NEWS Air China Boeing 737 flying with unlocked door at Beijing Airport

Photographs have surfaced online of an Air China jet with an door lock that appeared to be open mid-flight, local media reported on Monday.

But the airline denied that anything was amiss.

According to brief reports in response to photos posted on an aviation enthusiasts’ online chat group, the incident occurred on February 16 at Beijing Capital International Airport, but only came to local media attention on Monday. It was unclear whether the plane was approaching the airport or taking off.

The reports added that the plane was a Boeing 737-800.

Xinhua cited an Air China spokesman as saying late Monday night that the airline had conducted a thorough investigation with the staff and crew after the online reports, and found the lock was in the “normal” position when the flight took off. There was also no abnormal situation reported, the airline said.

Xinhua also quoted a Boeing specialist in China as saying human error or a mechanical problem with the lock could result in an external lock being out of position. But a mechanical problem would not affect flight safety in this case because of another locking system operated from within the cabin, Xinhua reported the specialist as saying.

The report added that this case appeared to be one of a mechanical failure in the lock.