3 for China with 250 hours more life and 1000 kg/f more thrust; the Series 3 would be equipped on the improved J-10B. Compared to the original Lyulka-Saturn AL-31F, the AL-31FN was fitted to the J-10 by rotating the gearbox and accessory pack to the underside. The J-10s intended engine is the Chinese Shenyang WS-10. The WS-10 suffered development difficulties and production of the aircraft went ahead with the Salyut AL-31FN as a substitute. A pre-production J-10C flew with a WS-10 at the 2018 China International Aviation & Aerospace Exhibition; the engine nozzle was modified for stealth and thrust vectoring (TVC). In March 2020, a video from Chinese state media showed a J-10C in PLAAF livery equipped with the WS-10B; WS-10B-powered aircraft were in service by November 2021. Weaponry and external loads The aircraft's internal armament consists of a Gryazev-Shipunov GSh-23 twin-barrel cannon, located underneath the port side of the intake. Other weaponry and equipment is mounted externally on 11 hardpoints, to which of either missiles and bombs, drop-tanks containing fuel, or other equipment such as avionics pods can be attached. Air-to-air missiles deployed may include short-range air-to-air missiles such as the PL-8 and PL-10 (on J-10C), medium-range radar-guided air-to-air missiles such as the PL-12 and PL-15 (on J-10C), unguided and precision guided munitions such as laser-guided bombs, air-to-surface missile such as KD-88, anti-ship missiles such as the YJ-91A, and anti-radiation missiles such as the YJ-91. Operational history China The first aircraft were delivered to the 13th Test Regiment on 23 February 2003. The aircraft was declared 'operational' in December of the same year, after 18 years in development. The J-10C entered combat service in April 2018. Pakistan The J-10 was offered to Pakistan in 2006 and negotiations persisted into 2012. In September 2020, it was reported that Pakistan was interested in the J-10C. In December 2021, Pakistan announced the purchase of 25 J-10Cs, with an option for 11 more; they were expected to enter service in March 2022. On 4 March 2022, the first batch of 6 PAF J-10Cs landed at PAF Base Minhas (Kamra) after a ferry flight from Chengdu, China. They were officially inducted into the airforce on 11 March 2022. Exports to other countries In 2009, the Aviation Industry Corporation of China (AVIC) planned to offer the J-10 and the CAC/PAC JF-17 Thunder for export. Flightglobal speculated an upgraded J-10B would be offered. Variants J-10A: Single