In the early 1950's the US Air Force needed a new high-speed jet transport that was capable of providing mid-air refueling for the new high speed jet bombers coming into service. The C/KC-135 design was chosen and has now served in the United States Air Force for almost 60 years making it among the longest serving "front-line" aircraft in history. The new Minicraft KC-135R represents the KC-135 as the airplane appears today. Extensive modifications have been made to extend the service life of the KC-135.