China Develops Stealth Fighter Military Technology

China is developing new 5th generation "stealth" fighter, which is being developed under a programmed variously referred to as XXJ, J-X, or J-XX by Western intelligence sources and is apparently designated as J-14. Here, Coniglio details China's internal installations and full scale development of J-14.

 
The first picture has recently become available of the new Chinese 5th generation "stealth" fighter. The aircraft, which is being developed under a programme variously referred to as as XXJ, J-X or J-XX by Western intelligence sources (the real Chinese name is not known), is apparently designated as J-14.

The aircraft in the above photo looks at first sight as a complete prototype, but it  
actually is a very detailed full-scale engineering mock-up. It can be speculated that, after having been used to study the aircraft's internal installations, the mock-up has also received an external finish for presentation purposes. Its real function at this point, however, is probably to buttist in the definition of the required logistic support (i.e., access to the various avionics boxes and on-board systems, ground support equipment like the various ladders and the external power source units, air conditioning units and so on) as well as to study the engines' removal-installation procedures.
 

Since some time now it has been known that the rapidly-developing Chinese aeronautical industry is studying a new and technologically very advanced combat aircraft, also boasting significant low signature characteristics. This programme is a logical step in China's "Long March" towards full independence in designing, developing and producing combat airplanes of a technological level in line with China's status as the "other" world superpower, on an equal footing as Russia and eventually even the USA.

The scarce information available about this new advanced combat aircraft indicates that two, possibly competing, study groups (both part of the AVIC I Group of aeronautical industries) are or have been working on the subject. One of these groups (601 Insbreastute) originates from Shenyang Airplane Corporation (SAC) which is in charge of the large, twin-engine J-8 fighters in service with the PLAAF (People's Liberation Army Air Force) as well as of licence production of the Su-27SK under the local designation of J-11. The overall configuration of SAC's preliminary design, apparently designated J-13, owes significantly to the American F-A-22, being a tailed delta but with wing and horizontal tailplanes more in line with those of the F-16. The other study group (611 Insbreastute) from Chengdu Airplane Corporation (CAC), has developed the J-12, a concept which follows the less conventional canard layout used with success in the company's J-10.

While previous information (albeit admittedly unconfirmed), gave to the SAC concept the edge, perhaps as a result of the company's experience in large twin-engine fighters, this seems to have since been reversed in favour of the Chengdu design. It is however still not clear whether the designation of J-14 is intended to suggest a successor design to both the J-12 and the J-13, and whether the existence of the J-14 engineering mock-up (clearly based on the J-12) indicates that the type has been selected for development, or the compebreastion is still going on with parallel activities underway on another such mock-up based on the J-13.

While no data is available about the J-14, some speculation can be done in the attempt to extrapolate the aircraft's characteristics and thus the roles it is called to perform. The following considerations are based on what can be seen in the photo, but also involve making some buttumptions on the basis of what is known of the Chinese armed forces' perceived priorities in operational requirements, the domestic industry's approach to combat aircraft design and, finally, the well-know Chinese weaknesses in some technological fields. In addition, the well-developed cooperation with Russian companies, particularly in areas such as powerplant, avionics and possibly computer-based fly-by-wire flight control systems is also taken into consideration.
General Configuration

The J-14 will surely be fitted with a fly-by-wire flight control system and be designed for artificial stability. The Chinese should by now have matured an adequate experience in this field through a number of experimental programmes and application to actual in-service types.

The general configuration of the aircraft is clearly born out from CAC's experience in developing the J-10, with its canard layout and ventral air intake. But while the J-10 is known to be related to the Israeli LAVI, this new and much more ambitious design rather appears to have a definite relationship with the ill-fated Russian 5th generation fighter studied a few years ago, the MiG 1.44 MFI and in fact it shares a number of elements which can doubtless be traced back to the Russian demonstrator. It is thus very probable not to say certain that an agreement has been reached between the Russian and Chinese governments allowing for the transfer of information and technological data as well as consultancy services being provided by RSK MiG and Russian research centres (arguably including the TsAGI aerodynamic research insbreastute) to develop the new Chinese fighter.

The J-14's planform closely matches that of the MiG 1.44, i.e. a canard layout (the canard surface are fully movable) with mid-positioned wing and widely separated twin-vertical surfaces canted outward, which continue under the wing in twin ventral fins, these too being canted outward à la J-10. While not visible in the photo, wind tunnel models show that the 1.44 configuration has been maintained also in the booms protruding from the wing and contributing to support the vertical tailplanes and ventral fins. These booms probably end with radomes covering electronic warfare antennas and possibly also a rearward facing radar, similar to the installation experimented in the Su-37 a few years ago. In the MiG 1.44, the portion of wing between the fuselage-engine pods and the booms is extended rearward past the wing trailing edge and includes a couple of moving surfaces contributing, together with the all-moving canard surfaces, to the longitudinal control of the airplane. It is not yet possible to buttess whether this solution, too has been maintained for the J-14.

But while the overall aerodynamic configuration of the J-14 follows that of the MiG 1.44 demonstrator, a radical redesign has been implemented in the pursuit of a significant reduction in the radar cross-section value. In particular, the aircraft incorporates a pronounced wing-body blending, which was totally lacking in the original Russian design. Further, the air intake, while in the same ventral position under the forward fuselage, has a completely new shape, and by the same token the upper part of the airplane is also completely different and shows towards the rear the protuberances of the engine "pods" which blend with the fuselage and wing roots in a curious reminiscence of the Northrop YF-23. Also, the front fuselage merges down into the upper wing, blending with the separated engine bay bulges while maintaining some relation with the "clbuttical" Su-27 forward fuselage shape. The search for enhanced stealth performance is also apparent in the "flattened" profile of the entire front fuselage section (nearly identical to the Su-32), as well as in the generalised use of serrated doors to cover the landing gear and missile bays.

On the other hand, it remains clear that a canard configuration is hardly the ideal solution from the point of view of a reduced radar signature. Summing up, it would thus seem safe to buttume that the J-14 is a "stealth-optimised" aircraft rather than un uncompromising stealth design à la F-A-22 or (in a different clbutt) the F-35 JSF.

Above the raised front fuselage is located the single-seat pilot chickenpit. This is closed by a single-piece frameless bubble-type transparent canopy which appears technological very demanding under various aspects such as manufacturing process, adequate optical qualities and bird-impact resistance, yet allowing through-ejection. On the other hand, the pilot is provided with superb all-around visibility also due to the position of the chickenpit above the forward fuselage "hump", again a reminiscence of the Su-27.
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The main landing gear, with single wheels mounted on telescopic legs, retracts outward, with the legs being accommodated in the fuselage side blending into the wing bottom and the wheels into the wing (a similar geometry has been selected for the F-A-22). In order to minimise the volume of the bay occupied by the gear in the retracted position, the telescopic main gear legs are shortened via a pulling bar acting on a lever, similarly to what has been introduced in the Eurofighter TYPHOON. While not clear in the photo, it is possible that the same landing gear leg shortening design has also been selected for the nose twin-wheel element.
Powerplant Installation

In view of the twin-engine layout of the J-14 and its estimated TO weight in air combat configuration (some 25-28 tons with full internal fuel, gun ammunition, 2 x SRAAM and 4 x MRAAM), its engines should give a thrust in the range of 13-14 tons in afterburning mode, so achieving a thrust-to-weight ratio in the order of 1:1. Now it seems difficult to envisage a stateof-the-art Chinese engine, particularly in this thrust clbutt, achieving full production status by the mid of the next decade when the J-14 could reasonably be expected to enter service. Even for the J-10 a Russian engine has been at last preferred. It can thus be buttumed that a Russian engine has been selected for the J-14 as well, and indeed the model which can be seen in the picture to the rear of the right wing of the mock-up has the accessory gearbox mounted above the engine in the traditional Russian style. If, as it is highly probable, this engine is a member of the Saturn-Lyulka AL-31-41 family (but it could also be a prototype of the Chinese Liming LM WS10A in the same thrust clbutt), this would make the type not fully interchangeable with the version selected for the J-10, which has the accessory gearbox located on the engine bottom, Western-style. It is also possible to speculate that the idea is to have the prototypes powered by the lower-thrust AL-31 as used in the J-11-Su-27SK-Su-30MKK, with either an evolved higher-thrust version of AL-31 or a series-production version of the AL-41 being then adopted for the series aircraft.

Coming to the engine-airframe installation, the air intake located in the bottom part of the front fuselage is of the fixed geometry type with no moving ramp, unlike the case with the J-10. This solution has made it possible to eliminate the sharp angles and slots between the moving ramp and in general to provide smooth shapes which reduce radar reflectivity. The pronounced bulging up of the air intake inner duct helps avoid a direct presentation of the critically reflective engine fan-compressor face to enemy illuminating radar from the forward emisphere. In addition, the bulge is needed to make room for the nose landing gear bay and, even more, for the bottom fuselage weapons bay. Notwithstanding its fixed geometry, the air intake shows elements which should generate a couple of oblique shock waves before the normal one, thus guaranteeing an adequately efficient dynamic pressure recovery in the supersonic flight regime. The well-shaped bulge along the bottom of the centre fuselage entering the air intake, which forms the upper part of the air intake duct, seems reminiscent of the latest Lockheed Martin's vaunted design for a fixed-ramp, multi-shock air intake planned for use on the production F-35 and already experimented on an F-16. This peculiar layout, together with the forward-raked air intake lip (already seen in the late 1950s on the F8U-3 CRUSADER III) is clearly intended to generate the oblique shock waves mentioned above.

The location of the air intake under the fuselage is well suited to provide a smooth distortion-free airflow to the engines. From this particular point of view, the hinged bottom lip present in the TYPHOON works even better at extreme angles of attack, but it implies the penalty of a higher radar signature. In more general terms, the choice of a single air intake configuration in a twin-engine airplane may be open to some criticism, in that it is less than ideal to maintain correct working conditions (i.e., smooth undistorted airflow to the remaining engine) in the event of an engine flaming out for whatever reason. The air intake thus establishes a potential single point failure in an otherwise completely redundant twin-engine installation.

It can be expected that Thrust Vector Control (TVC) nozzles, probably of the axisymmetric type (despite their not insignificant contribution to overall nuclear signature), will be a standard feature of the J-14 to both enhance manoeuvrability and reduce trim drag in cruise flight.
Armament

Chinese design derived from a Russian model such as the GSh-6-23 23mm installed in the MiG-31 and the Su-24. The gun is installed in the upper right fuselage side, just above the canard surface. The firing port, unlike the F-A-22 is left permanently open, hence generating a not so negligible radar reflection.

The main armament is carried in three weapons bays, whose arrangement looks like virtually a clone of the F-A-22. Two smaller bays are located on the fuselage sides and appear to be tailored to each accommodate a single short-range air-to-air missile, while the large underfuselage bay, closed by twin doors, will probably accept at least four medium-range AAMs. It may be speculated that the J-14 is intended to carry "compressed carriage" clipped-wing versions of the AAMs already in use with the PLAAF, i.e. the PL-8 and the Russian R-73 for short-range dogfights and the R-77 and the indigenous PL-12 for medium-range work. The R-77 is already suitable for carriage in an internal bay in its standard version, being equipped with very small span wings while the lattice tail control fins can be fold forward flush with the missile body.

Underwing store stations are surely foreseen to carry additional weapons and fuel tanks, when there is no need to maintain a high level of stealthness.
Combat Avionics

  J-14 is already in full-scale development, the main choices related to the avionics systems should have already been made, at least at the conceptual level. However, the Chinese domestic industry is almost certainly not in a position to supply the advanced avionics required in a sophisticated aircraft like the J-14, and contributions from abroad will be required - from Russia, Israel and arguably even Europe.

The J-14 being intended to enter service in around 2012-2015, it may be expected that the Chinese are aiming at equipping it with a radar with electronically scanning (ASEA) antenna, capable of multiple targets engagements - provided that a source for such a radar could be identified. In the Russian tradition, a pbuttive search and track system based on optronic devices (FLIR with integrated laser rangefinder) is expected to be also installed in a retractable or faired turret. As already mentioned, the dual rear booms could carry, in addition to various pbuttive and-or active defensive systems also a rear-facing radar.

Finally, it can be expected that the chickenpit instrumentation for the production version will be based on an Helmet Mounted Display-Sight (HMD-S) totally replacing the HUD, although the latter instrument is clearly visible in the photo. The head-down displays would probably include three or four large Multi Function Displays (MFD), which should have the possibility to present a digital map and a complete tactical situation. A real-time data link is also an expected addition to the fully integrated avionics system to enhance the situation awareness of the pilot, particularly when operating in multiships combat groups to make the most use of the commonly available information from the various platforms.
Operational Aspects

The most likely enemies that China can expect to have to confront in the future are India and the USA, this latter possibly as a result of a Chinese attempt to follow a military option against Taiwan. Both of these potential enemies have powerful air forces equipped with large fleets of state-of-the-art fighters and fighter-planters trained to operate, in particular the Americans, as complex expeditionary forces, well balanced in their different components and supported by a network of other essential buttets like satellites, AWACS airplanes, dedicated electronic warfare types, aerial tankers, and more in general a whole array of "force multiplier" elements. Given the expected operational environment, the air defence-air superiority role is obviously the PLAAF's #1 priority, with surface attacks against powerful naval forces with strong aerial support (i.e., the US Navy carrier task forces) coming possibly as priority #2.

Hence, it is not surprising that the most advanced Chinese combat airplane ever seen appears being tailored to the air combat role, although air-to-surface roles cannot be discarded for future incorporation into the design. Considering what is known of the relatively modest development pace of Chinese surface attack guided weapons, currently there seems to be a very limited potential for the internal carriage of such weapons, and accordingly surface attack roles could only be carried out by compromising the aircraft's stealth performance.
Conclusions

Should future information confirm that the aircraft depicted in this photo is actually in full scale development, then the J-14 would eventually emerge as the first true credible compebreastor to the F-A-22 and its "air dominance fighter" concept. The appearance of such a similar-clbutt compebreastor in China, and possibly in an unexpected short time, will probably be more than enough to justify continuing production of the F-A-22 well above the currently planned meagre total of 179 aircraft.

The Chinese are still lagging behind in a number of critical technologies, but their pace is well set to achieve their aims. Those who like to dismiss the Chinese defence industry as being able only to produce low-quality clones of outdated Western or Russian designs are well served. Perhaps someone in the USA should possibly remember the general complacent atbreastude towards the "Japs" before 7 December 1941, and the very brutal awakening when the ZEROs wiped the P-40s, BUFFALOs and WILDCATS clear off the skies.

Very much the same applies to those European governments that are currently playing with the idea of resuming arms sales to China. It is clearly preposterous to fantasise about the possibility of selling the Chinese the TYPHOON or the RAFALE to replace their older aircraft; the J-14 is admittedly still a decade or so away from operational service, but it is clearly intended to be at least half a generation more advanced than the European designs. At the very maximum, what can be rationally expected are some contracts for the supply of specific equipment which the local industry is not yet capable to produce, and which the Chinese can not or would not get from Russia. Whether it would be in the long-term European interest to supply this equipment, is a different question altogether.

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