What happened
On September 27, 2006, a Bell 206A helicopter, registration PT-HBJ, was performing a takeoff from a soccer field in São João do Caru, Maranhão, destined for São Luís. The aircraft was operating near its maximum takeoff weight in high ambient temperatures of approximately 30°C.
During the initial climb, the pilot encountered a strong wind gust from the right side. This gust caused a momentary loss of lift, which the pilot described as being "thrown downward." Attempting to abort the takeoff, the pilot attempted to maneuver the aircraft toward an open area to the left. However, due to the restricted takeoff axis and the lack of available space for an aborted maneuver, the pilot lost control and the helicopter struck a dirt road with a high rate of descent. All four occupants—the pilot and three passengers—escaped the crash without injury, though the aircraft sustained severe damage, including the destruction of the tail cone and damage to the main rotor blades and transmission.
The investigation
CENIPA's investigation focused on the operational environment and the decision-making process regarding the takeoff site. The investigation established that the takeoff area, while permitted under RBHA 91 for occasional operations, was highly restricted by obstacles. The specific takeoff axis used did not allow the pilot to approach into the wind.
Investigators examined the aircraft's performance capabilities under the prevailing high-temperature and high-weight conditions. The analysis revealed that a significant portion of the engine power was being diverted to the tail rotor to maintain directional control against the wind, leaving insufficient power margin for the main rotor to compensate for the sudden loss of lift caused by the gust. The investigation also reviewed the operator's management oversight regarding the use of uncertified landing sites.
Findings
- The pilot's flight planning failed to account for the lack of an available abort area and the impact of environmental factors.
- The takeoff site's configuration prevented an approach into the wind, limiting the pilot's ability to manage the wind gust.
- The aircraft was operating near its maximum takeoff weight in high temperatures, which reduced the performance margin.
- The pilot's judgment contributed to the accident by proceeding with the takeoff without verifying sufficient space for an emergency maneuver.
- The operator's managerial supervision was a contributing factor, as the company authorized services at an uncertified and unregistered site without ensuring all safety requirements were met.