The EADS/Northrop Grumman KC-45 was a proposed aerial refueling tanker aircraft based on the Airbus A330 MRTT. The United States Air Force (USAF) had ordered 179 KC-45As in the first stage of replacing the aging Boeing KC-135 Stratotanker tankers currently in service. However, the contest was reopened in July 2008, after Boeing's protest of the award was upheld. In response to the new contest, on 8 March 2010, Northrop Grumman announced it was abandoning its bid for the new contract, with its CEO stating that the revised bid requirement favoured Boeing. On 20 April 2010, EADS (now known as Airbus SE) announced it was re-entering the competition and entered a bid with the KC-45. Eventually, the USAF selected the Boeing KC-46 Pegasus.