According to fellow passenger Barry Clark, the 17-year-old became upset when questioned by cabin staff when he boarded the plane. Clark, a former professional boxer and sheep shearer, immediately noticed a rifle barrel, he tells TV channel Network 10.
I then did what I had to do and simply put him in a small lock, took his hand and twisted it, and put it up his back, threw him to the floor and then put my knee in his back and held him in a position where he couldn't get out.
According to the police, the boy had climbed in through a hole in the airport's security fence and made his way to the plane's stairs.
The plane, which was due to depart for Sydney, had around 150 people on board. No one was injured and the flight was cancelled.
