A Connecticut woman was the first of the week, walking her child through security at New York’s JFK airport with a loaded gun in her purse and “one in the chamber”, as officials put it.

Over the following days, an X-ray machine detected a 9mm pistol and ammunition in the hand luggage of a passenger in Philadelphia, a .45 caliber handgun and seven bullets in the carry-on bag of a man boarding a plane at New York’s Westchester airport, and a loaded weapon carried through screening in Wisconsin.

Security officers confiscated two firearms in two days at the Columbus, Ohio international airport. Other arrests for guns turned up by searches were made at terminals in Virginia, Pennsylvania and Connecticut.

And that was just a fraction of the 18 guns confiscated every day on average from passengers traversing flight security across the US – a number that has been rising for years and is likely to continue doing so as firearms sales rise and more states make it easier to carry concealed weapons – even in airports.

Two decades after 9/11, thousands of passengers who are otherwise conditioned to remove their shoes, bag their liquids and all too often surrender their dignity at security screenings somehow manage to forget they are carrying an object that is the very reason they are being searched in the first place.

Last year, the US Transport Security Administration (TSA) seized 6,542 guns from people about to board planes at 262 airports – a sixfold increase since 2010. Nearly nine in 10 of the weapons were loaded.

Jeffrey Price, former assistant director of security at Denver international airport and co-author of a book on aviation security, said he wasn’t surprised.

“One of our unique American traits is the number of people who purchase a weapon and forget they even have the thing with them. It seems like every time there’s another active shooter incident, a lot more people go out and buy guns because they feel scared,” he said.

“A lot of those people who buy a gun in the heat of the moment, they toss it in their laptop bag or in their purse, and then they forget they have it. Next thing you know, they’re at the airport and oh, my gosh, I forgot I put that in there. Which in itself is pretty scary because it could mean they’re leaving a bag lying around at home with a gun in for a kid to get to.”

The TSA says that passengers claiming to forget they even have a gun is the most common explanation and is frequently accepted by the police. Although officials were more skeptical about a man who blamed his mother for packing a rifle found in his bag at Baltimore airport.

Price said other factors are also at work.

”There’s also [a] certain percentage of people that think because they’ve been issued a permit (to carry a gun) they can carry it anywhere, anytime, which is not true. And then you’ve got people that just think they can slip it through. The TSA won’t notice,” he said.

They would include the passengers caught trying to smuggle guns stuffed inside a raw chicken, jars of peanut butter, a PlayStation and an arm sling.

Some cities and states press criminal charges, and the offending individual is marched out the airport in handcuffs. But it is not uncommon in gun-friendly parts of the country for a passenger to be allowed to put their weapon in their car and return to board their flight.

Atlanta airport tops the gun seizure table with more than one a day found in passenger hand luggage.

“It is very alarming,” Balram Bheodari, manager of Atlanta airport, told a congressional hearing last year about the record number of guns seized on his watch. “Eighty-six percent of those weapons had a round in the chamber or a loaded magazine in the weapon. Very, very alarming.”

Bheodari had to contend with an incident 15 months ago in which a passenger “lunged” for a bag as a TSA agent began to search it and accidentally fired a gun inside, sending people around him diving for the floor and shutting down flight departures. The airport put out a message assuring passengers “there was not an active shooter”.

The man ran out the airport with the gun but left his boarding pass behind and was arrested three days later.

It was perhaps no surprise that Atlanta leads the nation. In 2014, Georgia’s Republican-controlled legislature passed a law pushed by the National Rifle Association allowing people to carry loaded guns in the state’s airports.

Georgia was also one of 10 states to pass laws over the past couple of years no longer requiring a permit to carry a concealed firearm. Tennessee was another. The state’s TSA’s security director, Steve Wood, drew a direct line between weaker gun regulation and weapons at airports.

“Since the implementation of new gun laws in the state last year, we’ve seen a significant increase in the number of firearms brought to Tennessee security checkpoints,” he said.

There is also the disturbing question of how many guns go undetected.

In 2015, ABC News revealed that the TSA sent undercover investigators through airport checkpoints carrying real guns and fake bombs. Security officers only discovered three of the 70 smuggled items.

The TSA’s director was sacked. The Department of Homeland Security promised reforms but two years later security agents were still failing to detect about 80% of weapons in tests because of a mix of inadequate equipment and human failings.

Since then the TSA has stopped talking publicly about such tests of its system.

Price said travelers should assume that some guns get on to planes.

“It’s really a matter of deterrence. Can we catch enough prohibited items to make it not worth a terrorist or criminal’s effort to try and get through the system with one? We’re never gonna catch everything. That some guns will get onto planes is just one of those things we have to accept if we’re going to accept aviation as part of our daily lives,” he said.

Which makes it something of a miracle that no one has been shot accidentally mid-flight.

“It is kind of amazing,” said Price. “One of the few that did go off accidentally was when a US Airways pilot, who was authorized to carry on a gun on the flight deck, fired off a round as he was putting it back in its holster.”

The pilot said he was trying to stow the gun for landing when it went off, blowing a hole in the cockpit just below the window.