What happened
On 02 January 2013, a Bell Helicopter-Textron 206-3B, registration A6-FTI, was conducting a training flight in the north western training area of the United Arab Emirates. The flight, originating from Al Ain International Airport, was part of a dual proficiency check intended to prepare a student pilot for their first solo flight.
During the session, an instructor pilot briefed the student on a specific maneuver: transitioning to a hover and then lowering the collective to judge lateral control, specifically noting a change in the aircraft's center of gravity. The instructor remained on the ground at the edge of the helipad, monitoring the student via hand signals rather than radio.
As the student pilot attempted to lift the aircraft into a hover, the helicopter began to yaw toward the right. While the instructor signaled for a left cyclic input, the student applied left pedal to correct the yaw. This action caused the aircraft to roll rapidly to the right. The main rotor blades struck the ground, resulting in a 90-degree rollover. The student pilot was able to evacuate the aircraft without serious injury, though the aircraft was destroyed beyond economic repair.
The investigation
An investigation by the GCAA AAIS examined the aircraft's configuration, the flight conditions, and the sequence of control inputs. Investigators reviewed the aircraft's maintenance and airworthiness status, finding it was valid and the aircraft was airworthy at the time of the event. The investigation also looked into the center of gravity (CG) management, noting that the instructor had specifically briefed the student on a shift in the CG to the right.
Findings
- The aircraft experienced a dynamic rollover triggered by a rapid roll rate that became unrecoverable.
- The student pilot applied left pedal input to arrest a rightward yaw, which contributed to the rapid rightward roll.
- A lateral center of gravity offset to the right was a factor in the instability during the hover transition.
- The aircraft's main rotor system made contact with the terrain, causing the primary structural damage.