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.