Appalling footage has emerged of the moment an aggressive and unruly American flight passenger got himself so riled up at an airport that he reduced a Ryanair worker to tears after relentlessly taunting her.

The incident reportedly took place at Brussels Airport and began when the man was told he would need to pay €50 to get onto a flight he had already booked himself onto - because he failed to print out his boarding pass.

Taking out his phone and recording his seven-minute-long rant - in which he even challenged another passenger, calling him fat - he repeatedly barks orders at the woman, Sabrina.

The man even tells the male passenger defending Sabrina: “Lose some weight - get on the treadmill. You out-of-shape, doughnut-eating, bald piece of c**p.”

When it finally becomes too much for the woman - who then breaks down into tears - the obnoxious passenger shouts: “Now you’re having an emotional breakdown?”

Uploaded just five days ago, the video has already been widely shared online, having been viewed close to 100,000 times as people from across the globe hit out at the man for behaving in such a way.

Ryanair has since issued a short statement, and said: “Our handling agent at Brussels Airport, Aviapartner, is looking into this matter.

“We will not tolerate unruly or disruptive behaviour at any time.”

The complete clip can be viewed here.