I think what high spirits is trying to make clear is that if Mk 3 remains so, and it can't be folded up to put on a ship, then why go to the expense of retraining 2 sets of crews when you could possibly retrain CHF onto the new Chinooks ? Gives them a new aircraft and a frame that will do everything they need - ok, the numbers are less but the lift capacity evens it all out. I read somewhere that the lifts on the new carriers are to be big enough for a Chinook anyway, if this is true then there is no requirement for a Merlin Mk4.