.
Malabo, you're probably right. I'm not up-to-speed on GPS types. I am however interested in the aparatus atop the Lynx's instrument panel (the one with the balck and yellow device to the left).
Probably not as much heave there as you think, ship's roll is going to make the horizon move up and down like that.
So .. what
is the correct procedure for a deck-landing with a vessel underway? I was told:
a) Never approach direct from astern but to the port of the helideck where one can maintain a clear view of the landing area.
b) Once established to port of helideck begin to contour (mimic) the vessel's movements (ie. pitch and roll) while awaiting a 'flat spot' in the vessel's undulations.
c) When 'flat spot' arrives manoeuvre aircraft overhead helideck.
d) From a position directly above the designated landing area on the helideck commence measured inputs to effect a vertical descent while maintaining situational awareness of the vessel's movements (specifically the deck-closure-rate and watching out for deck 'bucking').
e) Implement a firm (ie. positive - no faffing around trying to kiss the deck with the undercarriage) but safe touchdown.