The rival contenders for the huge U.S. Air Force KC-X competition for a new aerial tanker have been briefing the relative merits of the KC-30 and the KC-767 all round the show this week. But political considerations apart–and there are plenty of those–it all boils down to a simple fact: size matters.

The KC-30 that is proposed by the EADS/Northrop Grumman team can be viewed at the end of the flight line–and it’s a big bird. As Northrop Grumman CEO Dr. Ron Sugar noted Tuesday, that means “more refueling capability, more station-holds and more cargo.” Since it is based on an A330-200 commercial airliner, Sugar was also able to claim that the KC-30 is a more modern platform than the KC-767, which derives from Boeing’s 767-200.

Boeing vice president and general manager for global mobility systems Ron Marcotte wasn’t impressed by size, however. “In the final request for proposals, it became clear that the Air Force wants an agile, medium-size tanker,” he said. “It’s all about the number of booms in the sky,” he added. The KC-767 can operate out of more airfields and is air-refuelable itself, for maximum operational flexibility. 

And so the battle lines are drawn, as the countdown to an expected October decision continues. But given the troubled history of this procurement, that date could slip. Certainly, as Marcotte noted, “The customer is being very, very careful about how he proceeds.” Meanwhile, he added,  “Boeing has continued to improve its corporate governance.”  That is a reference to the earlier, tainted decision for the KC-767 that ended with jail sentences for Boeing’s defense chief and a senior government procurement official.  

There are those who doubt whether the U.S. could possibly hand such a large contract (179 aircraft in the first round alone) to an Airbus derivative. EADS cochief  Tom Enders had an answer for them: “A free marketplace provides the best technologies in the world through collaboration and cooperation. We’ll build the KC-30 in the U.S., with U.S. labor, under U.S. management.” He noted that EADS and Northrop Grumman were already engaged in significant transatlantic cooperation with Germany’s Euro-Hawk and NATO’s Air Ground Surveillance system.

The tanker in the static park is the first of four for Australia. It first flew after conversion in Spain only last Friday. EADS officials explained that Australia has chosen the designation KC-30B for its aircraft, instead of the manufacturer’s A330MRTT (for multirole tanker transport). The A330MRTT has also been chosen by the UK, Saudi Arabia and the UAE, though none of these countries has yet firmed up an order. The UK procurement is via a huge and controversial private finance initiative and will only proceed if EADS can persuade the banks to finance the assets. “We’re confident about that…it’s a solid business case,” said Enders. 

Boeing displayed a KC-767 here two years ago and had a head start with orders for four each from Italy and Japan. But development ran into aerodynamic problems with the wing-mounted refueling pods and the digital fuel-transfer system. Deliveries of KC-767s to both countries are seriously behind schedule, though Boeing said that fixes are in hand and about to be flight-tested.