The Chengdu J-20 (simplified Chinese: 歼-20; traditional Chinese: 殲-20) is a stealth, twinjet, fifth-generation fighter aircraft prototype being developed by China's Chengdu Aerospace Corporation for the Air Force (PLAAF).Its Nato reporting name is Black Eagle.The J-20 made its first flight on 11 January 2011, and is expected to be operational in 2018.Two prototypes were developed in November 2010 for aerial and ground testing.
Potential customers of the J-20 are Pakistan, the Middle East, Latin America, South-East Asia and African countries.
The J-XX program was started in the late 1990s. A proposal from Chengdu Aerospace Corporation, designated Project 718, won the PLAAF endorsement following a 2008 competition against a Shenyang proposal that was larger than the J-20.
In 2009, a senior PLAAF official revealed that the first flight was expected in 2010–11, with an service entry date by 2019.
On 22 December 2010, the first J-20 prototype underwent high speed taxiing tests outside the Chengdu Aircraft Design Institute.
Design
The J-20 is designed to execute ground attack missions even in hostile environments. The aircraft can reach higher altitudes with its delta wings in supersonic speeds.
It is larger than Sukhoi T-50 and Lockheed Martin F-22 Raptor. The front portion of the prototype looks similar to the F-22 Raptor and the rear section looks like a Sukhoi T-50.
China chose not to participate in the joint development of fifth-generation aircraft by Russia and India as Russia was seen to be more profitable with the Chinese participation. In an effort to build a fifth generation aircraft as competitor to the Russian aircraft, CAIG started the development of the J-20 in late 1990s under the J-XX programme.
Also referred as Project 718, the J-XX programme depicts the development of fourth and fifth-generation aircraft carried for the PLAAF.
The J-20 has a long and wide fuselage, with the chiseled nose section and a frameless canopy resembling that of the F-22 Raptor. Immediately behind the cockpit are low observable intakes. All-moving canard surfaces with pronounced dihedral are placed behind the intakes, followed by leading edge extensions merging into delta wing with forward-swept trailing edges. The aft section features twin, outward canted all-moving fins, short but deep ventral strakes, and conventional round engine exhausts.
One important design criterion for the J-20 describes high instability.This requires sustained pitch authority at a high angle-of-attack, in which a conventional tail-plane would lose effectiveness due to stalling. On the other hand, a canard can deflect opposite to the angle-of-attack, avoiding stall and thereby maintaining control.Canard is also known to provide good supersonic performance, excellent supersonic and transonic turn performance, and improved short-field landing performance compared to the conventional delta wing design.
Leading edge extensions and body lift are incorporated to enhance performance in a canard layout. This combination is said by the designer to generate 1.2 times the lift of an ordinary canard delta, and 1.8 times more lift than an equivalent sized pure delta configuration. The designer claims such combination allows the use of a smaller wing, reducing supersonic drag without compromising transonic lift-to-drag characteristics that are crucial to the aircraft's turn performance.
J-20 features
The J-20 will feature a blended fuselage with low radar cross section, low jet engine intakes, canard delta configuration, modern fly-by-wire (FBW) system, diverterless supersonic inlet (DSI), V-shaped tail and tail fins. The FBW system is equipped with a fire control system and engine management system. The active electronically scanned array (AESA) radar will scan the target information and transmit it to the fire control system.
The J-20 prototype is powered by Saturn 117S engines supplied by Russia. Each engine produces 32,000lb of thrust.
The production aircraft will be powered by two WS-10G thrust vectoring turbofan engines each generating 30,000lb of thrust. The engine is being designed and manufactured by Shenyang Liming Aircraft Engine Company. It will feature a single high-pressure turbine, dual low-pressure turbine, annular combustors and compressors.
The WS-10G will be fitted with thrust vector controlled (TVC) nozzles to decrease radar cross section (RCS) and infrared (IR) emissions. The diameter of the engine is 0.95m. The dry weight is 1,494kg.
Avionics
The aircraft features a glass cockpit, with two main large color liquid crystal displays (LCD) situated side-by-side, three smaller auxiliary displays, and a wide-angle holographic head-up display (HUD).
A PLAAF Tupolev Tu-204 testbed aircraft was seen featuring a J-20 nose cone. It is believed to house the Type 1475 (KLJ-5) active electronically scanned array (AESA) radar with 1856 transmit/receive modules.
Prototype "2011" featured a revised nose section with elements resembling a IRST/EOTS system, and a metal finish that loosely reminds the radar absorbing Haze Paint first used on F-16s, and reportedly included sensor fusion technology.Chinese company A-Star Science and Technology has developed the EOTS-89 electro-optical targeting system and EORD-31 IRST for the J-20 and potentially other PLAAF fighters to detect and intercept stealth aircraft.
The J-20 will be armed with internal cannon for close range combat missions. It will comprise eight hardpoints and a large belly weapon bay to incorporate long range PL-12C/D and PL-21 air to air missiles (AAM).
The aircraft will also be equipped with two small lateral weapon bays beneath the air inlets to integrate PL-10 short range AAM. It is also expected to be equipped with air to surface missiles, anti-radiation missiles, laser-guided bombs and drop bombs.
Stealth
Analysts noted that J-20's nose and canopy use similar stealth shaping design as the F-22, yielding similar signature performance in a mature design at the front, while the aircraft's side and axi-symmetric engine nozzles may expose the aircraft to radar.One prototype has been powered by WS-10G engines equipped with a different jagged-edge nozzles and tiles for greater stealth.
Others have raised doubts about the use of canards on a low-observable design, stating that canards would guarantee radar detection and a compromise of stealth.However, canards and low-observability are not mutually exclusive designs. Northrop Grumman's proposal for the U.S Navy's Advanced Tactical Fighter (ATF) incorporated canards on a stealthy airframe.Lockheed Martin employed canards on a stealth airframe for the Joint Advanced Strike Technology (JAST) program during early development before dropping them due to complications with aircraft carrier recovery.McDonnell Douglas and NASA's X-36 featured canards and was considered to be extremely stealthy.Radar cross-section can be further reduced by controlling canard deflection through flight control software, as is done on the Eurofighter.
The diverterless supersonic inlet (DSI) enables an aircraft to reach Mach 2.0 with a simpler intake than traditionally required, and improves stealth performance by eliminating radar reflections between the diverter and the aircraft's skin. Analysts have noted that the J-20 DSI reduces the need for application of radar absorbent materials.Additionally, the "bump" surface reduces the engine's exposure to radar, significantly reducing a strong source of radar reflection.
Landing gear
The aircraft will be fitted with a tricycle-type landing gear comprising a single wheeled nose gear leg and two single wheeled main gear legs. The nose gear will drawback into the cockpit floor upon take-off, while the main gear retract forward into the fuselage section.
Performance
The J-20 can climb at the rate of 304m/s. The maximum speed will be 2,100km/h. The range and service ceiling will be 3,400km and 18,000m respectively.