The tanker will be ready for Preliminary Design Review in March, Boeing said.
"I'm very proud of our joint team," said Maureen Dougherty, Boeing KC-46 Tanker vice president and program manager. "We're drawing on the best of Boeing's industry-leading commercial airplane and defense expertise as we design and develop the KC-46A, which is a next-generation derivative aircraft.
"We remain on plan to deliver the first 18 combat-ready tankers by 2017."
Milestones achieved in the 12 months since the contract was awarded to Boeing include a System Requirements Review, Integrated Baseline Review, 767-2C PDR and Firm Configuration Reviews for the 767-2C and the KC-46A Tanker.
The PDR will ensure that Boeing's design meets system requirements. Boeing said the Critical Design Review scheduled for in the third quarter of 2013 will evaluate the maturity of the aircraft design before manufacturing begins.
Based on Boeing's 767 commercial plane, the KC-46A will replace aging KC-135 tankers operated by the Air Force.