China only publicly admitted its new J-10s jet fighter existed two years ago, even though the first few entered service in late 2003. There are only about a hundred J-10As are in service, and they are being offered to export customers for about $42 million each. Currently, China is producing 2-3 J-10s a month.
Pictures recently appeared showing the improved J-10B model. This version carries improved electronics, including better radar warning, a laser range finder and targeting electronics. The new nose cone looks like the one on the F-16, indicating that the J-10B is now ready to be fitted with an AESA (phased array) radar (which is more capable and more reliable than older types, but also more expensive.) The cockpit also has a larger and more detailed HUD (Head Up Display).
The J-10 already has a reputation as a maintenance nightmare, and that the Chinese are having a hard time keeping the aircraft operational in reasonable numbers. But the J-10 is the first modern jet fighter designed and built in China. The aircraft is an attempt to create a modern fighter-bomber that could compete with foreign designs. The experiment was not completely successful.
Work on the J-10 began over twenty years ago, in an attempt to develop an aircraft that could compete with the Russian MiG-29s and Su-27s, and the American F-16. But the first prototype did not fly until 1998. There were problems, and it wasn't until 2000 that the basic design flaws were fixed. By 2002, nine prototypes had been built, and flight testing was going forward to find, and fix, hundreds of smaller problems. It was a great learning experience for Chinese engineers, but it was becoming apparent that the J10 was not going to be competitive with the Su-27s/30s China was buying from Russia.
The J-10 looks something like the American F-16, and weighs about the same (19 tons). Like the F-16, and unlike the Su-27, the J-10 has only one engine. Originally, the J-10 used a Russian AL-31FN engine, but China has been working for a decade to manufacture their own version of this, the WS10A. The WS10A is something of an acid test for them, as it is a powerful military engine, and a complex piece of work. Russia refused to license China to produce the AL-31FN, so the Chinese stole as much of the technology as they could and designed the WS10A. This engine has been tested, and officially approved for production, but apparently still has quality control and performance problems.
It's no accident that the J-10 resembles the F-16, because Israel apparently sold them technology for the Israeli Lavi jet fighter. Israel abandoned the Lavi project, because of the high cost and availability of cheaper alternatives (buying F-16s and F-15s from the United States.) But the Lavi was meant to be a super F-16, and incorporated a lot of design ideas from the F-16 (which the Israelis were very familiar with, as they used them, and had developed new components for them.)