SHANGHAI (AFP, REUTERS) - 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 (July 13).
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 north-eastern 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.
“In the preliminary investigation, the co-pilot was found to be smoking an e-cigarette,” state-owned China News said, citing the CAAC.
The co-pilot accidentally switched off air-conditioning instead, leading to a decrease in cabin oxygen levels, Qiao said. That set off an emergency warning system indicating that the Boeing 737 jet may have flown too high and instructing the pilots to quickly descend.
It went down to 10,000 feet (3,048 m), with oxygen masks deployed.
The crew realised the problem after the descent and restored the air conditioning, allowing cabin pressure to return to normal, Qiao said.
The aircraft then climbed again to continue to its destination.
Smoking is not allowed aboard Chinese commercial passenger flights. Chinese airlines have a good safety record in general, but passengers have, on occasion, accused pilots of smoking during flights. Few such incidents have been confirmed, however.
The CAAC said it was continuing the investigation and was analysing the aircraft’s flight data recorder and cockpit voice recorder. Air China did not immediately respond to requests for comment.
It vowed a “zero tolerance” approach towards wrongdoing by any crew, on its official account on China’s Twitter-like Weibo on Wednesday.
The incident featured heavily on Chinese social media on Friday, with some commentators demanding harsh punishment and revocation of the pilot’s flight licence. China’s aviation regulations, which bar flight crew from “smoking on all phases of operation”, also banned passengers from using e-cigarettes on flights in 2006.
Users of online airline forums have occasionally accused pilots of smoking during flights, however.
In 2015, government-run China National Radio said four passengers on an Air China flight from Hong Kong to Beijing smelt strong smoke emitted from the cabin.
In 2016, the United States prohibited the use of e-cigarettes on commercial flights.