The unruly behavior of tourists has come into the spotlight on a plane bound for Northeast China's Shenyang from Shanghai on Monday. Three windows on the aircraft had been carved with Chinese and foreign words, Shanghai Morning Post reported.
The men who took the photos of the inscribed windows and posted them online said the letters are not obviously noticeable as the windows are transparent and one can only spot them at certain angles.
The pilot of the plane, who refused to be identified, said it was first time that he encountered this kind of uncivilized behavior in his nine years of piloting planes.
The pilot said the letters must have been inscribed some time ago. Some of the letters are Russian, about the Sochi Winter Olympics which were held last year.
A senior pilot condemned the behavior and said it poses potential safety risks. The tourists must be using keys as hard metals like knives are forbidden on board.
Diao Weimin, a legal expert on civil aviation law, said the people who are caught in the act should not only be criticized, but also punished.
There was a previous report about someone who took away the life jacket on a plane and was punished with a fine, and held in custody as well.
