What happened
On May 9, 2018, a Bell 206B helicopter, registration PT-HKY, was performing a private passenger flight from Recreio Helipad to Cabo Frio, Rio de Janeiro. While maintaining level flight, the aircraft encountered an emergency and lost altitude, ultimately colliding with the sea approximately 20 and 200 meters off the coast of Barra da Tijuca beach.
The impact caused substantial damage to the aircraft. The pilot sustained fatal injuries, while one passenger suffered serious injuries and the remaining two passengers sustained minor injuries. All occupants were rescued by the Rio de Janeiro State Military Fire Department.
The investigation
CENIPA investigators examined the wreckage and analyzed engine components, including the Fuel Control Unit and Power Turbine Governor. Analysis of the engine revealed that the rotating parts were still in motion at the moment of impact. While the engine itself showed no mechanical defects that would prevent operation, investigators found that the fuel in the tank had been contaminated by seawater.
Testing of the fuel filler cap assembly revealed that it allowed leakage in both directions. A visual inspection of the sealing O-ring showed damage that compromised its ability to prevent fluid ingress. Furthermore, surveillance footage from the departure location showed that the pilot did not perform the pre-flight inspection required by the flight manual, which included the mandatory procedure of draining the fuel to check for contaminants.
Findings
- The primary cause of the power loss was likely fuel contamination by water, which entered the tank through a faulty fuel filler cap seal.
- The pilot failed to perform the prescribed pre-flight inspection and fuel drainage procedure.
- The maintenance organization may have performed the inspection of the fuel filler cap inadequately, and there was a possible lack of effective oversight regarding the quality of the maintenance service.
- The aircraft's airframe and engine logbooks were not up to date.