While I haven’t flown the type specifically mentioned by SirVivr, I must say my convictions are with Nick on this one. I fly a light, non-Cat-A-certified twin off-shore to smaller decks than SirVivr refers to.
My first priority on an approach is to fly it in such a manner as to preclude hitting something or losing control due to uncommanded yaw. This means no fast approaches, and only as shallow as absolutely necessary to see enough of the rig to fly an accurate approach. Wind speed and particularly direction are important factors to consider when planning the approach.
The second priority is to fly an approach in such a manner as to avoid overtorques / temps / speeds, which can be done (again) by playing to the wind and taking things slow.
After these considerations are satisfied, I will choose from the options available (if available) an approach path / profile combination that will allow in the case of a single engine failure, a nose-over to Vtoss and climb away (in the early stages of the approach) or (from short final, probably a hard) landing to the deck whether or not with an overtorqued transmission and/or burnt engine. In some cases (heavy load, no wind) this is not continuously possible, but the probability of losing one engine during such a short segment of the approach is far smaller than that of hitting something you can’t see, and so receives less consideration.
The end result may be a straight-in approach, an approach to a spot beside and above the deck followed by a slide over the deck, or an approach terminating in a curved segment of about 30 degrees. Often I fly the last 100-200 feet of the approach out of trim for better visibility – no problem if you keep in mind and anticipate pedal requirements.
The greatest asset of helicopters, to my mind, is their flexibility. But that requires an equal mental flexibility from the crew in order to get the most out of the machine.
If one’s SOPs require the LHS handling pilot to fly an approach in such a manner as to not be able to keep either deck or obstacles in sight, then the SOPs are setting one up for an accident. If this is because of a regulatory requirement, then the regulations are wrong. If this situation cannot be changed (why not?), then the SOPs should dictate that approaches to the decks in question may only be flown from the RHS.