An aerial photo of the South China Sea. File photo: Xinhua

A Hong Kong-based media outlet on Wednesday reported that the US military spy aircraft E-8C was first recognized as a civilian flight during a night sortie in the South China Sea, and experts reached by the Global Times noted such a move, if confirmed, will risk involving civilian flights in military confrontations. 

The South China Morning Post, citing source close to the Chinese military, reported that an aircraft was initially identified by the air control as a commercial airliner flying at more than 9,000 meters over the South China Sea. It was later identified as a military aircraft when it flew close to Guangzhou, capital of South China's Guangdong Province. 

US military uses multiple reconnaissance aircraft developed on commercial airplane platforms, and they usually follow civil aviation flights as cover when approaching China's airspace, said the report. 

The report didn't provide details of the "following" or where the aircraft was when it was identified as military aircraft, but experts warned that such behavior is very dangerous. 

A airline pilot told the Global Times on Wednesday that civilian flights have a unique code to communicate with air traffic control and flight information will appear on radar systems. All information regarding civilian flights is part of the civil aviation monitoring system. 

Wang Yanan, chief editor of Aerospace Knowledge magazine, said that if a civilian flight approaches China's airspace, the monitoring system will receive data via the radar system when it enters a controlled zone. 

Civil aviation routes are like open roads where military aircraft are allowed but they seldom use these routes because they may disturb the civilian flights. Military aircraft will be quickly identified as they don't conform to the routine of a civilian flight, and radar signals don't match, Wang told the Global Times on Wednesday. 

Flying over the exclusive economic zone without entering China's airspace may not have violated international law, but analysts said a military flight pretending to be a civilian one trying to trick the radar system is risky. 

If a military aircraft was attempting to masquerade as a civilian aircraft, the  sovereign country's air defense system may trigger a response, Wang said. Another insider also noted such a move by the US military could lead to misjudgments and dangers.

Since the South China Sea is a busy zone with many civil flights passing by, US reconnaissance planes pretending to be a civilian aircraft pose risks to civilian flights, analysts said. 

If the US military aircraft is disguised as a civil plane, the chance of being intercepted by the PLA may be much smaller. At least, it would likely confuse the PLA, Hu Bo, director of the Beijing-based think tank the South China Sea Strategic Situation Probing Initiative, told the Global Times on Wednesday. 

"But mixing military and civil  aircraft can lead to military confrontations and even accidental injuries," Hu said. 

The right of navigation and overflight granted by international law to foreign military aircraft and ships is to ensure normal operations. But the US military aircraft and warships' move is an obvious abuse of this legal right and a hostile provocation that seriously endangers China's national security, said Hu.