What happened
On January 24, 2015, at approximately 14:00 UTC, a Robinson R44 II helicopter, registered as PR-HMC, was performing a local flight from Fazenda Parque Maeda in Itu, São Paulo. The aircraft was carrying a pilot and three passengers.
During the initial takeoff phase, while the helicopter was in a hover approximately 30 cm above the ground, the aircraft began an uncontrolled pendulum motion, oscillating from right to left. This movement led to a loss of control, causing the helicopter to tilt heavily to the right and collide with the ground. Despite the impact, all four occupants remained uninjured.
The investigation
CENIPA investigators established that the pilot was fully qualified, holding a valid Commercial Helicopter license and a current medical certificate. The aircraft was airworthy, with all maintenance logs up to date and the weight and balance within safe limits. Weather conditions were favorable for visual flight operations.
The investigation focused on the sequence of events immediately following the passenger exchange. It was determined that after ground crew assisted with the passenger boarding, the pilot initiated the takeoff. During the hover, a passenger seated to the left of the pilot attempted to wave to a person on the ground. This motion caused the passenger's right arm to strike the cyclic control, which escaped the pilot's grip and triggered the sudden, unintended maneuver.
Furthermore, the investigation revealed that neither the pilot nor the ground support personnel had provided safety briefings to the passengers regarding the operational characteristics of the helicopter or the importance of remaining clear of the flight controls.
Findings
- The primary cause of the accident was an unintentional abrupt maneuver caused by a passenger's arm striking the cyclic control.
- The aircraft sustained substantial damage to the main rotor blades, horizontal stabilizer, fuselage, and left skid, along with a broken windshield.
- A lack of safety instructions provided to passengers regarding cockpit movement and control clearance contributed to the occurrence.