When you're settling in for a long flight, every inch counts _ including the ones you can lose when the passenger in front of you reclines their seat.
American Airlines, United Airlines and Southwest Airlines already limit coach passengers to a 2-inch recline on most domestic flights, and some budget carriers have switched to "pre-reclined" seats that don't lean back at all.
Now holdout Delta Air Lines is testing whether flyers are willing to accept seats with less reclining capability. It's a change that cuts both ways for travelers, who lose the ability to recline but also gain the assurance that no one else is invading their personal space. Seats on Delta's Airbus A320 aircraft that once reclined 5.4 inches in first class and 4 inches in coach will now recline 3.5 and 2 inches, respectively.
Some see the shift away from La-Z-Boy-like seats as the result of a long-running effort to find the best way to smush more passengers into the same amount of space. Over the years, airlines have determinedly reduced the space from the beginning of one seat to the beginning of the one behind it _ called the pitch _ to as low as 30 inches today, or even 28 on some budget carriers.
But travelers like Austin Fortner prefer to accentuate the positive _ he cheered Delta's announcement, tweeting that passengers who recline as much as possible are "the literal worst."
"I just feel it's rude," said Fortner, 26, who works as a business analyst in Northfield, Ill., and flies about once a month.
He rarely reclines, but said other travelers aren't so considerate.
"It's nice to have an airline step in and restrict how far back they can go," he said.
Delta seems to think most passengers feel the same, especially on the shorter flights where it uses the A320. The seat adjustments will be made over the next two months.
In a statement, Delta struck a reassuring tone. "Delta has no plans to add seats or reduce space between rows with this test. It's all about protecting customers' personal space and minimizing disruptions to multitasking in-flight."
At Allegiant Air, the Las Vegas-based discount carrier, doing away with reclining seats was about keeping costs and fares down, said Allegiant spokeswoman Sonya Padgett. The mechanisms that let passengers control a seat's angle weigh about 3 pounds, which adds to fuel costs, she said. They can also break, requiring maintenance.
Traditional carriers have avoided scrapping reclining seats altogether but say travelers don't seem to mind when they trim the range.
At United, economy seats generally recline about 2 inches on domestic flights, though the A320 offers 3 inches.
American moved from a 4-inch recline to 2 inches on most domestic flights in coach about three years ago.
The carrier noticed passengers saying the 4-inch recline in coach "was a lot when you were the one being reclined into," said spokeswoman Leslie Scott.
Feedback since American made the change has been positive, she said.
Reclining might not be so contentious if cabins hadn't grown tighter. Airlines have tried to make seats feel more spacious with changes such as skinnier backrests, but travelers say they still feel the squeeze.
Patrick Allen, 35, of Chicago said he prefers having the option to lean back. He feels bad about bothering the person behind him but said the extra inches can make flying a lot more comfortable since he's over 6 feet tall and suffers from lower back pain.
He understands when the person in front of him chooses to recline, even when the seat bangs into his laptop.
"They bought a seat, and the seat reclines, so who I am to tell them they can't use a feature on the plane that they paid for," he said.
Daniel Post Senning, author and spokesman for the Emily Post Institute, agrees that passengers have the right to recline, but said it's a right that comes with responsibilities.
"It's not just about what you can do and are entitled to do, but what that means for the people around you," he said.
Post Senning said he doesn't mind seeing airlines reduce the extent to which seats recline if it removes a potential source of conflict.
But Chris Buccafusco, law professor at the Benjamin N. Cardozo School of Law in New York, didn't mince words when asked about Delta's solution: "Not helpful at all."
Restricting recline limits the benefit to the person leaning back without getting rid of the controversy, he said.
"The right answer is to try to allow people to sort it out and get to the best outcome without being jerks about it," he said.
In 2014, Buccafusco and a colleague conducted online surveys attempting to settle a debate over whether the pleasure passengers got from leaning back outweighed the aggravation to those behind them. It was around the time a squabble over a Knee Defender _ a gadget that blocks an airline seat from reclining _ forced a United Airlines flight to make an unscheduled landing in Chicago.
Among their results: About 78 percent of people who responded were willing to forgo reclining on a six-hour flight if the person behind them offered to buy them a snack or drink.
But only 36 percent of people surveyed said they'd be willing to make the offer.
Post Senning said he would be hesitant to make such a request.
"It's easier to take a look at yourself and manage what you can control: how you treat others and manage your reactions and responses, especially when others don't treat you as well as you'd like," he said.
But Buccafusco said he doesn't think travelers need to be so cautious. On a dozen or so flights, he has offered to buy the person in front of him a drink if they agree to keep their seat upright, explaining that he plans to work in-flight.
It generally works, he said, and he's only had to buy the drink once.