China Southern Airlines later urged passengers to comply with civil aviation laws and regulations and avoid behaviour that could prove detrimental to the safety of passengers travelling on its flights.
According to a statement issued on the official Weibo microblog of the Shanghai police, the 80-year-old woman - identified by her surname, Qiu - threw nine coins toward the engine as she was ascending steps to the China Southern Airlines aircraft.
You've probably seen people tossing coins in a fountain for good luck, but throwing change into the engine of an airplane you're boarding seems a little counterproductive. One of the coins entered the engine.
Crews recovered one coin that landed inside the engine and eight more in the surrounding area during the inspection, which lasted about five hours. The captain was said that if the metal was sucked up by the engine, it could have caused a catastrophic failure.
Ground staff said the woman, who appeared to be about 80 and had limited mobility, was accompanied by her husband, daughter and son-in-law.
Qiu had no criminal record or mental disease.
After a five-hour delay the airplane finally took off to travel to Guangzhou.
She told police she launched the coins as she "prayed for safety" on Tuesday.
Neighbors of the suspect said that Qiu believes in Buddhism.