What happened
On July 19, 2003, an EMB-720D, registration PT-RRX, departed from Feijó Airport (SWFJ) bound for Rio Branco, Brazil. During the initial climb, the pilot experienced a sudden and unexpected increase in engine RPM, reaching 2,800 RPM. In response to this instability, the pilot reduced power and began a left-hand turn to attempt a return to the departure airfield.
During the final approach, the engine failed completely. The aircraft lost altitude rapidly, striking a tree approximately six meters in height before impacting the ground near the runway threshold. The impact caused the left wing to detach, and the aircraft subsequently caught fire. While the pilot and several passengers survived, two passengers suffered serious injuries, and five others sustained minor injuries.
The investigation
CENIPA investigators examined the wreckage and the engine components to determine the cause of the power loss. The investigation focused on the mechanical state of the engine and the operational procedures of the operator, Rio Branco Aerotáxi Ltda.
Technical analysis of the engine revealed that the oil pump shaft had fractured at the coupling end of the crankshaft. This fracture likely compromised the engine's lubrication, leading to internal damage, including ruptures in the engine block walls, which ultimately caused the engine to seize. The investigation also noted that the aircraft was carrying seven passengers, exceeding its certified capacity of six, and examined the organizational structure of the operator, noting that the company's president also held the role of operations director.
Findings
- The primary cause of the engine failure was the fracture of the oil pump shaft, which likely resulted from inadequate maintenance practices.
- The engine failure occurred during the final approach after an initial period of overspeed during the climb.
- The aircraft's organizational management was a contributing factor, as the accumulation of operational and executive roles may have led to insufficient oversight of maintenance and flight operations.
- The presence of an extra passenger (seven occupants in a six-seat certified aircraft) and the potential lack of standardized emergency briefings may have contributed to the severity of the injuries and the difficulty in evacuating the aircraft.