What happened
On June 13, 2012, an EMB-721C aircraft, registration PT-EKM, departed from the Sinop Aerodrome in Mato Grosso, Brazil, bound for Juara. The flight was carrying a pilot and five passengers. Approximately two minutes after takeoff, while climbing through 1,200 feet, the aircraft began emitting abnormal noises and vibrations.
The pilot attempted to switch the fuel selector and activate the electric fuel pump, but the noise persisted. After realizing that a return to the departure runway was not possible due to insufficient altitude, the pilot executed a forced landing in a flat area of low vegetation within a cotton plantation. The aircraft sustained substantial damage, but all six occupants emerged uninjured.
The investigation
CENIPA investigators examined the engine, propeller, and fuel systems. Laboratory analysis of the propeller hub revealed a damaged blade root pin, which showed evidence of an overload fracture. However, investigators could not determine if this failure occurred during flight or upon impact with the ground.
While the engine components, including cylinders, connecting rods, and oil pump, were found to be in excellent condition, the investigation noted that the fuel distributor valve and the fuel supply line were dry, indicating an absence of fuel. Although the pilot stated that emergency procedures were followed according to the operational manual, the lack of fuel in the lines was a significant finding. Due to damage sustained during collection and transport, fuel samples could not be analyzed.
Findings
- The engine experienced a loss of power during the initial climb.
- The fuel distributor valve and fuel lines were found to be empty of fuel.
- The specific cause of the engine failure could not be determined due to the lack of conclusive evidence regarding the fuel supply interruption or the exact timing of the propeller pin fracture.