What happened
On December 1, 2003, a Bell 206B helicopter, registration PT-HHV, departed from Bacacheri Aerodrome in Curitiba, Brazil, for a local flight. The aircraft was carrying a crew of two and three passengers. Approximately two minutes after departing the traffic pattern, the engine failed, triggering an engine failure warning light and a loss of power.
The pilot immediately initiated emergency procedures, executing an autorotation to perform an emergency landing. During the descent, the tail cone of the helicopter struck high-voltage power lines, which severed the tail section behind the horizontal stabilizer. Following this impact, the aircraft struck several tree branches and collided with the roof of a nearby building before coming to a rest in a parking lot. Despite the severe damage to the aircraft, which was later deemed a total loss, all five occupants escaped the crash without injury.
The investigation
CENIPA investigators examined the engine and the maintenance records of the aircraft. While testing by Rolls-Royce Brasil Ltda. showed that the engine's operating parameters were within manufacturer limits, investigators discovered a discrepancy in the maintenance logs. Specifically, an injector with a serial number different from the one recorded in the engine logbook had been installed, and there was no record of when or why this part was replaced.
The investigation also analyzed the flight path and the impact sequence. It was determined that the pilot followed the correct emergency procedures for an engine failure. However, during the autorotation, the crew failed to perceive the electrical wires, making the collision unavoidable. The loss of the tail cone significantly compromised the pilot's control of the aircraft during the final moments of the descent.
Findings
- The primary cause of the accident was an engine failure in flight of undetermined cause.
- The collision with power lines was a result of the crew not perceiving the obstacles during the emergency descent.
- Maintenance oversight was a contributing factor, evidenced by the installation of an undocumented injector.
- Inadequate management supervision regarding the tracking of maintenance services and parts was identified as a potential contributing factor.