Is it OK to recline your airplane seat? Some travel experts say no.

As millions of Americans prepare to jet off on their annual summer vacation, they'll face a delicate — and potentially painful — question of air etiquette that often leads to bruised feelings and knees: to recline or not to recline? 

Air travel is expected to be more crowded, expensive and uncomfortable than ever this summer, with tensions sure to be running high among testy travelers clinging to their limited personal space. And while airlines invite passengers to sit back and relax, some travel experts insist that passengers should never recline their seats.

"You can recline the airline seat, but not without potentially hurting someone, spilling wine on them [or] whatever it is that happens," consumer advocate Chris Elliott told CBS MoneyWatch, noting that he has seen reclined seats damage laptops and that he himself has suffered the indignity, not to mention the pain, of having his legs smashed by the person in front of him suddenly tipping back.

Selling the same space twice

Elliott puts the blame for such incidents mostly on airlines. By effectively selling a seat space twice — to the passenger directly in front of the seat as well as the person immediately behind it — carriers have left it to passengers to duel over precious cabin space.

"The airlines are intentionally selling that space to the person in front of you and to you, so it's just incredibly disingenuous of the airline," he said. "I understand why they like leaning. It's more of an airline issue because they're cramming seats so close together and pitting passengers against each other."

Etiquette expert Diane Gottsman also never reclines her seat, saying that "there are very few circumstances" under which others should do so. 

"We know it's going to interfere with other people's personal space," she told CBS MoneyWatch. 

Indeed, what's relaxing for one customer could be uncomfortable or even injurious for another. And while travel experts have different views on whether it's acceptable to recline, they agree that airlines have worsened the problem by shrinking the distance between rows of seats in order to sell more tickets.  

"If airlines add seats to planes, they need to adjust the amount of recline each seat can have," travel industry analyst Henry Harteveldt told CBS MoneyWatch. "Airlines do have a responsibility to make sure the seat recline is adjusted in a way that it provides enough recline to the passenger, but doesn't encroach too much on the person sitting in the row in back."

Short of airlines adjusting cabin configurations or seat features, however, it's up to passengers to use their own common sense on when to recline, he said.

"A little bit of kindness" goes a long way 

Although passengers are within their rights to recline their seats as they wish, Harteveldt recommends at least taking a quick glance to ensure that leaning back won't hurt the person in back of you, and even politely inform that you plan to recline. 

"Remember, the airplane cabin is a shared space, and a little bit of kindness and consideration go a long way," he said.

That small measure of courtesy can help avert ugly altercations among passengers. "Reclining your seat simply because you say I'm entitled to do so could risk creating tense situations between passengers," Harteveldt added. 

In 2020, Delta CEO Ed Bastian told CNBC that passengers on the airline "have the right to recline." But he sparked consumer backlash by suggesting that "the proper thing to do if you're going to recline into somebody is that you ask if it's OK first and then you do it." 

By contrast, Elaine Swann, an etiquette expert and founder of The Swann School of Protocol, advises against asking for permission to recline. 

"It's nice to just be mindful when you are leaning that seat back that the person doesn't have a drink on their table, they're not leaning forward digging under the seat to get bag," she said. "But a simple glance in your peripheral vision is acceptable. You don't have to go so far as asking the other person if you can lean back prior to doing so. That's not necessary."

In fact, passengers should operate under the default assumption that others will recline, she added. "What if the person says no and now you're stuck? You've set yourself up for failure on what could be a long flight."

Flight attendants' advice

Flight attendants, many of whom had to deal with an upsurge in disruptive behavior on flights during the pandemic, have long known about the tension over reclining. 

"It's nearly impossible to recline without bumping into the person behind you, and that's not fair to either passenger. It makes our job as flight attendants harder, as we're tasked with calming conflict and keeping tempers from flaring into violence in the aircraft cabin," Sara Nelson, president of the Association of Flight Attendants-CWA, said in a statement to CBS MoneyWatch.

Her advice? Don't ask — tell. 

"For passengers who want to recline, it makes a world of difference if you just look back and give a heads up to the traveler behind you — to avoid spilled coffee, broken laptops or smashed body parts."