The co-pilot of a Sichuan Airlines flight that was forced to make an emergency landing on Monday was "sucked halfway" out of the plane after a cockpit windshield blew out, media reported, citing the aircraft's captain.

Liu Chuanjian, hailed a hero on social media after having to land the Airbus A319 manually, told the Chengdu Economic Daily his aircraft had just reached a cruising altitude of 32,000 feet when a deafening sound tore through the cockpit.

The cockpit experienced a sudden loss of pressure and drop in temperature and when he looked over, the cockpit's right windshield was gone.

"There was no warning sign. Suddenly, the windshield just cracked and made a loud bang. The next thing I know, my co-pilot had been sucked halfway out of the window," he was quoted as saying.

"Everything in the cockpit was floating in the air. Most of the equipment malfunctioned ... and I couldn't hear the radio. The plane was shaking so hard I could not read the gauges."

The co-pilot, who was wearing a seatbelt, was pulled back in. He suffered scratches and a sprained wrist, the Civil Aviation Administration of China said, adding that one other cabin crew member was also injured in the descent. None of the plane's 119 passengers was injured.

The Civil Aviation Administration of China (CAAC) said France's BEA accident investigation agency and Airbus would send staff to China to investigate, according to CAAC News which is affiliated to the aviation regulator.

Sichuan Airlines Flight 3U8633 left the central Chinese municipality of Chongqing on Monday bound for the Tibetan capital of Lhasa. It made its emergency landing in the southwest city of Chengdu.

"The crew were serving us breakfast when the aircraft began to shake. We didn't know what was going on and we panicked. Then the oxygen masks dropped... We experienced a few seconds of free fall before it stabilized again," an unnamed passenger told the government-run China News Service.

"I'm still nervous. I don't dare to take an airplane anymore. But I'm also happy I had a narrow escape."

The windshield shattered about half an hour after the plane had taken off, the Chengdu Economic Daily said. A separate report said the aircraft had accumulated 19,912 flight hours since entering service at Sichuan Airlines in July 2011.

CAAC also said that the windshield was part of the original aircraft and had no previously recorded faults.

Incidents involving cracked windshields do happen on a regular basis due to bird or lightning strikes but ones involving entire windshields coming off are rare.

In 1990, one of the pilots on British Airways Flight 5390 was blown partially out of the cabin window after its windshield blew out at 23,000 feet. He survived the incident, which occurred on a BAC-111 jet.