British Aerospace 146
The British Aerospace 146 is a short-haul and regional airliner that was manufactured in the United Kingdom by British Aerospace, later part of BAE Systems. Production ran from 1983 until 2001. Production figures include the Avro RJ, an improved version from Avro International Aerospace, a subsidiary of BAE Systems. Production for the Avro RJ version began in 1992. The Avro RJX, a further-improved version with new engines, was announced in 1997, but only two prototypes and one production aircraft were built before all production ceased in 2001. With 387 aircraft produced, the Avro RJ/BAe 146 is the most successful British civil jet airliner programme.
The BAe 146/Avro RJ is a high-wing cantilever monoplane with a T-tail. It has four geared turbofan engines mounted on pylons underneath the wings, and has a retractable tricycle landing gear. The aircraft operates very quietly, and as such has been marketed under the name Whisperjet. It sees wide usage at small, city-based airports such as London City Airport. In its primary role, it serves as a regional jet, short-haul airliner, or regional airliner, while examples of the type are also in use as private jets.
The BAe 146 was produced in -100, -200 and -300 models. The equivalent Avro RJ versions are designated RJ70, RJ85, and RJ100. The freight-carrying version carries the designation "QT", and a convertible passenger-or-freight model is designated as "QC". A "gravel kit" can be fitted to aircraft to enable operations from rough, unprepared airstrips.
Development
Origins
In August 1973, Hawker Siddeley launched a new 70-seat regional airliner project, the HS.146, to fill the gap between turboprop-powered airliners such as the Hawker Siddeley HS.748 and the Fokker F27 Friendship and small jet airliners such as the BAC One-Eleven and Boeing 737. The concept of a feeder jet had, however, been "one of the many speculative ideas on the drawing boards of British aircraft manufacturers" as far back as 1958.The chosen configuration had a high wing and a T-tail to give good short-field performance, while the aircraft was to be powered by four 6,500 lbf thrust Avco Lycoming ALF 502H turbofan engines. There were several reasons why a twin engine configuration was not chosen, this being a controversial decision for a relatively small aircraft and dictated by the choice of engine which, despite its "rugged, quiet and fuel efficient" characteristics, needed to be deployed in a four-engine configuration to provide the power and range required by the concept. Such a configuration was considered by British Aerospace to be advantageous in the event of a single engine failure, offering "exceptional three-engine performance" that would appeal to operators in mountainous environments and from "high, hot or poor grade airfields".
The programme was initially launched with backing from the UK government, which agreed to contribute 50% of the development costs in return for a share of the revenues from each aircraft sold. In October 1974, all work on the project was halted as a result of the world economic downturn resulting from the 1973 oil crisis.
Low-key development proceeded, however, and in 1978, British Aerospace, Hawker Siddeley's corporate successor, relaunched the project. British Aerospace marketed the aircraft as a quiet, low-consumption, turbofan aircraft, which would be effective at replacing the previous generation of turboprop-powered feeder aircraft. The first order for the BAe 146 was placed by Líneas Aéreas Privadas Argentinas in June 1981. Prior to the first flight, British Aerospace had forecast that the smaller would significantly outsell the 146-200 variant; however, airlines showed a higher level of interest in the larger 146-200.
By 1981, a large assembly line had been completed at British Aerospace's Hatfield site, and the first completed aircraft flew that year, quickly followed by two more prototypes. By then, the unit cost of the 146-200 was £11 million, and the program cost was £350 million. Initial flight results showed better-than-predicted takeoff and climb performance. In 1982, British Aerospace stated that the sale of a total 250 aircraft was necessary for the venture to break even. The BAe 146 received its Certificate of Airworthiness on 8 February 1983. Upon its launch into service, it was hailed as being "the world's quietest jetliner".
Production
Early production aircraft were built at Hatfield, which had originally been a de Havilland factory. The Avro RJ family of aircraft was assembled at the Avro International at Woodford Aerodrome in Greater Manchester, England. Production of various sections of the aircraft was carried out at different BAE plants: the rear fuselage section was manufactured at the former Avro site at Chadderton, Greater Manchester; the centre fuselage section was manufactured at Filton; the vertical stabilizer came from Brough; the engine pylons were made at Prestwick; and the nose section was manufactured at Hatfield, where the assembly line for the early aircraft was located. Some manufacturing was subcontracted outside the UK; the wings were made by Textron in the United States and the tailplane and control surfaces were made by Saab-Scania in Sweden.Due to the sales performance of the BAe 146, British Aerospace announced a development project in early 1991 to produce a new variant of the type, powered by two turbofan engines instead of four, that was offered to airlines as a regional jet aircraft. Dubbed the new regional aircraft, other proposed alterations from the BAe 146 included the adoption of a new enlarged wing and a lengthened fuselage.
In 1993, the upgraded Avro RJ series superseded the BAe 146. Changes included the replacement of the original Lycoming ALF 502 turbofan engines by higher-thrust LF 507 turbofan engines, which were housed in redesigned nacelles. The Avro RJ series also featured a modernised cockpit with EFIS replacing the analogue ADI, HSI, and engine instrumentation. An arrangement between British Aerospace and Khazanah Nasional would have opened an Avro RJ production line in Malaysia, but this deal collapsed in 1997.
In 2000, British Aerospace announced that it was to replace the Avro RJ series with a further-improved Avro RJX series, however on 27 November 2001 BAE announced the cancellation of the RJX programme as part of the closure of its regional aircraft business. BAE also announced 1,669 job losses and a £400m charge as part of the decision. The Financial Times stated that BAE had "draw a line under a business that once threatened to destroy the whole group. In 1992, the regional aircraft operation blew a hole in the then British Aerospace's balance sheet, forcing it to take a £1bn write-off."
Production of the Avro RJ ended with the final four aircraft being delivered in late 2003; a total of 173 Avro RJ aircraft were delivered between 1993 and 2003.
Design
Overview
British Aerospace promoted the BAe 146 to airlines as a "feederliner" and short-haul regional airliner. The airframe of the aircraft and many other key areas were designed to be as simple as possible. The engines lack thrust reversers due to their perceived reduced effectiveness in anticipated conditions. Instead, the BAe 146 features a large airbrake with two petals below the tail rudder at the rear of the fuselage, which has the advantage of being usable during flight and allowing for steep descent rates if required. In addition, the aircraft has full-width wing spoilers, which are deployed immediately on landing.The aircraft proved to be useful on "high-density" regional and short-haul routes. In economy class, the BAe 146 can either be configured in a standard five-abreast layout or a high-density six-abreast layout, making it one of few regional jets that can use a six-abreast layout in economy class. Reportedly, the aircraft is profitable on most routes with only marginally more than half the seats occupied.
The BAe 146 is also known for its relatively quiet operation, a positive feature that appealed to those operators that wanted to provide services to noise-sensitive airports within cities. The aircraft is one of only a few types that can be used on flights to London City Airport, which has a steep approach and short runway; for several years, the BAe 146 was the only conventional jet aircraft capable of flying from London City Airport.
Features
According to the BAe 146's chief designer, Bob Grigg, making the aircraft as easy to maintain as possible and keeping operators' running costs as low as possible were considered high priorities from the start of the design process. Grigg highlighted factors such as design simplicity, using off-the-shelf components where possible, and the internal use of firm cost targets and continuous monitoring. British Aerospace also adopted a system of cost guarantees between component suppliers and the operators of the BAe 146 to enforce stringent requirements.Drawing on experience from the Hawker Siddeley Trident and the Airbus A300, both the fuselage and wing were carefully designed for a reduced part-count and complexity. A high-mounted wing was adopted with an uninterrupted top surface; the BAe 146's wing did not make use of leading-edge extensions, which also enabled a simplified fixed tailplane. The undercarriage of the aircraft is toughened to resist damage and stability is maximised by the placement of landing gear, of particular value when operating from rough airstrips.
The engines are not fitted with thrust reversers, instead the aircraft has a clamshell air brake in the tail and full width spoilers on the wings.
The BAe 146 was the second aircraft, after the Concorde, to use carbon brakes. The aircraft features a low amount of composite material, used in parts of the secondary structure only. Initial production aircraft featured a conventional cockpit and manual flight controls. At launch, the onboard auxiliary power unit consumed only half the fuel and weighed only a third as much as other contemporary models.
The aircraft can be fitted with auxiliary fuel tanks to extend its range. So-called "pannier tanks" fit in the inner wing either side of the fuselage, while more tankage can be fitted in the under-floor baggage compartment, fore and aft of the undercarriage bay.