Air China flight attendants have been accused of being ‘ sloppy and careless ’ after a plane was photographed in flight with its door not properly locked . The photo of the Boeing 737-800 was snapped this month at Beijing Capital International Airport and went viral after it was uploaded onto Chinese social media networks . It showed the door ’ s lock out of position while the plane was in the air at China ’ s busiest airport , drawing criticism from air safety experts . This photo showing a plane door 's lock out of position went viral on Chinese social media networks . Air safety expert Guang Yu told local media : ‘ It is probably not dangerous because there are various safety measures in place but it shows an extremely sloppy and careless attitude on behalf of the cabin crew. ’ Chinese state media agency Xinhua quoted an Air China spokesman as saying that the airline conducted a thorough investigation , including interviews with the plane ’ s crew and other staff , after the photo surfaced online . It said the investigation found that the lock was in the ‘ normal ’ position when the flight took off . A Boeing specialist quoted by Chinese state media said that human error or a mechanical problem with the lock could result in an external lock being out of position . Air China said an investigation found that the lock was in the proper position when the flight departed . The expert added that a mechanical problem would not affect flight safety because of another locking system operated from within the cabin . The report also said that it appeared to be a case of mechanical failure . The photo sparked debate on Chinese social media website Weibo , and was shared after several incidents involving Chinese passengers opening plane doors before take-off or after landing . Last week a 42-year-old Chinese man was detained for 10 days after he opened an emergency exit shortly before a Urumqi Airlines plane was due to take off . The man told authorities that he thought the door handle was a handrail that he could grab onto for support , ‘ like the handrail on a bus ’ . A Urumqi Airlines flight was delayed last week after a passenger opened the emergency exit . He was removed by police and detained for causing a disruption for others on board the plane , which was travelling from Urumqi to Zhengzhou . That incident was at least the fifth time since December a passenger has opened an emergency exit on a plane in China . Last month , an unidentified man was detained for 10 days after opening a plane emergency exit as passengers were boarding at Nanjing airport , the South China Morning Post reported . He told airline staff ‘ The door is not important ’ when they asked him why he opened the door , the newspaper reported . In January , angry passengers opened emergency exit doors on a China Eastern flight in Chengdu . In January , angry passengers opened emergency exit doors in protest of a weather-related delay as their China Eastern flight taxied to a runway in Chengdu . It led to a longer delay for everyone on board . A month earlier , a man was arrested after he opened the emergency exit ‘ to get off quicker ’ after a China Eastern flight landed in Hainan . By unlocking an opening the emergency exit , he deployed the emergency slide . Also in December , a rookie traveller yanked open a door on a Xiamen Air flight from Hangzhou to Chengdu to ‘ get some fresh air ’ shortly before it was supposed to take-off .
Air China said it conducted an investigation after the photo surfaced . It said that the lock was in the 'normal ' position during take-off . Photo sparked debate on Chinese social media after recent incidents . Passengers have opened emergency exits on at least five occasions .