KC-135E Tanker Model
The Boeing KC-135 Stratotanker is a United States aerial refueling tanker aircraft. It has been in service with the United States Air Force since 1957. Besides its primary role as an inflight aircraft refueler the KC-135 designated NKC-135 has assisted in several research projects at the NASA Dryden Flight Research Center at Edwards Air Force Base California. One such project occurred between 1979 and 1980 when special wingtip "winglets" developed by Richard Whitcomb of the Langley Research Center were tested at Dryden using an NKC-135A tanker loaned to NASA by the Air Force. Winglets are small nearly vertical fins installed on an aircraft s wing tips. The results of the research showed that drag was reduced and range could be increased by as much as 7 percent at cruise speeds. Winglets are now being incorporated into most new commercial and military transport jets as well as business aviation jets. NASA also has operated several KC-135 aircraft (without the tanker equipment installed) as their infamous Vomit Comet zero-gravity simulator aircraft. The longest-serving (1973 to 1995) version was KC-135A 59-1481 named Weightless Wonder IV registered N930NA.