Thanks for the link, El Bunto. That's really interesting, especially the requirement for twice-daily service, which makes me wonder whether the reference to "a" daily return service in the press release was just some sloppy editing, or a deliberate reduction in the frequency.
I'd started off by thinking that maybe Executive Helicopters could make a cheaper bid by running a once-daily service on a marginal-cost basis, but if they were to have to source a larger helicopter principally for this contract, I just don't see how the numbers can work.