Why airlines make you check your carry-on bags

For the past few years, whenever I take a flight, I’ve noticed that about halfway through boarding, a gate agent will announce that all carry-ons must be checked going forward. It’s an added inconvenience — having to wait at the baggage claim is terrible — and an added stressor: Everyone has a story about an airline losing a checked bag, and many keep essentials in our carry-ons, so handing over potentially valuable goods knowing they may not make it to the destination when we do can be frustrating.

So why does this happen? Is there not enough room for carry-ons on every flight? And at what point do gate agents make the call to stop allowing carry-ons on board?

The obvious explanation would seem to be that there is simply no longer space available in the overhead bins after a certain point, but according to aviation economics expert and senior vice president of ICF Aviation Samuel Engel, it has more to do with time than space. For every minute a plane isn’t flying, it is losing money, and carry-on luggage is “the biggest bottleneck” when it comes to boarding, he told me. “You have this $35 million asset you want to make sure you’re flying 10 or 11 hours of the day,” he says.

Chris Kress, who has been a gate agent at Dallas Fort Worth airport for 30 years, says at American Airlines, agents are allotted 20 minutes for boarding, and if the process takes any longer, gate agents are held accountable. “They are written up,” she tells me. “They could be fired for that.” Departure delays are publicly reported, just like the number of lost bags or passenger complaints. Airlines feel the need to perfect that performance and the pressure often comes down on gate agents. While boarding time allotments vary, all flights must close their door 10 minutes before departure.

Kress says the timing of when a gate agent announces that all carry-ons must be checked can depend on a number of factors. Gate agents have a pre-flight meeting with flight attendants where they are required to come up with a plan for the boarding process, especially if the flight is full. Experienced gate agents also keep a mental tally of how many passengers with carry-on bags that cannot be put under a seat have boarded.

Agents make the announcement based on their communication with flight attendants, how many passengers are on board, and how many bags a carrier has space for. No airplane has overhead bin space for each person to carry on a bag, Kress tells me.

So why, although so many processes are put in place in ensure overhead bins are used efficiently, are there still empty bins, occasionally? Sara Nelson of the Association of Flight Attendants says that could be due to insufficient staffing, which leads to poor communication between the gate agents and flight attendants about the amount of overhead bin space available.

According to the Legal Information Institute, for airplanes that can hold between 50 and 101 passengers, two flight attendants are required. If an airplane can carry more than 100 people, the flight is required to have one more flight attendant for every additional 50 passengers. Nelson says that this minimum was set in the 1950s but was typically surpassed by at least one or two attendants. But after 9/11, airlines lost money, and staffing cuts led to carriers only staffing the minimum. Today, airlines are still only staffing the minimum but the number of passengers is no longer as low as in 2001.

“There used to be at least an additional gate agent and one additional flight attendant so they could walk up and down the jet bridge and talk with each other,” Nelson says. “Flight attendants used to be able to manage the boarding more easily.”

Kress also mentioned that a flight attendant can call the gate agent from a phone, but Nelson says because the phone is on the jet bridge and the flight attendant cannot leave the plane to get to it, which is often the case due to the low staffing, they aren’t able to relay information about carry-ons to the gate agent. So the gate agent has to rely on their mental estimate as passengers board.

There is, of course, another factor in the number of carry-ons on flights: Airlines charge for checked bags, so more customers may be opting to carry on their luggage. The carry-on bags are also getting larger and larger, whereas in the past, someone may have only brought a purse on board and checked a maybe-too-large suitcase.

Kress says this is compounded by the fact that people can check in online, which means they never have to see an agent and can make it all the way to the gate with luggage that probably should have been checked. “People have learned how to beat the system,” she says. The bigger the carry-on bags, the less space for everyone else’s.

But airlines seem to have found a solution: Many now don’t include even a carry-on bag in “basic economy” fare, meaning you’ll have to pay a fee anyway — or just learn to pack really light.