What happened
On March 27, 2011, at approximately 20:15 UTC, a Robinson R44 helicopter, registration PP-MIE, was performing a flight from the Atibaia Residence Hotel in Atibaia, São Paulo. The flight, which included the pilot and three passengers, was a courtesy flight requested by hotel guests. Due to the presence of nearby obstacles, the pilot performed a vertical takeoff from an area within the hotel grounds.
As the aircraft began to move forward, the pilot reported a loss of lift. The pilot attempted to execute a right-hand turn to return to the original takeoff point, but after a rotation of approximately 270 degrees, the aircraft could no longer maintain flight. The helicopter descended onto the roof of a warehouse, where the structural fragility of the building caused the aircraft to sink and become trapped by the building's framework. The impact caused the roof tiles to break and resulted in substantial damage to the helicopter's rotors, transmission, tail cone, and cabin. One passenger sustained minor injuries, while the pilot and the other two passengers were uninjured.
The investigation
CENIPA investigators determined that the takeoff was being conducted from an unauthorized and unregistered landing site. The investigation focused on the aircraft's performance capabilities under the specific environmental conditions at the time. While the pilot was fully qualified and experienced, the investigation revealed that the pilot had used incorrect performance data, calculating the maximum takeoff weight based on the aircraft'2 limitations section rather than the appropriate performance charts.
At the time of the accident, the aircraft's weight was 2,373.6 lb (1,077 kg). Based on the altitude of 2,650 ft and an estimated temperature of 25°C, the maximum allowable takeoff weight for an Out of Ground Effect (OGE) maneuver was 2,300 lb (1,043 kg). This meant the aircraft was operating 37 kg above the maximum allowable weight for the intended maneuver.
Findings
- The aircraft was operating in excess of its maximum allowable takeoff weight for the specific environmental conditions.
- The pilot failed to use the correct performance graphs, leading to an inaccurate calculation of the maximum takeoff weight.
- The loss of control was likely caused by the transition from Ground Effect (IGE) to Out of Ground Effect (OGE) while overweight, compounded by a wind component from the left side and tail.
- The takeoff occurred at an uncertified and unregistered location.
- Inadequate flight planning and pilot judgment regarding operational limitations.