UK Funding for ‘Captor-E’ AESA Radar Announced – Better Late than Never

At the Farnborough International Airshow on 14 July 2014, David Cameron announced that the UK was committed to upgrading its Typhoon FGR.4 fast jet fleet with the ‘Captor-E’ Active Electronically Scanned Array (AESA) radar as part of a £1.1 billion ($1.88 billion) defence spending package. This welcome and long-overdue step will not only provide a significant boost to RAF Typhoons’ combat capabilities, but may also help reverse the type’s declining fortunes on the international export market, especially in the Middle East.

The ‘Captor-M’ radar which currently equips all Eurofighter Typhoon aircraft is a mechanically scanned, multi-mode pulse doppler radar. Despite having a reputation as the most effective and advanced mechanically scanned radar in the world, the ‘Captor-M’ is outclassed in many respects by AESA type radars which are offered by many aircraft manufacturers for an increasing variety of combat jets worldwide, including Lockheed Martin’s F-22, F-35 and F-16 Block 60, Boeing’s F/A-18E/F and EA-18G, Dassault’s Rafale, Saab’s Gripen-E and Chengdu’s J-10B.

Why AESA?

AESA radar systems use very large numbers of individual transmit and receive (TR) modules to emit signals at varying frequencies and in varying patterns, with the process being controlled by powerful software algorithms. The returns generated are then analysed using similarly complex computing processes and then combined to form a similarly detailed and complex picture to that possibly using a single, very powerful radar beam. The advantage of this is that it is extremely difficult for potential opponents to detect the emissions from an AESA radar, even though they can be extremely powerful. Because the frequencies and scan patterns being broadcast by every TR module that makes up the AESA array are constantly changing, it is very difficult for a ‘radar warning receiver’ (RWR) on an opposing aircraft or platform to pick out any particular signal against standard electro-magnetic ‘background noise’. Typhoons equipped with ‘Captor-E’ as opposed to the older ‘Captor-M’ will be much more able to see without being seen in hostile airspace.

AESA radars are also capable of performing far more simultaneous tasks at higher resolution than older mechanically scanned systems. ‘Captor-E’ can, for example, scan a wide area for new contacts, track existing contacts, and guide multiple missile launches against those contacts simultaneously. AESA radars such as the APG-81 (for F-35) have also shown themselves to be capable of both offensive and defensive electronic and cyber warfare, as well as functioning as high-powered transmitters and receivers of wideband data streams between allied assets. It is currently unclear whether ‘Captor-E’ incorporates these functions in its current form, but even if it does not, mid-life software upgrade packages could certainly add these capabilities for Typhoons equipped with the array.

Typhoon’s Competitive Advantage

Figure 1: Increased coverage of Captor-E over fixed AESA arrays. Source: www.eurofighter.com

Typhoon as an airframe is particularly well adapted to mounting an AESA radar due to the comparatively wide nose cross section which allows the mounting of a larger AESA array than many competing aircraft such as the Rafale, F-35 or F/A-18E/F. This is important because the capability of an AESA radar corresponds closely with the total number of TR modules that are incorporated within the array. Therefore, a larger nose section can mount a wider AESA with more TR modules. ‘Captor-E’ incorporates around 20% more TR modules than the AESA radars mounted on the F/A-18E/F and F-35 and up to 40% more than the Rafale’s RBE2-AA, giving greater range and resolution over those systems. In addition, the Captor-E will also be mechanically gimballed so that it can be slewed within the nose of the Typhoon, increasing the coverage of the radar from around 90° to 120°. (See Figure 1)

Given the huge capability advantages of AESA radars over older mechanically scanned radar systems, there is a strong argument that ‘Captor-E’ should have been funded by the Eurofighter partner nations several years ago. The technology has been ready but the commitment from partner nations has been lacking. The result has been the decline in Typhoon’s fortunes on the international export market.

In fighter-procurement competitions where the tendering nation perceives an existential peer threat (such as South Korea, Japan and Israel), ‘4.5 generation’ fighters like the Typhoon, Rafale and Gripen were always unlikely to beat the ‘5^th Generation’ F-35. However, in other regions, particularly the Gulf States, where stealth capabilities are not currently seen as necessary, the Typhoon was the front runner in the mid-late 2000s with orders from Saudi Arabia (72) and Oman (12), and potential orders from the United Arab Emirates, Bahrain and Qatar. However, the momentum seems to have stalled, with the UAE walking away from a deal for sixtyTyphoons in 2013 and India selecting the Dassault Rafale in a huge order for 126 aircraft.

Part of the problem now is that, with F-16 Block 60, F/A-18E/F, Gripen-E and Rafale being marketed in the region with AESA radar capability and for lower unit costs than Typhoon, the latter’s biggest unique selling point – exceptional air superiority capability – is being undermined. Saudi Arabia, the largest export customer for the aircraft, have made it clear that AESA radar is a prerequisite for any further orders of the type.  It would, therefore, seems sensible to conclude that without swift ‘Captor-E’ integration, Typhoon’s export prospects seem gloomy. If the process takes much longer, F-35 will likely reach full scale production and costs for the currently troubled 5^th generation jet may drop low enough to kill off the market for 4.5 generation combat jet exports altogether.

Overall, the Prime Minister’s announcement that the British government will at last fund ‘Captor-E’ AESA integration into the Typhoon programme via Selex and BAE Systems represents an essential and welcome policy. It will not only provide greatly increased capabilities for the RAF’s Typhoon fleet but might also be in time to revive the type’s hopes on the global export market. As matters stand, Typhoon production lines will close by 2018 without further foreign orders. Even worse, the production lines for certain sub-assemblies and components may shut as soon as 2015. For the sake of defence industrial resilience, as well as safeguarding the sustainability of current partner nation fleets, the Typhoon consortium needs new export success, and soon.