Celia Hahn didn't think much of it when she didn't receive a seat assignment while booking flights for her family last year.
On her Delta Air Lines reservation she entered the ages of her two twin boys, then 8, and assumed they'd be seated next to her. Instead, because of the type of tickets she booked, they were scattered throughout the plane from Atlanta to Minneapolis-St. Paul. They weren't allowed to swap seats with generous strangers until the flight took off.
"We took off and my kids were in different parts of the plane crying," she said. "People were willing to give up their seats, but it was stressful and more so than it needs to be."
Air travel experts say holiday periods like this week are ripe for such problems.
The U.S. Department of Transportation recently decided against implementing a policy that would require airlines to seat minor children next to an accompanying adult. This leaves it up to the discretion of the airlines as to how it handles family bookings when seat assignments are not included in the price of their tickets.
Each U.S. airline's policy is different, but parents like Hahn often realize once it's too late they'll be separated from their children.
Changes in the airline industry over the past several years have created prime conditions for such situations to arise. First, airlines started packing planes fuller, leaving less wiggle room for swapping seats. Second, the airline's number crunchers realized not every airplane seat is worth the same amount of money. They assigned incremental values to each seat based on a variety of desirability factors -- like legroom, exit rows, amount of recline, distance from a bathroom and the age-old window, middle or aisle seat preference.
But it wasn't until the advent of "basic economy" airfares, the cheapest seats that don't allow customers to pick their seats without paying a fee, that family seating really got complicated.
"These problems are just going to occur more frequently," said Bob Mann, a Port Washington, N.Y.-based aviation analyst. "It's a real issue and I don't think the DOT has done itself any favor by taking a pass on it. The industry also needs to take a step back and decide if they want a black eye on this or solve it."
In 2016, Congress instructed the DOT to review and, if appropriate, establish a policy for airlines to seat passengers under 13 next to an accompanying family member or adult who was over 14 years old.