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JF-17 Block-III: Pakistan’s New Fighter

On 15 December 2019, the first known prototype of the JF-17 Block-III performed its maiden test flight in Chengdu at Chengdu Aircraft Industry Group’s (CAIG) facilities.[1]

The JF-17 Block-III is the first major upgrade of the JF-17 Thunder, a lightweight multi-role fighter that is co-produced by CAIG and Pakistan Aeronautical Complex (PAC). The JF-17 is one of the mainstay combat aircraft of the Pakistan Air Force (PAF), which now operates roughly 120 fighters across multiple variants.

As previously noted, the Block-III retains the airframe design of the preceding Block-I and Block-II, though with visible modifications. The most apparent of these changes include an unknown addition to the base of the vertical stabilizer, repositioned sensors on the vertical stabilizers, and sensors to the main inlets.

Though it includes a new head-up display (HUD), it is unclear how many of the new intended subsystems are already in this Block-III prototype, but it is not yet equipped with a radar. It seems testing will be done in phases, with subsystem and weapon integration coming towards the end (and potentially in Pakistan).

Currently, the PAF intends to procure 50 Block-IIIs, the first two of which are due in 2020. Deliveries of all aircraft are due by 2024. In effect, the JF-17 Block-III will be the first (and potentially only) so-called 4+ or 4.5-generation multi-role fighter addition through the 2020s, making this test flight a key milestone.

The Value of Retaining the Same Airframe

The main objective of the JF-17 Block-III was to equip the PAF with new generation subsystems, especially an active electronically scanned array (AESA) radar, integrated electronic warfare (EW) and self-protection suite, helmet mounted display and sight (HMD/S) system, and other essentials.

For the PAF, there likely was limited reason or purpose to significantly altering the JF-17 airframe as long as those new subsystems could work within the current design. Based on the prototype Block-III, it seems that the existing JF-17 design was able to support the new subsystems, albeit with some changes.

The most significant of these changes (aside from new subsystems) was, arguably, the replacement of the hybrid flight control system with a new three-axis fly-by-wire (FBW) system. The three-axis FBW was first put to use on the dual-seat JF-17B (of which the PAF will procure 26 aircraft).

It is not known how the new FBW system has impacted the Block-III, though one can speculate that it may have freed up internal space for more fuel or electronics (e.g., cooling for the AESA radar). In theory, the FBW might allow CAIG/PAC to relax the JF-17’s stability, which may improve maneuverability.

It was reported that the Block-III would feature widened main inlets, ostensibly to improve the air flow. It is unclear if that intended change was retained, though if implemented by a factor of millimetres, it might not be noticeable to the naked eye. That notwithstanding, the PAF will retain the RD-93 turbofan engine.

The main benefit of retaining the same airframe design is lower development and production cost. Though one might point to the fact that the Block-III required over four years of development (in which time Saab had enlarged the Gripen’s airframe and changed the engine), the JF-17 project runs on a smaller budget.

Pakistan’s fiscal limitations are a genuine constraint, particularly for the PAF, which – despite maintaining a large technologically-driven force – does not have the largest share of the defence budget. Though the Block-III may not improve much in terms of range, payload, or low-observability, it still brings the essential elements of 4+/4.5-generation fighters, such as an AESA radar and new integrated EW suite.

In addition, by retaining much of the core, PAC need not change much in terms of its jigs, it should be able to transition to the Block-III smoothly. Interestingly, having rolled-out eight JF-17Bs, it appears that in the 2020s PAC will only work on either the JF-17B or Block-III – i.e., airframes with the new FBW system. So, in a sense, one could say that PAC is already primed to manufacture its share of the Block-III.

Finally, there is sufficient evidence to suggest that retrofitting the Block-I and Block-II with most Block-III subsystems is doable. So, for example, the PAF could replace the KLJ-7/V2 with the LKF601E AESA radar – which the Aviation Industry Corporation of China (AVIC) markets as a backwards compatible system. Once an HMD/S is selected, that too could make its way to older JF-17s, alongside other systems.

However, it is unclear if the PAF will commit to an upgrade. First, it will cost money, and it should be noted that the earliest Block-Is will be 20 years of age in 2030. In other words, those fighters would likely close-in on their 3,000-hour airframe lifespan. Second, upgrading would mean withdrawing the fighters – albeit temporarily – from frontline service. If an upgrade is slotted, it should occur now as those fighters proceed with major maintenance, repair and overhaul (MRO) work, not into the mid-2020s.

Starting 2025, the PAF could simply exercise the option of rolling-out new JF-17B and Block-III-based jets, perhaps with smaller or iterative updates (e.g., a hypothetical ‘Block-IV’ or ‘Block-V’). Moreover, even if Project Azm (the PAF’s next-generation fighter program) hits technical snags or delays, the PAF could roll-out additional JF-17s so as to replace older JF-17s and induct new subsystems and weapons.

A Major Investment in New Subsystems

The PAF has not yet disclosed the subsystem suppliers it has chosen to equip the Block-III, but observers noted that the prototype appears to use a holographic HUD comparable to the one onboard the Chinese J-20, a fifth-generation fighter. Likewise, the sensors around the airframe seem similar to the missile alert warning system (MAWS) integrated to the Chengdu J-10C, China’s mainstay 4+/4.5 generation fighter.

With the JF-17 Block-III, the PAF seems to be investing in the best available electronic subsystems, and if it is drawing on the J-10C and J-20, then it is not compromising. Moreover, the integration facility at PAC could see the PAF add the best available European and Turkish subsystems to the Block-III as well.

In effect, the PAF could be aiming to equip the JF-17 with the same caliber of subsystems and weapons as those on larger aircraft (e.g., J-10CE). This should, to an extent, alleviate the concern of not procuring an off-the-shelf 4+/4.5 generation fighter – the JF-17 Block-III will deliver the same core capabilities.

Be it in terms of the AESA radar, integrated EW suite, or even new missionized cockpit environment, there are options for the PAF. The one apparently elusive area has been HMD/S, which is a result of the reality that very few suppliers around the world offer a contemporary capability.

In the West, the HMD/S market is dominated by one supplier (Elbit), with Thales and BAE Systems serving niche needs. Though Thales and BAE Systems could supplier their respective solutions in theory, technical and political factors will prevent that outcome. Thus, the PAF will have to wait (if it has not already) for an original HMD/S, likely from China (though Turkey and South Africa may have the means to develop HMD/S as well due to their next-generation fighter needs or optronics expertise, respectively).

If the PAF did not invest in improving the Block-III’s maneuverability, then HMD/S with a high off-boresight air-to-air missile (HOBS AAM) will be critical. This pairing would make the JF-17 a credible threat at within visual range (WVR). Though the PAF may believe most air combat will occur at beyond visual range (BVR), a credible WVR capability would be a worthwhile contingency.

Finally, the dedicated hardpoint for special mission pods would open the JF-17 Block-III to multiple niche roles. The PAF will certainly have advanced targeting pods and EW pods available, equipping the JF-17 to manage precision-strike and radar jamming, respectively. In addition, the PAF could also look into photo-reconnaissance pods and infrared search and track (IRST) in pod form.

By minimizing the added development overhead to the Block-III, the PAF could have more resources for new munitions, subsystems, and special mission capabilities. Moreover, by eschewing an off-the-shelf jet for the time being, it can use the funding towards more JF-17s (and developing Project Azm).

Fundamentally, modern air warfare is geared towards having contemporary capabilities in ample quantity – the JF-17 Block-III and JF-17B can deliver on those fronts. Yes, the platform is not the best on the market, but the PAF can invest in the world-class subsystems and weapons for the fighter.

The key would be having those systems across enough fighters – for building a numerically large fleet with limited funding, the JF-17 is the most affordable means. If anything, the concerning part is not Pakistan’s inability to import another fighter, but if it is unable to field enough JF-17s. If the PAF acquires enough JF-17s, it will need to reorient its doctrine and support assets to extract the most out of the fighter.

[1] Andreas Rupprecht. “Sino-Pakistani JF-17/FC-1 Block III prototype makes maiden flight.” Jane’s Defence Weekly. 02 January 2020. URL:

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