Originally Posted by
KenV
Adding a center tank on a -300 fuselage would then make no sense because the extra empty weight means you can't fill that center tank. By comparison, each time Boeing stretched the 767, it also increased the MTOW, thus increasing payload weight capacity to match the increase in payload volume.
I've no idea who does your math(s) but trying to play top-trumps with fuel/range/payload when you are holding the KC-46 card seems rather odd. Oh and the max weights for the A330 have increased significantly over the years.
In round figures, if you fill the A330-300 till every tank is full you still have well over 10 Tonnes of freight to offer in an otherwise empty and voluminous lower cargo bay, with the pax fit still installed above.
Somebody else can work out how much fuel a KC-46 can realistically carry with 10 Tonnes of freight. I do recall though that, at one point, the extra capacity offered by the MRTT was rather appealing to the USAF. The complaint from the other side was that it was unfair to consider the increased capacity and that only meeting the minimum specification should count and nothing more.
2. The Air Force’s use as a key discriminator that Northrop Grumman proposed to exceed a key performance parameter objective relating to aerial refueling to a greater degree than Boeing violated the solicitation’s evaluation provision that “no consideration will be provided for exceeding [key performance parameter] objectives.”