What happened
On November 8, 2012, at approximately 12:10 UTC, an EMB-202A aircraft, registration PT-VUF, was performing an agricultural spraying operation departing from Fazenda Aliança Aerodrome in Araputanga, Mato Grosso. Shortly after takeoff, the pilot experienced a sudden loss of engine power.
In an effort to manage the emergency, the pilot jettisoned the agricultural payload from the hopper. The pilot then performed a forced landing on irregular terrain, which resulted in the aircraft coming to a stop in a flooded area. The aircraft sustained substantial damage, but the pilot remained uninjured.
The investigation
CENIPA investigators examined the aircraft's Lycoming IO540K1J5 engine and propeller assembly. Initial inspections revealed damage to one propeller blade tip and a fractured propeller pin. Stereoscopic analysis at the DCTA revealed that the propeller pin had undergone plastic deformation and crushing due to overload, while the propeller body showed warping consistent with ground impact.
Upon disassembly of the engine, investigators inspected the ignition system, fuel pumps, fuel injectors, and magnetos. While these components showed no signs of malfunction, the investigation focused on the fuel distributor valve. Testing revealed that the valve's plunger had seized due to corrosion. Although the fuel (ethanol) was found to be within standard specifications upon testing, evidence suggested that the presence of non-standard fuel at an undetermined time in the past had likely initiated a long-term corrosion process within the valve.
Findings
- The seizure of the fuel distributor valve plunger prevented the proper distribution of fuel to the injectors, leading to the engine failure.
- Maintenance practices and management supervision were identified as contributing factors.