Although the operator’s procedures for winching and night vision imaging system operations included the need to have adequate hover references and a method of recovery in the event of a night vision goggle failure, there was limited guidance to ensure these requirements were confirmed by the flight crew on‑site before commencing precision hover operations.
New operational guidance regarding pre-mission and pre-winch risk assessments emphasises the requirement to confirm that suitable hover references exist in the winch position. This, combined with the addition of Trakka search lights, significantly reduces the likelihood of a loss of visual cues (including in the event of goggle failure) leading to a loss of control and collision with terrain.
On 27 June 2023 the ATSB was advised that TOLL had made signification changes to sections of the operations manual related to the conduct of winching. The changes include additional guidance regarding risk management, pre‑mission and pre‑winch risk assessment, as well as specific guidance emphasising the requirement to confirm and maintain adequate visual references during winch operations.