Shenyang J-15

The Shenyang J-15 (Chinese: 歼-15), NATO reporting name: Flanker-X2, also known as "Flying Shark" (), is a 4th generation, twin-jet, all-weather, carrier-based fighter aircraft in development by the Shenyang Aircraft Corporation and the 601 Institute for the Chinese People's Liberation Army Navy's aircraft carriers. 
It is developed from J-11B as well as from studying of a prototype of Su-33. An unfinished Su-33 prototype, the T-10K-3, was acquired from Ukraine in 2001 and is said to have been studied extensively, reverse engineered, with development on the J-15 beginning immediately afterward. While the J-15 appears to be structurally based on the prototype of Su-33, the indigenous fighter features Chinese technologies as well as avionics from the J-11B program. In February 2018, discussions about replacing the aircraft appeared in several Chinese media outlets including Xinhua and China's main military newspaper, discussing that it belongs to the 4th or 4.5 generation fighters. Thus, the J-15 is viewed as an interim carrier-based fighter until a 5th generation successor enters service, one that may be based on the J-20 or FC-31 (J-31).
Development.
China has sought to purchase Su-33s from Russia on several occasions—an unsuccessful offer was made as late as March 2009—but negotiations collapsed in 2006 after it was discovered that China had developed a modified version of the Sukhoi Su-27SK designated the Shenyang J-11B, in violation of intellectual property agreements. However, according to Chinese sources, the reason China withdrew from talks is that Russia wanted large amounts to re-open Su-33 production lines, insisting on a Chinese purchase of at least 50 Su-33s, towards which China was reluctant as it believed the aircraft would become outdated in a few years. China hence decided on an indigenous variant instead of continuing to assemble the licensed Su-27, or J-11. 
J-15 program was officially started in 2006. The deputy general designer of J-15 is Wang Yongqing (王永庆).
The first J-15 prototype made its maiden flight on 31 August 2009, believed to be powered by Russian-supplied AL-31 turbofan engines. Video and still images of the flight were released in July 2010, showing the same basic airframe design as the Su-33.
On 6 May 2010 the aircraft conducted its first takeoff from a simulated ski-jump.
On 25 November 2012, the aircraft successfully performed its first takeoff and landing on China's first aircraft carrier "Liaoning".
A twin-seat variant made its maiden flight on 4 November 2012.
The initial WS-10 engines proved to be unreliable under oceanic conditions, and the early J-15s were fitted with Russian-made AL-31F. Several years later, WS-10 entered mass-production and late J-15 variants were gradually replacing their engines with modified WS-10.
Design.
An article in the China Signpost believes the J-15 "likely exceeds or matches the aerodynamic capabilities of virtually all fighter aircraft currently operated by regional militaries, with the exception of the U.S. F-22 Raptor", alleging that the J-15 likely possesses a 10% superior thrust-to-weight ratio and a 25% lower wing loading than the F/A-18E/F Super Hornet. However, one of the authors of that same article described the J-15 in another as no game changer; the reliance on ski-jump launches and lack of Chinese carrier based refueling capabilities are believed to greatly reduce its effective range. Hu Siyuan of the National Defense University PLA China has said that "the current weak point of the J-15 is its Russia-made Al-31 engines which are less powerful than that of the American F-35 fighter".
The J-15's chief designer, Sun Cong of the National Committee of the Chinese People's Political Consultative Conference, has said that the J-15 could match the F/A-18 in bomb load, combat radius and mobility. However, in a similar statement, he said more work was required in its electronics and combat systems. He also indicated the lack of mature domestically produced engines as a current weak spot. Rear Admiral Yin Zhuo stated that the aircraft's air combat capabilities were better than that of the F/A-18E/F Super Hornet. However, he also stated that its ability to attack land and sea targets was slightly inferior to the F/A-18E/F; it is also stated that its electronic equipment meets the standards of those on a fifth generation fighter.
Operational history.
On 25 November 2012, Chinese media announced that two J-15s had made successful arrested landings on the aircraft carrier . The first pilot to land on "Liaoning" was named as Dai Mingmeng (戴明盟). Luo Yang, the aircraft's head of production and designer, died the same day. PLA Daily newspaper indicated the first five naval pilots including Dai conducted J-15 fighter landing and taking off. Test and training program officials confirmed the carrier-borne aircraft and special equipment for the landing flight had gone through strict tests, and fighter jets can be deployed on the carrier.
In December 2013 Chinese media reported that mass production of J-15s in full operational condition with combat markings had begun.
In January 2017, the carrier "Liaoning", having returned to the South China Sea after its first deployment into the western Pacific, conducted a series of take-off and landing drills with its force of embarked J-15 fighters.
In July 2018, Lieutenant General Zhang Honghe of the PLAAF stated that China is developing a new carrier-based aircraft that will replace the J-15 due to four crashes and numerous technical problems. One problem with the aircraft is that it is the heaviest carrier-borne fighter in current operation with an empty weight of 17,500 kg compared to the F/A-18E/F Super Hornet's 14,600 kg (though it is less than the F-14 Tomcat's weight of 19,800 kg). Weight problems are compounded when operating off "Liaoning", as its STOBAR launch and recovery method further limits payload capacity.