BEIJING -- Chinese airlines aren't exactly known for flying on time. Four of them ranked among the worst last year when it comes to on-time arrivals and departures.

Not all delays are the airlines' fault, of course. For instance, it wasn't China Southern airline's fault this week when a Guangzhou-bound flight was delayed for more than five hours at Shanghai Pudong International Airport.

The culprit was a woman in her 80s, who was just trying to keep everyone safe.

The woman, identified only by her last name, Qiu, is apparently a Buddhist who, like many of the faith, put a lot of stock in good luck.

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Another passenger saw Qiu behaving strangely around their plane as they boarded -- throwing a handful of coins straight at the jet's engine. She did it, it turns out, with a little prayer for good luck, hoping to bring herself and the other passengers in for a safe landing at their destination.

China Southern Flight 380 was delayed at Shanghai Pudong Int'l Airport on Tues after an elderly woman threw coins into the engine for luck.. pic.twitter.com/wSSWJg9bcE — Flight (@flightorg) June 27, 2017

Police have said only one of the nine coins (with a total value of about 25 cents) actually made it into the engine, but that was enough to force the airline to pull everyone off the flight while engineers ensured no damage had been done and the jet engine was clear.

Chinese passengers have some history with disrupting air travel. In 2016, a Chinese woman was arrested for common assault after throwing orange juice at a flight attendant. Another flier poured hot water and threw noodles at a Thai AirAsia flight attendant.

They also can't seem to stop opening emergency exit doors, for a variety of reasons, including simple curiosity, innocently mistaking it for the toilet, and a misguided attempt to get some fresh air.

With a booming economy and a fast-growing middle class, Chinese are traveling more than even. The country's tourists spent more money overseas last year -- $261 billion -- than travellers from any other single nation, according to the United Nations World Tourism Organization. That represents an increase in Chinese tourism spending of 12 percent over the previous year.

The problem of misbehaving, or simply inexperienced Chinese fliers who then went on to cause problems at their destinations got so bad a couple years ago that the national tourism regulator had to step in.

A "blacklist" of offenders, those who have demonstrated illegal or inappropriate behavior abroad, was established in 2015.

Banned behavior includes "acting antisocially on public transport, disrespecting local customs, sabotaging historical exhibits or engaging in gambling or pornographic activities." In the two years since the domestic travel ban went into effect, 29 Chinese nationals have been blacklisted.

As for Mrs. Qiu, police pulled her aside and asked some questions, but they let her go without filing any charges, and there's no indication she will be blacklisted for her well-intended coin toss.