A China Eastern Airlines Airbus A321-200 has had its oxygen maskes deploy automatically.
The aircraft, B-8568, was performing flight MU-5257 from Qingdao to Guangzhou (China). They were enroute at FL341 about 140nm northeast of Nanchang (China) when the passenger oxygen masks were automatically released, cabin pressure and all other indications remained normal however. The crew decided to divert to Nanchang. They performed a precautionary descent to 9800 feet and landed safely in Nanchang about 30 minutes after leaving 10400 meters.
A replacement Airbus A321-200 registration B-6642 reached Guangzhou with a delay of 3 hours.
The occurrence aircraft is still on the ground over 17 hours after landing.