South China Sea: A Chinese fighter jet confronts a US Navy plane with a CNN crew on board

Kadena Air Base, Japan (CNN) A US Navy reconnaissance plane is flying at 21,500 feet over the South China Sea, 30 miles from the disputed Paracel Islands, a group of about 130 tiny atolls, the largest of which is home to Chinese military bases.

A voice, saying it is coming from a People’s Liberation Army (PLA) airfield, blares over the radio of a US Navy P-8 Poseidon as the CNN crew listens, given its rare entry on the US flight.

“American aircraft. Chinese airspace 12 nautical miles. No longer approaching, or you take full responsibility,” the statement read.

Within a few minutes, a Chinese fighter jet armed with air-to-air missiles intercepted the American plane, just 500 feet from the port side.

The Chinese fighter jet was so close, the CNN crew could see the pilots turning their heads to look at them — they could see the red star on the tail fins and the missiles it was armed with.

Lt. Nicky Slaughter, the pilot of the American plane, praised the two-seat, twin-engine People’s Liberation Army plane.

“PLA fighter jet, this is a US Navy P-8A… I have removed you from the left wing and intend to turn to the west. I ask you to do the same, more so.”

There was no response from the Chinese fighter jet, which escorted the American plane for 15 minutes before turning away.

For the CNN crew aboard the US flight, this is stark evidence of the tensions brewing in the South China Sea, and between the US and China.

The commander of this US Navy mission has a different view.

“I would like to tell her on Friday afternoon again in the South China Sea,” the Navy Cmdr. Mark Haynes tells the CNN staff.

potential flash point

Over the past several years, the South China Sea has emerged as a potential major point of tension in the Asia-Pacific region. Islands in it, such as the Paracels near which a US Navy plane was intercepted on Friday, are the subject of partially overlapping territorial claims from China, the Philippines, Vietnam, Malaysia, Brunei and Taiwan.

Not only does the strategic waterway contain vast fish, oil and gas resources, but about a third of global freight passes through it – worth about $3.4 trillion in 2016, according to the Center for Strategic and International Studies (CSIS) China Power Project.

China claims historic jurisdiction over nearly the entire vast sea, and since 2014 has erected small reefs and sandbars on artificial islands heavily fortified with missiles, runways and weapons systems — to the ire of other claimants.

The Paracels Islands, called Xisha Islands by China, lie in the northern part of the South China Sea, east of Da Nang, Vietnam, and south of China’s Hainan Island.

Named by Portuguese mapmakers in the 16th century, they have no indigenous people to speak of, only Chinese military garrisons numbering 1,400, according to the CIA Factbook.

They are surrounded by 12 nautical miles of airspace that China was claiming as its own on Friday – a claim Washington does not recognize.

The Spratly Islands chain lies in the extreme southeast, just 186 miles from the Philippine island of Palawan.

In 2016, in a case brought by the Philippines, an international tribunal in The Hague to rule China’s claim of historical rights to the bulk of the sea has no legal basis.

But Beijing rejected the court’s ruling and continued its military buildup by building bases in the Spratlys, which it calls the Nansha Islands.

China also conducts regular military exercises in most areas of the South China Sea and maintains a large coast guard and fishing vessel presence in the disputed waters – which has often raised tensions with its neighbours.

On Friday, while flying close to the Philippines, the US Navy spotted a P-8 guided missile destroyer of the Chinese People’s Liberation Army Navy and descended to an altitude of 1,000 feet for a closer look — bringing more warnings from the People’s Liberation Army.

“American planes. American planes. This is a Chinese Navy warship .173. You are approaching me at low altitude. Set your intention to finish,” a voice comes over the American plane’s radio.

The PLA’s 173rd warship is the destroyer Changsha, and it is likely to be armed with dozens of surface-to-air missiles.

The aircraft’s commander, First Lieutenant Slaughter, replied that the American aircraft would maintain a safe distance.

The Chinese ship says: “American planes. American planes. This is a Chinese Navy warship 173. You are clearly endangering my safety. You are clearly endangering my safety.”

Slaughter replies, “I am a US military aircraft. I will keep a safe distance from your unit,” and the US mission continues.

The US Navy says these missions are routine.

The Pentagon says US ships and aircraft operate regularly where international law allows. But China claims that it is the US presence in the South China Sea that is fueling tensions.

When a US guided-missile cruiser steamed near the Spratly Islands in November, the People’s Liberation Army said such an action “seriously violates China’s sovereignty and security” and is “conclusive evidence that the United States seeks maritime hegemony and militarizes the South China Sea.”

The US Navy said the US ship carried out the operation “in accordance with international law and then continued its normal operations in the free waters on the high seas”.

For Heinz, the US Friday mission commander, tensions always lessen when he talks with the Chinese side.

He says silence brings uncertainty.

“When there is no response, it leaves questions. Do they understand what is being said? Do they understand our intentions? Do they understand that we mean no harm?” He says.

For the most part of Friday, the answers were there. Hines says the encounters were “professional.” And he wants to keep it that way.

CNN’s Nectar Gan and Brad Lyndon contributed to this report.