Hawker Siddeley Trident
| Hawker Siddeley HS-121 Trident | |
|---|---|
 Trident 1 G-ARPC at Farnborough Airshow, 1962 |
|
| Type: | three-engine airliner |
| Design country: | |
| Manufacturer: | |
| First flight: |
January 9, 1962 |
| Commissioning: |
1964 |
| Number of pieces: |
117 |
The Hawker Siddeley HS-121 Trident was designed for short and medium haul jet powered airliner . It was originally developed by the de Havilland Aircraft Company in the 1950s under the model designation DH.121 . After de Havilland was absorbed into the Hawker Siddeley Group in 1959 , the DH.121 was further developed as the HS-121 and finally built.
The Trident went back to a tender by British European Airways (BEA), which made it only moderately attractive to other airlines. However, it played an important role within Europe, even if it was only in use for a relatively short time due to its high operating costs. BEA merged with British Overseas Airways Corporation in 1972 , which later became British Airways , which replaced its Tridents with Boeing 737 and Boeing 757 in the 1980s .
history
In July 1956, BEA requested offers for a new medium- haul aircraft in order to be able to replace its Vickers Viscounts with jet-powered aircraft on longer intra-European routes. The new type to be developed should be used in addition to a smaller short-haul model (the tender for this won the BAC 1-11 ). Various designs for the medium- haul type were submitted, including the Bristol 200, the Avro 740, the Vickers VC11 - and the de Havilland DH 121, which was officially named the winner of the BEA competition in 1958.
The DH 121 was the first " Trijet ", that is, the first design ever with three engines. The developers chose this configuration because, in their opinion, it represented the best compromise between economical cruising and a safe take-off in the event of an engine failure. Unsurprisingly, the aircraft initially looked like a scaled-down De Havilland Comet with three engines. The tail with the horizontal and vertical tail was also initially similar to that of the Comet, in contrast to the later T-tail of the HS-121 Trident. As with the Sud Aviation Caravelle, the engines were already at the stern, so that the wings did not have to carry any engines and could be designed for high speed. The goal was about 965 km / h (600 mph). In a two-class configuration, the DH 121 was to seat 111 passengers, have an average range of 3,330 km and an all-up weight of 63,000 kg and be powered by three Rolls-Royce Medway engines, each with 13,790 lb f (61.34 kN) of thrust.
At this point, BEA decided that a 111-seater was too big for the existing routes, whereupon BEA carefully tried to tailor "their" aircraft to their needs. As a result, the Trident design was reduced in size, which among other things led to the fact that only the much smaller Rolls-Royce Spey 505 engines with 9,850 lb f (43.8 kN) thrust were provided, with an all-up weight of 48,000 kg, an average range of 1,500 km and space for 97 passengers. This design was the first to have the T-tail, which all subsequent versions should also have. In addition, the bow was redesigned, which also made this version look very different from the Comet-like original design. The aircraft has since been called "Trident 1" after a competition to name it. BEA was much more satisfied with this smaller design than before and initially ordered 24 copies on August 12, 1959.
Hawker Siddeley Aviation , founded in 1959 as a merger of several British aircraft manufacturers, has meanwhile started to look out for other customers as well; In 1960 discussions began with American Airlines , but they demanded a greater range - which was not without a certain irony, since the original DH 121 met American's requirements almost perfectly. Nevertheless, the development of a new "Trident 1A" began, which offered a higher takeoff mass of 54,000 kg and an increased average range of 2,900 km and was powered by more powerful Spey 510 engines with 10,700 lb f (47.6 kN) thrust . American Airlines ultimately decided against the Trident 1A and in favor of the Boeing 727 , which almost exactly matched the specifications of the original DH 121.
Some of the changes to the Trident 1A compared to the Trident 1 were nevertheless implemented in the first prototype, which was eventually called the "Trident 1C". The main difference was a larger fuel tank in the middle section of the wing, bringing the all-up weight to 52,000 kg and increasing the average range to 2,250 km. The first Trident 1, registered G-ARPA, made its maiden flight on January 9, 1962 and was put into service by BEA on April 1, 1964. In 1965, BEA had a fleet of 15 Tridents; by March 1966 there were 21.
Hawker Siddeley proposed an improved Trident 1C under the name "Trident 1E" at this time. It should have an all-up weight of 58,000 kg, Spey 511 engines with 11,400 lb f (50.7 kN) thrust and a larger wing area (due to greater wing extension ). The fuselage remained unchanged, but - with seven seats per row - offered space for 149 passengers. These changes brought the 1E closer to the original concept of the DH 121, but with a total of 7,000 lb f (31 kN) less drive thrust. The wing designed for high speeds produced less lift at lower speeds, which together with the weak thrust meant that the Trident 1E took a very long time to take off. This earned her the nickname "Ground Gripper" in the press. The new version was hard to sell - Kuwait Airways and Iraqi Airways ordered three each, PIA four (which were later sold to CAAC ), Channel Airways and Northeast Airlines two each, and Air Ceylon one.
At that time, BEA found that the Trident no longer offered sufficient range for the constantly expanding route network, so a version with an increased range was needed. Hawker Siddeley then designed another further development, the "Trident 1F". She got the Spey 511 engines of the 1E and a 2.8 m stretched fuselage. Its flight weight was 60,000 kg and in the original seating configuration with five seats per row it offered space for 128 passengers. BEA wanted to order 10 Trident 1Fs and include options for another 14. In the course of the development of the 1F it became apparent that so many changes were made that Hawker Siddeley decided to finally refer to it as the “Trident 2E”, where E stood for “Extended Range”. The 2E was eventually equipped with Spey 512 engines with a thrust of 11,930 lb f (53.1 kN) each and had a flight weight of 65,000 kg and an average range of 3,200 km. In addition, the leading edges of the wing were equipped with slats and the wingspan was increased with wing tips based on the research carried out by Erich von Holst and Dietrich Küchemann . BEA bought 15 copies, Cyprus Airways 2 and the Chinese national airline CAAC 33. The first flight of the Trident 2E took place on July 27, 1967, and BEA started service with this type in April 1968.
In the meantime, the Trident formed the backbone of the BEA fleet - now that it was in widespread use, BEA requested an even larger sample. Hawker Siddeley offered two possible types in 1965: on the one hand the HS-132, a larger, only twin-engine aircraft with space for 158 passengers, which otherwise was still very similar to the Trident; on the other hand the HS-134, with engines mounted under the wings and space for 185 passengers. The HS-134 was a very advanced design that resembled the Boeing 757 launched a good 15 years later . Both the HS-132 and HS-134 were to be powered by the Rolls-Royce RB-178, which was then in development , a jet engine that was one of the first to have a high bypass ratio . BEA decided instead to buy Boeing 727 and 737 to replace both the BAC 1-11 and the Trident. However, the British government (owned by BEA) later vetoed this plan.
BEA then turned back to Hawker Siddeley and instead opted for a stretched Trident version, the "Trident 3". The Trident 3 had a fuselage stretched by 5 m with space for up to 180 passengers, an increased flight weight of 65,000 kg and a modified wing to increase the wing extension. The engines, however, should remain unchanged; BEA then rejected the pattern because, due to the start and climb problems of the Trident 2E, it was feared that the Trident 3 would no longer be able to take off at all in hot and high-altitude surroundings. Since the Spey 512 was the last model in the Spey range, it was difficult to give the aircraft any extra thrust. Instead of installing a new type of engine - which would have been difficult since there was one in the vertical tail that would have had to be aerodynamically adjusted accordingly - Hawker Siddeley decided to install a fourth engine in the stern. It was the tiny Rolls-Royce RB.162-86 turbojet engine , which had its own air supply through two movable flaps in the tail fairing. The engine was only used when necessary and gave the Trident 15% more thrust for take-off with only 5% more weight. BEA accepted this somewhat strange mixture under the name "Trident 3B" and ordered 26 copies. The first flight took place on December 11, 1969, the first scheduled flight on April 1, 1971. A further increase in fuel capacity led to the "Super Trident 3B", two of which were sold to CAAC.
In 1977, fatigue cracks were found in the wings of British Airways' Trident 3. All copies were ordered back to the manufacturer, where repairs were carried out, after which all Trident 3s were put back into service. British Airways put the machines out of service in 1985; in China, the machines were in service until well into the 1990s. Today there are no more airworthy specimens.
In total, only 117 Tridents were built. The irony here is that the Boeing 727 , which almost completely met the original Trident specification, sold over 1,700 units.
construction
The entire chassis construction of the Trident showed some special features. The nose landing gear was extraordinarily far back. The reason for this was that a lot of space was required in the bow of the aircraft for the computers of the automatic blind landing system. For the same reasons of space, the nose landing gear was not (as is usual with most aircraft) retracted forwards or backwards, but transversely, so that when extended it was not in the center but offset to the left, which gives the Trident a curiously asymmetrical appearance when viewed from the front awarded (see illustration). The design of the main landing gear also differed greatly from those of other aircraft in this class: since four tires were mounted side by side on one axis on each chassis , but their intake shafts in the fuselage extended lengthways , the two axes always had to be at 90 when retracting and extending ° to be folded or brought into rolling position. Such complex landing gear constructions are or were only very rarely found in airplanes, especially in passenger planes, such as the Soviet Tu-144 supersonic aircraft or the US long-range bomber B-52 .
A key technological feature of the Trident was its fully automatic blind landing system, which was based on the Smith Industries SEP5 autopilot. It allowed the plane to land in weather conditions where most of the other types would have been diverted to other airports, which improved the Trident's punctuality rate. In 1964, a Trident was the first large airliner to perform an automatic blind landing on a test flight. This later made it possible to land in very dense fog. Fog was previously a major problem at Heathrow , leading to many flight cancellations and delays. After the Sud Aviation Caravelle , the Trident was the second type of airliner to be equipped with an approved Autoland system that was used in scheduled operations . The system was tested from 1964 and approved for regular use in accordance with CAT II ( Category II ) from 1968 . By the end of 1970, BEA had already carried out 7,500 landings with this system. In 1972 the approval was extended to CAT IIIA and in 1975 to CAT IIIB.
The Trident was the first airliner to be fitted with flight recorders as standard (from 1964).
The Trident's thrust reverser could be activated in flight, allowing her to descend safely at a rate of descent of 10,000 feet / minute (approx. 3050 m / minute). However, this option was rarely used.
The Trident reached cruising speeds of over 965 km / h and was thus one of the fastest subsonic airliners.
use
Civil users
Operator of brand new machines
- 1 Air Ceylon
- 2 BKS Air Transport
- 65 British European Airways (BEA)
- 35 CAAC
- 2 Channel Airways
- 2 Cyprus Airways
- 3 Iraqi Airways
- 3 Kuwait Airways
- 4 Pakistan International Airlines (PIA)
Operators of used machines
Military users
-
People's Republic of China , used machines from CAAC and PIA -
Pakistan
Incidents
From the first flight in 1962 to the end of its mission in 1995, the Trident suffered 17 total losses. In 8 of them, 336 people were killed. Examples:
- On June 3, 1966, came at a Trident 1C (G-ARPY) on a test flight of Hawker Siddeley into a stall in the form of a deep stall and crashed near Felthorpe to the ground. All four occupants of the machine died (see also the aircraft accident involving the Hawker Siddeley Trident G-ARPY ) .
- On July 3, 1968, two parked Trident 1Cs of British European Airways ( aircraft registration numbers : G-ARPI and G-ARPT ) were struck by an Airspeed Ambassador of BKS Air Transport at London-Heathrow , which got out of control on landing and over the apron lap. The five occupants of the Ambassador were killed and 28 airport employees were injured. The G-ARPI could be repaired, the G-ARPT had to be written off. The cause of the accident was considered to be a defective landing flap that caused the Ambassador's wing to touch the ground.
- On June 18, 1972, a British European Airways (G-ARPI) Trident 1C crashed after taking off from London Heathrow for Brussels . All 118 people on board were killed in the impact near Staines . Up until 1988 (Lockerbie attack) it was the worst aircraft accident on British soil. The cause was presumably a mistake by the pilots who introduced the slats required for lift before the required minimum speed was reached (see also British European Airways flight 548 ) .
- On September 15, 1975 a Trident 1E (G-AVYD) of the British Airways Regional Division Northeast (formerly Northeast Airlines) had an accident while taking off at Bilbao Airport. The machine that carried out flight NS552 to London Heathrow was written off as a total loss.
- On September 10, 1976, a British Airways (G-AWZT) Trident 3B collided in flight over Yugoslavia with a Douglas DC-9 operated by Inex Adria , registration number YU-AJR . All 176 people on board the two machines were killed. The collision was later an error by the air traffic control is returned (see also aircraft collision of Zagreb ) .
- On March 14, 1979, a Trident 2E of the Chinese CAAC (B-274) crashed into a factory building after taking off from the Beijing / Xijiao military airfield on a training flight. The crew of 12 and 32 people on the ground were killed.
- On April 26, 1982, a CAAC (B-266) Trident 2E launched at Guangzhou-Baiyun Airport (old) collided with a mountain about 60 km southeast of it while approaching Guilin Qifengling Airport . All 112 people on board were killed. There are contradicting information on the cause of the accident (see also CAAC flight 3303 ) .
- On August 31, 1988, Trident 2E of the CAAC (B-2218) launched at Guangzhou-Baiyun Airport (old) slipped into the port basin at Hong Kong 's Kai Tak Airport during a crash landing. The cause of the accident was presumably a sudden deterioration in visibility due to heavy rain, 7 occupants drowned (see also CAAC flight 301 ) .
Technical specifications
| Parameter | Trident 1C | Trident 1E | Trident 2E | Trident 3B |
|---|---|---|---|---|
| Number built | 24 | 15th | 50 | 28 |
| Cockpit crew | 3 | |||
| span | 27.38 m | 28.96 m | 29.87 m | |
| length | 34.98 m | 39.98 m | ||
| height | 8.23 m | 8.80 m | ||
| Wing area | 126.20 m² | 134.30 m² | 135.82 m² | 138.70 m² |
| Wing swept | 35.0 ° | |||
| Wing extension | 5.94 | 6.24 | 6.57 | 6.43 |
| Empty mass | 30,595 kg | 33,203 kg | ||
| Max. Takeoff mass | 52,160 kg | 58,000 kg | 63,500 kg | 68,039 kg |
| Max. Passenger capacity | 103 | 149 | 180 | |
| Cruising speed | 959 km / h | 926 km / h | 959 km / h | 935 km / h |
| Max. Range | 4,602 km | 3,611 km | 4,148 km | 2,750 km |
| Service ceiling | 8,992 m | |||
| Engines | 3 × Rolls-Royce Spey 505-5 à 9,850 lb f (43.8 kN) |
3 × Rolls-Royce Spey 511-5 at 11,400 lb f (50.7 kN) |
3 × Rolls-Royce Spey 512-5W at 11,930 lb f (53.1 kN) |
3 × Rolls-Royce Spey 512-5W at 11,930 lb f (53.1 kN) 1 × Rolls-Royce RB.162 -86 at 5,250 lb f (23.4 kN) |
| Source: Günter Endres, William Green, Gordon Swanborough: The great book of passenger aircraft. Motorbuch, Stuttgart 2000, ISBN 3-7276-7129-7 . | ||||
Preserved copies
Four complete Tridents have survived in the UK : a Trident 1C, registration G-ARPH , in Cosford, Shropshire ; a Trident 2E, registration G-AVFB , at Duxford near Cambridge ; a Trident 3B, registration G-AWZM, on display at the British Science Museum in Wroughton, Wiltshire ; Another Trident 3B, registration number G-AWZK , which was partially dismantled for transport reasons in September and October 2005, was transported from the previous location in London- Heathrow to the Aviation Viewing Park at Manchester Airport , where it is to be exhibited. All four of the named tridents previously flew for British Airways.
Picture gallery
Hawker Siddeley Trident 3B G-AWZK
Flight deck (cockpit)
Primary flight instrument panel P2 (First Officer / Copilot)
Position P3 (flight engineer)
Passenger cabin
Web links
Individual evidence
- ↑ a b Hapless Trident - 50 years ago: First flight of the Hawker-Siddeley Trident. In: FliegerRevue. February 2012, pp. 50–51.
- ↑ List of accidents with Hawker Siddeley HS-121 Trident , Aviation Safety Network WikiBase , accessed on August 3, 2019.
- ^ Accident report Trident 1C G-ARPI , Aviation Safety Network (English), accessed on November 11, 2018.
- ^ Accident report Trident 1C G-ARPT , Aviation Safety Network (English), accessed on November 11, 2018.
- ^ Accident report Trident 1C G-ARPI , Aviation Safety Network (English), accessed on November 11, 2018.
- ^ Accident report Trident 1E G-AVYD , Aviation Safety Network (English), accessed on November 11, 2018.
- ^ Accident report Trident 2E B-274 , Aviation Safety Network (English), accessed on November 11, 2018.
- ^ Accident report Trident 2E B-266 , Aviation Safety Network (English), accessed on November 11, 2018.
- ↑ ebook.lib.hku.hk Official accident report