Was it a crew who got used to habitually cancelling the gear warning when approaching a manual hover with the gear up? I think the gear warning in the AW139 is designed to remain supressed if the auto hover mode is used because the designers expected that was how everyone would do hoisting.
However #ome crews flew hoisting manually and so had to constantly acknowledged the gear alert. They got used to cancelling the alert every time they came to a hover. I wonder if these guys had just finished a hoisting period where they had been spamming the audio alerts acknowledge for the last 2 hours
This exact issue took out a Spanish AW139 crew in 2010.
AW139 accident