Questions are raised over how a 17-year-old boy was able to evade security at Avalon Airport and board a flight with a loaded shotgun, in a breach one aviation security expert described as "unacceptable".

When the security crisis unfolded on Thursday afternoon, local police from Lara - nine kilometres away - were the ones that responded.

The 17-year-old is facing eight charges while a sheepshearer who stepped in to disarm him is being praised as a hero and has been offered free flights for life.

Home Affairs Minister Tony Burke has initiated the audit to determine what security upgrades are necessary to prevent such incidents after a teenage alleged gunman tried to board a Jetstar flight.

A teenager who allegedly boarded a Jetstar flight armed with a shotgun has triggered a review of security at airports around Australia.

A lack of police presence at the airport meant officers had to race nine kilometres to arrest a teenager who claimed to be carrying a bomb on board a Jetstar flight.

The Australian Federal Police have charged a man after he was allegedly caught with a knife at Sydney Airport after slashing the inside of a bus.

A teenager accused of attempting to hijack a Jetstar flight allegedly declared “I’ve got bombs in my bag” before he was tackled by passengers.

Regional airports across the country, including NSW, have been ordered to undertake rapid security assessments after a teenager allegedly tried to board a Jetstar flight near Melbourne while armed with a shotgun.

No South Australian regional airports are included in a major national security review of aviation sparked by a terror scare at Victoria’s Avalon Airport – despite some passengers boarding local planes without any screening.

Police say a 17-year-old boy with a loaded shotgun boarded a plane in Australia before being restrained by a pilot and two passengers