China's first stealth fighter jet staged a runway test on Wednesday and could undergo its first flight on Thursday, according to Chinese media reports.
Both the English and Chinese language editions of the Global Times ran front-page articles on the leaked photos of a J-20 fighter, along with extensive reports on the buzz the pictures have generated overseas.
Photos of the plane appeared on unofficial military news websites and hobbyist blogs last week and were still viewable on Wednesday.
The Global Times did not comment on the authenticity of the pictures, but since the government wields extensive control over state media, the report's appearance and the fact that censors have not removed images from websites suggest a calculated move to leak the information into the public sphere.
That in turn would reflect the growing confidence of the traditionally secretive People's Liberation Army, which is pushing for greater influence and bigger budgets.
Calls to the spokesman's office at the Defense Ministry rang unanswered on Wednesday.
Aviation websites said the photos were taken from outside a fence at the Chengdu Aircraft Design Institute's airfield in southwestern China. The plane appeared to be undergoing a taxiing test of the sort that precedes an actual flight test.
China has seen the development of its own stealth fighter as a priority since the mid 1990s and He Weirong, the deputy air force head, told Chinese Central Television in November 2009 that a "fourth-generation" fighter would begin flight testing in 2010/2011 and enter service in eight to ten years.
China's aviation industry – both military and civilian – has made rapid progress in recent years but still relies heavily on imported technology. Propulsion technology has been a particular problem, with Russian engines still employed on China's homemade J-10 fighter jets and the J-11, a copy of Russia's Su-27 fighter jet.
Stealth technology is even more difficult to master because it relies on systems to hide the presence of the plane while equipping the pilot with enough information to attack an enemy. Emissions must be hidden and the plane's fuselage sculpted to avoid detection by radar and infrared sensors.
Chinese progress in that field calls into question U.S. Defense Secretary Robert Gates' decision to cap production of the F-22 Raptor stealth fighter at 187 planes. Supporters of the F-22 have warned of growing threats from China, as well as Russia, which has developed a stealth prototype that is already in the test flight stage.
Analysis of the J-20 photos shows it to be larger than either the Russian or U.S. planes, likely allowing it to fly further and carry heavier weapons.
There were also unanswered questions about persistent cyber-attacks in 2006 – around when the J-20 fighter programme was started – on US military contractors working on American fighters.
Between 2009 and early 2010, Lockheed Martin found that "six to eight companies" among its subcontractors "had been totally compromised, emails, their networks, everything," according to Anne Mullins, the company's Chief Information Security Officer. Meanwhile, analysts said that while the J-20 is larger than the F-22, it bears an uncomfortable resemblance to the US jet.