What happened
On October 22, 2006, a Bell 206L-3 helicopter, registration PT-YHA, was performing a passenger transport flight between the Interlagos Autodrome and the World Trade Center helipad in São Paulo, Brazil. The flight was being conducted under Visual Flight Rules (VFR) at an altitude of approximately 500 feet.
During the final approach to the elevated helipad, the pilot lost directional control of the aircraft. The helicopter began to yaw to the right, causing the tail rotor to strike a building. Following the collision, the aircraft continued to spin and ultimately impacted the ground in a vacant lot near a construction site. The impact was characterized by high energy and a vertical descent.
As a result of the accident, the pilot and one passenger sustained serious injuries, while the remaining four passengers suffered minor injuries. The aircraft sustained severe damage.
The investigation
CENIPA's investigation focused on the aircraft's performance capabilities and the pilot's operational decisions. Investigators examined the aircraft's weight and balance, noting that the helicopter was operating significantly above its maximum allowable weight for the prevailing density altitude. While the aircraft's maintenance records and airworthiness certificates were valid, the investigation found that the aircraft's weight was estimated at approximately 4,209 lbs, exceeding the maximum takeoff weight of 4,150 lbs and significantly exceeding the performance-limited maximum of 3,800 lbs.
Analysis of the wreckage showed no evidence of mechanical failure in the tail rotor system. Instead, the investigation pointed toward a loss of tail rotor efficiency. The investigation also noted that the pilot had relatively recent flight training on this specific model, having completed instruction and a check flight only months prior to the accident.
Findings
- The aircraft was operating above its maximum operational weight for the specific altitude and density altitude conditions.
- The pilot made an erroneous judgment regarding the availability of power and the ability to safely execute an approach and landing at an elevated helipad.
- There was a lack of adequate flight planning, specifically regarding fuel and weight limitations required by the flight manual.
- The pilot's limited experience with the Bell 206L-3 likely hindered the ability to react effectively to the loss of tail rotor efficiency.
- The loss of directional control was likely caused by insufficient pedal authority to counteract torque during the reduction of airspeed, leading to the tail rotor strike.