Unless the rules have changed it is twin only for night helilanes, singles not allowed.
Pilot DAR - we don't switch off our nav lights when we are conducting NVG searches, HISLs maybe but nav light no, so I don't think the Cormorant crew had any defence for their actions at all. As far as the search goes, the light on a cell phone can be seen from miles away on NVG so next time get him to point it at you instead of his ear
