I wonder if this is more common with non-U.S. carriers and/or with long-haul aircraft.

In the U.S., I've both done OLCI and arrived at physical check-in with our family split up and there's nothing the airline can do. This is usually with me having some type of elite status as well. (Granted, kids are older and sometimes we just fly seated separately...it's not that big of a deal.) I get the sense that a lot of seat-blocking for gate assignment is a thing of the past.

When I've flown European carriers, even with no status and on the bottom fare basis with no advance seat assignments, they've always gotten us all seated together. I've braced for receiving 4 middles...or even IDB...but it has not happened.

This is a great idea, but in the U.K. it was bandied about as a tax on parents. I've just booked a RyanAir flight with my 3 yo son and this has guaranteed that we will sit together. It was £12.

Hypothetical situation: if you boarded and found your kid was sitting 3 rows away from you next to a person you didn't like the look of wouldn't you pay £12 to resolve it immediately without having to have a stressful argument with an FA and other pax?

Just pay the fee.

It's actually quite straightforward, for UK carriers when there is a booking with a child the seats are fully assigned there and then, although you may not be aware of it until getting to the airport. Among other things this prevents people deliberately booking split seating arrangements and then causing an upset at the desk. Carriers know the likely percentages of bookings with children and offer/block seats accordingly.

Bottom line is that the enacted statute was simply designed to placate a segment of the traveling public. It does not require FAA to issue rules (which FAA could do without having Congress enact the statute) and it does not require that the rules do much if anything.

It also does not require family seating (just one parent/guardian with the kids) and does not require that the carrier assign what amount to premium seats, e.g. those for which you pay extra.

The government is making a fuss about this because the airlines are unable to handle it. To me, it is simple human decency to make sure a child can sit next to a parent, but the airlines would rather monetize the cabin in a way that forces the family to pay extra to avoid being separated. There were enough incidents that got bad publicity, so Congress decided to intervene. I don't feel sorry for the airlines, they brought this on themselves due to excessive greed.

In what situation would it not be practicable? I can't think of too many situations when the airline could claim that it would be impracticable to let a parent and child sit together. "We can't move that lady because she paid extra for that seat assignment" probably isn't going to fly.

The FAA regulations will probably spell out what terms like "adjacent" and "practicable" mean.

Something like an adult traveling with two children on a flight with 1x2 or 2x2 seating.

Or a flight filled with families, in a 3-3 configuration, where the available seats are a window in one row, and aisle in another row, etc. with the remaining 2 / 3 seats in those rows being occupied by parents and their 1 or 2 children.

Or flights in which there are other considerations - e.g. disabled passengers in rows with movable arm rests, accommodation of service animals, broken seats / seat belts, lap infants in bulkheads, more than 1 lap infant in a row (oxygen issues), aircraft where lap infants cannot sit on the port side, only starboard (because there are no spare oxygen masks on the port side, only starboard), people using car seats for infants (they cannot go in aisle seats on most aircraft) etc.

I do feel that parents wanting to sit with their kids should book seats ahead of time, paying any necessary fee so to do. Whilst there are times where **** happens and things go wrong (and those families do have my sympathy), most of the time it is poor planning, and I do not see why an adult, for their own reasons, say, claustrophobic, or with non visible medical issues such as needing to use the restroom frequently or urgently at times, has purchased a seat assignment, should be less important than a family who simply did not want to pay the fee.

It's less about greed than it is about economics. Airlines are businesses.

Travel classes didn't take hold until the 70s. Airlines didn't even charge separate fares for the same seats on the same flight until the early 50s -- and when they did, it was usually just two different fares: "standard class" and "tourist class". Of course, airlines needed to differentiate the two products in other to compel certain travelers (mainly businesspeople) to buy the pricier tickets. Standard class tickets could be purchased at the airport and you could sit at the front of the plane; tourist class tickets had to be purchased in advance.

Fast forward to now, and you've got as many fare codes as you've got letters in the alphabet. Why? Not because airlines are greedy -- but to cater to travelers with various budgets. And that's what precisely has happened in the past few decades: more and more Americans can afford to fly. Obviously, people who pay for J should have an incentive to do so compared to the much cheaper cost of Y -- flat-beds and multi-course meals, for example.

The same applies to people flying the same class as well. Why should someone pay for full-fare Y as opposed to basic Y? Because of seat selection, mileage and points, flexibility, number of carry-ons, etc...

And that has less to do with the greed of the airline than it has to do with the greed of the consumer. Consumers want cheaper and cheaper fares, but they want to maintain the same level of service of air travel in the 70s. That's simply not happening. Airlines are essentially forced to unbundle their fares -- charge separately for every part of the travel experience, because they can't compete on travel search websites without doing so. There are a lot of people out there who would take an extra stop to save $20.

Airlines don't really make a profit on the lower-end Y fares -- essentially, if you buy a ridiculously cheap ticket, your trip is being subsidized by F, J, and full-fare Y pax. And in return, they get perks that you don't. One of those now includes seating choices in advance. If I happen to buy a pricier fare, or pay to choose my seat in advance -- and someone wants me to sit in an inferior seat just so they can be with their kid -- NO WAY.

You pay for what you get. Families shouldn't be treated any differently. If they want their travel experience to be smoother, they should fork up money for F/J/more expensive Y classes. You can't book a room at the Holiday Inn and expect the presidential suite at the Ritz-Carlton.

I turn 17 next month and I've flown around 300,000 miles in my lifetime. That's nothing compared to most of my FTers here, but a good number of those miles were on trips I took before I even became a teenager, and I managed to survive long-hauls without sitting next to my parents. It's hardly necessary for kids to sit next to their parents unless they're bawling infants who need to be calmed down for the sake of everyone else in the cabin.