Aviation authorities in China say that the flight crew may have been violating regulations, including smoking in the cockpit, before an Air China Boeing 737 plummeted 25,000 feet in just 10 minutes.
The Hong Kong Civil Aviation Department (CAD) and the Civil Aviation Administration of China (CAAC) have confirmed that the agencies are investigating the actions of the pilots of Air China Flight 106 following an incident in which the aircraft reportedly rapidly descended from an altitude of 35,000 feet to nearly 10,000 feet in less than ten minutes. The flight crew announced to passengers that the emergency descent, during which oxygen masks were deployed, was taken in response to a loss of cabin pressure. A government spokesperson, however, suggested that the dramatic loss of altitude itself caused the oxygen masks to deploy and may have been related to crew members smoking cigarettes on the flight deck prior to the incident.
“If the investigation reveals that the crew has violated regulations, the company will seriously deal with the responsible person with zero tolerance,” Air China officials told the South China Morning Post on Wednesday.
According to media accounts, the flight had departed Hong Kong International Airport (HKG) bound for Dalian Zhoushuizi International Airport (DLC) approximately 30 minutes before the aircraft unexpectedly plunged 25,000 feet in less than 10 minutes late Tuesday evening. An eyewitness on the flight reported that immediately after the emergency descent, the captain announced that action had been taken because “the ability to increase oxygen in the cabin malfunctioned – so the plane lost pressure.”
Despite accusations that crew members may have been smoking cigarettes just before the emergency, it is not clear how the cigarette smoke on the flight deck could have caused the events that followed. The fact that the pilots took the plane to an altitude of of less than 10,000 feet along with reports that the oxygen masks automatically deployed, would seem to indicate that the crew was responding to an emergency involving a potential loss of cabin pressure.
After the rapid descent, the aircraft is said to have leveled out at an altitude of just under 10,000 feet, before returning to a cruising altitude a short time later. The flight did not divert to an alternate airport and instead continued on to its original destination where it eventually touched down at DLC without further incident.