The British Aerospace 125 is a twin-engine mid-size corporate jet. Originally developed by de Havilland and initially designated as the DH125 Jet Dragon, it entered production as the Hawker Siddeley HS.125, which was the designation used until 1977. Later on, more recent variants of the type were marketed as the Hawker 800.
The type proved quite popular overseas, more than 60% of the total sales for the aircraft were to North American customers. It was also used by the Royal Air Force as a navigation trainer, as the Hawker Siddeley Dominie T1, and was operated by the United States Air Force as a calibration aircraft, under the designation C-29.
One of the prototypes on display at the 1962 Farnborough Air Show
In 1961, de Havilland began work upon a small business jet, then known as the DH.125 Jet Dragon, which was intended to replace the piston enginedde Havilland Dove, a successful business aircraft and light transport. Prior to the start of the project, de Havilland had determined that a successful business jet would require several variables to be met, including a range of at least 1,000 miles, the speed and cost factors of a suitable jet engine to outperform turboprop-propelled competitors, and an engineering philosophy that favored reliability and conventionality. The design team settled on a twin-engine aircraft with the engines mounted on the rear fuselage, the Armstrong Siddeley Viperturbojet powerplant was also selected to power the type.
On 13 August 1962, the first of two prototypes conducted its first flight, a second aircraft followed it on 12 December that year. The second prototype was more aerodynamically-representative of a production aircraft, and was fitted out with more equipment than the first prototype; the subsequent production-standard aircraft incorporated several changes and improvements from the prototypes, such as a longer fuselage and a greater wingspan. The first production-standard aircraft performed its first flight on 12 February 1963. The first delivery to a customer took place on 10 September 1964.
Hawker Siddeley DH-125 Series 400A in San Francisco, United States, 1971
The aircraft went through many designation changes during its service life. Hawker Siddeley had bought de Havilland the year before the project had started, but the legacy brand and "DH" designation was used throughout development. After the jet achieved full production, the name was changed to "HS.125" except for American exports which retained the DH.125 until it was replaced by BH.125 for Beechcraft-Hawker. When Hawker Siddeley Aircraft merged with the British Aircraft Corporation to form British Aerospace in 1977, the name changed to BAe 125. When British Aerospace sold its Business Jets Division to Raytheon in 1993, the then-main variant of the jet became widely referred to as the Hawker 1000.
While the two prototypes were assembled at de Havilland's Hatfield site, final assembly of all production aircraft would take place at the Broughton factory near Chester until the 1990s. By the 2000s, the fuselage, wings and tailfin of the aircraft were still being assembled and partially equipped in the Broughton site, now being owned and managed by Airbus UK; various sub-assemblies were also produced in Airbus UK's Buckley facility. From 1996 onwards, the assembled sections and components were shipped to Wichita, Kansas in the United States, to undergo final assembly. Writing in 1993, Flying Magazine said of the type "In numerical terms, the 125 series is the most successful British commercial aircraft ever built, and the world's longest in-production business jet".
Production of the aircraft came to an abrupt halt in 2013 due to the bankruptcy of owner Hawker Beechcraft, whom has suffered during the Great Recession of the late 2000s in which demand for business jets had slumped for a number of years. The type had been in production for more than 50 years when manufacturing stopped, during which time over 1,600 aircraft had been produced. In April 2013, the type certificate and support responsibility for all 125s built was transferred to the reformed Beechcraft Corporation. As of October 2012, Beechcraft does not intend to restart production of its business jet lines; instead the company intends to alternatively sell or dismantle the production facilities for the 125 family.
The DH.125 is a low-winged monoplane, powered by two engines mounted on the rear fuselage. The wing is slightly swept, being based upon the larger de Havilland Comet's wing planform, and employs large slotted flaps and airbrakes to better enable operations from small airfields; the aircraft can be flown from hardened grass airstrips. The type has a perfectly cylindrical fuselage with the one-piece wing mounted upon the underside of the fuselage; this design allows for the majority of manufacturing and assembly work of the wing and fuselage to be performed as separate sections with the two being joined together late in the production process. The wing also houses integral fuel tanks which contain the majority of the aircraft's fuel.
Early models of the aircraft were powered by several versions of the Bristol Siddeley Viperturbojet engine, while later aircraft have adopted more recent turbofan powerplants such as the Garrett TFE731 and Pratt & Whitney Canada PW300. As well as providing the propelling thrust of the aircraft, each of the engines are connected to independent gearboxes which provide electrical power via generators and drive the onboard fuel, oil and hydraulic pumps and a generator for electrical power. The design is redundant so that in the event of a single engine failing, all aircraft systems shall continue to operate normally.
All control surfaces of the aircraft are aerodynamically balanced via set-back hinges and geared tabs. The flaps and airbrakes are operated using the aircraft's hydraulics, while the ailerons, elevators, and rudder are manually-actuated. The design of the control circuits allows for an Collins-built A.P.103 autopilot to be incorporated. Each aircraft is typically equipped with a de-icing system, which uses a mixture of bleed air from the engines and electronic heating to prevent ice formation. From the type's introduction to service, weather radar was incorporated into the aircraft's avionics fit out. Some operators, such as the Royal Air Force, have equipped their 125s with electronic countermeasures to defend against hostile missile attacks upon the aircraft.
The pressurised fuselage was designed to accommodate two pilots and six passengers. Various interiors were offered for the aircraft, the standard interior offered a high degree of comfort to the passengers. In an executive configuration, the flight desk is separated from the main passenger cabin; the single entrance of the aircraft, located directly behind the cockpit and forward of the passenger cabin, forms a vestibule area in which luggage can be stored and meals prepared during flight. An unobstructed cabin floor with 5 ft 9in of headroom and a 3 ft wide cabin door also allowed the loading of bulky equipment, which was seen as particularly attractive to military operators. In addition to the entrance door, an emergency escape door is also located in the passenger cabin midsection over the wing. The rear of the fuselage is occupied by a large equipment bay and, on some aircraft, two additional fuel tanks for extended operations.
Having entered service as one of the first-generation executive jets, the British Aerospace 125 has been operated by a wide variety of customers, ranging from government and military operators to private customers and businesses, it has also seen use by several airlines. Many of the aircraft's customers have been located in North America; in 1990, out of the 650 aircraft then being operated, more than 400 were being flown in the United States. Reportedly, one aircraft was being sold every seven working days for a substantial period of the type's production life. Successively larger versions were introduced to extend the type's appeal and to better compete against larger jets being used for business travel, such as the Gulfstream IV and Falcon 900.
The Royal Air Force was a significant early operator of the type, receiving a number of aircraft for multiple roles, including some of the first batch of 30 aircraft to be produced. The majority of 125s were operated in an airborne training capacity for air force navigators, aircraft in this role were named as the Hawker Siddeley Dominie; the Dominie served in excess of 45 years before being retired in 2011 due to diminishing requirements. Additional 125s were acquired and operated by No. 32 Squadron RAF as communications and light transport aircraft; these are also occasionally operated to transport Queen Elizabeth II and other members of the British Royal Family. In the later stages of the War in Afghanistan, various 125s have been used to transport military officers and other key personnel in and out of the country. As of 2010, the type is scheduled to be withdrawn from RAF service in 2022.
By the early 1990s, British Aerospace, the manufacturer of the type at this point, had two main variants of the aircraft in production; the smaller 125-800 and larger 125-1000. The 125-1000, which conducted its first flight on 16 June 1990, had several changes to give the type a reported intercontinental range, including the adoption of the newly developed Pratt & Whitney Canada PW300 engine and new digital avionics, such as FADEC. Following Raytheon's purchase of British Aerospace's Business Jet Division during the 1990s, the two in-production variants were re-designated as the Hawker 800 and Hawker 1000 respectively.
The 125 has had the dubious distinction of being the only business jet to have ever been hijacked; in 1967, a chartered 125 carrying the former Congolese Prime Minister Moise Tshombe was diverted to Algeria by armed individuals on board. The 125 is also likely to have been the only business aircraft to have ever survived being hit by an air-to-air missile; in August 1988, a British Aerospace 125-800 transporting Botswanan President Quett Masire was stuck by an missile which had apparently been inadvertently launched by a nearby AngolanMikoyan-Gurevich MiG-21. While badly damaged by the direct hit, which resulted in the loss of an engine, the cabin decompressing, and fuel tanks being ruptured; the aircraft was successfully landed by BAe demonstrator pilot Arthur Ricketts, it was later rebuilt.
In 2013, the FAA modified 14 CFR part 91 rules to prohibit the operation of jets weighing 75,000 pounds or less that are not stage 3 noise compliant, specifically mentioning the 125 series of aircraft. This shall require any aircraft of the type to either have Stage 3 noise compliant engines installed or to be fitted with "hushkits", or otherwise will not be permitted to fly over the majority of the United States after 31 December 2015, unless special permission has been granted.
First version, powered by 3,000 lbf (13 kN) Viper 20 or 520 engines. Nine built, including two prototypes (43 ft 6 in (13.26 m) long, 44 ft (13.41 m) span) and seven production aircraft (47 ft 5 in (14.56 m) long, 47 ft (14.33 m) long.
Series 1A/1B - upgraded Bristol Siddeley Viper 521 or 522 engines with 3,100 lbf (14 kN) of thrust each, and five cabin windows instead of six. Series 1A for US FAA certification (62 built), Series 1B for sale elsewhere (13 built).
Series 1A-522 and 1B-522 - Series 1A/B aircraft with Viper 522 engines.
Series 1A-R522 and 1B-R522 - Series 1A-522 and 1B-522 aircraft with long-range fuel tanks, modified flaps and main landing gear doors.
Series 1A-S522 and 1B-S522 - Some aircraft were structural modified to Series 3 standard but without a change in maximum landing weight or maximum operating altitude.
Series 3A/B - Viper 522-powered variant with increased weights.
Series 3A/R and 3B/R - early aircraft modified to the series 3 standard but without a change in maximum landing weight or maximum operating altitude.
Series 3A/RA and 3B/RA - Series 1A/B aircraft modified to Series 3 standard with structural changes for increased maximum zero fuel weight and maximum rampweight.
Series 3B/RB - variant of the 3B/RA with increased maximum ramp weight and maximum take off weight.
Series 3B/RC - variant of the 3B/RA modified as a navigation aid checker with four-seat cabin configuration and addition of avionic and flight inspection equipment.
F3B - re-engined
F3B/RA - re-engined
Series 400A and 400B - increased maximum ramp and brake-release weights and addition of a outward-opening main entry door. From 1970 the Series 400A aircraft for the United States were marketed as the Beechcraft Hawker BH.125 Series 400A.
Series 401B - Increased maximum take off and zero fuel weights and allteration to cabin loading.
Series 403A(C) - The same as a 403B but for use in Canada.
Series 403B - Increased maximum take off, zero fuel and ramp weights, alteration to cabin loading.
HS.125 CC1 - British military designation for a series 400 liaison aircraft for the Royal Air Force
Series 600A and 600B - Change to Viper 601-22 engines, increased weights and operating speeds, 3 ft 1 in (0.94 m) fuselage stretch to increase capacity to 14 passengers, increased fuel capacity including an additional tank in the dorsal fairing, revised aileron tab arrangements and aileron control gearing and improved aerodynamics. from 1976 the Series 600A aircraft were marketed as the Beechcraft Hawker BH.125 Series 600A.
Series F600B - re-engined
HS.125 CC2 - British military designation for series 600 liaison aircraft for the Royal Air Force
Series 700A and 700B variants had the Honeywell TFE731-3RH turbofan engines with 3,720 lbf (16.5 kN) of thrust each, first flight 19 June 1976. All early models could also be re-engined.
BAe 125 CC3 - British military designation for Series 700 liaison aircraft for the Royal Air Force
HS.125 Protector - Series 700-based maritime patrol aircraft with a search radar and cameras
BAe 125 Series 800 - increased wingspan, streamlined nose, tailfin extension, increased fuel capacity, first corporate jet to feature an EFIS cockpit, upgraded engines, first flight 26 May 1983.
U-125 - Series 800-based flight inspection aircraft for Japan (similar to C-29A)
U-125A - Series 800-based search and rescue aircraft for Japan, equipped with the APS-134LW radar system.
British Aerospace BAe 125 Series 1000A and 1000B - intercontinental version of the Series 800, 2 ft 9 in (0.84 m) fuselage stretch to increase capacity to 15, increased fuel capacity, Pratt & Whitney Canada PW-305turbofans with 5,200 lbf (23 kN) thrust each, first flight 16 June 1990, 52 built
Hawker 1000 - BAe 125-1000 after 1994
Handley Page HP.130
A 1965 proposal with boundary layer control wings (not built). It was to be powered by two Bristol Siddeley Viper 520s of 3,000 lbf (13 kN) thrust with a projected Maximum speed of Mach 0.8. This conversion was for laminar-flow research purposes.
In July 1967, Air Hanson HS.125 (G-ASNU) carrying former Congolese president Moise Tshombe was hijacked and taken to Algeria.
On 23 December 1967 a Hawker Siddeley HS.125 (registration: G-AVGW) of Court Line crashed shortly after taking off from Luton Airport, killing both pilots. The aircraft had been on a training flight. The crash occurred when the crew simulated an engine failure on takeoff. The HS 125 lost height rapidly and hit the roof of the nearby Vauxhall Motors factory. This resulted in a post-crash fire.
On 20 November 1975, a British Aerospace BAe 125 overran the runway at Dunsfold Aerodrome after a bird strike on takeoff. The aircraft hit a car that was travelling along the A281 at the time and stopped in a nearby field, killing six people in the car and injuring one crew member out of nine passengers and crew. The aircraft was being flown by the well-known, World War 2 fighter ace John Cunningham.
On 8 September 1987: a Brazilian Air Force Hawker Siddeley HS.125 registration FAB-2129 crashed upon takeoff from Carajás. All nine occupants died.
On 7 August 1988, a BAe-125 owned by the Botswana Government was carrying the President of Botswana, Quett Masire, and his staff to a meeting in Luanda. An Angolan MiG-23 pilot fired two R-60 (AA-8) missiles at the plane. One missile hit the no. 2 engine, causing it to fall off the aircraft. The second missile then hit the falling engine. The crew was able to make a successful emergency landing on a bush strip at Cutio Bie.
On 16 March 1991, a Hawker Siddeley charter aircraft carrying band members for Reba McEntire crashed into the side of Otay Mountain. The accident occurred shortly after takeoff from a municipal airport outside of San Diego, California. All eight band members aboard plus two pilots were killed in the crash believed to have been caused by poor visibility.