The oxygen masks were deployed approximately half an hour into the Tuesday night trip when it began to lose altitude. Registered data proved the plane falling from 35,000 feet to 14,000 feet before levelling off. The aircraft did not divert and continued on its journey. One flyer said of the incident: “The announcement from the cockpit said the ability to increase oxygen in the cabin malfunctioned so the plane lost pressure.” But suspicions are the crew caused the incident by smoking in the cockpit. The airline has vowed for “zero tolerance” if crew members are found guilty of wrongdoing. The plane landed without incident.
Image from inside the plane during flight
The airline has cancelled some scheduled flights following the incident. Addressing the claims of misconduct, Air China confirmed the pilots were under investigation by the Civil Aviation Administration of China (CAAC). The CAAC passed a regulation in 1997 stipulating that smoking is not allowed in the cabins and lavatories of domestic airlines and smoking has also been completely banned on international airlines. One cannot smoke on flights which are parked on the ground, either.