KC-X

KC-X was the United States Air Force (USAF) program to procure its next-generation aerial refueling tanker aircraft to replace some of their older Boeing KC-135 Stratotankers. The contest was for a production contract for 179 new tankers with estimated value of US$35 billion. The two contenders to replace the KC-135 aircraft were Boeing and EADS, following the elimination of US Aerospace, Inc. from the bidding process.

The KC-X program followed earlier attempts by the USAF to procure a new tanker. A 2002 plan had the USAF leasing Boeing KC-767 tankers, followed by a 2003 modification where the USAF would buy most of the KC-767 aircraft and lease several more of them. Corruption investigations revealed wrongdoing in the award of the contract and the contract was canceled in 2005, setting the stage for the KC-X program.

The USAF issued the KC-X request for proposal in January 2007, then selected the Northrop Grumman/EADS team and their Airbus A330 MRTT-based tankers in February 2008. In June 2008, the U.S. Government Accountability Office sustained a protest by Boeing on the award of the contract. In July 2008, the U.S. Defense Department reopened the bidding process, but canceled the KC-X solicitation in September 2008. In September 2009, the USAF began the first steps toward accepting new bids. In March 2010, Northrop Grumman announced that it would pull out of the bidding process. Despite Northrop Grumman's withdrawal, EADS decided to remain in the ongoing competition alone. The Air Force selected Boeing's KC-46 bid on 24 February 2011.