SHANGHAI, July 13, 2018 (BSS/AFP) – An Air China jet made a rapid
emergency descent after a co-pilot mistakenly turned off air-conditioning
systems in a bid to conceal his e-cigarette smoke, Chinese media quoted the
country’s civil aviation authority as saying Friday.
The incident, which resulted in the deployment of passenger oxygen masks,
occurred Tuesday on a flight by the Chinese flag carrier from Hong Kong to
the city of Dalian in northeastern China.
The Civil Aviation Administration of China (CAAC) said in a press
conference in Beijing that the drama was triggered when the co-pilot sought
to turn off a ventilation system to prevent his smoke spreading into the main
cabin, the respected news site Caixin said.
Smoking is not allowed aboard Chinese commercial passenger flights.
But the co-pilot accidentally switched off air-conditioning instead,
leading to a decrease in cabin oxygen levels.
That set off an emergency warning system indicating that the 737 jet may
have flown too high and instructing the pilots to quickly descend.
Chinese media reports quoted passengers and flight-tracker sites as saying
the plane may have descended as much as several thousand metres.
The CAAC said the aircraft dropped down to low as 3,000 metres (10,000
feet), without specifying its original altitude.
Video from aboard the flight that was later posted on social media showed
oxygen masks hanging down from the ceiling throughout the cabin, but no signs
The CAAC has said there were no injuries to the 153 passengers and nine
It added that it was continuing to investigate the incident.