The Boeing 767-based NewGen Tanker is pictured in this undated photo illustration, obtained on February 24, 2011.[Agencies]

WASHINGTON - Capping a decade of delays and embarrassing missteps, the US Air Force on Thursday awarded to Boeing Co. one of the biggest defense contracts ever, a $35 billion deal to build nearly 200 giant airborne refueling tankers. The decision was a major blow to Europe's aviation giant EADS, the European Aeronautic Defence and Space Co.

The contract will mean tens of thousands of jobs for a recession-weary United States, with huge numbers going specifically to Washington state on the West Coast and Kansas in the US heartland. getting the bulk of the work building a replacement for the 1950s-era tanker fleet. The decision was a blow to the Gulf Coast and Alabama, which had been counting on EADS to assemble the aircraft at a long-shuttered military base in Mobile

Air Force Secretary Michael Donley said the contract "represents a long overdue start to a much-needed program" as somewhat relieved Pentagon officials announced the decision, a clear surprise as defense analysts, lawmakers and even company executives had expected EADS to prevail.

"What we can tell you was that Boeing was a clear winner," said Deputy Defense Secretary William Lynn.

Replacing the KC-135 planes, the equivalent of a flying gasoline station, is crucial for the US military. Pilots who were not even born when the last aircraft was delivered in 1965 are operating air tankers that the Pentagon is struggling to keep in flying shape.

The refueling tankers allow jet fighters, supply planes and other aircraft to cover long distances, critical with fewer overseas bases and operations far from the United States in places like Iraq and Afghanistan.

Pentagon leaders said both bidders met all 372 mandatory requirements for the contract. They said because the difference in price between the two bids was greater than 1 percent of the total, the cost was essentially the deciding factor and other non-mandatory requirements were not used to make the decision.

The award gives Boeing the initial $3.5 billion for engineering, manufacturing and development of the first four aircraft. Under the contract, 18 tankers will be delivered to the Air Force by 2017.

Lawmakers who lobbied for Boeing to win the contract were gleeful.

"I'm in the middle of a blizzard, but it's all blue skies," said Republican Sen. Pat Roberts of Kansas.

Said Deocratic Rep. Norm Dicks of Washington: "This is the happiest day of my professional life." He called the win decisive.

Lawmakers from Alabama were bitter in defeat and suggested politics played a role.

"I'm disappointed but not surprised," said Republican Sen. Richard Shelby. "Only Chicago politics could tip the scales in favor of Boeing's inferior plane. EADS clearly offers the more capable aircraft."

Not only does President Barack Obama call Chicago home, but his new chief of staff, William M. Daley, resigned in January from the Boeing board of directors where he had served since 2006. The White House had said Daley would have no role in the Air Force decision.

Republican Rep. Jo Bonner vowed to get a full accounting of why the EADS bid was rejected.

"This competition has been challenged before, and it's not unlikely it will be challenged again," he said. "It will ultimately be up to EADS to determine whether they will protest this decision, and I will fully support whatever decision they make."

Lynn said that while the losing bidder has a right to appeal the decision, he believes that the process was clear, transparent and fair enough that there will be no grounds for a protest.

The $35 billion contract calls for producing 179 tankers. Boeing would base the tanker on its model 767 aircraft.

The amount could end up being a first installment on a $100 billion deal if the Air Force should decide to buy more aircraft.

Through the years, the Air Force's efforts to award the contract have been undone by Pentagon bungling and the criminal conviction of a top Defense Department official.

Initially, the Air Force planned to lease and buy Boeing planes to serve as tankers, but that fell through. The Air Force later awarded a contract to Northrop and EADS, but in 2008 the Government Accountability Office upheld Boeing's protest of the contract.

The GAO said it found "a number of significant errors" in the Air Force's decision, including its failure to judge fairly the relative merits of each proposal.

The Air Force reopened the bidding in 2010 only to be embarrassed again as it mistakenly gave Boeing and EADS sensitive information that contained each other's confidential bids.

Production will occur in Everett, Washington, Wichita, Kansas, and dozens of other states where hundreds of jobs will be created. Boeing has said that the contract will mean some 50,000 jobs.

Boeing workers leaving the Everett plant after shift change Thursday afternoon greeted the news with blaring car horns.

"We are absolutely delighted, obviously," said Bill Dugovitch, spokesman for the Society of Professional Engineering Employees in Aerospace, the union representing Boeing's engineers and technical workers. "Our work force is ready to go to produce the world's best tankers."

State political leaders quickly weighed in.

"This decision is a major victory for the American workers, the American aerospace industry and America's military. And it is consistent with the president's own call to 'out-innovate' and 'out-build' the rest of the world," said Democratic Sen. Patty Murray.

Boeing has highlighted its offering as an "American-made" tanker, in contrast to the European roots of its competitor. Both companies had planned to make their tanker in the United States.

EADS has 11 of its tankers in production and 28 more on order for countries including Australia and the United Kingdom. Boeing built a handful of its tankers based on its 767 passenger jet for Japan and Italy.

The two companies have tussled over whether they receive unfair subsidies from the governments in their home countries. Last month, the European Union said the World Trade Organization found US aid to Boeing Co. violated international rules. The EU has claimed that Boeing received almost $24 billion in illegal subsidies, such as research grants and free use of technology from NASA, the Defense Department, and the states of Illinois, Kansas and Washington.

Associated Press writers George Tibbits in Seattle, Washington, Bob Johnson in Mobile, Alabama, Josh Freed in Minneapolis, Minnesota and Chris Rugaber and Ben Evans in Washington contributed to this report.