Andy deLivron says he’s no threat to aviation security. But he flies with box cutters in his checked luggage — the same weapon used by the 9/11 terrorists. And he recently packed the sharp tools in the wrong suitcase.By the time deLivron, a sales manager from Pottersville, NY, realized the box cutters had been misplaced in his carry-on bag, it was too late. He was already past the TSA screening area at Dallas Love Field and boarding his flight to Orlando, where he planned to catch a connecting flight to Albany, NY.DeLivron missed his connection and had to spend the night in Orlando.“But now I had a problem toss the knife or try to get it home in my carry-on bag,” he says. “I decided if I could place the knife on edge in my carryon it would be highly likely that security would miss it again. Sure, enough I was right. My carryon went right on through in Orlando.”Yes, you read correctly. TSA agents missed a box cutter in his carry-on luggage. Twice in a day.And no planes fell from the sky.“I’m an experienced business traveler and not a threat to my fellow travelers,” deLivron adds. “But imagine what a mercenary is capable of doing?”Coming full circleAirport security is devolving before our eyes. The latest slip is the TSAs surprise announcement that it would allow pocket knives — but still, no boxcutters — to be carried on to a plane starting April 25.Why? TSA says a committee reviewed its prohibited items list “based on an overall risk-based security approach” and decided the knives, as well as selected sports equipment such as ski poles and golf clubs, could be carried on board.Never mind that any knife can be used as a weapon. For reasons that remain unclear to many air travelers and to America’s flight attendants, blades will soon be OK on planes.But this is as good a time to any to ask where this is all heading, and whether the last decade has done little more than make us feel better about aviation security.Rewind to Sept. 11, 2001, the day terrorists boarded several aircraft armed with the same kind of box cutters deLivron carried to Orlando and Albany. Back then, the private airport security guards screened us almost exactly the same way we screen elite-level frequent fliers, passengers with Pre-Check clearance, flight attendants, pilots, members of the military and dignitaries today — which is to say, they walked through a metal detector with their shoes on.No body scan, no pat-down or chat-down. It was a quick common-sense screening, and it worked.If there’s a consensus among security experts, it’s that the meaningful screening takes place long before you arrive at the airport, and that’s where the failures of 9/11 happened, and why we now have a formidable new Department of Homeland Security, no-fly lists and pre-checks for every passenger.No size fits allWhen TSA Administrator John Pistole says we’re moving away from a “one size fits all” approach to security, what he really means is that we are returning to airport screening that actually works, which is pretty much what we had before 9/11.I’m confident the TSA won’t contact me to find out the specifics of deLivron’s flight because it knows that stuff gets through its vaunted 20 layers of security, and it knows there’s nothing it can do about it.But that should be reassuring to all of us, in a way.The faster the agency assigned to protect America’s transportation systems returns to a common-sense screening approach, the better off all travelers will be. And by “common sense” I mean decommissioning the hated full-body scanners, banning “enhanced” pat-downs, retraining agents in the basics of customer service, allowing all passengers to leave their shoes on and travel with liquids, and using metal detectors as a primary screening method.The heavy lifting of airport security should take place long before you arrive at the terminal. That’s where your name should be vetted and compared against a list of known terrorists. That’s where they’ll catch the next hijacker.Eventually, we will come full circle and airport screenings will devolve to where they were before 9/11. It’s only a matter of time.