What happened
On November 27, 2004, an Embraer EMB-201A, registration PT-GQO, was conducting agricultural spraying operations near the Mata-Fome Aerodrome in Itaqui, Rio Grande do Sul. While performing a reversal maneuver to begin a new pass, the aircraft experienced a loss of engine power. The pilot attempted to recover power, but after a subsequent engine failure, was forced to perform an emergency landing in an unprepared field.
Following the impact, the aircraft caught fire, resulting in substantial damage to the airframe. The pilot was able to exit the aircraft unharmed.
The investigation
CENIPA investigators examined the engine and its components, finding no mechanical evidence of internal failure that would account for the power loss. The investigation then focused on potential fuel contamination.
Investigators reviewed the fuel handling procedures used by the operator. The company utilizes a system where fuel is transferred from a suspended tank to refueling trucks and then into canisters. Filtering is typically performed using a piece of chamois cloth during the transfer from the truck to the canister. On the day of the accident, however, the pilot reported that fuel was transferred directly from the canisters to the aircraft's tank without being filtered or drained.
While no fuel samples were available for laboratory analysis, the engine's behavior—characterized by intermittent failures and abrupt fluctuations in RPM—was consistent with the symptoms of fuel contamination.