Hawker Siddeley Trident

Hawker Siddeley Trident
clipperarctic · CC BY-SA 2.0 · source
Name	Trident
Caption	Trident 1E in British European Airways livery
Type	Airliner
Manufacturer	Hawker Siddeley
First flight	9 January 1962
Introduced	1964
Retired	1995 (civil)
Primary users	British European Airways; British Airways; Civil Aviation Administration of China
Produced	1962–1978
Number built	117

Hawker Siddeley Trident was a British three-engined narrow-body jet airliner developed and produced by Hawker Siddeley Aviation in the 1960s. Conceived to meet a specification from British European Airways and influenced by requirements from the British government, the type became noted for its advanced automated systems, distinctive T-tail and three-engine rear fuselage arrangement and for service with airlines and military operators. The Trident's development and operational life intersected with manufacturers, regulators and airlines including De Havilland, Vickers-Armstrongs, Rolls-Royce, Civil Aviation Authority, and state carriers such as Air France and Aer Lingus.

Development and Design

Initial work derived from a BEA requirement in the late 1950s, connecting the project with design bureaux at Aston University and engineering facilities formerly of Handley Page and English Electric. The design team at Hawker Siddeley incorporated lessons from contemporary types like the Boeing 727, Douglas DC-9, BAC One-Eleven and drew on turbine expertise from Rolls-Royce Limited powerplants and auxiliary systems developed with Marconi Company and Smiths Industries. Political decisions by the Macmillan ministry and procurement choices influenced specification changes that resulted in a production airframe optimized for BEA's short-stage European network and later stretched to compete with the Boeing 737 family.

The programme moved through iterations, reflecting input from British European Airways executives and standards set by the International Civil Aviation Organization and the Civil Aviation Authority. The Trident featured pioneering flightdeck automation developed with partners including Automatic Telephone & Electric Company and avionics suppliers such as Ferranti and Bosch; these systems aimed to reduce crew workload on approaches to constrained airports like London Heathrow and Gatwick Airport.

Technical Description

Structurally, the airframe used a conventional monoplane configuration with a low-mounted wing and a T-tail, adopting materials and methods common to contemporaries like Vickers Vanguard and De Havilland Comet. Propulsion for early marks was provided by rear-fuselage-mounted turbofan engines from Rolls-Royce Spey family, with later variants receiving uprated Spey or alternative turbofans developed alongside suppliers such as Snecma and General Electric in comparative studies. The Trident's trijet arrangement paralleled layouts on the Boeing 727 and allowed redundancy for performance over routes to destinations including Malta and Athens.

Avionics architecture integrated automatic descent control and autoland capability, using systems derived from trials with British European Airways and certification processes administered by the Air Registration Board. Landing performance and systems were tailored for operations into airfields like Kai Tak and Gatwick Airport, with high-lift devices, spoilers and robust hydraulic systems supplied by contractors such as Messier-Bugatti and Dowty. The cabin accommodated typical two-class layouts influenced by airline standards set by carriers such as Pan American World Airways and Trans World Airlines.

Operational History

Entry into service with British European Airways in the mid-1960s coincided with expansion in European short-haul networks and competition with types operated by British Overseas Airways Corporation and other flag carriers. The Trident served scheduled routes across Europe, the Middle East and parts of Asia, operating from hubs including Heathrow Airport, Gatwick Airport and Manchester Airport. Operators included British Airways (post-merger), Cathay Pacific affiliates in early licensing talks, and regional carriers such as Eastern Provincial Airways and China Civil Aviation Administration.

Commercial experience saw the Trident praised for approach automation but constrained by BEA-driven initial size and range choices, which later affected export competitiveness against the Boeing 737 and McDonnell Douglas DC-9 families. Fleet renewals and corporate restructurings involving British Airways, Caledonian Airways and leasing companies influenced retirements through the 1980s and 1990s.

Variants

- Trident 1C/1E: Original BEA-focused models, with aerodynamic and seating modifications inspired by British European Airways operational needs and upgraded avionics from Ferranti. - Trident 2E: Stretched fuselage and boosted range, incorporating higher-thrust engines from Rolls-Royce and wing modifications akin to those studied with Vickers. - Trident 3B/3R: Long-range versions with re-engined options and increased payload, developed amid comparisons with the Boeing 727-200 and Douglas DC-8 stretch studies; systems upgrades included new flight management components from Smiths Industries.

Developmental prototypes and test airframes were utilized by research establishments such as Royal Aircraft Establishment and avionics firms including Marconi, informing civil certification and export negotiations with carriers like Air France and Aer Lingus.

Military and Special Roles

Beyond civil service, airframes were adapted for airborne testbeds, calibration duties and VIP transport for agencies including the Royal Air Force and civilian ministries. Modified Tridents performed roles analogous to conversions of Vickers VC10 and offered platforms for avionics evaluation by contractors such as Ferranti and BAE Systems research units. Special missions included navigation aid calibration and diplomatic transport for delegations to events such as summits involving NATO and state visits to Washington, D.C..

Accidents and Incidents

Throughout its operational history the type was involved in several notable accidents and incidents investigated by authorities like the Accident Investigation Branch and the Air Accidents Investigation Branch. High-profile occurrences prompted reviews of approach procedures at airports such as Kai Tak and Heathrow Airport and led to procedural revisions coordinated with agencies including the Civil Aviation Authority and manufacturers like Hawker Siddeley and Rolls-Royce. Lessons informed international standards administered by International Civil Aviation Organization.

Preservation and Legacy

A number of Tridents have been preserved in museums and at historic aircraft collections including exhibits in the United Kingdom, China and continental Europe, curated by organizations such as the Royal Air Force Museum and volunteer groups similar to those supporting de Havilland Comet restorations. The Trident's influence is seen in subsequent British airliner projects and in avionics developments that fed into programmes by British Aerospace and BAE Systems. Its pioneering autoland and systems integration work influenced modern air transport developments overseen by regulators such as the Civil Aviation Authority and international bodies including ICAO.

Category:British civil aircraft