What happened
On July 21, 2020, at approximately 11:30 UTC, a Cessna A188B, registration PR-FEK, was performing an agricultural spraying operation near Patrocínio, Minas Gerais. The aircraft took off from a landing strip at Fazenda Engenho Velho. During the takeoff phase, the engine experienced a gradual loss of power. In response to the emergency, the pilot jettisoned the agricultural chemical load and executed an emergency landing within a nearby plantation. The aircraft sustained substantial damage, but the pilot remained uninjured.
The investigation
CENIPA investigators examined the engine, fuel system, and aircraft maintenance records. Laboratory analysis of the ethanol fuel and lubricating oil showed no signs of contamination. Fuel flow, cylinder pressure, and fuel injector tests revealed no discrepancies. However, a detailed inspection of the engine-driven fuel pump identified internal wear points.
Furthermore, investigators discovered a non-compliant modification to the instrument panel: the original Fuel Shutoff Valve Control Knob had been replaced with an adapted device that did not match the manufacturer's specifications and lacked the required safety lock. Additionally, while the aircraft's airworthiness certificate was valid, investigators noted that the usage logs for the airframe, engine, and propeller were not up to date.
Findings
- Internal wear in the primary mechanical fuel pump likely compromised fuel delivery.
- The installation of an unauthorized, non-conforming fuel shutoff valve knob may have altered the expected fuel flow behavior during critical phases of flight.
- The auxiliary fuel pump switch was found in the OFF position; had the pilot followed emergency procedures to activate the auxiliary pump, the engine might have maintained sufficient power for the maneuver.
- Inadequate management supervision regarding maintenance conformity and adherence to technical procedures.