Landing is no one’s favorite part of a plane ride. Aside from the bumps and jolts, you have to interrupt your nap and put your seat-back into its rigid, straight-up position, which is comfortable for exactly no one. Like many quirks of air travel, the requirement has its roots in safety regulations. There are multiple reasons that flight attendants are insistent about your seat-back position during takeoff and landing, according to Condé Nast Traveler.

Airplane seats are the main source of protection for passengers during a crash, and the upright position is their locked position. In the event of a crash, the whiplash movement of a reclined seat poses a threat to both the passenger sitting in it and the passenger behind it. Plane seats are required to be able to withstand impacts 16 times the force of gravity in a crash, and safety standards like these are widely credited with making plane crashes far more survivable than they used to be. Given that your seat is the one padded thing between your butt and the ground you’re crashing into, you want it to be in its sturdiest position. When the seat isn’t secured in its upright position, you also can’t get into a proper brace position, which the FAA says is three times safer than staying sitting up during a crash.

Plus, putting seats in the upright position makes it significantly easier for the window and middle-seat passengers to exit the row in an emergency. New airplane models have to undergo a mock emergency evacuation before they're cleared to fly to prove that all passengers can get out in 90 seconds or less. It’s much harder to slither out into the aisle if the seats in front of you are reclined and blocking the path. This 90-second requirement has prompted some to question whether planes can still be evacuated quickly enough as legroom shrinks—in 2016, a Tennessee senator unsuccessfully proposed a law to establish a minimum seat pitch on planes (meaning the distance between a seat and the one behind it) on the grounds that there haven’t been safety tests on seats with a pitch of less than 29 inches. Most U.S. planes have a 31-inch pitch, but some, like those used by Spirit Airlines, are even more cramped.

Keeping seats upright during takeoff also makes the plane windows more visible to flight attendants, so that in the event of a crash, they can see out the window to assess whether there’s a fire or another hazard outside the plane. They need to be able to see quickly whether one wing is on fire, say, so that they can direct passengers to exit elsewhere.

Sure, the upright plane seat isn’t terribly comfortable, but those few inches really could save your life.

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