Kansas leaders are speaking out about the Pentagon's decision to award a multi-billion deal to an overseas company.

The Defense Department announced Friday that it chose Los Angeles-based Northrop Grumman and its partner, Airbus of France, over Boeing for a $40 billion contract to build refueling tanker aircraft for the US Air Force.

Defense officials say Northrop's ability to make bigger planes factored into the decision. One Air Force general explained that bigger aircraft mean "more passengers, more cargo, more fuel to offload."

Boeing's Wichita facility would have served as a finishing location for the planes before delivery to the military. Workers there say the decision is a blow, one saying it would have meant more security for the plant.

Boeing had been supplying refueling tankers to the Air Force for nearly 50 years and was expected to win the contract. A few dozen Boeing workers have fashioned signs and marched in Washington state. The company itself also has the option to protest the decision in a more official capacity. Defense officials say they plan to offer a more detailed explanation to Boeing on its decision by March 12th, and company officials say they'll wait until then to decide whether to appeal.

Kansas Senators Pat Roberts and Sam Brownback both say they're disappointed in the Air Force's decision and will insist on seeing justification for it.

“I'll be calling upon the Secretary of Defense for a full debriefing and expect there will be a protest of the award by Boeing," Brownback said in a statement. "I also expect Congress will take a very long look at the selection process and criteria. I hope the decision will be reversed."

While Defense officials say their decision is in the best interests of taxpayers, Kansas Gov. Kathleen Sebelius was doubtful in a statement she released expressing disappointment with the decision.

"We are incredibly disappointed and surprised Boeing was not selected to fulfill this important contract," Sebelius said. "Because it is more fuel efficient, selecting Boeing's model would have saved American taxpayers an estimated $10 billion in fuel costs."

This is the first of three awards worth up to $100 billion over 30 years to replace the entire Air Force fleet of nearly 600 tankers.