The next generation carrier-based stealth fighter was rumored to be under development at the 611 Institute based on J-20. A recent rumor (September 2013) suggested that it is still competing with the smaller FC-31 (navalized) from the 601 Institute.
J-20 Mighty Dragon
The J-20 (K/JJ20?) #2001 technology demonstrator made its maiden flight on January 11, 2011 over the city of Chengdu, wearing a distinctive dark green color scheme and powered by two AL-31FN turbofan engines. The prototype features a pair of all-moving tailfins and Russian 1.44 style twin ventral stabilizing fins and tail booms, which shield the engine nozzles and its heat exhausts but might increase RCS. Also there are four large underwing actuator fairings but their size was reduced on later prototypes. It also features an F-22 style forward fuselage, including adjustable Caret inlets but with DSI bumps installed at the upper inner corners, as well as a one-piece frameless canopy. Small LERX are installed between the canards and main wings in order to generate vortex together with the canards at high AoA. Two small dark diamond shaped windows can be seen on both sides of the nose, which could house a certain kind of EO sensors. Two more diamond shaped windows are seen underneath the rear fuselage, plus two more located forward and aft the cockpit, suggesting a distributed situational awareness system similar to the EODAS onboard American F-35 could have been installed to provide a full 360° coverage. Besides a large belly weapon bay for medium/long-range AAMs (up to 4 PL-15, or 4 PL-21?), two smaller lateral weapon bays have been identified behind the air inlets for short-range AAMs (1 PL-10 in each). The 2001 prototype appears to fly without an internal gun, which is expected to be installed onboard later ones. It also may be flying without the RAM coating applied but this may change later. First disclosed by US Office of Naval Intelligence (ONI) in 1997 as XXJ, J-20 (Project 718) is a 4th generation heavy air superiority fighter to enter the service with PLAAF between 2016 and 2018, a time frame much faster than the one (>2020) anticipated by the western military analysts. Since early 90s both CAC/611 Institute and SAC/601 Institute had been working their own designs to bid for a twin-engine heavy fighter with stealth capability and maneuverability comparable to American F-22. It was speculated that 601 Institute was working on a "tri-plane" design based on canard/conventional layout/V-shape tailfin while 611 Institute working on a design based on canard/tailless delta wing/V-shape tailfin/lateral DSI/bump inlet layout. All designs would feature a belly internal weapon bay to reduce RCS, which has been speculated to be <0.05m2 (head-on). J-20 also incorporates an advanced optic HSDB system fully integrating the fire-control and the engine systems. The aircraft has a smooth surface without any protruding tubes or inlets, suggesting an FADS has been installed in order to reduce RCS. Its fire-control radar is expected to be AESA (Type 1475/KLJ5?) based on the less powerful model being tested onboard J-10B, both are developed by the 14th Institute. The radar is thought to be comparable to American APG-77. Both the radar and the CNI system are being tested onboard a modified Tu-204C testbed, similar to American Boeing 757 testbed for F-22. The next generation secure datalink is believed to be installed as well which provides secure networking with other J-20s and KJ-200/2000 AWACS. The aircraft also features a "pure" glass cockpit (three large color LCDs plus a few smaller ones and a wide-angle holographic HUD) and possibly an HMDS. J-20 has a retractable IFR probe hidden beneath a cover on the starboard side of the cockpit similar to the one onboard American F-35. Many of these subsystems have been tested onboard J-10B to speed up the development. The exact types of engine powering the prototypes are unclear, even though a Russian or Chinese turbofan engine including AL-31FN/FN Series 3 (12.7t/13.7t class) and enhanced WS-10 (WS-10G? 13t class) was speculated. In the end the Russian engine is believed to be the likely candidate (AL-31FN onboard initial #200x prototypes then AL-31FN Series 3 onboard #201x prototypes). The engine features a silver color (ceramic coating?) "stealth" nozzle with saw tooth edges to reduce RCS and IR emission. However the nozzle has yet to demonstrate an axisymmetric TVC capability. It was reported in November 2006 that a 16-17t class T/W=9 turbofan (WS-15/"Large Thrust"/Emei?) with a TVC nozzle is being developed and will eventually power J-20s of later production batches. J-20 appears slightly longer and slimmer than both F-22 and T-50, suggesting a compromise between achieving high speed/maneuverability and the less powerful engines available. Therefore currently the J-20 prototype still lacks the supercurise capability until the planned WS-15 turbofan becomes available. Russian assistance was also speculated in terms of software support for calculating the RCS and aerodynamics of various designs. The overall performance of J-20 is thought to be superior to that of Russian T-50 but still inferior to that of American F-22. In August 2008 it was reported that 611 Institute was selected to be the main contractor for the development of J-20 and 601 Institute as the sub-contractor. Subsequently a full-scale metal mockup was built at CAC. One rumor in May 2010 claimed that 611 Institute started to construct the first prototype, which was expected to fly by the end of 2010. Two prototypes were constructed and the first low-speed taxi trial by 2001 took place on November 4, 2010. The #2002 technology demonstrator made its maiden flight on May 16, 2012. Both #2001 and 2002 were sent to CFTE in Yanliang in 2012, where #2002 prototype was renumbered as 2004 and #2001 flew with a new gray RAM paint. The #2002 technology demonstrator was seen conducting weapon integration tests with a dummy PL-10 IIR guided short-range AAM on its retractable side missile launch rail in March 2013. Unlike that of F-22, the weapon bay door is closed while the missile is fully exposed to maintain low RCS and reduce drag during dogfight. In July 2013 it conducted similar tests carrying dummy PL-15 AAMs inside the belly weapon bay. The completion of building the third prototype was delayed until late 2013 due to the fact that the #2011 prototype would feature certain "major improvements" and is no longer considered as a "technology demonstrator". The first low-speed taxi test of #2011 prototype took place on January 16, 2014, high-speed taxi test on February 18, 2014. The aircraft was seen to have a nosed mounted EOTS and frame-strengthened one-piece canopy similar to those of American F-35 plus a new frameless holographic HUD. The emergence of EOTS suggests that J-20 could possess a limited AG capability using laser or TV guided PGMs. In addition it has numerous aerodynamic refinements including reshaped tailfins, extended tail booms, nose landing gear door, LERX and engine intakes with hexagonal side fuel-air exchangers as well as smaller underwing actuators to further reduce RCS. Two large tail booms appear to house additional ECM or rear-view radar antennas to protect the rear hemisphere of the aircraft. A new ECM antenna can be seen aft the air intake as well. The prototype also started to wear a new light blue/gray RAM coating. A more powerful engine (AL-31FN Series 3) was believed to have been installed. The #2011 prototype first took off into the sky on March 1, 2014. Different types of"stealth" nozzle were tested on one of the engines onboard #2011 in April 2014. The first flight of #2012 took place on July 26, 2014. The #2013 prototype took off for the first time on November 29, 2014, and the #2015 prototype on December 19, 2014. Both 2013 and 2015 have the pitot tube removed from the nose and both feature a further refined nose radome and tail booms, suggesting the AESA radar has been installed. They have been speculated to represent a nearly "frozen" technical configuration before the initial production. The relatively fast pace of two aircraft being rolled out within one month suggested that the J-20 program is moving towards the low-rate initial production which could start as early as 2016. The initial batches are still powered by the AL-31FN Series 3 engine. Once entering the service, J-20
could pose a significant impact/challenge to the air power balance in
eastern Asian and western Pacific region. It has prompted the
neighboring countries including Japan and South Korea to pursue other
5th-generation stealth fighters such as F-35. It was rumored in April 2015 that both 2013 and 2015 prototypes were to be transferred to CFTE for further testing, after that various weapon tests are expected to start at the PLAAF Test and Training Base. Recent images (September 2015) confirmed that the #2016 prototype had been constructed and was undergoing taxi test in preparation of its maiden flight. The aircraft appears to feature slightly reshaped DSI bumps as well as dark engine nozzles. The #2016 prototype made its first flight on September 18, 2015.
- Last Updated 9/18/15
The FC-31 (Project 310) 01 prototype was approaching the SAC airfield after its successful maiden flight on October 31, 2012. A scale-down model (F-60) of FC-31 was first unveiled by the 601 Institute at the first International UAV Innovation Grand Prix held in Beijing in September 2011. It was first rumored in April 2011 that 601/SAC was developing a 4th generation medium multi-role stealth fighter as Project 310 since 2007 after its own heavy stealth fighter design lost the bid to 611/CAC's J-20 (see above). The aircraft has a conventional design with twin engines and two large canted trapezoidal tailfins similar to American F-22. As the result the ventral stabilizing fins are eliminated to save weight and reduce RCS. In addition it features DSIs, two piece canopy and a pentagon shaped nose similar to F-35. A Russian K-36D ejection seat was also installed. Like J-20, a retractable IFR probe could be installed on the starboard side slightly forward of the canopy. A similar EOTS might be installed under the nose in the future. As a 4th generation fighter FC-31 is expected to be equipped with advanced avionics such as an AESA radar and a wide-angle holographic HUD. The prototype is initially powered by the indigenous WS-13A turbofan (8.5t class) but later by the new 9.5t class "Medium Thrust" engine (WS-19? might feature 2D TVC). The WS-13A engine nozzles on the prototype initially appeared without any stealth measures applied. However they are partially shielded by the two horizontal tailfins extending rearward, similar to F-35, thus reduces the IR and radar signatures. FC-31 features a single internal weapon bay inside its belly housing up to 4 AAMs including PL-10, PL-12, PL-15 and PL-21. It may also be able to carry the larger YJ-83K AshM and YJ-91 ARM externally. An internal gun is thought to be installed as well. However due to its relatively small size and lower engine thrust compared to J-20, FC-31 might suffer from either a limited internal payload or a shorter combat radius. It is not expected to have the super-cruise capability initially either when it is powered by RD-93. However it does carry a relatively cheaper price tag and a relatively "balanced" performance. Some specifications (speculated): length 16.8m, height 4.8m, wingspan 11.5m, normal TO weight 17.5t, MTOW 25t, combat radius 1,200km with internal fuel, max level speed Mach 1.8, ceiling 16km, TO distance 400m, max g load +9/-3, max weapon load 8t. A full-scale metal model was probably built in early 2011. One airframe was transported to the 623 Institute in Yanliang for static tests in June 2012. The first prototype was under construction since late 2011. Its first flight took place on October 31, 2012, powered by two smoky RD-93 turbofans. So far only a single prototype was constructed for test flights. As a private venture of AVIC, FC-31 (dubbed AFC/Advanced Fighter Concept) is expected to be promoted at the international market as a low-cost alternative to American F-35. Therefore it could have some negative impact on the prospects of FC-1/JF-17 in 7-10 years. Its first foreign customer is likely to be Pakistani AF. As for the domestic market, it appears to be a good candidate to replace some of the remaining J-7/8 series fighters still in service with PLAAF and PLAN, together with the 3.5th generation J-10B/C and J-11D. It was rumored that FC-31 could compete with the other stealth fighter design from 611 Institute for the next generation PLAN carrier-based stealth fighter but this has not been confirmed. FC-31 was partially unveiled at 2012 Zhuhai Airshow as an "advanced fighter concept". Recent images (December 2013) suggested that FC-31 is testing a new silver color "stealth" nozzle similar to those onboard J-20. The second prototype which could feature "major" improvementsin order to meet PLAAF's requirements is anticipated to fly by 2016. They might include a one-piece canopy, domestic WS-13A turbofan engines with new stealth nozzles, an EOTS (EOTS-86?) under the nose, retractable IFR probe on the starboard side, a slightly longer and fatter fuselage, reshaped F-35 style vertical tailfins and cropped wing tips and tailfin tips similar to those of F-22. Currently the 02 prototype is being assembled at SAC.