What happened
On March 21, 2016, an AS-3-50B helicopter, registration PP-MBN, was performing a passenger transport flight from Nazaré to Morro de São Paulo, Bahia. After conducting a local flight over Nazaré, the aircraft encountered an electrical power line, which the crew managed to fly through without significant damage. However, during the subsequent flight, the engine lost power, causing the aircraft to descend and collide with dense Atlantic Forest vegetation in the municipality of Jaguaripe.
The impact resulted in substantial damage to the airframe, including the cockpit, landing skids, rotors, and tail section. The pilot sustained severe injuries and passed away 25 days after the accident. Of the three passengers on board, two suffered minor injuries and one was uninjured.
The investigation
CENIPA investigators examined the wreckage and found that the fuel system, including the tank, remained intact with no evidence of leaks. Crucially, the investigation revealed that only 1.75 liters of fuel remained in the tank at the time of the crash, an amount insufficient to maintain engine operation.
Technical analysis of the main rotor blades and the engine-to-transmission coupling indicated that the impact with the ground occurred while the engine was producing low power. The investigation also noted a significant lack of documentation; the aircraft's logbook had not been updated since December 26, 2015, meaning there was no reliable record of recent flight hours or fuel quantities replenished. This lack of traceability made it difficult to verify the aircraft's recent operational history.
Findings
- Fuel exhaustion was the primary cause of the engine power loss.
- The pilot's failure to maintain accurate fuel records in the logbook contributed to a loss of situational awareness regarding available fuel.
- Inadequate flight planning led to a takeoff with insufficient fuel to reach the intended destination.
- Poor decision-making was evident in the choice to continue the flight after striking a power line and while operating with unverified fuel levels.
- A lack of managerial oversight, as the pilot also acted as the operator, allowed for the gradual erosion of safety barriers and operational standards.