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NRIET to Integrate KLJ-7A AESA Radar to JF-17

Hu Mingchun, the head of the Nanjing Research Institute of Electronics Technology (NRIET), told the China Daily that NRIET’s new active electronically-scanned array (AESA) radar, the KLJ-7A, will be integrated onto to the JF-17 Thunder multi-role fighter.[1] This would imply that the Pakistan Air Force (PAF) selected NRIET to supply the AESA radar for the forthcoming JF-17 Block-III – the previous PAF Chief of Air Staff (CAS) had stated that the Block-III’s design was finalized, which means the subsystem selection has been frozen.

Overall, the PAF selecting the KLJ-7A would not be surprising. First, the KLJ-7A had the fewest obstacles in the way of delivering the Block-III into an operational factor. Second, this could involve a long-term play for securing sensitive Chinese technology for Project Azm, the PAF’s next-generation fighter program.

The KLJ-7A’s Value to the JF-17 Block-III

In general, an AESA radar’s improvements stem from its use of multiple transmit/receive modules (TRM). In contrast to mechanically-steered radars, which can transmit in one frequency per pulse, an AESA radar can leverage multiple TRMs to transmit in multiple different frequencies simultaneously. This shields the AESA radar from electronic warfare (EW) jamming in that if one of its frequencies are jammed, the radar can still undertake its detection, tracking and targeting functions.

However, because these TRMs are fixed, an AESA radar generally has a relatively limited field-of-view (FOV), usually 90-120°.[2] Comparatively, this is new technology, so its applications are still evolving, with innovation emerging to rectify its limits (e.g. the mechanical swashplate of the Raven ES-05, enabling it to have a wider FOV). Practically, multiple JF-17 Block-IIIs will engage – alongside airborne early warning and control (AEW&C) support – in a mission, so the limited FOV is not a decisive inhibitor (relative to the gains).

The KLJ-7A was formally revealed during Air Show China 2016. In terms of specifications, Henri Kenhmann of East Pendulum learned that the KLJ-7A uses 1,000 TRMs and has a stated maximum air-to-air detection range of 170 km, but it is unclear if this is for targets with 5m2 radar cross-section (RCS) or 3m2 RCS. However, the KLJ-7A could track 15 targets and engage four simultaneously.[3] It is likely that the KLJ-7A is using gallium arsenic (GaA)-based TRMs; not only are the manufacturing processes for these established, but the much-improved gallium nitride (GaN) TRM is a very recent entry in the market. The sole airborne GaN AESA radar available is the Saab Erieye Extended Range for AEW&C, all other applications of the TRM are for land and sea-based air surveillance and air defence radars.

Compared to the KLJ-7A, the KLJ-7 of the Block-I has a detection range of 75 km for 3m2 RCS targets. [4] The KLJ-7V2 that is onboard the Block-II reportedly has a range of 110 km for 3m2 RCS targets.[5] NRIET said that the KLJ-7A provides a range improvement of 55% – if this is in reference to the KLJ-7V2 and its reported range of 110 km for 3m2 RCS targets, then the 170 km detection range should be for 3m2 RCS targets.

For the PAF, these are key technical improvements, but the KLJ-7A selection also confirms that the radar is sufficient for fulfilling the PAF’s requirements. This is important because the inability to secure another fighter platform positions the Block-III at the center of the PAF’s defensive strategy against a plethora of high-performance fighters in the Indian Air Force (IAF) and Indian Navy (IN). Granted, the Block-III will not be superior to many of these platforms, but the objective is to create a credible threat to the Rafale et. al; fitting the JF-17 with broadly analogous subsystems is a start, though the key rests in the JF-17’s inherent advantages of being low-cost and procurable in high quantities (i.e. sustain attrition and outnumber).

Why the KLJ-7A?

For the PAF, the benefit of acquiring the KLJ-7A runs beyond simply its technical performance, though an essential aspect, it is not alone. First, China is the most accessible path in terms of cost-effectiveness and regulatory/government obstacles. In 2007, the PAF had sought to equip the Block-I/II with Thales’ RC400 radar and MBDA’s MICA beyond-visual-range air-to-air missile (BVRAAM). However, the ill-fated program – reportedly valued at $1.2 billion US[6] – collapsed, most likely because of Paris prioritizing a more lucrative Rafale sale to India. The risk of repeating such an episode (over the Vixen 1000E), be it due to concerns of the UK (where Leonardo’s Selex division is located) or inability to find compatible munitions, would delay the Block-III’s entry as an operational asset. With the KLJ-7A, that is not a concern as the Block-III can use the PAF’s existing SD-10 BVRAAM and C-802 anti-ship missile (AShM) stocks.

Second, the issue of cost-effectiveness is more than just the cost of the radar, but the cost of integration, testing and qualification. The Aviation Industry Corporation of China (AVIC) has a commercial interest in exporting the JF-17 as well as the KLJ-7A. It would be easier for the PAF to draw upon joint-funding for the requisite engineering costs of integrating the KLJ-7A to the JF-17. Ease also extends to simply leveraging AVIC’s internal development processes – i.e. it is easier for NRIET to collaborate with the Chengdu Aircraft Corporation (CAC) than it is for CAC to be roped in with Leonardo (or vice-versa). With the design frozen, the Block-III program is effectively in the process of materializing into a prototype for testing; the PAF is evidently looking to compress the lead-time ahead of bringing the fighter into full operating capability.

Third, leveraging China’s research and development (R&D) depth and economies-of-scale. Supporting the cost-effectiveness of the KLJ-7A is the fact that Chinese TRMs are being used in many domestic programs, from AEW&C through current and next-generation multi-role aircraft. In a sense, embarking on the NRIET path for AESA radar could future-proof the JF-17 by better positioning the PAF to request next-generation AESA radars from China, which could plausibly involve GaN-based TRMs and other innovations. However, the key is China’s scale, which supports a rapid iterative cycle by amortizing the prior R&D overhead on a relatively frequent basis. For the PAF, it would mean improving the JF-17 on that same cycle.

Fourth, the aspect of future-proofing the JF-17 could also apply to a next-generation suite of air-to-air and air-to-surface munitions. In theory, such weapons could be sought from outside China, but as discussed in the Quwa Premium article, “China’s Scale Gives Flexibility for High-Tech Arms Development”, it is China that is optimally positioned to develop and innovate at the pace and cost closest to the PAF’s limitations.[7] In practical terms, the PAF could look for analogous solutions to the MBDA Meteor and the BrahMos for use on the JF-17 through China. Certainly, the Chinese face these very threats from India as well, so there is a strategic interest in undertaking such development, besides the commercial value of Pakistani sales. Should these solutions materialize, the JF-17 – through the KLJ-7A – will be ready to utilize those weapons.

Fifth, acknowledging China’s strengths in R&D and scale, the PAF would have understood that there is no other partner but China through which it can have a viable next-generation fighter. Selecting the KLJ-7A helps build goodwill for the PAF as it requests China’s assistance in more sensitive and complex areas. In a sense, the KLJ-7A is not just a step forward for the Block-III, but a progression towards Project Azm (i.e. the PAF’s fifth-generation fighter program). In fact, the PAF could stage the subsystems and weapons of the JF-17 and Project Azm along the same continuum, i.e. have the JF-17 help in the maturation process while also scaling the PAF’s own expenditure by applying its investment to both programs. For example, the PAF could invest in a next-generation BVRAAM with China and use it from the JF-17 and Project Azm.

Retrofitting the JF-17 Block-I and Block-II

Retrofitting the JF-17 Block-I and Block-II with the KLJ-7A would depend on the structural changes required to make an AESA radar feasible for the JF-17. The Block-III has key differences, such as the three-axis fly-by-wire (FBW) flight control system, which might have contributed to freeing space for additional cooling systems for the KLJ-7A. However, the advantage of using the existing design of the JF-17 for the Block-III is that the gap for upgrading older variants is comparatively minimal.

However, retrofitting the older JF-17s comes at the cost of pulling those fighters out of operational service. The point in the JF-17’s lifecycle where retrofitting would make sense is during a major overhaul – the first PAF JF-17 is undergoing that through a pilot program in China. However, with the airframe having a life of 15-20 years (3000 hours),[8] the PAF must examine if it is worth spending as much for another 10 years of usage. Granted, the Block-I/II could be upgraded to the Block-III,[9] the PAF might find its funds better spent on new-build JF-17s (e.g. a Block-IV or Block-V) to supplant its oldest fighters.

Interestingly, the Block-III could be the bridge between redefining the JF-17 from its original (1990s-era) goal of simply replacing the F-7P, A-5 and Mirage III/5 with a “medium-tech” BVRAAM-capable fighter to a high-tech (albeit lightweight) solution for the 2030s and 2040s. Indeed, the Block-III would be the first PAF fighter to deploy an AESA radar; such qualitative leaps have traditionally occurred through Western imports, but now, the technology can be had through a lower-cost workhorse.

[1] Zhao Lei. “Pakistan fighter jets to get radar upgrade”. China Daily. 28 March 2018. URL: (Last Accessed: 29 March 2018).

[2] “Making AESA Radar More Flexible”. Aerospace & Defense Technology. 01 December 2015. URL: (Last Accessed: 29 March 2018).

[3] Henri Kenhmann. “Airshow China 2016: KLJ-7A, the AESA radar” East Pendulum. 01 November 2016. URL: (Last Accessed: 29 March 2018).

[4] KLJ-7/10 Fire Control Radar (FCR) (China). Airborne Radar Systems. IHS Jane’s. 19 January 2009. URL:

[5] Andreas Rupprecht. “Eye on the East: The JF-17’s Dilemma”. Combat Aircraft. July 2016.

[6] Alain Ruello. “Pakistan calls on France to beef up its fighter planes”. LesEchos. 23 September 2009 URL: (Last Accessed: 29 March 2018).

[7] “China’s Scale Gives Flexibility for High-Tech Arms Development”. Quwa Premium. 09 February 2018. URL:

[8] Tomislav Mesaric. “Pride of Pakistan”. Air International. December 2013. p.47.

[9] Alan Warnes. “Chinese-Pakistani JF-17 Thunder Fighter will fly in 2017”. Aviation Week & Space Technology. 13 February 2017. URL: (Last Accessed: 29 March 2018).

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