I sat next to a bloke while he won his AFC on a task involving a small ship, sea state 4-5 and an awful lot of double-lift and single-lift winching in the second part of the Op (much of it trapped deck). I don't know if it's been improved since, but the hoist failed at least a dozen times at various stages during the op - probably heat-related issues even though it was over the North Sea. Winch operator was Kev Hardie, who sadly died a few months later on the Mull. In a strong wind, downwash from the Chinook wasn't as big a problem as it would've been on a calm day.