Drunk man restrained on flight after allegedly smoking in toilet and brawling with flight attendant

A passenger on a Korean Air international flight had to be tied up by the hands and feet after he allegedly injured a flight attendant who wouldn't serve him more beer.

And he now faces up to 20 years in jail for his alleged bad behaviour.

The man, Kwon Woo Sung, acted up while he was on a four-hour flight from Seoul to the US island territory of Guam, court documents show.

According to Pacific Daily News, the man drank about five beers when, about three hours into the flight, he went into the plane's toilet cubicle and lit up a cigarette, which is illegal under US aviation law.

A flight attendant who noticed the cigarette smell approached Sung and asked if he had been smoking, and he allegedly admitted to it.

But Sung then asked for two more beers and became enraged when he was refused, with court documents stating his behaviour began "creating an issue".

The irate passenger then allegedly lunged at a supervising flight attendant who had intervened and tried to punch him, it is alleged.

Sung allegedly then grabbed the attendant and dragged him through the aisle of the plane.

About four of five passengers tried to break up the struggle and helped to eventually restrain Sung by tying him up at the hands and feet for the remainder of the flight.

The supervising flight attendant allegedly received a cut on his hand, bruising on his chest and back and a puncture wound on his chest during the altercation.

Sung was charged with interference with flight attendants, according to a magistrate's complaint filed in the US District Court of Guam, the Pacific Daily News reported.

If convicted, Sung faces fines, a 20-year jail sentence or both, according to US federal law.

Earlier this year, a drunk passenger on a Qantas flight from Perth to Sydney had to be restrained after he allegedly became aggressive when he was refused more alcohol.

The man allegedly became "abusive" and "violent" until an air marshall restrained the man with elastic handcuffs for the rest of the journey.

- news.com.au