How Airlines Move Your Checked Bag Through Connections

So you left your bag at check-in. Now what?

You’ve weighed your bag, received a tag, and now you’re waving a tearful goodbye as the agent takes your bag away, not knowing when you’ll see each other again. So, what’s happening right now? Let’s start with what you can see: the baggage tag that the check-in agent adds before the bag is taken away. It includes a three-letter code for your final destination and, in smaller text, any of your connecting flight information. Then the bag goes down a conveyor belt and is screened by TSA for any prohibited items. Then it moves through another series of belts to a baggage hold room, where the bags are typically sorted and placed onto carts – or cargo containers for widebody jets – that are pulled out to the planes and loaded onboard.

As an added measure of diligence, the barcodes on the tags and a visual check of the three-letter airport code are conducted to ensure bags make it where they are supposed to be, explains Scott Mayerowitz, founder of GlobeTrotScott Strategies and former executive editor at The Points Guy. “Redundancies are built in by airlines,” Mayerowitz says. “The tags are often checked when the bag is first loaded into the cart and then again when it is placed into the plane. Some carriers, like Delta, have gone one step further and have individual RFID transmitters inside the bag tags, which track suitcases at each step of the trip.”

Matt Sparks, Delta’s senior vice president of airport operations, explained the importance of RFID tags on an episode of the Freakonomics podcast. The RFID tag acts as a reassurance that the barcode scan for destinations matches up.

Other airlines use different, yet equally effective, technology. “Some use laser scanners that direct bags to the appropriate belts under the airports to ensure they are sent to the accurate pier, loaded on the right baggage cart and land up on the correct flight,” says Ross Feinstein, a consultant and aviation expert who used to lead communications for American Airlines and the TSA. “The system works very well, and that is the reason that the majority of customers never experience a delayed bag. Delayed bags usually occur when there are some other issues occurring that day, especially extensive delays and cancellations.”

But it’s not all about technology. Airlines also implement hands-on systems and procedures to ensure bags get where they’re supposed to go.

“Many airlines will load the connecting bags last, so that those bags are the first to be offloaded in the connecting city,” Feinstein says. “This varies by city and the type of baggage system they have, but usually those connecting bags are loaded on a cart once offloaded from the plane, and an airline employee will scan each bag individually. The driver of that cart now has a list of the bags that he or she is driving to the connecting flights for the passengers. The driver will be provided the exact order of where to drop off each bag, which takes into account the quickest way to get all the bags to their respective connecting flights.

How airlines ensure bags make it into connecting flights

In many cases, a fate even worse than missing a connecting flight is to make the flight but your checked bags didn’t. Connections make things more complicated, especially tight connections.

“Most of the time, connecting bags are taken off planes, brought back to the terminal, loaded back into the baggage system to be sorted,” Mayerowitz says. “However, with a short connection, there are special tugs and carts that bring suitcases from one plane directly to another. These are called ‘HOT bags’ or ‘hold for transfer,’ and don’t go back through sorting and are driven from plane tail to plane tail.”

So that’s reassuring, right? Well, connections are still tough for airlines, and it doesn’t always work out.

“Short connections are always the biggest challenge for airlines when it comes to connecting bags,” Feinstein says. “While a passenger can run for their connecting flight, it might take a little longer for the bag to be offloaded and then driven to the next gate. This is where you might have a bag that gets delayed and won’t be loaded until the next flight. I’ve also seen cases, however, where the passenger couldn’t make the connection because they were in the back of the plane, but the bag actually arrived at the final destination before the customer.”

What happens when a bag is lost?

Okay, so the system fails and your bag is lost. It happens. About two million bags are lost every year in the United States, according to FOX. Though it’s only about .5 percent of all checked bags, the prospect is still enough to make some of us wary of checking our luggage at all.

Short connections are one of the biggest culprits.

“Usually, bags don’t make it when there is a very tight connections,” says Mayerowitz. “Or sometimes a bag will make the connection and the passengers won’t. Occasionally, a bag tag can’t be read.”

The most common reason bags are disrupted, however, has nothing to do with connections at all.

“The overwhelming majority of bag issues happen when big storms cause large-scale flight delays and cancellations,” Mayerowitz says. “Airlines are much better today at handling bags than a decade or two ago, but there are still a handful of truly lost bags. There’s also always the chance that somebody steals a suitcase. That’s why I try to be at the baggage claim as quickly as I can and put an Apple AirTag inside my suitcase.”

People stealing bags isn’t as uncommon as you might think, Feinstein says. More likely, though, a missing bag tag could be to blame. “Oftentimes,” he says, “the bag tag came off the bag, and the customer had no other identifying information on the bag or in the bag. That is why if an airline can’t locate a bag, they ask for a description of the bag itself, including the contents of the bag. If the airline finds a bag that has no bag tag or name on it, they might open the bag to try to figure out if they can locate the owner of the bag based on the contents inside. I can’t stress enough how rare it is for an airline to actually lose a bag.”

Sparks corroborates this assertion, claiming, “the vast majority of the time a bag doesn’t get lost, it gets delayed.”

That might not give you a ton of peace of mind, especially if you’re really in a hurry, but clearly lost bags are the overwhelming exception rather than anything approaching a norm.