Passenger tells of 'terrifying' moment teen allegedly boarded flight with gun

A passenger has described the "terrifying" moment when a teenager, allegedly armed with a shotgun, boarded a Jetstar flight on the tarmac of a Victorian airport yesterday.

The 17-year-old boy has been arrested and charged following the incident, that unfolded at Avalon Airport on board Jetstar flight JQ 610 headed for Sydney.

The airport in Geelong, located 53km from Melbourne, was placed in lockdown shortly after 2.20pm.

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Passenger Daniel Defina was sitting next to Barry Clark when the teenager allegedly boarded the flight.

"He tried to walk into the cockpit. The airline (attendant) stopped him and asked if he was meant to be on the plane and asked for the boarding pass," Defina told Today.

"He tried to point to the cockpit and said he needed to do something in there.

"That's when they turned around and saw a shotgun."

Defina said Clark, along with the pilot, acted swiftly to tackle the teenager and restrain him on the floor of the plane. They detained him until police arrived.

"Everyone leapt up and the guy next to me, Barry leapt up and the pilot got him to the ground, got him in a headlock and got him down," Defina said.

"They acted smart, fast and it was terrifying. You would never expect that to happen."

There were about 160 passengers on board.

No one was physically injured.

Police allegedly found two bags and a vehicle belonging to the boy.

Officers from the Bomb Response Unit were called to help with the bags as a safety precaution.

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The teenager, from the Ballarat region, has since been interviewed by detectives and charged with numerous offences, including possessing a firearm, bomb hoax and endangering the safety of an aircraft.

He was remanded in custody to appear at a children's court at a later date.

The airport was closed but reopened late yesterday.

Melbourne Avalon Airport chief executive Ari Suss confirmed all flights and operations were back to normal scheduling.

"The safety and security of our passengers, staff, and community, as always remains our highest priority," Suss said.

"As part of our ongoing commitment to security, we have implemented further measures across the airport, including within the terminal and surrounding areas. We continue to work closely with authorities to maintain a safe and secure environment for all travellers.

"Our teams are on hand to assist travellers as normal operations resume."

Anyone with information should call Crime Stoppers on 1800 333 000, or make an online report.