As a result of the KC-46A debacle - particularly the Rear Vision System that will take 3 > 5 years to fix - the procurement rate has been slowed down.
It is also unlikely in my opinion that the full quantity originally envisaged under what was the KC-X and KC-Y recapitalization programs will be proceeded with. The money is needed for other priorities (plenty of references out there).
US TRANSCOM / USAF AMC is currently looking at multiple options for contracting out a significant part of the overall requirement - any would take 5 to 7 years to materialize.
Airbus is a potential bidder with the A330-MRTT (the irony !) but the production line is spoken for over the next 4 years - including the NATO MRTT Fleet orders..
30% of the US TRANSCOM requirement is for "hose and drogue" - ideally from dual method tankers. Currently all the KC-10s are and some KC-135Rs are (such as those on 100 ARW at RAF Mildenhall and those used to refuel SOC assets).
The US TRANSCOM requirement is in addition to the small USN contract that Omega has for "probe and drogue" only.
Omega is not capable of meeting the latest increased USN requirement on its own - even with the additional assets it is getting eg ex-RNethAF KDC-10s (which are not KC-10s) and an additional old B707 it is converting.
Therefore, it looks like there may be a medium term market for any retired already converted tanker - however expensive it might be to get airworthy and operate - given the huge difference between what it would cost to get a Tristar or VC-10 back up and running compared to a new A330-MRTT at $300M a copy (which can't be produced anyway for another 4 years).
One of the options being looked at by US TRANSCOM does include transferring KC-135Rs to contractors to get the overhead costs and maintenance liability off the USAF books. Many of the KC-135Rs have had significant upgrades including glass cockpits fairly recently.
In any contract, contractors would get paid "by the minute" on AAR task so there are a lot of calculations that go into what is viable - with a big driving factor being the transferable fuel load of one type compared to another - which in turn affects the number of take-off / landing cycles - which in turn affects fatigue and maintenance cost considerations.
I was personally shocked to discover that the off-load capacity of a KC-46A is not a huge amount more than a KC-135R given the comparative sizes - only 10% more.
Report to US Congressional Committees here:
http://lignesdedefense.blogs.ouest-f...h%2Bsig%29.pdf