China's second stealth fighter has made its first test flight, state media reported Thursday, in a boost to the country's air capabilities even though the plane is unlikely to be deployed for years.

The J-31, the second stealth plane to be unveiled by China in less than two years, flew for 11 minutes on Wednesday morning, the state-run Global Times reported, citing an eyewitness.

Photos posted online by Chinese military enthusiasts appeared to show the black-painted combat plane in mid-flight. Images of the aircraft were first leaked online in September.

China's first stealth fighter, the J-20, was unveiled in early 2011 but is not expected to enter service until 2018. The country's first aircraft carrier entered service last month, with others capable of carrying aircraft expected to follow.

The J-31 appears to be more mobile than the J-20, with its landing gear suggesting it is designed to be launched from an aircraft carrier, military expert Andrei Chang told AFP.

He said the J-31 appeared similar to the latest "fifth" generation of US-designed stealth fighters, but with a less powerful engine and a lower proportion of sophisticated radar-blocking composite materials.

"In terms of design it appears the J-31 is inferior to the latest US planes," said Chang, head of the Kanwa Information Centre which monitors China's military.

"The layout is similar, but the material and quality are inferior."

A long testing process means the aircraft is unlikely to be put into action for nearly a decade.

"It will take at least seven or eight years before it can be commercially sold," Chang said, adding that the test flight was timed to coincide with the run-up to China's once-in-a-decade leadership transition next month.

"I think the regime is trying to to show off to their colleagues that the Hu Jintao regime achieved a lot for China," he said, adding that the J-31's manufacturers hoped to export the plane to Chinese allies such as Pakistan.

China says its defence spending will top $100 billion in 2012, the latest in a series of budget increases to the country's 2.3 million-strong military.

Decades of increased investment saw the country fall from being the world's largest importer of arms in 2007 to the fourth largest by 2011, the Stockholm International Peace Research Institute said.

Arms exports rose 95 percent in the same period.

The US ordered 31 fifth-generation F-35 stealth fighter jets in one 2010 deal, the same year it deployed four F-22 Raptor stealth fighters in joint drills with South Korea in the Sea of Japan.