According to the Norwegian Accident Investigation Board (Statens Havarikommisjon for Forsvaret), a combination of human and organisation faults were at fault in the November 2017 incident, in which an AW101-612 search and rescue helicopter operated by the Royal Norwegian Air Force rolled over during testing.
The incident occurred, according to the Board, during a test run of the aircraft’s engines following a compressor wash. The investigation found that: “Because the rotor was accelerated using two engines rather than one, it achieved full rotational speed. The combined forces from the main rotor and the tail rotor were sufficient to make the helicopter roll over.”
The acquisition timeline for the new rescue aircraft, asserted the Board, was ambitious, and this, combined with delays in the development of the helicopter, meant that there were subsequent challenges in the provision of training aids and documents for the pilots. The Board reported: “The constant demand for progress negatively affected quality assurance in various parts of the organization, and contributed to elevated and unidentified operational risk.”