To: SPS
I quote,"Over the Deck there will be ground effect for 1/2 of the disc and over the sea there will be none for 1/2 of the disc (depending on height and the effect of the water). The blades will experience the resulting differences in ground effect earlier and indeed, if alongside the ship heading to the stern (for instance) it will drift to sea".
Actually, the helicopters as described above will not drift out to the sea. In fact they will fall into the sea. This was the subject of one of my posts on another thread. Many years ago a US Marine HRS (S-55) helicopter battalion was operating off of an aircraft carrier. They were positioned with their main landing gear at the edge of the flight deck. After loading of the troops the helicopters lifted off one by one, and one by one they tipped over backwards because of only one half of the disc being in ground effect. I don’t know how many fell into the sea before the rest of the air group stopped their take off.
I flew as a crewmember in an HTL-1 (early B-47) and we operated off of an Icebreaker. The pilots would normally pull collective and move sideways in relation to the ships path. One day the pilot decided to just lift off from the flight deck and let the ship move away from the helicopter. After the flight deck and fantail moved away from us we were about 40 feet in the air with no ground cushion. Needless to say, we almost bought the farm.
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The Cat