What happened
On March 11, 2011, a Beechcraft A36, registration PT-LFL, departed from an unregistered airstrip near Aveiro, Pará, bound for Santarém. The flight, which included the pilot and three passengers, was intended for personnel transport. Approximately ten minutes into the flight, the pilot experienced an engine malfunction and attempted to switch to the right fuel tank. However, twenty minutes later, while approximately 10 nautical miles from Santarém, the engine ceased operation entirely.
Unable to restart the engine, the pilot performed an emergency landing on a local road roughly 1.1 nautical miles from the Santarendum airport. While the pilot and all three passengers escaped uninjured, the aircraft sustained substantial damage to its landing gear, propeller, and wings.
The investigation
CENIPA investigators examined the fuel levels and flight logs to determine why the engine failed despite calculations suggesting sufficient reserves. Records indicated that the aircraft had been fueled with 60 liters of AVGAS in Santarém, and based on previous consumption rates, the tanks should have contained approximately 200 liters at takeoff. However, post-accident inspections revealed that the fuel gauges indicated only about one-quarter of the total capacity, and the tanks contained only unusable fuel.
The investigation focused on the discrepancy between the expected fuel load and the actual availability. The pilot reported that the aircraft had been left unattended in Aveiro, and a police report was filed regarding the theft of fuel from the aircraft at that location. Investigators found no evidence of leaks in the fuel system, making the theft of fuel a highly credible explanation for the engine failure.
Additionally, the investigation noted that the pilot's fuel gauges were unreliable, which prevented the crew from identifying the low fuel state before the engine failure occurred. The investigation was also noted to have operated from an unregistered airfield, which was in violation of Brazilian aeronautical regulations.
Findings
- The engine failure was caused by fuel exhaustion (dry tank).
- The depletion of fuel was likely caused by the theft of fuel from the aircraft while it was unattended in Aveiro.
- Unreliable fuel gauges prevented the pilot from detecting the critical fuel shortage during flight.
- The aircraft was operated from an unregistered airfield, contrary to regulatory requirements.
- Maintenance logs for the airframe, engine, and propeller were not up to date.