BEIJING - An elderly passenger on a flight from Shanghai to Guangzhou allegedly threw coins into the plane's engine for "good luck" while boarding, according to Chinese media reports, forcing the plane to remain on the tarmac for five more hours.

China Southern Airlines Flight 380 was held up at the Shanghai Pudong International Airport after passengers saw the woman throwing coins at the engine from the middle of the boarding staircase and alerted the crew, reported The South China Morning Post.

After maintenance crew inspected the aircraft, they found nine coins in one engine. The captain was quoted as saying that if the metal was sucked up by the engine, it could have caused a catastrophic failure.

“A senior passenger threw coins to the plane’s engine and delayed the flight. The passenger involved has been taken away by police,” China Southern Airlines said in a statement on its Twitter-like Weibo account, reported AFP.

“In order to make sure the flight is safe, China Southern maintenance has conducted a full exam of the plane’s engine.”

The incident was soon trending on Weibo and police added in a statement: “After investigation, the involved passenger surnamed Qiu said she threw the coins to pray for safety. According to Qiu’s neighbour, Qiu believes in Buddhism."

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.

The flight eventually took off at 5.52pm local time, more than five hours late, and was due to arrive in Guangzhou at 8.14pm.

Chinese air travellers have earned a notorious reputation for disregarding air safety in recent years, with their shenanigans including opening emergency doors to deboard quickly and assaulting cabin crew.