Biggus
I don't know what the exact figures are for RJ, but comparing it to "Dragmaster 9000" E-3D (with a 7T RADAR in the breeze) the RJ should fly for at least 12-14 hours unrefuelled if the internal fuel loads are the same. So for "UK only", where there are no friendly (NATO E-3 component, US, Dutch, Turkish or Israeli) boom tankers about, then that is still a worthwhile capability - worst case estimate on flight time would give, I would imagine, ~1,800nm radius with a 2 hour collect before ~1,800nm return. In my opinion that's pretty damn good.
You're right, in a perfect world we should have a probe - but the world isn't perfect...Hence we have
no AAR on Sentinel, Shadow, Puma and Reaper
plus no UK means to A-A refuel Chinook, Merlin and now RJ. As an aside, does the UK have anything that can refuel our C-130s either?
LJ