The US Air Force has announced the award of a $3.5bn engineering and manufacturing development contract to Boeing for the KC-46A aerial refueler.

Experts from the US Department of Defence, including staff from the Defence Secretary office and independent review teams, evaluated the proposals and awarded Boeing the contract after a selection process.

Secretary of the Air Force Michael Donley said: “Selection took into account mission effectiveness in wartime and life cycle costs as embodied in fuel efficiency and military construction costs.”

First delivery of the aircraft is due in 2017, and basing decisions will be made over the coming years.