I suspect they weren’t thinking the aircraft would be available for AAR and AEW - the two roles aren’t compatible as the radar would be not emitting whilst refueling for one. AAR aircraft often fly random tracks (depending on what the receiver is coming from and going to, and where their next receivers are coming from) which again isn’t compatible with AEW as they will generally fly a more stable orbit in the location determined to give best observation and control.
Oh, I'm pretty sure they're not suggesting both roles be undertaken at the same time - but they are depending on being able to use those surge aircraft from the airtanker fleet, and that gets us into contractual issues, as Airtankers books are written around the assumption they'd be able to charter the surge fleet out and would lose that ability once Saab presumably start removing comfy seats and flat screen TVs etc and replace it with a pile of consoles,
Point being, we don't own the birds and we'd effectively have to lease them from Airtanker on a permanent basis to convert or buy the fleet out - it looks at a casual glance that it'd be an easy peasy thing as at a casual glance the tankers fly in RAF colours and it probably looks like we can do what we like with them.
However :
Voyager | RAF Live
"
Under a March 2008 agreement, the AirTanker consortium was selected to provide 14 aircraft under a 27-year contract. This includes a so-called ‘Core Fleet’ of eight military serialled and one civilian-registered aircraft, supplemented by a ‘Surge Fleet’ of five civilian-registered aircraft that AirTanker uses commercially to generate additional revenue. The surge aircraft are demodified very close to A330-200 standard and can be recalled for military use if required.
AirTanker owns, manages and maintains the aircraft and provides infrastructure,
support, training facilities and some personnel, in particular Sponsored Reserve pilots and engineers. Named Voyager in service, the A330 MRTT began RAF operations with 10 Sqn on May 12, 2012, flying an air transport sortie from its Brize Norton home base to RAF Akrotiri, Cyprus."
It's possible that Airtanker could be contracted to do the same job as they do for AAR and provide a fleet of AEW spec jets but that's a PFI contract and PFI's were killed dead in this year's budget as "not providing best value".
It's also possible that the end result could swing between roles but I'm feeling that there won't be enough spare cabs from the AEW pool to be able to shunt them around much so we might lose some of the flex capability for a refuelling fleet.
Or, we could just buy E7, and own the cabs etc.