The British Aircraft Corporation One Eleven, more commonly known as the BAC-111, was designed as a short-range jetliner intended to replace the Vickers Viscount turboprop airliner.

The original design was conceived by Hunting Aircraft during 1956 as the Hunting 107. In 1960 Hunting Aircraft, along with Vickers-Armstrong, Bristol and English Electric were merged to form the British Aircraft Corporation. BAC decided to continue design work on the Hunting 107 as a private venture. The designed matured into the BAC-111 powered by a pair of Rolls Royce Spey turbofan engines, greatly improving its fuel economy. The first variant of the BAC-111 was the 80 seat series 200.

On 9th May 1961, British United Airways (BUA) placed the launch order for ten One-Eleven 200s, followed on 23rd October by Braniff in the USA for a further four aircraft.

The prototype BAC-111 (G-ASHG) was rolled out of the assembly hall at Bournemouth/Hurn airport on 28th July 1963 and first flew on 20th August 1963. Unfortunately, she crashed on 22nd October, killing all onboard, due to a deep stall.

The type was introduced into service during 1965 and production continued in the UK until 1982. Licence production in Romania was initiated during 1982 (known as the ROMBAC 1-11) and continued until 1989. In total, 244 airframes were produced between the two production plants.

Limited military interest was shown in the design and the BAC-111 saw service with the Australian Air Force, Brazilian Air Force, Royal Air Force of Oman, Philippine Air Force and the Royal Air Force (at various experimental establishments).

The BAC-111 makes an ideal platform for the experimental testing of various military systems such as new airborne radars and has served as trials aircraft at various establishments over the years.

Five aircraft have been used. BAC-111 XX105 served at the Royal Aircraft Establishment (RAE) Bedford before being withdrawn from use at Boscombe Down; XX919 was used by RAE Farnborough before being scrapped at Boscombe Down; ZE432 is currently in use with the Empire Test Pilots School (ETPS); ZE433 is currently conducting Eurofighter radar trials at the GEC-Marconi Avionics plant at Edinburgh/Turnhouse airport in conjunction with QinetiQ and ZH763 is also conducting radar trials with QinetiQ at Boscombe Down.