It is not uncommon for airliners to be converted for military use and the Vickers VC10 was no exception. Developed initially as a transport aircraft, it was later also used as a tanker and remains in service today in that role with the RAF ending up possessing all surplus airliners for conversions and spares. Superficially there is little difference between the airliner and military versions, the most noticeable ones being a large cargo door, different cabin configurations (for dual-role passenger/freight or full-freight use), and an APU in the tail. Likewise, the tankers are fitted with either double or triple (depending on variant) hose-and-drogue inflight-refuelling units and can also be refuelled themselves via a permanently placed probe in the nose. Although nearing the end of their service life, RAF VC10s will continue to be used until possibly replaced by the A330 MRTT.

The civilian prototype of the VC10 was first flown on 29 June 1962, two years after the RAF had issued a specificiation for a strategic transport which is was eventually to fulfill. Service deliveries of the VC10 C.1 began in 1965 and featured the improved engines of the Super VC10 airliner. These were eventually converted to tankers and redesignated VC10 C.1K reflecting their dual role. Newer versions, however, were converted directly as tankers and known as the VC10 K.2, K.3 and K.4 of which the last two remain in service today. These feature three hose-and-drogue units unlike the C.1K which had two.