History of the Flight
The flight originated from Antwerp Airport (EBAW) with an instructor and a student pilot on board. After a preflight check determined that refueling was needed to complete the return to EBAW, enough fuel remained to reach Hoevenen Airfield (EBHN). The purpose of the flight was to practice low-level maneuvers. Upon arrival at EBHN, the crew exercised set-downs and pick-ups before proceeding to refuel at the helibed alongside the runway.
After refueling, the student began a hover taxi toward the hangars. During the hover taxi, the helicopter deviated to the right; the student corrected with left cyclic input. The helicopter lost height, and the rear end of the left skid contacted the ground. The instructor moved the cyclic to the right, but a dynamic rollover was initiated, and the helicopter rolled onto its left side.
Injuries and Damage
Both the instructor and the student sustained minor injuries and climbed out of the helicopter.
The helicopter sustained damage including a broken main rotor blade, deformed vertical firewall, deformed tail boom at both ends, broken left door window, broken engine power transmission belts, and deformed yoke and flexplate (transmission components).
Pilot Information
The instructor was a 34-year-old male holding a Commercial Pilot Licence (Helicopter) valid until November 24, 2015, with ratings for Robinson R44 and R22 and a Flight Instructor rating. Total flight experience: 529 hours (328 PIC, 223 FI(H)). On the R22: 138 hours (119 PIC, 119 FI(H)).
The student was a 24-year-old male holding a Student Pilot License issued on January 9, 2013. Total flight experience: 12 hours 12 minutes. He had completed 10 training sessions, including three with hover taxiing and spot turns.
Meteorological and Airfield Information
At 12:20 UTC at Antwerp Airport, wind was from 240 degrees at 8 knots, visibility more than 10 km, temperature 8°C, dew point 5°C, QNH 1024 hPa. Hoevenen Airfield has a 600 m by 18 m grass bidirectional runway oriented 153°/333°.
Wreckage and Impact
Inspection of the wreckage revealed impact traces on the ground and left skid consistent with the rear of the skid contacting the ground first, followed by rotor blade contact. All damage was consistent with a dynamic rollover.
Cause and Contributing Factors
The investigation determined that the cause of the dynamic rollover was an inadequate lateral cyclic input while flying close to the ground. Contributing factors were that the flight was conducted at low level while the student could not yet adequately master the controls, and the instructor was late in reacting to prevent the inadequate control movement.