While this is for a number of reasons, the president of the Australian and International Pilots Association (IAPA), Tony Lucas, says that finding room for carry-on is a contributing factor.

“It is an issue for (pilots) and absolutely it causes delays when we can’t fit it all on board the aeroplane,” said Lucas.

“We don’t like getting delayed. We like getting people to where they want to go on time.”

With passengers breaching airline carry-on limits, the workload for security screening staff has increased, making the process longer and risking it becoming less thorough.

“With every single item needing to be scanned to ensure safety, this obviously increases the amount of time it takes to screen each passenger,” said Peter Doherty, corporate communications manager at Brisbane Airport.

Lucas says that the other concern that comes with an increased carry-on is safety. In the event of an accident, with more carry-on in the plane’s cabin, more people are going to want to take bags full of valuables off, leading to slower evacuation and subsequently greater risks.

“The other concern is that the more carry-on people take, the less likely they will be willing to leave it in the event of an emergency evacuation.”

Lucas also said that passengers were generally quite educated on what they could and couldn’t take on a flight, which meant when asked to check in their baggage, the response was one of frustration.

“It is frustrating when you’re within the limits of the carry-on allowance, only to be told it has to travel downstairs (in the cargo hold),” said Lucas.

“That’s another 20 to 30 minutes of waiting at the baggage carousel at the end of the flight and there’s always anxiety as to whether your bag will emerge.”

The increased volume of carry-on luggage can be attributed to a number of reasons. Last year saw numerous issues with mishandled bags. According to a baggage handler working for a Qantas contracted company, as many as one in ten pieces of luggage on average was lost or did not make it onto its destined flight.

Increased airfares mean people are cutting costs, such as not opting for checked-in baggage on airlines where it costs an additional fee, while travellers are also taking shorter trips, meaning less need for checked-in baggage.

“The shorter trips we were seeing last year didn’t need as much luggage and that’s starting to change as people are tending to have longer trips which has increased the need for check-in,” said James Goodwin, chief executive of the Australian Airports Association.

“I wouldn’t see it as a permanent switch,” he added.