South America

Given the circumstances in which the accident occurred, it would be considered a CFIT (Controlled Flight Into Terrain) type accident, which occurs as a result of unintentional impact on the ground, when the aircraft is under the control of the pilot in command. It is considered that the most probable cause of the accident was the loss of situational awareness, caused mainly by the concern that he was becoming distracted by the emergency of the aircraft preceding him on the approach, because of his administrative relationship with this aircraft and its crew.

The decision of the pilot to continue the flight under VFR mode in IMC conditions. As a result, he lost visual references and was unable to maintain a safe separation with the ground, causing the aircraft to impact terrain. Inadequate planning by the pilot by not considering the existing weather conditions en route and at destination was considered as a contributing factor.

The failure of the right engine was the result of the failure of the fuel pump due to poor maintenance and a possible use beyond prescribed limits. The presence of iron oxide inside and outside the fuel pump as well as the lack of cleanliness of the internal components indicates a probable lack of maintenance. When the right engine stopped running, the generator No. 1 was then responsible for powering the aircraft's electrical system. As the latter was not in good working order, the primary generator could not withstand the overload and ceased to function, leaving only the battery to power the entire electrical system. To maintain power to critical systems, the crew would have had to select the backup power system. Since after the engine stopped, there was no monitoring of the electrical system, the pilots only realized the failure of the electrical system when they attempted to extend the landing gears. The emergency hydraulic system was then used to lower the gears, after which the crew did not return the system selection valve to the 'normal' position, resulting in the brakes and the steering systems to be inoperative after landing. The chain of failures may be associated with not reading the checklist when performing procedures after the engine failure.
The following contributing factors were identified:
- Poor flight preparation,
- The crew failed to follow the SOP's, and took the decision to initiate the flight with an aircraft that was overloaded by 503 kilos,
- When the emergency situation presented itself to the crew, they failed to follow the checklist,
- On an organizational level, the company did not have an effective personnel training system in place, so that the crew did not have sufficient skills to respond to emergency situations,
- Because the aircraft was overloaded and that one engine was inoperative, the crew was forced to complete the approach with a speed higher than the reference speed,
- An improper use of the controls allowed the aircraft to land 700 meters past the runway 28 threshold, reducing the landing distance available,
- The crew focused their attention on the failure of the right engine and did not identify the failure of the electrical system, which delayed their tasks assignment, all made worse by the failure to comply with the checklist,
- The operations cleared the crew to start the flight despite the fact that the aircraft was overloaded on takeoff based on weight and balance documents,
- The crew did not prepare the flight according to published procedures and did not consider the total weight of the aircraft in relation to the number of passengers on board and the volume of fuelin the tanks, which resulted in an aircraft to be overloaded by 503 kilos and contributed to the failure of the right engine,
- A lack of maintenance on the part of the operator.

The decision of the captain to continue the approach under VFR mode in IMC conditions to an airport that was not suitable for IFR operations. The following contributing factors were identified:
- The lack of ground references may have contributed to the commander's spatial disorientation,
- Although the weather conditions made it impossible to land under VFR conditions, the captain insisted on landing, neglecting IFR procedures,
- The captain ignored the copilot's advice and continued with the approach procedure,
- The captain put the aircraft in an attitude that caused it to stall,
- Poor judgment on part of the captain,
- Despite the implementation of a CRM program, the operator was unable to identify that the captain was violating the published procedures.

After departure from runway 25, the crew planned to use an unpublished procedure. Climbing through clouds a 180-degree turn was initiated. Using the unreliable magnetic compass, the flight made a 270 degree turn, heading towards rising terrain. The captain took over control from the copilot. When visual contact with terrain was regained, the crew noted they were heading for mountains. The captain tried to avoid rising terrain but the aircraft impacted the side of a mountain at 4,100 metres.