The biggest threat in the air is... you

The skies are under threat. Not from terrorists or hardened criminals, but from everyday passengers who seem to go a little loco when the airplane leaves the tarmac.

According to the International Air Transport Association (IATA), there have been 28,000 reported cases of unruly passenger incidences from when the organization started recording in 2007 to 2013. It's a number that, according to aviation experts, is both underrepresented and on the rise.

Unruly passengers have become enough of a disturbance to airline professionals to warrant a two-day conference dedicated to the topic.

Last week, London hosted DISPAX World 2014, the second international conference on how to handle disruptive travelers.

Approximately 100 professionals -- made up mainly of airline training managers and regulators -- representing 35 different countries attended the event.

We're not really sure of the number of incidents taking place, though it's safe to assume there are about 300 to 400 per week happening on board airliners," says Philip Baum, the managing director of Green Light Limited, the company that organized the event.

In addition to the passenger bad behavior in the news (Justin Bieber and Ralph Lauren's niece are two of the more high profile fliers that made headlines with their on-board antics this year), Baum notes that there are many more low-key altercations that don't ever get reported.

"The definition of unruly behavior can range from disobeying crew commands, to becoming verbally abusive, then escalating to becoming physically abusive, then potentially life-threatening," says Baum.

"IATA reports there having been 8,217 unruly passenger incidents in 2013, but this is only the tip of the iceberg. IATA's figures are based solely on a limited number of IATA member airlines reporting. Most airlines are not IATA members and few are willing to share their incident reports."