What happened
On 8 October 2017, a Robinson R44 was preparing for a non-commercial flight at the Namur/Suarlée aerodrome. The pilot, who was operating under a private license, intended to provide complimentary flights to several passengers. During the transition from the ground to a stabilized hover, the helicopter entered a rapid counter-clockwise rotation. The aircraft banked sharply, causing the main rotor blades to strike the ground. The helicopter eventually came to rest on its right side. There were 4 slightly injured occupants on board, all of whom were able to evacuate the aircraft.
The investigation
The AAIU(Be) investigation examined the pilot's actions, the aircraft's mechanical condition, and the operational environment. The inquiry established that the pilot was managing several simultaneous stressors, including a malfunctioning intercom and a difficult engine start that required six attempts. Additionally, a group of approximately nine bystanders was positioned near the helicopter during the take-off sequence. The investigation also reviewed the legal status of the pilot's organization, 'Lore Hélicoptère,' which did not hold an Air Operator Certificate (AOC) despite organizing flight events involving fare-paying passengers.
Findings
- The primary cause of the accident was the pilot's inability to neutralize the helicopter's movement using the cyclic and pedals during the critical transition from ground to hover.
- The pilot was under significant stress due to external factors and technical difficulties during pre-flight.
- A fuel leak occurred during the impact due to the rupture of a rubber vent line connecting the fuel tanks.
- The presence of bystanders in close proximity to the aircraft during take-off increased the potential for injury.
- The pilot's organization was conducting 'first flight' activities for paying customers without the required Air Operator Certificate.
Safety action
Following the investigation, several safety issues were identified:
- Airfield Oversight: A recommendation was made for the Namur airfield operator to proactively verify safety measures for organized events.
- Design Improvement: Following a recommendation to the Robinson Helicopter Company, the manufacturer moved to redesign the fuel vent system to eliminate the crossover hose and mitigate future leak risks.
- Regulatory Oversight: The investigation highlighted the need for the Belgian Civil Aviation Authority to monitor organizations offering 'first flights' to ensure they comply with commercial operation regulations.