Pakistani officials attending this year’s Defence Services Asia (DSA) exhibition told IHS Jane’s that the Pakistan Air Force (PAF) is actively considering the idea of swapping out the JF-17’s existing turbofan (i.e. RD-93) with either the Klimov RD-33MK or Guizhou WS-13.
In November 2015, the PAF told IHS Jane’s that it was committed to sticking with the RD-93. In fact, representatives from Pakistan Aeronautical Complex (PAC) even mentioned that talks were underway to bring a maintenance, repair and overhaul (MRO) facility for the RD-93 to Kamra, hence signaling the PAF’s commitment to working with Klimov (we discussed this in greater detail in an earlier article).
That said, the selection of a lighter and more powerful engine to replace the current RD-93 is a natural step forward, especially for the JF-17. The Klimov RD-33MK is the latest iteration of the RD-33 turbofan, but with a higher thrust output, full authority digital engine control (FADEC), and a lifespan of 4000 hours. The RD-33MK is currently used by the MiG-29M/M2 and MiG-35.
Last year, we had speculated that the JF-17 Block-III could potentially be equipped with a higher thrust turbofan, thus enabling the fighter to boast a higher thrust-to-weight ratio (TWR), especially if a higher proportion of composite materials are incorporated into the airframe. Besides improving the JF-17’s basic performance benchmarks (e.g. speed), an uprated engine could offer the PAF greater flexibility in arming the JF-17 for payload intensive roles, such as air-to-ground and sea missions.
Of the options available, the RD-33MK would seem to be the most seamless, especially considering that it is an evolution of the RD-93, which is a modified RD-33. The evolution in this case could be analogous to the JAS-39 Gripen’s transition from the GE404 to the GE414 (via the Gripen NG). In fact, improvement in thrust is only one benefit. The RD-33MK’s use of FADEC enables for more efficient engine usage, thereby extending time between overhaul (TBO). It is also smokeless.
Some may be familiar with the so-called RD-93MA, which is said to be an upgraded RD-93 in development for the JF-17. It was reported that the RD-93MA’s thrust output would be in the area of 91kN, that is not too far off from the RD-33MK’s 89kN. It is worth noting that the recent Jane’s article lists the RD-33MK’s thrust output at 9.4 tons, which essentially means 92kN. In any case, it is possible that the RD-93MA emerges as a modified RD-33MK.
Some might be wondering about the possibility of adding a thrust-vectoring nozzle (TVN) through the RD-33MK. This is not an aspect the PAF has seriously considered. We can only speculate as to why, but the added costs associated with a TVC-equipped JF-17 (from acquisition to potentially maintenance) are probably not worth the gains, which may not even be enough to offset the challenges of increasingly accurate (as well fast and maneuverable) air-to-air missiles.
The Guizhou WS-13 is noted as an alternative. Specific details about this engine are not easy to come by, at least in English. Fortunately, Georg Mader from Defence Industry Bulletin was able to offer some insight into the WS-13 and its development via a source at the Guizhou Aviation Industry Corporation (GAIC). Like the RD-33MK, the WS-13 has a higher thrust rating compared to the RD-93, it also uses FADEC. Moreover, a Chinese official told IHS Jane’s that the WS-13 was already being test flown on the JF-17.
In the end, the PAF may prefer sticking to Klimov. It is already accustomed to the RD-93, and despite some issues in terms of fuel consumption and TBO, the PAF has praised its durability and reliability. One would expect that the RD-33MK (or RD-93MA) would draw a lot in terms of commonality from the RD-93, and rectify some of its concerns with the RD-93. But although Russia and Pakistan have made some headway in improving their defence ties, China will remain anchored as a time-tested partner, especially given its own strategic concerns in regards to the pressure it is feeling in Pacific Asia. If the WS-13 emerges as a capable solution, the PAF could consider it. In fact, the FC-31 is likely slotted to use the WS-13, which is an important point considering the PAF may use the FC-31 as the basis for its next-generation fighter.
PAF/PAC officials also told IHS Jane’s that the twin-seat JF-17 will likely begin its flight tests in late 2016 and early 2017. Furthermore, the refuelling probe configuration shown in China is the configuration the PAF will be using for its own aircraft. No updates were offered in regards to the JF-17 Block-III.