Two Airbus A330 airliners – types 343 and 243 – met emergency situations in China on August 9. 

Passengers on both planes were supposed to have a normal trip but ended up in places they didn't want to be at.

The type 343 was planned to fly from Shenzhen to Xi'an. Soon after the ascent, the plane dropped thousands of meters in just a few minutes.

Flight monitoring software, which is openly available in China, showed the flight sending out emergency code 7700 and soon returned to where it took off.

The plane belongs to Shenzhen Airlines, which announced later that the cabin pressure of the plane went irregular and triggered alerts, forcing the flight to go back.

Maintaining air pressure in an airplane is crucial. Insufficient cabin pressure may kill the people inside.

Survivor's words

"I was sleeping when it happened. I was so confused," a passenger surnamed Chen told local media. "A male voice in broadcast told us we are making an emergency landing. He sounded very serious." 

She also noticed that most passengers on the plane remained calm. "Most of us were concerned that our trips would be delayed," she recalled.

The investigation carried out by the Civil Aviation Administration of China (CAAC) showed that the airplane was not perfectly sealed up.

"The incident was caused by a breakdown in the sealing gate of the rear cargo hold of the aircraft," said Wu Shijie, deputy director of the Office of Aviation Safety, CAAC. "The crew handled this correctly during the whole process," he stressed.

Investigation results published on Thursday showed that the crew strictly followed the emergency procedures, and no one was injured in the incident.

Rumor has it that the plane dropped 6,000 meters in two minutes, which is obviously not the case.

"Dropping that fast in the sky would tear the plane into pieces. That didn't happen. So, the number must be wrong," Chen Jianguo, captain of another flight in China, explained to the media.

The other flight

The other Airbus A330, from the China Eastern Airlines, successfully made it to Xi'an though it was supposed to fly from Chengdu to Beijing.

The crew initialized emergency process after the computer on the plane displayed "mechanical failure."

Considering the error notice and ongoing thunderstorm in Beijing on Sunday, the crew decided to land in Xi'an, a major airport hub halfway between Chengdu and Beijing.

Investigation revealed that an engine electronic control computer had failed. The error notice disappeared after the computer was replaced.

(CGTN's Ning Hong also contributed to the story.)