Hawker Siddeley Trident

HS-121 Trident
British Airways Trident 3B
Role	Narrow-body airliner Type of aircraft
National origin	United Kingdom
Manufacturer	Hawker Siddeley
Designer	de Havilland
First flight	9 January 1962
Introduction	1 April 1964 with BEA
Retired	1995
Status	Retired
Primary users	British European Airways British Airways CAAC Airlines Cyprus Airways
Produced	1962–1978
Number built	117

The Hawker Siddeley HS-121 Trident (originally the de Havilland DH.121 and briefly the Airco DH.121) is a British airliner produced by Hawker Siddeley. In 1957, de Havilland proposed its DH.121 trijet design to a British European Airways (BEA) request. By 1960, de Havilland had been acquired by Hawker Siddeley. The Trident's maiden flight happened on 9 January 1962, and it was introduced on 1 April 1964, two months after its main competitor, the Boeing 727. By the end of the programme in 1978, 117 Tridents had been produced. The Trident was withdrawn from service in 1995.

The jetliner is powered by three rear-mounted Rolls-Royce Spey low-bypass turbofans, it has a low swept wing and a T-tail. Advanced avionics allowed it to be the first airliner to make a blind landing in revenue service in 1965. The initial Trident 1/2 could seat 101–115 passengers over up to 2,350 nmi (4,350 km). The Trident 3 was stretched by 5 m (16 ft) to seat 180 over 1,940 nmi (3,590 km; 2,230 mi), and had an additional RB.162 booster engine in the tail.