Flight 3U8633, operated by Sichuan Airlines, prepares to conduct emergency landing after a mechanical failure in Chengdu Shuangliu International Airport in Chengdu, capital of southwest China's Sichuan Province, May 14, 2018. Part of the cockpit window broke as the Airbus A319 flew over Chengdu. The plane was en route from southwest China's Chongqing Municipality to Lhasa, capital of Tibet Autonomous Region. It was forced to divert to an alternate airport in Chengdu. All passengers are safe, although the co-pilot sustained injuries to the face and waist, and another crew member was slightly hurt during the emergency landing. After the landing on Monday morning, the airline has arranged another flight to take the passengers to Lhasa. (Xinhua/Wan Bi)

CHENGDU, May 15 (Xinhua) -- As pilot Liu Chuanjian flew over Chengdu, capital of southwest China's Sichuan Province, on Monday, the righthand side cockpit window broke, and his co-pilot was almost sucked out.

"The cockpit window broke all of a sudden, followed by a loud noise," Liu recalled. "The sudden decompression sucked part of my co-pilot's body out and left him hanging by his safety belts."

Flight 3U8633, operated by Sichuan Airlines, was forced to divert to Chengdu due to mechanical failure on Monday morning, according to the Civil Aviation Administration of China (CAAC). The flight was en route from southwest China's Chongqing Municipality to Lhasa, capital of Tibet Autonomous Region.

The CAAC said the cockpit window broke as the Airbus A319 flew over Chengdu. The aircrew enacted emergency code 7700 and landed in Chengdu. All passengers were safe, although the co-pilot sustained injuries to the face and waist, and another crew member was slightly hurt during the emergency landing.

Sichuan Airlines confirmed the diversion, and said that an investigation is under way. Meanwhile, Airbus China said that they have sent a team to help with the investigation.

The plane landed in Chengdu at 7:42 a.m. on Monday. There were 119 passengers and nine crew members on board, according to the airline, which arranged another flight to take the passengers to Lhasa.

Video footage shot by passengers showed baggage falling from overhead lockers during the emergency landing and oxygen masks dropping for use.

MALFUNCTION IN THE AIR

Liu said that the plane was at cruising altitude about 150 km from Chengdu when the accident occurred.

"All of the objects in the cockpit just dropped to the floor suddenly, and the operating equipment began to malfunction," Liu said. "The noise was so loud that we could barely hear the radio."

Liu said it was hard to see the dashboard clearly, and it became very difficult for him to operate the plane.

"The plane was flying at a speed of more than 900 km per hour. The sudden decompression and low temperature made us feel very uncomfortable," Liu said.

Liu said he has flown the route 100 times, and is familiar with many different flight situations. To avoid further damage, he manually slowed the plane, as the auto-pilot system was not operational.

Liu was previously a military pilot before he started working for Sichuan Airlines in 2006.

Jiang Wenxue, a civil aviation official, said that under such emergency circumstances, the pilot "truly performed a miracle" by keeping the plane under control.

A passenger who gave his name as Phuntsog said that when the accident occurred, the cabin lights and electronics went out, and flight attendant's intercom service was cut. The cabin crew calmed the passengers and helped them put on oxygen masks.

"Some people were screaming, but the crew told us that the pilot had the ability to bring us home safely, which calmed our emotions," said Phuntsog, 25. "All we could do was wait."

Zeng Shibin, another passenger, said that his wife Ai Zehua was terrified by the accident.

"It was her first ever flight, and she never expected anything like this," Zeng said. "She fainted twice after landing."

"The plane started to drop really quickly," said passenger Ma Chuanfa. "It felt like we descended several thousand meters in several seconds, and the baggage was tossed around in the cabin."

When the plane landed in Chengdu, many started to cry. Phuntsog hugged the passenger sitting next to him.

"I want to thank the pilot and the cabin crew for staying calm and helping us land safely," Phuntsog wrote on his WeChat social media account. "You performed a miracle!"

An Air China pilot, who declined to be named, praised Liu's skills and calmness.

"It is a huge challenge facing decompression and low temperatures," said the Air China pilot. "With a broken cockpit window, the temperature would drop to well below zero degrees Celsius, and the equipment would defunction."

"The pilots would be operating with compromised abilities under such extreme conditions," he said. "But they made it, they saved many lives."

China has many airports in mountainous and high altitude areas which place huge physical and psychological pressure on pilots.

"The plane was nearing mountainous areas, which makes it more difficult to descend," said another pilot with Sichuan Airlines. "They descended from 32,100 feet to 24,000 feet, and hovered near the plains, which means that the pilot remained very calm."

"They are truly heroes," said the Sichuan Airlines pilot.