What happened
On April 11, 2022, a Cabri G2 helicopter, registration PR-EFC, was performing a local training flight from the EFAI Helipad in Contagem, Minas Gerais. The crew consisted of a flight instructor and a student pilot, the latter of whom was performing his very first rotary-wing training flight.
Shortly after takeoff, the aircraft encountered a high-voltage power line positioned along the standard departure axis. During the attempt to clear the obstacle, the helicopter experienced a significant left yaw. The aircraft subsequently lost altitude, entered a spin, and collided with a truck parked in a nearby cargo-loading area before striking the ground. The impact caused substantial damage to the airframe, including the detachment of the landing gear and damage to the rotor blades. Both the instructor and the student pilot sustained serious injuries.
The investigation
CENIPA's investigation focused on human and operational factors, as no mechanical failures were identified in the Cabri G2. Investigators examined the flight instructor's experience, noting that while he was highly experienced in other models, he had limited hours in this specific aircraft. The student pilot, despite having extensive fixed-wing experience, had no prior experience in helicopters.
The investigation also reviewed the training environment and procedures. It was established that the student had not been specifically briefed on the presence of the high-voltage power lines, nor were specific procedures provided for operating near such obstacles. Furthermore, the investigation noted that the instructor may have been overconfident in the student's abilities due to his extensive background in fixed-wing aviation, which led to a lack of proper supervision during the critical takeoff phase.
Findings
- Improper flight control inputs were a primary factor, specifically the failure to apply sufficient right pedal input to compensate for the increased torque during collective input.
- Inadequate training and briefing contributed to the accident, as the student was not informed of the overhead obstacle during the pre-flight briefing.
- Pilot overconfidence may have led the instructor to allow excessive student participation in the controls during a phase of flight that required high levels of instructor demonstration and supervision.
- Limited rotary-wing experience for the student pilot contributed to the inappropriate execution of the takeoff maneuver.