Richard Marx Tees Off On Korean Airline Security

Richard Marx learned a valuable lesson from his 4-hour mid-flight ordeal with an out of control passenger ... and he's begging South Korea to learn it too.

The '80s and '90s pop star talked to a photog about the scary incident that went down right next to Richard and his wife, Daisy Fuentes, aboard a Korean Air flight.

Richard ended up helping flight attendants restrain the guy, and was very critical of the crew's emergency training. But check out his takeaway from the whole mess. It's a direct shot, and while it's unclear if he's pissed only at the airline or the entire nation -- it's 100% clear he won't be a frequent flyer.