Air China flight flight #CA106 from Hong Kong to Dalian made emergency descent after a sudden loss of cabin pressure.
Air China Boeing 737-800 (reg. B-5851) made an emergency descent to 10,000ft after a sudden loss of cabin pressure.
The plane dropped 25,000 feet in 10 minutes, triggering the release of oxygen masks from the cabin ceiling.
Then the aircraft climbed to en-route level again and continued to Dalian.