What happened
On December 26, 2020, an EMB-711C aircraft, registration PT-NPF, departed from the Brigadeiro Protásio de Oliveira Aerodrome in Belém, Brazil, to perform a systems verification flight following a scheduled inspection. Approximately 15 minutes into the flight, the engine experienced a sudden drop in RPM to roughly 800, followed by a total engine failure. The pilot performed an emergency landing in the Guam River, near Marituba, Pará. Following the impact with the water, the aircraft submerged. The pilot was able to exit the aircraft uninjured, though the aircraft sustained substantial damage.
The investigation
CENIPA investigators examined the aircraft's maintenance records, the pilot's credentials, and the fuel system. The investigation confirmed that the pilot was properly qualified and held valid medical and flight certifications. The aircraft's airworthiness certificate was valid, and the weight and balance were within certified limits.
Investigators analyzed the fuel levels and the fuel selector position. Upon inspection, the fuel selector was found set to the left tank, which was empty. The right tank contained approximately 42 liters of AvGas. The investigation focused on the fuel replenishment process following a recent aircraft weighing procedure. During that procedure, the aircraft had been drained of fuel, and while some fuel was returned to the tanks, there were no precise records regarding the exact amount returned to the right tank. Furthermore, the investigation found that the pilot's flight plan declared an endurance of three hours, which was inconsistent with the actual fuel remaining in the tanks.
Technical analysis of the engine, including the fuel distributor, injectors, and ignition systems, showed no signs of mechanical failure or systemic malfunction. While metallic wear was noted in the valve train, it was not determined to have impacted available power. Crucially, no residual fuel was found in the fuel distributor connections, indicating the engine was no longer receiving fuel.
Findings
- Fuel mismanagement caused the left wing tank to be depleted, leading to the engine failure.
- Inaccurate fuel planning, as the pilot was unaware of the actual fuel quantity following the maintenance weighing procedure.
- Errors in pilot judgment regarding the aircraft's remaining endurance.