Of course you could take the world's premier MPA - the Nimrod MR2 - and re-engine it - say with RR BR700 type engines. You could give it a 14 hr unrefuelled endurance as well as increasing, exponentially, the amount of information that could be processed. It could be capable of monitoring 64 sonobuoys as well as carrying the full arsenal of weapons. And, of course, it could be crewed by highly professional, determined and motivated individuals.
Or not.
Duncs
