Accident
On 29 March 2014 at 1734 UTC, a Robinson R22 Beta helicopter, registration G-BYCF, sustained substantial damage during a dynamic rollover at Elstree Aerodrome, Hertfordshire. The solo student pilot reported minor injuries.
Aircraft and Pilot
The aircraft was a 1998 Robinson R22 Beta (serial no. 2866) powered by a single Lycoming O-360-J2A piston engine. The student pilot, aged 45, held a student pilot licence and had accumulated 39 hours total flight experience, all on type. His recent flying included 15 hours in the last 90 days and 5 hours in the last 28 days.
Event Sequence
The student pilot had just completed a dual lesson in fine weather conditions. The instructor then vacated the aircraft, permitting the student to fly a solo circuit, his second solo on type. During the lift-off from a grass surface, the student perceived the helicopter was right side low, which he attributed to the absence of the instructor in the left seat. He applied left cyclic input to correct the attitude and continued raising the collective. The helicopter suddenly and rapidly rolled to the left, causing the main rotor blade to strike the ground. After the helicopter came to rest on its side, the student secured the aircraft before evacuating.
Findings
The student pilot's instructor commented that the accident had been caused by dynamic rollover. Dynamic rollover occurs when a sideways force from a horizontal component of total rotor thrust is applied at the rotor mast while a skid or wheel contacts the ground or a fixed object. The helicopter then pivots around the fixed point and rolls. Raising the collective to fly away from the problem increases the horizontal component and exacerbates the situation.