A rapid emergency descent by an Air China aircraft after cabin oxygen levels dropped has been linked to a co-pilot smoking an e-cigarette.
An Air China co-pilot is being investigated after the plane was forced to make an emergency descent when his e-cigarette smoke entered the cabin.
The Boeing 737 aircraft, flying from Hong Kong to the Chinese city of Dalian, dropped in altitude to as low as 3,048m (10,000ft).
State media reported that the air conditioning was turned off, prompting the crew to perform an emergency pressure relief procedure.
The incident also resulted in the deployment of passenger oxygen masks.
“Smoke diffused into the passenger cabin and relevant air conditioning components were wrongly shut off, without notifying the captain, which resulted in insufficient oxygen,” Qiao Yibin, an official of the regulator’s aviation safety office, said.
The Civil Aviation Administration of China has said there were no injuries to the 153 passengers and nine crew.
