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Air-to-air missiles for the new fighter generation
By Karl Schwarz
For many years now air combat between opposing fighters has been the exception rather than the rule. Especially in the recent conflicts of Iraq, Afghanistan and the Lebanon, for example, the USA or Israel was pitted against extremely weak or non-existent enemy forces. Despite this, Forecast International believes that demand for air-to-air missiles will continue unabated, as those conditions cannot be guaranteed everywhere. In view of the entry into service of a new generation of fighters (Eurofighter, Gripen, Rafale, F-22, F-35, Su-35) currently in progress, the US market research institute has even revised its forecasts upwards: between now and 2015 it sees a requirement for over 52,000 missiles worth $15.4 billion or Euro 12 billion.
MBDA Meteor fired from Saab Gripen
By far the biggest player in this market is Raytheon. The US company is benefiting from the massive domestic market for its AIM-9X Sidewinder and AIM-120 AMRAAM and from the fact that export customers which operate US fighters usually stick with American weapons that are already certified for the type. Thus, in the view of Forecast International, over the next ten years Raytheon can look forward to sales of $4.5 billion (Euro3.5 billion).
In second place after Raytheon is MBDA (Germany, France, the United Kingdom and Italy) which, with MICA, ASRAAM and the future Meteor, has a wide product base and can count on earnings of $3.3 billion (Euro2.6 billion) between now and 2015. At the same time an international consortium led by Diehl BGT Defence is offering the IRIS-T. Not to be forgotten, of course, are the Russian missile manufacturers and Rafael of Israel. Air-to-air guided missiles are also under development in China, South Africa, Taiwan and Japan, but these countries play only a negligible role in the export market.
The latest air-to-air missiles can all generally be assigned to one of two categories: missiles with infrared seeker and enormous agility for engaging agile targets at short range, and long-range missiles with radar seeker.
Infrared guided missiles are already achieving distances of up to 30km, albeit only under ideal conditions, for example, engagement of a high altitude approaching target. In normal conditions the range is likely to be a lot less, especially if the energy of the solid-propellant motor, which burns for only a few seconds, is dissipated over tight manoeuvres. Extreme agility is the hallmark of the new products which, mostly with the aid of thrust vector control, can also engage targets “around the corner” or even behind the firing aircraft.
Such manoeuvres call for seeker heads with “squint angles” of about 90°, which are best guided by the pilot with the aid of a helmet-mounted sight. In addition to agility, a good infrared sensor must today be capable of more than just tracking the hot exhaust gas released by the adversary. Today's sensors produce rough images enabling target aircraft to be distinguished from chaff and flares. On account of the light fragmentation warhead it is important to also have an intelligent fuze which triggers detonation at the shortest distance from, and by the most sensitive point of, the hostile aerial target.
The first highly agile air-to-air missile to enter service was the R-73 (NATO code AA-11 Archer) produced by Vimpel in the 1980s – which proved an unpleasant surprise for the West. At present the Russian design bureau is working on the K-74M2, a completely overhauled version with digital signal processor, new seeker head and motor with higher thrust.
High agility was also the objective behind the development of the Rafael Python 4, although this does not have thrust vector control. The Python 5, its successor, took over the aerodynamic configuration with four delta-shaped control surfaces at its tip and extremely large fins, but has an imaging seeker which operates in two wavelength ranges, plus improved electronics.
In the USA, Raytheon has developed another member of the Sidewinder family in the form of the AIM-9X. Once again this missile uses thrust vector control and has an imaging seeker head. Following the completion of field trials in November 2003, full production of the AIM-9X was approved in May 2004. The US Air Force and the US Navy alone plan to procure over 10,000 of these missiles in the long-term. Export customers already signed up include Denmark, Finland, Poland, Saudi Arabia, Switzerland, Singapore, South Korea and Turkey.
IRIS-T (InfraRed Imaging System- Tail/Thrust-Vector Control), the product of a consortium led by Diehl BGT Defence in Überlingen, Lake Constance, has also enjoyed a good customer base right from the start. In December 2005 the Luftwaffe took delivery of the first IRIS-T. The other partner nations are Greece, Italy, Norway, Sweden and Spain. Together they plan to purchase over 4,000 IRIS-T missiles between now and 2011, to equip aircraft types such as the Eurofighter, Gripen, F-16, F-18 and Tornado. Austria has also ordered 25 of the missiles for its Eurofighters.
The first aircraft to gain IRIS-T certification will be the Eurofighter. However, the full capabilities with digital link to the aircraft will not be available until the upgraded Tranche 2 aircraft are delivered. According to Diehl BGT Defence, the heart of IRIS-T is the imaging infrared target seeker head with exceptionally high resolution, large squint angle, extremely high tracking speed and intelligent image processing.
In parallel to IRIS-T, MBDA has developed the ASRAAM in the UK. The Royal Air Force (Eurofighter and Tornado F3) is not the only customer for the ASRAAM, but the Royal Australian Air Force has also selected it for its F/A-18 Hornets. On the other hand, the A-Darter developed by Denel Aerospace Systems has not yet entered into service. Due to the shrinking domestic market, this South African company is reliant on international partners and in July 2006 signed an agreement with Brazil, which will contribute around $50 million (Euro39 million) towards the cost of the development work.
A new missile supplier appeared on the scene last summer in the form of the Luch Scientific Production Association from the Ukraine, which has developed the Gran (= “Frontier”). This missile makes use of components from the R-73, which was built in the former Soviet republic. According to the Ukrainian Ministry of Defence in Kiev, it is currently in the final stages of development.
In the area of radar-guided air-to-air missiles some interesting projects are currently under way as well, notably the European Meteor programme involving six nations (Germany, France, the United Kingdom, Italy, Sweden and Spain). According to the specification, Meteor should be capable of taking out all targets (including cruise missiles and manoeuvring fighter aircraft) at a range of over 100km. This capability depends on a controllable, air-breathing solid-propellant ramjet, which is being developed by Bayern Chemie on the basis of boron. After the nozzleless booster has burnt out, the two asymmetrically arranged air inlets open up and Meteor accelerates to velocities of well over Mach 3.
During its flight, the MBDA Meteor receives updated target coordinates over a data link. In the final stage of the engagement, the guided missile operates autonomously with its active radar homing head. The system, which works in the Ku band (12 to 18GHz, i.e. in the wavelength range 2.5 to 1.7 cm) should be less vulnerable to jamming.
The first three test firings of the Meteor were carried out in 2006 above the test centre of Vidsel, in the north of Sweden, from a Saab Gripen. Development of the seeker head will entail captive flight tests with the JAS 39. The first controlled firings are planned for 2008, and the Meteor is expected to enter into service on the Eurofighter in 2012, at a unit price of £1,000,000 (Euro1.5 million), according to the UK National Audit Office.
The Europeans are expecting Meteor to not only deliver superior performance compared with the present market leader, the AMRAAM, but also to give them independence over exports. Meanwhile Raytheon is not resting on its laurels but is currently working on an upgraded version, the AIM-120C-7, which will have a better seeker head and new electronics on compact, round plug-in boards. After several setbacks, the field trials currently under way are expected to be completed by the summer of 2007. Production of the approx. $700,000 (Euro550,000) missile has commenced at Raytheon's Tucson plant.
Following close on the heels of the C7 version, the AIM-120D is already under development. This is to be equipped with a GPS receiver which will offer greater accuracy of position finding and hence more efficient flight profiles. On top of this, an improved datalink is to be installed in the tail and a new datalink antenna in the nose. The launch aircraft will no longer need direct line of sight to the tail of the missile to receive target updates and will be able to manoeuvre more freely after firing. According to provisional plans, the AIM-120D should enter into service in the autumn of 2009. In the long term, the AMRAAM could be equipped with small control nozzles for better agility. The US armed forces are also considering developing a completely new Joint Dual Role Air Dominance Missile.
The French MICA from MBDA, which is available with both infrared and radar seekers, already offers some multi-role capability. The missile will be deployed on the Mirage 2000 (also in Qatar and Taiwan) and on the Rafale. Rafael is also offering an interesting concept in the Derby, which, despite its radar seeker and datalink, is lighter than the AMRAAM and hence well-suited to fighter aircraft such as the F-5. Chile and Brazil are already customers. South Africa has a similar model in the R-Darter, which is said to have been developed during the 1990s with Israeli support.
The Russian AMRAAM equivalent is the R-77 (AA-12 Adder), although only small numbers of this missile were produced after the disintegration of the Soviet Union. Vimpel is planning to develop a much improved version, the K-77M, by 2010. A more powerful motor should increase its range by a factor of 2 to 3.5 and the improved radar will reduce vulnerability to jamming. The most visible change is the use of normal control surfaces instead of lattice fins, which reduces resistance.
Russia is also active in the ultra-long-range area. Thus, the upgraded MiG-31BM will probably be armed with the K-37M (AA-13 Arrow), which during tests in the 1990s succeeded in shooting down targets at a distance of 240km. The K-100 under development at the Novator design bureau from Yekaterinenburg, which Sukhoi has selected as the preferred armament for the Su-35 and the future fifth generation of Russian fighters, should have a range as great as 300km. Several test firings have already been carried out. KARL SCHWARZ
From page 40 of FLUG REVUE 1/2007
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