The Trident was originally conceived by de Havilland in the late 1950s as the DH 121 in response to British European Airways (BEA)'s request for a new short to medium haul haul jet airliner, in competition with the Vickers VC-11.  The DH 121 was the winning proposal and development of the aircraft began.  At the time, speed was one of the most important considerations in airliner design so the aircraft was designed with a low drag wing, with the engine mounted at the rear of the aircraft so the wing was kept as clean as possible.  de Havilland became part of the Hawker Siddeley (HSA) group in the government forced mergers in the industry in 1960.  The original DH 121 was a reasonably large aircraft with a high passenger capacity but due to a downturn in the air travel market, BEA requested that the aircraft's dimensions be reduced.  As a result the aircraft now seated far fewer people and was to be powered by three Rolls Royce Spey engines as opposed to the planned Medways.

The DH 121

The first Trident 1C aircraft entered service with BEA in 1964, having first flown in 1962.  The aircraft performed well and was reliable, but BEA soon realised that they had made a mistake with the specification and that they indeed required a larger aircraft.  Hawker Siddeley responded first with the 1E variant, primarily for the export market and the 2E for BEA, featuring uprated engines, larger wing span, improved high lift devices (slats) and greater capacity and range.  Whilst export orders for the aircraft were limited, China purchased a Trident from Pakistan International Airways (PIA) and as a result placed an order with HSA for more.

Trident 1E, image courtesy Neil Lomax Collection

Meanwhile, BEA again required a larger aircraft.  Several options were explored including the purchase of the Boeing 727 (a design inspired by the Trident, to go on to sell over 1800 examples) but the government was insistent they should "buy British".  HSA came up with two proposals, the HS.132 and HS.134, based on the Trident airframe, but with larger capacity and other improvements.  The HS.134 concept bares remarkable similarity to today's Boeing 757, but in the end, for reasons of cost, it was decided to build another uprated version of the Trident.  The new model, the 3B, was the first to feature a stretched fuselage, which could carry up to 180 people.  The same engines were supplemented by a Rolls Royce RB162 "boost" engine on the 3B to increase the total thrust on take off.

A Trident 3B of BEA which became British Airways in 1974.  Neil Lomax Collection

The Trident always had a weak point in this area and was nicknamed the "gripper" by pilots for the difficulty with which it took to the air.  The low drag wing also produced limited lift at low speed with the consequence that although once airborne it was one of the fastest subsonic airliners, it required high lift devices - and care when handling - at low speeds.  A total of 117 aircraft were built with the last being in 1978 for CAAC.  Tridents served with BEA until its successor, British Airways, began retiring the oldest aircraft in 1976 with the final 3Bs retiring in 1985.  Most were scrapped, some were used for fire crew training at airports around the UK and later broken up with only 3 complete aircraft now preserved.

Tridents being broken up at Heathrow, probably around 1984

A few aircraft have been preserved, both in the  UK and in China and a number of others have been used for various training duties, mainly for airport fire services and many these have now been broken up.Elsewhere, four ex-BA aircraft were sold to a company in Zaire but these were all scrapped by 1989.  The Chinese aircraft tended to leave service with their national airline to join their air force.  It is believed that they may have flown until 1997.

The Tridents were assembled at the de Havilland site at Hatfield in Hertfordshire, England, a part of Hawker Siddeley Aviation from 1960. It then became part of the nationalised British Aerospace in 1978.  After the end of production of Tridents at Hatfield, assembly work continued with the new BAe 146 and the design and manufacture of wings for the Airbus A310 and A310. Design and development work for the Airbus A330/340 and BAe 125 continued as did development of the 146.

As a result the economic troubles of the early 1990s, Hatfield was closed in 1993, with Airbus wing work being transferred to Filton and Chester, BAe Corporate Jets (the 125 family) being sold to Raytheon in the United States and the 146 continuing production as the Avro RJ in Woodford, Manchester.  The Hatfield site was redeveloped and now comprises a business park, University campus and housing.

Hatfield Aerodrome, 1988.  Photo: T. Vickers Collection