operating from the outside at the main base of operation.

The accident was the consequence of a controlled flight into terrain after the crew decided to continue the flight at low height in IMC conditions.
The following contributing factors were identified:
- The foreign crew was not familiarized with the area of flight,
- Poor flight planning,
- CFIT.

The decision of the crew to abandon the takeoff procedure at a speed that was 12 knots above the V1 speed on a wet runway surface, following an EGT warning on engines n°1 and 4. The following contributing factors were identified:
- Failure of the crew to take into consideration the wet runway factor in the takeoff performances calculation,
- Absence of a flight dispatcher properly certified and qualified for the equipment,
- Failure of the engine number n°1 for undetermined reasons.

Controlled flight into terrain after the crew took the decision to continue the approach under VFR mode in IMC conditions until the aircraft impacted terrain. Poor CRM and lack of situational awareness were considered as contributing factors.