Most of us know the routine of boarding an airplane: First, there's the patient waiting in line at the gate, and then again on the jet bridge, and waiting yet again for fellow passengers to put luggage in the overhead bins, before finally it's your turn to find your seat and do the same.
Now, actually getting into the that narrow window or middle seat is another problem.
If you're like me, you suck in your gut, squeeze over the outer seats, twist, bend and turn to stuff a bag under the seat in front of you, before finally wedging your backside down into your seat. When sitting, your knees are almost touching the back of the seat in front of you.
The safety announcements begin, and though they might be a little hard to make out, you're told to pay close attention to the instructions for evacuating the plane in an emergency.
How many exit doors are there? Where are they? Ask yourself, "how quickly could I get to an exit?"
Now, look around the cabin. See any empty seats? Those are increasingly rare as airlines pack planes to max capacity. Is everyone sitting around you trim, fit and spry? Could they leap up and into the aisle and rush off the plane in less than 90 seconds, as the Federal Aviation Administration requires?
The government agency's safety officials think so, and they've based that decision, in part, on videos of test evacuations provided by airplane manufacturers. These are drills are not run in a real airplane cabin, but a simulator configured to mirror various planes.
All the passengers are sitting quietly, but alert. None of them are sleeping, reading, working on a laptop or watching a movie on a tablet or phone, as most airline passengers do.
When an alarm sounds and shouting ensues, it sounds chaotic, but it's not. The screaming is off-camera. In the video, passengers calmly get up and move quickly to the proper exits.
"Those people are volunteers; they know exactly what they're going to be doing," says Erin Bowen, chair of the Behavioral and Social Sciences department at Embry-Riddle Aeronautical University. "They have dressed appropriately for that task, in the right kind of shoes, and they're not stopping to get their phone out to record the evacuation. They're not stopping to grab their overhead bags or their underseat bags."
None of the test passengers appear to be obese or have physical disabilities, Bowen says, and there are no children.
She's done research on how people really behave in an aviation crisis, and it's often more like what happened on American Airlines Flight 383 at Chicago's O'Hare airport on Oct. 28, 2016.
As the Boeing 767 started speeding down the runway to take off, an engine blew and caught fire. The pilots aborted the takeoff and stopped the plane, but panic ensued inside the aircraft.
Cell phone video from inside the cabin shows passengers screaming and shouting, some cursing. Some are pushing and shoving their way toward the exits, even while others still struggle to get out of their seats.
About 20 people were hurt, and the National Transportation Safety Board found that flaws in the evacuation procedures led to some of those injuries. It took more than two minutes to evacuate the burning plane.
Again, the FAA's standard is 90 seconds — and Bowen points out that was set in 2006, when most Americans were a little slimmer, and when planes had fewer seats and flew, on average, about 60 percent to 65 percent full.
"You've got passengers who are getting larger, and you've got seats that are not only themselves getting smaller, but are getting crammed into more narrow aisles and more narrow rows," Bowen says.
The FAA declined to speak with NPR for this story, but in a six-page filing in response to an appeals court ruling ordering the FAA to review safety rules for seating, Dorenda Baker, executive director of aviation safety at the FAA, said there is "no evidence" that smaller seat dimensions "hamper the speed of passenger evacuation, or that increasing passenger size creates an evacuation issue."
The agency cites seven recent incidents, including fires on planes, in which passengers were able to evacuate, though some did sustain injuries in those incidents
The FAA's decision to refuse to regulate airplane seats isn't sitting well with some passengers, who often complain about shrinking seat space, especially in economy class.
"It's really become almost like a torture class," says Paul Hudson, president of the group Flyers Rights.
Hudson argues that tinier seats are not just unsafe for evacuations, but can cause blood clots and other health problems, and lead to more passenger conflicts.
"We have space regulations for transporting animals, for transporting prisoners," he says. "But we don't seem to have anything for regular passengers."
Hudson is hoping that outraged passengers will pressure Congress to force the FAA to regulate seat size. A provision to do just that was in an FAA reauthorization bill that passed the House earlier this year and is now pending in the Senate.