Two JF-17s, co-produced by China and Pakistan, have just made their international debut at an ongoing major international air show.

Gary Li, who analyzes the People's Liberation Army for London-based International Institute for Strategic Studies, also told China Daily that the Chinese air force is already "one of the strongest" in the world.

"Currently China is engaged in a very rapid series of aircraft upgrades and diversification," Li said, noting that the PLA Air Force (PLAAF) is currently strong only in terms of size.

Earlier this month, The Diplomat magazine, based in Tokyo and Sydney, as well as London's Jane's Defence Weekly, almost simultaneously published stories expressing concerns over the buildup of the PLAAF, entitled "China air force steps it up" and "Chinese military aircraft: up and coming".

The Diplomat even said China is "building a force that will be without rival in the Asia-Pacific".

Despite such a rapid upgrade, Li said China should work on "technological choke-points" .

A big problem, he said, is China's heavy reliance on Russian-made engines. Most of the country's latest aircraft, including JF-17s, still use engines bought from its northern neighbor.

"How many aircraft can China produce a year if Russia stops selling its engines to Beijing?" Li asked.

"China needs to solve this problem within 10 years if it wishes to continue the overhaul of the PLAAF and the development of the new generation of fighters".

China has been active in the international aircraft market in recent years.

The total value of China's arms exports from 2005-9, according to Sweden's Stockholm International Peace Research Institute, was $2.73 billion, only about 2.3 percent of the world's total.

But Beijing's aircraft sales - worth up to $815 million - are larger than any other of its weapon exports.

Though Chinese aircrafts are not comparable with US or Russian ones, Li said, "Chinese companies offer very attractive packages."

"The US never sells its latest generation of aircraft, or sell critical technologies," he said. In contrast, "China sells packages", not just the aircraft, but also technology and expertise - such as production licenses for domestic assembly, technical assistance and other after-sales support.

Almost all Chinese aircraft exports go to less developed countries, like Egypt, Venezuela and Myanmar. And Pakistan, China's "all-weathered friend", is the biggest recipient of Chinese planes.

The Pakistan Air Force (PAF) received its first two JF-17 Thunder fighters from China in July 2007. Last year, the PAF started its own assembly line, which saw the first aircraft roll out in November.

In February, the PAF activated its first JF-17 squadron, with 14 aircraft in service and another 24 to be delivered from the initial contract batch. Pakistan's total requirement for this type of single-engine plane is reported to be as high as 250.

Li said the JF-17 is an "excellent aircraft", available at a cheap price (about $15 million each), with a good avionics system and good radar. "It is a successful product of a successful partnership Chinese design really shines."

Significantly, the plane fits into Islamabad's needs, as "countries like Pakistan or Egypt don't need F-22s", Li added.

"If China decides to export its newer aircraft such as the J-11B and J-10, then it will make a significant impact on the world arms market, by offering attractive and cost effective alternatives to Western and Russian planes."

Long March

Also at the show, the China Academy of Launch Vehicle Technology presented China's next-generation heavy-duty launch vehicle, Long March-5, slated to take off in 2014.

The Long March-5 launch vehicle is currently China's largest, designed for transporting heavyweight satellites and space stations. It has entered the test stage.