British Aerospace Nimrod AEW3: Difference between revisions
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==Issues== |
==Issues== |
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The thinking behind the attempted development of the Nimrod AEW was to maintain Britain's position at the forefront of radar technology and development as part of defence. However, the complexity of the AEW requirement proved too much for British industry to overcome by itself. The choice of the Nimrod airframe proved to be the wrong one, as it was too small to accommodate the radar, electronics, power generation and cooling systems required for a system as complex as the one required<ref>{{cite web |url=http://www.ausairpower.net/TE-AEW-AWACS.html |title= AEW and AWACS|author=Kopp, C |date=March/May 1989 |work=Australian Aviation |publisher=Air Power Australia |accessdate=12 May 2011}}</ref> – at just over {{Convert|38.5|m|ft|abbr=on}}, the Nimrod was close to {{Convert|8|m|ft|abbr=on}} shorter than the [[Boeing 707]] aircraft that formed the basis of the [[Boeing E-3 Sentry|E-3 Sentry]], but was expected to accommodate sufficient crew and equipment to perform a similar function. The choice of computer to integrate the various sensor systems was wrong, as the 4080M was simply too slow and too underpowered to perform the tasks required of it, while using the FASS method to gain full 360° radar coverage proved problematic – the concept involved the scanner in the nose making a left to right sweep, with the signal then immediately passed to the scanner in the tail, which would sweep right to left.<ref>{{cite journal |last1=Hewish |first1=Mark |last2= |first2= |year=1981 |title=Britain's air defences grow new teeth |journal=New Scientist |volume=89 |issue=1244 |pages=682–684 |publisher= |doi= |url=http://books.google.co.uk/books?id=x57gHRJjGC4C&lpg=PA684&ots=l4HC4b0ZXY&dq=NIMROD%20AEW%20radar&pg=PA684#v=onepage&q=NIMROD%20AEW%20radar&f=false |accessdate= 12 May 2011}}</ref> However, getting the two scanners to synchronise proved difficult, resulting in poor all-round surveillance capability.<ref name="spyflight"/> |
The thinking behind the attempted development of the Nimrod AEW was to maintain Britain's position at the forefront of radar technology and development as part of defence. However, the complexity of the AEW requirement proved too much for British industry to overcome by itself. The choice of the Nimrod airframe proved to be the wrong one, as it was too small to accommodate the radar, electronics, power generation and cooling systems required for a system as complex as the one required<ref>{{cite web |url=http://www.ausairpower.net/TE-AEW-AWACS.html |title= AEW and AWACS|author=Kopp, C |date=March/May 1989 |work=Australian Aviation |publisher=Air Power Australia |accessdate=12 May 2011}}</ref> – at just over {{Convert|38.5|m|ft|abbr=on}}, the Nimrod was close to {{Convert|8|m|ft|abbr=on}} shorter than the [[Boeing 707]] aircraft that formed the basis of the [[Boeing E-3 Sentry|E-3 Sentry]], but was expected to accommodate sufficient crew and equipment to perform a similar function. The choice of computer to integrate the various sensor systems was wrong, as the [[GEC 4000 series|GEC 4080M]] was simply too slow and too underpowered to perform the tasks required of it, while using the FASS method to gain full 360° radar coverage proved problematic – the concept involved the scanner in the nose making a left to right sweep, with the signal then immediately passed to the scanner in the tail, which would sweep right to left.<ref>{{cite journal |last1=Hewish |first1=Mark |last2= |first2= |year=1981 |title=Britain's air defences grow new teeth |journal=New Scientist |volume=89 |issue=1244 |pages=682–684 |publisher= |doi= |url=http://books.google.co.uk/books?id=x57gHRJjGC4C&lpg=PA684&ots=l4HC4b0ZXY&dq=NIMROD%20AEW%20radar&pg=PA684#v=onepage&q=NIMROD%20AEW%20radar&f=false |accessdate= 12 May 2011}}</ref> However, getting the two scanners to synchronise proved difficult, resulting in poor all-round surveillance capability.<ref name="spyflight"/> |
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==Specifications (Nimrod AEW3)== |
==Specifications (Nimrod AEW3)== |
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Revision as of 12:08, 18 August 2011
| Nimrod AEW3 | |
|---|---|
| |
| Nimrod AEW3 at the Farnborough Airshow, 1980. | |
| Role | Airborne early warning and control |
| Manufacturer | British Aerospace |
| First flight | 16 July 1980 [1] |
| Status | Development cancelled |
| Produced | 11 |
| Number built | 3 prototype 8 production (all converted from MR1) |
| Developed from | Hawker Siddeley Nimrod |
The British Aerospace Nimrod AEW3 was a planned airborne early warning (AEW) aircraft intended as to provide airborne radar cover for the air defence of the United Kingdom by the Royal Air Force (RAF). The project was designed to use the existing Nimrod airframe, in use with the RAF as a maritime patrol aircraft, combined with a brand new radar system and avionics package developed by Marconi Avionics.
The Nimrod AEW project proved to be hugely complex and expensive for the British government, as a result of the difficulties of producing brand new radar and computer systems and integrating them successfully into the Nimrod airframe. Despite close to a decade's work, the project was eventually cancelled, with the RAF instead purchasing new build Boeing E-3 Sentry aircraft to fulfil the AEW requirement.[2]
Development
Background
In the mid 1960s following the development of the Grumman E-2 Hawkeye carrier-borne AEW aircraft and its associated systems, the British government began looking around for a radar system that could be used to provide airborne early warning for the United Kingdom. At the time, the only recognised AEW aircraft in British service was the Fairey Gannet AEW3 aircraft used by the Fleet Air Arm on board Royal Navy aircraft carriers. these were fitted with the AN/APS-20 Radar, which had been developed during World War II and was rapidly becoming obsolete.[3] To fulfill the planned requirements for a new AEW aircraft, the government had a number of factors to consider:
- British industry wanted to develop a type of radar that would not operate effectively near propellors, meaning a jet aircraft would be needed.
- The size of antennas needed for the required scanning range, together with the fairly large mission crew, meant that a large aircraft was required.
Engineers eventually decided that the new Hawker Siddeley Nimrod maritime patrol aircraft met these requirements
Eventually, a decision was taken to procure an aircraft fitted with a pulse-doppler radar system, which then proceeded to a range of options:[1]
- Purchase the AN/APS-125 pulse-doppler radar system and its associated avionics, as fitted to the E-2 Hawkeye, and fit them into the Nimrod.
- Purchase the AN/APS-125 radar and combine it with a British avionics package.
- Purchase the radome and antenna from the E-2 and combine with a British radar transmitter, receiver and avionics package.
- Develop a wholly British radar system and avionics package using a Fore Aft Scanner System (FASS) rather than the E-2 radome.
While the fourth option was the most attractive as far as British industry was concerned, in that it would sustain thousands of British jobs, it was also far riskier than purchasing an "off the shelf" product or spreading the risk across multiple partners. In 1977, the US had made an offer to NATO for purchasing several of the new Boeing E-3 Sentry aircraft, which were being delivered to the US Air Force; this was intended to provide airborne early warning cover for Europe's NATO nations without having torely on the US Air Force. However, the complex multi-lateral negotiations eventually led the United Kingdom to go it alone with the all-British development.[4]
Development issues
In 1977 an RAF Comet 4 was modified for flight testing with the nose radome and conducted a series of trials, the results of which proved promising enough for an order for three prototype Nimrods to be built using redundant MR1 airframes.[5] The first of these was rolled out in March 1980 and flew for the first time in July, and was intended to test the flight characteristics, with the second airframe planned to carry out trials on the Mission Systems Avionics (MSA) package.[1] The MSA was based around a GEC 4080M computer, which was required to process data from the two radar scanners, the ESM system, IFF and inertial navigation systems. The integration of all of these systems into a single package proved too difficult for the underpowered computer, which had an ultimate data storage capacity of 2.4 MB.[1] Additionally, when operating at full power the radar scanners and on-board electronic systems generated a significant amount of heat. A system was developed to channel this via the fuel system, from where it could then dissipate, but which only worked when the fuel tanks were at least half full.[1]
Cancellation
Despite the problems, the Nimrod was persevered with, and 8 production aircraft were ordered (which would also come from spare MR1 airframes), with the first of these flying in March 1982.[5] Even while the technical problems were being worked on, the aircraft was delivered to the RAF, with No 8 Squadron, the RAF's AEW squadron which at that time operated the Avro Shackleton, receiving its first in 1984 to begin crew training.[5] The problem was that, with an anticipated in-service date of mid 1982, No 8 Squadron had been reduced from 12 aircraft and crews to 6 as part of the 1981 Defence Review.[6] By the time of the Falklands War, the Nimrod AEW had been originally scheduled to be in service, however the technical problems proved insurmountable to be deployed in the conflict.[7] However, several Nimrod MR.2 were quickly modified to serve in the AEW role for the task force however.[8]
"...The choice of national procurement rather than the available US alternative, involved not only higher costs for Britain but also the lack of an adequate system in-service when needed... It appears that buying British was given a high priority than having a system available to meet the assessed Soviet threat"
However, at the same time, the MoD decided to conduct a complete review of the AEW programme. The result of this was the start of a bid process to supply AEW aircraft for the RAF that began in 1986. The primary bidders were GEC Marconi with the Nimrod, and Boeing with its Sentry. In December 1986, the Sentry was finally chosen and the Nimrod AEW programme was cancelled.[5]
The Nimrod programme had cost in the region of £1 billion up to its cancellation, contrasting with manufacturer claims in 1977 that the total cost of the project would be between £200-300 million.[4][9] The unused airframes were eventually stored and used as a source of spares for the Nimrod R1 and MR2 fleets, while the elderly Shackleton that had been commissioned in 1971 as a "stop-gap" measure for AEW cover until the planned entry of the Nimrod AEW were forced to soldier on until 1991 and the entry into RAF service of the Sentry. The scandal over the collapse of the Nimrod AEW project was a major factor in Prime Minister Margaret Thatcher's stance to open up the UK defence market to competition.[10]
Issues
The thinking behind the attempted development of the Nimrod AEW was to maintain Britain's position at the forefront of radar technology and development as part of defence. However, the complexity of the AEW requirement proved too much for British industry to overcome by itself. The choice of the Nimrod airframe proved to be the wrong one, as it was too small to accommodate the radar, electronics, power generation and cooling systems required for a system as complex as the one required[11] – at just over 38.5 m (126 ft), the Nimrod was close to 8 m (26 ft) shorter than the Boeing 707 aircraft that formed the basis of the E-3 Sentry, but was expected to accommodate sufficient crew and equipment to perform a similar function. The choice of computer to integrate the various sensor systems was wrong, as the GEC 4080M was simply too slow and too underpowered to perform the tasks required of it, while using the FASS method to gain full 360° radar coverage proved problematic – the concept involved the scanner in the nose making a left to right sweep, with the signal then immediately passed to the scanner in the tail, which would sweep right to left.[12] However, getting the two scanners to synchronise proved difficult, resulting in poor all-round surveillance capability.[1]
Specifications (Nimrod AEW3)
| External image | |
|---|---|
| Nimrod AEW3 Hi-res cutaway | |
 Nimrod AEW3 cutaway, by Flight Global. |
Data from Aeroflight - BAE Systems Nimrod,[5]
General characteristics
- Crew: Up to 12
Performance
Armament
- Guns: None
- Hardpoints: None
References
- Notes
- ^ a b c d e f "BAe Nimrod AEW3". The Spyflight Website. Retrieved 11 May 2011.
- ^ Aboulafia, Richard (May 2001). "Airborne Early Warning: An affordable necessity?". Aerospace America. Retrieved 12 May 2011.
- ^ Goebel, G (1 March 2011). "Project Cadillac: AN/APS-20". The Wizard War: WW2 & The Origins Of Radar. Vectorsite.net. Retrieved 11 May 2011.
- ^ a b c Bellany and Huxley 1987, p. 77.
- ^ a b c d e "BAE Systems Nimrod". Aeroflight. Retrieved 11 May 2011.
- ^ "The Nimrod AEW Saga". 8 Squadron History. 8squadron.co.uk. 4 September 2006. Retrieved 11 May 2011.
- ^ Braybrook 1982, p. 9.
- ^ Braybrook 1982, p. 40.
- ^ "Could Nimrod Clip AWACS Wings?" New Scientist, 73(1042), 10 March 1977. p. 586.
- ^ Chin 2004, p. 156.
- ^ Kopp, C (March/May 1989). "AEW and AWACS". Australian Aviation. Air Power Australia. Retrieved 12 May 2011.
{{cite web}}: Check date values in:|date=(help) - ^ Hewish, Mark (1981). "Britain's air defences grow new teeth". New Scientist. 89 (1244): 682–684. Retrieved 12 May 2011.
- Bibliography
- Bellany, Ian and Tim Huxley. (Ed.) "New Conventional Weapons and Western Defence". Routledge, 1987. ISBN 0-71463-310-0.
- Braybrook, Roy. Battle for the Falklands: Air Forces. London, UK: Osprey Publishing, 1982. ISBN 0-85045-493-X.
- Chin, Warren. "British Weapons Acquisition Policy and The Futility of Reform". Ashgate Publishing, 2004. ISBN 0-75463-121-4.
- Conner, Steve. "Nimrod Reaches to the End of the Runway". New Scientist, 111(1519), 31 July 1986, pp. 33–36.
External links
