The Boeing KC-135 Stratotanker is an aerial refueling tanker aircraft. It has been in service with the U.S. Air Force since 1957.*****************The KC-135 is derived from the original Boeing jet transport "proof of concept" demonstrator, the Boeing 367-80 (commonly called the "Dash-80"). As such, it has a narrower fuselage and is shorter than the Boeing 707 jetliner. Developed in the late-1950s this basic airframe is characterized by swept wings and tail, four under wing mounted engine pods, a horizontal stabilizer mounted on the fuselage near the bottom of the vertical stabilizer with positive dihedral on the two horizontal planes and a hi-frequency radio antenna which protrudes forward from the top of the vertical fin or stabilizer. These basic features make it strongly resemble the commercial Boeing 707 and 720 aircraft although, it is actually a different aircraft. The Strategic Air Command had the KC-135 Stratotankers in service from 1957 through 1991 and with the Air National Guard and Air Force Reserve from 1975 through 1991, when they were re-assigned to the Air Mobility Command. Reconnaissance and command post variants, including Boeing EC-135 Looking Glass, Post Attack Command & Control Systems were operated by SAC from 1963 through 1991, when they were re-assigned to the Air Combat Command. Boeing's 367-80 was the basic design for the commercial Boeing 707 passenger aircraft as well as the KC-135A Stratotanker. In 1954 the USAF's Strategic Air Command ordered the first 29 of its future fleet of 732. The first aircraft flew in August 1956 and the initial production Stratotanker was delivered to Castle Air Force Base, California, in June 1957. The last KC-135 was delivered to the Air Force in 1965.********************Four turbofans, mounted under 35-degree swept wings, power the KC-135 to takeoffs at gross weights up to 322,500 pounds (146,300 kg). Nearly all internal fuel can be pumped through the tanker's flying boom, the KC-135's primary fuel transfer method. A special shuttlecock-shaped drogue, attached to and trailing behind the flying boom, may be used to refuel aircraft fitted with probes. A boom operator stationed in the rear of the aircraft controls the boom while lying on his or her stomach. A cargo deck above the refueling system can hold a mixed load of passengers and cargo. Depending on fuel storage configuration, the KC-135 can carry up to 83,000 pounds (37,600 kg) of cargo. In Southeast Asia, KC-135 Stratotankers made the air war different from all previous aerial conflicts. Midair refueling brought far-flung bombing targets within reach. Combat aircraft, no longer limited by fuel supplies, were able to spend more time in target areas. Air Mobility Command (AMC) manages more than 546 total aircraft inventory Stratotankers, of which the Air Force Reserve and Air National Guard fly 292 in support of AMC's mission.