What happened
On May 14, 2008, a Robinson R44, registration PT-YON, was performing a takeoff from the Mahle Metal Leve factory premises in Mogi Guaçu, São Paulo. The flight was intended to proceed to the Amarais aerodrome. During the initial climb, the aircraft experienced a sudden loss of lift, which led to a collision with the ground.
As the aircraft descended, the skids made contact with the terrain before an asphalt road. In an attempt to correct the descent, the pilot applied pitch commands that caused the tail rotor to strike the ground. This impact triggered a leftward rotation, leading the main rotor to strike the ground and causing the helicopter to overturn. Both the pilot and the passenger escaped the accident uninjured, though the aircraft sustained severe damage, including broken main rotor blades, a destroyed windshield, and damage to the tail cone and tail rotor blades.
The investigation
CENIPA's investigation focused on the environmental conditions and the pilot's decision-making during the takeoff phase. Investigators examined the takeoff area, which consisted of a grassy area with a slight incline leading toward a perpendicular asphalt road. The investigation also reviewed the pilot's flight experience and the aircraft's maintenance status.
While the aircraft's airworthiness certificate was valid, investigators noted that the aircraft's logbooks were not up to date. The pilot, who held a valid commercial helicopter license, had relatively low flight hours and had not previously flown this specific route. The investigation also considered the possibility that the pilot failed to account for wind direction and intensity during flight planning.
Findings
- The pilot failed to consider wind direction and intensity during flight planning, potentially subjecting the aircraft to a tailwind component during takeoff.
- The pilot applied inappropriate flight controls in an attempt to correct the aircraft's attitude, which directly led to the tail rotor striking the ground.
- The pilot's limited flight experience and low frequency of flight may have contributed to errors in managing the emergency in an unprepared landing site.
- The takeoff location, an uncertified area with an incline, increased the risk of loss of control.