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| Hawker Siddeley HS 125 | |
|---|---|
| Name | Hawker Siddeley HS 125 |
| Caption | HS 125 in service |
| Role | Business jet / transport |
| Manufacturer | Hawker Siddeley |
| First flight | 1962 |
| Introduced | 1964 |
| Status | Retired/operational in limited numbers |
Hawker Siddeley HS 125 is a mid-size twinjet corporate and utility transport originally developed in the United Kingdom during the early 1960s. Designed and produced by Hawker Siddeley, later built by BAe Systems subsidiaries and British Aerospace, the type served in civil, government and military roles across Europe, North America, Asia and Africa. The airframe influenced business aviation markets alongside contemporaries from Cessna, Learjet Corporation, Gulfstream Aerospace, and Dassault Aviation.
The HS 125 program began when de Havilland designers collaborated with engineers from Gloster Aircraft and English Electric under the Hawker Siddeley group to produce a pressurized twinjet business aircraft to compete with models from North American Aviation and Lockheed Corporation. Early prototypes incorporated aerodynamic lessons from the English Electric Lightning and employed systems developed for Avro Vulcan. The first prototype's maiden flight in 1962 followed certification activities involving Civil Aviation Authority (United Kingdom) inspectors and test pilots with experience at Royal Aircraft Establishment facilities.
Design features included a low-mounted wing influenced by research at Cranfield University and a fuselage cross-section comparable to corporate interiors used by Rolls-Royce Holdings executives. Powerplant selection evolved through collaborations with Rolls-Royce and later with Honeywell Aerospace and Pratt & Whitney Canada as pressure for improved range and efficiency increased. Avionics suites were upgraded over production runs with components supplied by Collins Aerospace, Marconi Electronics, and later integrated flight decks from Rockwell Collins.
Civil service entry began with corporate operators in United Kingdom and expanded to airlines and charter companies in United States, Canada, Australia, and South Africa. The HS 125 served fringe roles such as air ambulance conversions for operators like Air Atlantique and as radar calibration platforms used by organizations including Royal Air Force squadrons and national civil aviation authorities. Long-term operators included executive flight departments for firms such as BP, Shell plc, General Electric, and multinational banks headquartered in London and New York City.
The type proved durable on regional routes, filling niches similar to those served by British Aerospace 146 and Dassault Falcon. Upgrades through the decades addressed noise regulations enforced by bodies like the International Civil Aviation Organization and the Federal Aviation Administration, while aftermarket completions were provided by firms such as St. Louis Aircraft Services and Jet Aviation. The HS 125 fleet gradually declined as owners favored newer models from Bombardier Aerospace and Embraer.
Numerous marks and designations reflect development and customer needs: early civil marks shared lineage with military derivatives produced for Royal Air Force special missions, while later commercial variants received larger fuel tanks and updated avionics from Honeywell. Manufacturer rebranding produced series labeled under British Aerospace and later licensees offering stretched fuselages and improved engines sourced from Garrett AiResearch and Rolls-Royce afterburner-free civil modifications. Corporate completion houses created bespoke interiors for executive customers including state delegations from France, Germany, and Japan.
Military adaptations were used for navigation training, radar calibration, communications relay and VIP transport by forces such as the Royal Air Force, Royal Australian Air Force, Japan Air Self-Defense Force, and air arms of several African states. Governments deployed HS 125 airframes as airborne command posts, liaison transports for ministries, and calibration platforms for civil defense organizations like national aviation authorities and meteorological services. The platform occasionally appeared at state visits alongside transport aircraft from Lockheed Martin and Airbus fleets.
Typical specifications for popular civil marks included twin turbofan engines driving a cruise capable of transcontinental sectors between hubs such as Heathrow Airport and John F. Kennedy International Airport. The HS 125 featured pressurization systems developed with suppliers like Bristol Siddeley and environmental control technology influenced by Sikorsky Aircraft cabin systems. Performance and weight figures were comparable to contemporaries from Rockwell International and Northrop Grumman business divisions, with later retrofits improving fuel burn and reducing emissions to meet ICAO noise standards.
Operators ranged from corporate flight departments of firms headquartered in London, New York City, Frankfurt am Main, and Tokyo to charter firms in Dubai, Johannesburg, and Singapore. Regional carriers used converted HS 125s for executive shuttle services between facilities of multinational corporations like Siemens, Siemens Energy, and Siemens Healthineers. Government VIP users included presidential flight units of smaller states and military transport squadrons that operated alongside types such as the Boeing 737 and Sikorsky S-92.
Accident records for the type involve a mix of small airframe mishaps, controlled flight into terrain events investigated by agencies like the Air Accidents Investigation Branch and the National Transportation Safety Board, and runway excursions subject to scrutiny by airport authorities including Heathrow Airport and Chicago O'Hare International Airport. Notable investigations prompted procedural changes implemented by corporate flight departments and regulators such as European Union Aviation Safety Agency.
Category:British business aircraft Category:Twinjets