Boeing C-135 Stratolifter

      The KC-135 is the most widely flown tanker aircraft in history.  It's principal mission is air refueling.  The KC-135 was originally purchased for the Strategic Air Command to refuel it's bombers in-flight, thus extending their range and flying time.  The huge bombers consumed a lot of fuel and its was transferred to them from the tanker through a huge four-inch diameter flying boom.  During the Vietnam War, KC-135 Stratotankers permitted B-52s to strike distant targets. 
     As the Cold War wound down, the planes were adapted to other aerial refueling missions.  Special drogue type refueling equipment was installed that permitted refueling several smaller planes, such as fighters, at one time.  This has helped the Air Force to accomplish its primary missions of Global Reach and Global Power.  This was well demonstrated during the Persian Gulf War.  With the help of aerial refueling, entire wings of relatively short-range fighters were able to fly directly from the United States to overseas bases.  A wing of B-52s flew from California to Iran, bombed Baghdad, then flew back home.  Combat aircraft, no longer limited by fuel supplies, were able to spend more time in target areas.   Today, the KC-135 Stratotankers provide aerial refueling support to Air Force, Navy and Marine Corps aircraft as well as the aircraft of allied nations.
      It all began with the Boeing Company's model 367-80, which was the basic design for the commercial 707 passenger plane as well as the 135 series.  The Air Force wanted it as an airborne tanker and in 1954 purchased its first 29 KC-135.  The first aircraft flew in August 1956 and the first planes were delivered to Castle Air Force Base, Calif., in June 1957. 
     749 tanker were built.  The last was delivered in 1965.  Boeing also built 88 similar aircraft for other Air Force uses.  The pure transports were designated C-135 stratofreighters,  but others were used for flying command posts, electronic reconnaissance and photo mapping. The last of these special-purpose aircraft was delivered in late 1966.  More than 600 of all types of C-135s / KC-135s are still flying. 
See the display models for KC-135 tanker and the
RC-135 "Looking Glass" and RC-135 Command Aircraft