Singapore Air Show

Pair of Chinese fighter planes form PLAAF’s high-low mix

 - February 11, 2008, 11:51 AM

China’s march to overhaul its front-line fighter fleet is making good progress, thanks to two major indigenous production programs involving the Chengdu J-10 and Shenyang J-11 models. The Chengdu product is an all-Chinese design that is now entering service in numbers. The J-11 is a license-built Sukhoi Su-27 Flanker, which in its latest production version incorporates important Chinese components.

Together, the two types are providing the People’s Liberation Army Air Force (PLAAF) with a “high/low” fighter mix, akin to those employed by the U.S. (F-15/F-16) and Russia (Su-27/MiG-29). The advanced nature of both types signals China’s intentions to transform its air force from one in which sheer numbers could carry the day to one in which a much reduced number of aircraft can maintain the force’s effectiveness through technology.

Vigorous Dragon
Called the “Vigorous Dragon,” the J-10 program dates back to 1983, when China initiated a multi-role fighter competition after the failure of several other programs. The Chengdu, Nanchang and Shenyang organizations submitted proposals and the first of these was chosen.

For the J-10, Chengdu drew upon its earlier J-9 fighter design. It also took full advantage of the developments of various Western technologies that were acquired in the 1970s under the Peace Pearl program, and subsequently in deals with Israeli and European companies.

In June 1997, the prototype was rolled out, making its maiden flight on March 23 the following year. An initial prototype batch of nine or 10 aircraft was followed by at least six preproduction aircraft. Exactly five years after the first flight, the aircraft’s test campaign officially ended in 2003, and a week later the first aircraft were delivered to the Chinese air force’s Operational Trials Regiment at Cangzhou.

The first front-line user was the 131st Regiment of the 44th Air Division at Kunming, which received its first aircraft on July 13, 2004. Later that year initial operating capability was declared and deliveries have subsequently been made to additional regiments. After years of speculation and sightings, the existence of the aircraft was made public officially only on Dec. 29, 2006.

Production of the J-10A single-seater runs at around 24 to 36 units per year and the production run is expected to reach 300 to 500 units. Partnering with the single-seater is a fully combat-capable two-seater, variously reported as the J-10B, J-10S or J-10AS. The first of two two-seater prototypes flew on Dec. 26, 2003, and since then J-10AS production has been interspersed with single-seaters on the assembly line. Trials have been performed with a retractable refueling probe, although this feature has not yet been seen on operational aircraft.

J-11’s Flanker Pedigree
In 1992 the PLAAF received the first of an eventual 36 single-seat Su-27SK and 40 two-seat Su-27UBK fighters to re-equip key air defense units. Experience with the Flanker led to the type being adopted as the primary heavy fighter for the PLAAF. As a result, China went on not only to procure 100 Su-30MKKs and Su-30MKK2s for the fighter-bomber and maritime roles, but also to negotiate a license to assemble Su-27SK fighters at Shenyang.

In 1996 Sukhoi and Shenyang reached agreement to assemble 200 aircraft, initially from Russian KnAAPO-supplied kits followed by increasing local component manufacture. Designated J-11, the first was rolled out in 1998, although manufacturing problems led to a delay in full-scale production until 2000. Observers believe that 96 standard J-11s were produced by 2003.

The following year it was reported that production stopped at around 100 aircraft and that the J-11 no longer satisfied Chinese requirements. Under the terms of the original coproduction agreement there was no technological transfer for avionics or engines, and they had to be bought from Russia.

While production of the baseline J-11 was under way, Shenyang began work on an advanced version known as the J-11B, with Chinese engines and avionics. The locally developed WS-10A Taihang engine was tested in an Su-27SK and has been fitted to trial versions of the J-11B. The improved aircraft also has an indigenous radar housed in a new style radome and the type is compatible with a range of Chinese weapons. J-11Bs have undergone tests since 2003, while the radar was tested in a modified Shaanxi Y-8 (An-12).

Engine Issues
China’s desperate search for a successful modern fighter turbofan reaches back decades, with a string of failures. In the 1970s and 1980s, Western technology was acquired in the shape of the Rolls-Royce Spey and the CFM International CFM56. The latter is thought to have provided the starting point for what became the Shenyang WS-10 turbofan. This engine was intended to power the J-10, although development was so slow it became obvious that it would not be ready in time for the new fighter.

In the early 1990s the embattled WS-10 program gained breathing space thanks to the Sukhoi fighter deal, which provided access to the Salyut (Lyulka) AL-31F engine that powers the Su-27. Negotiations soon began to procure AL-31Fs for the J-10. The first few prototypes flew with development WS-10s, but subsequent aircraft have been powered by the Salyut AL-31FN–a modified version of the Flanker engine with gearbox relocated to underneath to match the J-10’s single-engine requirements.

There have been four orders for the AL-31FN, the first reportedly totaling between 10 and 50, while the three subsequent purchases cover 254 engines.

Meanwhile, WS-10 development continued, including an increase in thrust to produce the WS-10A Taihang. As the Chinese engine was seen as a potential alternative to the AL-31F, the dimensions were kept the same as the Russian powerplant. Flight tests began in 2002, with one engine replacing an AL-31F in a test Su-27SK. The model was certified in 2006.

It now appears that J-11 production will use the WS-10A, while for the foreseeable future the J-10A will retain the Salyut powerplant. However, it is a stated aim to fit the WS-10A in the J-10. This program has ramifications in the export market, as a Taihang-powered J-10 would be an “all-Chinese” fighter completely free of outside export restrictions.

Missile Ready
Both the J-10 and J-11B are adapted to carry the PL-12 active-radar air-to-air missile (equivalent to the U.S. AMRAAM), as well as earlier Chinese weapons such as the PL-8 (similar to Rafael Python 3) and the PL-11 (semi-active radar honing missile based on the Italian Aspide). Both types also have an impressive air-to-ground capability and are being developed to carry a range of precision weapons.

According to reports in the Chinese media, the J-10 and Flanker have met several times in mock combats, with the J-10 reportedly coming out on top in most engagements. This indicates not only its superior flight control system, but also highlights the capabilities of the aircraft’s indigenous avionics. However, the Flanker scores well in terms of range/load characteristics.