[El Diablo]

iron,

Your post is incorrect. The Prime Minister, like the royal family, uses a mix of Royal Squadron planes, chartered planes, and commercial travel. I suspect that since some budgetary controversies regarding use of the royal planes, the PM has perhaps flown commercial more often when going on holiday. But, in general, your Head of State/Head of Government distinction is just plain false when it comes to stuff like travel on special government planes.