An official website of the United States government
Here's how you know
A .mil website belongs to an official U.S. Department of Defense organization in the United States.
A lock (lock ) or https:// means you’ve safely connected to the .mil website. Share sensitive information only on official, secure websites.

A Look Air Force aerial tankers of the jet age

  • Published
  • By Tony R. Landis
  • Air Force Materiel Command History Office

Though the first aerial refueling tests took place in 1929 with C-2A biplane 'Question Mark', the United States Army Air Corps were slow to adopt the concept of in-flight refueling. As the jet age began, the need for longer range from America's jet-powered fighters, bombers and cargo aircraft quickly grew.

Early jet engines used vast amounts of fuel and the demand for in-flight refueling became increasingly clear. At first, the U.S. Air Force modified many of the aging B-29 and B-50 bombers into tankers as well as constructing refueling variants of the C-97 Stratofreighter in the form of the KC-97. Even with jet engine pods added to their wings, the propeller-driven aircraft could barely hold formation with the latest jets coming into service. 

Upon seeing Boeing's newest all-jet airliner design in 1954, the 367-80, which would become the very successful Boeing 707 series, the U.S. Air Force immediately saw potential for an all-jet tanker aircraft. The KC-135 Stratotanker took to the skies for the first time on August 31, 1956 and it remains in front line service to this day.

The need for longer range and greater fuel and cargo capacity gave birth to the tanker variant of the McDonnell Douglas DC-10, first flown in 1970. The U.S. Air Force KC-10 Extender offered greater global mobility than the smaller KC-135. Performing its first flight in July 1980 and its first fuel transfer in October 1980, the KC-10 continues to be a backbone for aerial tanker support and airlift around the world.

Continuing the practice of modifying airliner designs for the aerial refueling mission, the latest aircraft to fill this roll, the Boeing KC-46 Pegasus, is based around Boeing 767 airliner which first entered service with United Air Lines in 1982. Unlike other aircraft types used in Air Force service, there has never been a clean-sheet tanker design put into production.

The Air Force selected Boeing's design as the winner of the KC-X competition in February 2011 as a replacement for the aging KC-135 and KC-10 fleet.  The KC-46 first took to the air on September 25, 2015 with the first delivery to the military taking place in January 2019. Though suffering from some early setbacks, the KC-46 is now certified to refuel nearly all U.S. aircraft used by the military services. With an intended purchase of 179 Pegasus airframes, in-flight refueling remains important to the Air Force's warfighting ability as it makes global reach a reality.