Over a decade since the original KC-X Tanker Modernization requirement to replace the aging U.S Air Force (USAF) fleet of KC-135 Stratotankers was first identified, it appears that a contract will finally be awarded that may stand up to the protests and legal scrutiny that have dogged the program.

In September 2009, the Department of Defense (DoD) formally announced the resumption of the KC-X procurement, with bids from Northrop Grumman/EADS and Boeing scheduled to be submitted in spring 2010. $864 million has been allocated in the FY2011 budget for initial procurement, with a planned buy of 179 aircraft costing approximately $35 to $40 billion.

Two industry teams are submitting three different aircraft for consideration by DoD, with a split buy from both teams possible. The proposed Northrop Grumman/EADS KC-45 is based on the Airbus A330 airliner, and would be assembled in Alabama. Boeing, with production facilities in Washington State, has submitted a pair of designs, based on their 767 and 777 jets, which they are characterizing as “medium” and “large” solutions respectively to the USAF requirement. The critical selection criteria, as best can be determined, are shown below:

Aircraft                                                KC-135R                KC-45                KC-767              KC-777

Fuel Offload@ 1,000 nm

(7,000′ runway)                                 79,000 lbs.           115,000 lbs.      97,000 lbs.         141,000 lbs.

Max Fuel Offload@ 1,000 nm

(>10,000′ runway)                            119,000 lbs.          153,000 lbs.     117,000 lbs.        199,000 lbs.

Max Passengers                                    37                            226                     190                       320

Max Patient Litters                               18                            108                      97                         156

Max 463L Cargo Pallets                       6                              32                        19                         38

The KC-45 is an evolution of the KC-30/330 Multi Role Tanker Transport (MRTT) being procured by Great Britain, Australia, Saudi Arabia, and the UAE. Fitted with a proprietary “flying boom” design and three probe and drogue refueling pods, the KC-45 will also have a universal refueling receptacle so that it can itself be refueled in flight. In addition, the KC-45 will be equipped with a large side cargo hatch, along with fuselage floors able to handle a variety of configurations. These can include passenger seats, patient litters, and cargo pallets, so that a KC-45 can not only refuel other aircraft, but also support unit deployments overseas. While much of the KC-45 would be composed of components procured from overseas, final assembly and installation of the mission packages would be done at a new plant in Alabama.

Boeing by comparison, is offering two different tanker configurations for consideration by DoD, based on their commercial 767-200 and 777 wide body airliners. The KC-767 has already been procured by Italy and Japan, and the USAF version would be equipped with a similar mission package as the KC-45. This would include Boeing’s famous “flying boom” refueling system, along with three probe and drogue refueling pods and a receiving receptacle for in-flight refueling. While smaller, and with less cargo/fuel capacity than the KC-45, the KC-767 meets all the minimum USAF requirements stated in the KC-X Request for Proposal (RFP). Nevertheless, Boeing has decided to offer the USAF something larger than the KC-45, just in case the Air Force decides that bigger is better. The proposed KC-777 would be the highest capacity tanker/transport in the world, should DoD decide to procure it. With the same basic mission package as the KC-45 and KC-767, the KC-777 would have roughly a third more “giveaway” gas than the proposed Northrop Grumman/EADS entry, while taking up about the same ramp space.

So, which proposed design will win the KC-X competition later in 2010? Frankly, there are a number of possible outcomes based upon a variety of factors, from national and international politics to how much space individual aircraft might occupy on the ramp. DoD has indicated that a split buy between the two contractor teams might be possible, but given the current budget climate in Congress this is an unlikely outcome. There is already a small war brewing between the Congressional delegations of Washington state and Alabama, where the aircraft would be assembled, which has included Senate holds on Obama administration appointments. Overseas, the Europeans are making the point that they are entitled to a fair chance at winning, while “buy American” fever is running high in the United States over the jobs involved.

From a purely technical point-of-view, the KC-45 sits between the KC-767 and KC-777 in terms of size, capacity, and likely cost per unit. In historical terms, the cargo/passenger/litter capacity of tankers has rarely been used, although the likely termination of C-17 production in the next few years may change the way Air Mobility Command uses the tanker/transport airframes. Most likely, the final award decision will come down to a question of ability to pass a maximum of airborne fuel to as many aircraft as possible, and the old maxim of cost. Then let the protests and legal challenges begin.