Boeing has decided to put the US Air Force on trial for the surprise decision to opt for an Airbus aircraft for a $12.1 billion tanker deal, legally challenging the KC-X contract award to the rival Northrop Grumman/EADS North America team.

The airframer's formal protest filed on 11 March argues the USAF's decision should be overturned mainly because of two reasons: a series of improper changes made to a key evaluation formula and a judging system that unfairly discounted the relevance of Boeing's past performance on commercial aircraft.

The first complaint alleges that the USAF inserted last-minute changes into a highly detailed formula used to evaluate mission performance for both teams, but failed to notify the two bidders.

Boeing believes this action put its bid at a disadvantage. A separate Northrop business unit helped the USAF develop the evaluation formula, which was likely to allow Northrop's tanker team to spot - and respond - to the changes much sooner, says Mark McGraw, Boeing's KC-767 programme manager.

 Boeing's KC-767

Boeing also complains that the same last-minute changes to the formula gave an unfair competitive advantage to the Northrop team. Northrop's larger KC-30 tanker bid suffered under the previous formula for lacking ramp space to complete certain missions.

Northrop's KC-30

The changes resolved that problem by inventing ramp capacity that does not exist in the real world, arbitrarily giving the Northrop team a boost, McGraw says.

Secondly, Boeing claims that the USAF refused to give proper credit to the company's experience making commercial airliners.

The USAF's method for evaluating programme risk discounted Boeing's experience based on commercial airliner programmes, such as the 777-200LR and the 737-900ER, McGraw says.


Moreover, Boeing is incredulous that USAF officials credited the larger size of Northrop's tanker as a key reason for rejecting the KC-767.

Boeing's tanker exceeded the USAF's fuel offload requirement by 20%, and USAF officials told Boeing that its bid could not be improved by increasing that figure, McGraw says. The USAF never stated or supported a preference during the competition for a larger aircraft, he adds, noting Boeing would have likely considered offering a 777-based platform instead.

USAF declines to comment on any of Boeing's claims, but vows to defend its source selection decision during the protest review by the US Government Accountability Office (GAO).

Boeing's protest filing at the GAO launches a 100-day review period by the agency's auditors, who are charged with determining whether the USAF committed any procedural errors in the acquisition process. As the GAO review proceeds, a separate influential debate among US lawmakers is already under way.

Meanwhile, scrutiny of Northrop's claims also is starting to grow. For example, Northrop defended its KC-X bid in a recent press release as a low-risk solution, citing Airbus's plan to deliver tankers to the Royal Australian Air Force "on schedule" in early 2009.

A spokeswoman for Australia's Department of Defense, however, points out that the early 2009 date is actually several months behind the original schedule. She also notes that the tanker modifications to the KC-30B airframe are "extensive" and even the delayed delivery in early 2009 carries risk.

An EADS spokesman counters, however, that Airbus was not at fault for the delays, which was "requested by the customer because of some changes they implemented".