But it really isn't that hard flying off a deck. No crosswind, no need to worry about divs, and if the weather is poor - ask the driver to go somewhere else. As for the engineers - it's just like working on land except a bit more cramped. All your spares etc are located within a 400yd radius, as is all your team and pretty much everything else you need. The aircraft parkers can practice on a dummy deck if they want. It really is not that hard.
Maybe it isn't that hard because of all the experience? The Dummy Deck at Culdrose can simulate the deck, however they cannot simulate the motion of the deck at sea or the ship steaming into the wind - which is what flight deck crews need to be able to deal with. What about other parts of the ship that are involved? From the bridge to the watchkeepers in the ship control centre, or the operators and maintainers of various sensors, communications systems, and landing aids, how will the hard won corporate experience be maintained?