Geoff, the S-92 doesn't have that problem, as - until recently - you couldn't use them in flight. The maximum airspeed for use was 40 kts!
Some operators would have been able to use them on the deck either! The new ones can be used up to 100 kts, though the retrofit is $16,000 per aircraft, so there are still plenty out there with the restriction. I recently flew with a new pilot, just joined from the North Sea, and when I asked him to turn on the wipers, he couldn't find the switch. He's never ever used them. That said - yes the deck was outside of the swept area........