What happened
On May 30, 2013, an EC 130 B4 helicopter, registration PR-DJC, landed at the Sítio Tibagi helipad in Guaramiranga, Ceará. After touchdown, the aircraft remained running with the rotors in motion. The pilot left the cockpit to assist passengers with their disembarkation.
During the process, a passenger exiting through the front left door used one of the collective lever controls as support. In doing so, the passenger inadvertently unlocked the collective and moved the twist grip from the ground idle position to flight idle. This caused the main rotor RPM to increase and triggered an unintended takeoff movement. The helicopter moved forward approximately three meters, lifted its tail, and then tilted sharply to the left, causing the main rotor blades to strike the ground. The impact resulted in substantial damage to the main rotor assembly, the main gearbox, and the tail drive shaft.
The investigation
CENIPA's investigation focused on the sequence of events during the ground operation. The investigation established that the pilot was qualified and experienced, and the aircraft was airworthy and within weight limits. However, the investigation highlighted that the pilot had not performed a safety briefing for the passengers prior to the flight. Furthermore, the pilot's decision to leave the controls while the engines were running was identified as a violation of safety norms.
Findings
- The unintentional movement of the collective lever by a passenger was the primary trigger for the aircraft's movement.
- The pilot's decision to leave the cockpit while the rotors were spinning left the aircraft without a qualified operator at the controls.
- A lack of passenger briefing contributed to the passenger using the flight controls for physical support during exit.
- An overconfidence in the routine nature of the flight led to a disregard for established safety risks.
- A prevailing culture among some private operators of performing disembarkation with rotors turning contributed to the unsafe environment.