What happened
On March 19, 2010, a Cessna 185, registration PT-LCI, departed from Fazenda Esmeralda, Mato Grosso do Sul, bound for the Santa Maria airfield. The flight, which included a pilot and one passenger, was conducting visual maneuvers when the engine suddenly stopped during the base turn of the landing pattern.
Unable to restart the engine, the pilot attempted an emergency landing in a small, wooded, and uneven area approximately 1,000 meters short of the runway threshold. In an attempt to minimize impact speed, the pilot pulled the control column fully aft; however, this likely caused the aircraft to stall at a high altitude, leading to a nose-down impact with the ground at an angle of approximately 30 degrees. The impact resulted in serious injuries for both the pilot and the passenger, and the aircraft sustained severe damage to the fuselage, engine, and propeller.
The investigation
CENIPA investigators examined the aircraft's fuel system and operational history. While the fuel selector valve was found to be in perfect working order, inspections of the fuel level transducers (floats) revealed that the right wing float was malfunctioning and heavily rusted, while the left wing float showed severe corrosion.
The investigation also noted that the pilot had not personally monitored the refueling process, relying instead on the cockpit gauges. Furthermore, the pilot failed to activate the electric boost pump when switching fuel tanks during the approach, a procedure noted on the fuel selector valve itself. The investigation also found that the aircraft's logbooks for the airframe, engine, and propeller were not up to date.
Findings
- Fuel starvation caused the engine to fail because the pilot judged the fuel quantity to be sufficient based on unreliable gauges.
- Inadequate flight planning, specifically the failure to verify actual fuel quantities and the failure to use the boost pump during tank switching.
- Improper emergency handling, where the pilot's attempt to reduce speed likely induced an aerodynamic stall prior to impact.
- Maintenance issues regarding the fuel level indicators, which provided inaccurate readings due to corrosion and malfunction.