A pilot of "Vaping" plunged the plane of Air China to 6,500 m

A co-pilot smoking an e-cigarette on an Air China flight caused a rapid emergency raid, investigators said.

They say that he tried to hide the fact that he was smoking but that he accidentally turned off the air conditioning, causing the drop in oxygen levels.

The flight crew from Hong Kong to Dalian City on Tuesday released oxygen masks and dropped the aircraft over 6,500 feet (21,000 feet).

An initial survey of the Chinese Civil Aviation Administration in China showed that the co-pilot had tried to extinguish a fan to prevent smoke from reaching the passenger cabin without prevent the captain, but he had turned off the air conditioning unit.

Passengers say that they were told to fasten their seatbelt while the plane was coming down

The regulator's safety officer, Qiao Yibin, said the crew needed to take urgent measures, dropping the oxygen masks until they could understand the problem.

If an airplane loses pressure in the cabin, the pilot must bring the plane to a lower altitude to ensure the safety of the crew and passengers.

Once they saw that the air conditioning had been turned off, they reactivated it and brought the flight back to its normal altitude.

Authorities would investigate the case "in more detail", examining both the flight data recorder and the cockpit voice recorder to determine precisely what caused the accident. incident

The airline promised a zero tolerance approach to crew misconduct on the Chinese social media site Weibo

The regulations prohibited all crew members from smoking and prohibited passengers to use electronic cigarettes on board in 2006.

But there have been accusations of pilots smoking on board other Chinese flights, including in 2015 on a Hong Kong-Beijing flight that claimed feel strong smoke from the cockpit.