What happened
On July 29, 2016, a Bell 407 helicopter, registration PT-YZK, was performing a transfer flight to the Guanabara Palace Helipad in Rio de Janeiro. The crew, consisting of two pilots and one special equipment operator, was part of a mission supporting the Olympics.
During the final approach, the aircraft began experiencing intense vibrations. Despite the instability, the pilot in command decided to proceed with the landing. As the helicopter neared the ground, the vibrations became uncontrollable, causing the tail rotor to strike a wall located just outside the designated landing area. Following this impact, the aircraft made a sudden, uncontrolled landing and continued moving forward until it collided with a second wall, where it finally came to a stop. The aircraft sustained substantial damage across its entire structure, including the main rotor, fuselage, and tail cone.
The investigation
CENIPA investigators examined the wreckage and the aircraft's maintenance history. Technical inspections of the engine and the main rotor damping system revealed no mechanical failures or fractures that could have caused the abnormal vibration; the engine was operating normally at the time of impact. The damage observed in the rotor blades and control links was determined to be the result of the impact with the ground and obstacles.
The investigation also focused on the crew's performance. While the crew was experienced and held valid licenses, investigators noted a breakdown in Crew Resource Management (CRM). The second in command (SIC) had attempted to direct a go-around procedure due to the vibrations, but the pilot in command claimed not to have heard the instruction. Additionally, the investigation noted that the SIC's attention was frequently focused on a tablet during the flight, which may have reduced situational awareness.
Findings
- The pilot in command's decision to proceed with a landing during an unstabilized approach characterized by excessive vibration.
- A failure in communication between the crew members, preventing the execution of a go-around.
- Inadequate evaluation of operational risks and parameters by the pilot in command.
- Reduced situational awareness due to the second in command's preoccupation with electronic equipment.
- A lack of standardized operating procedures (SOPs) and training programs within the operator's organization to guide crew conduct during abnormal in-flight conditions.