landing on oil rig with emergency
Shawn, just a quick note on your comment about being prevented from landing on an oil rig with an emergency.
I can't imagine any oil rig (in the north sea anyway, which is only offshore enviroment i have experience with) trying to prohibit an offshore helicopter landing after making a mayday call, if the crew felt there best chance was landing on a rig rather than ditching. For example, with the S76C: Transmission oil low pressure, the emergency check list states land as soon as poss.
Land as soon as poss, when offshore, is defined as fly to the nearest suitable helideck. The only reason we wouldn't land is if the crew were told of some specific safety reason that over-rode the low oil pressure danger eg the nearest rig was operating cranes over the deck that couldn't be cleared in time. If the deck was safe to land, no OIM would try and prevent an emergency landing. Andy