Recently, industry trade group Airlines for America said they expect a record 234.1 million passengers to travel worldwide on U.S. airlines this season, a reflection of vacation-hungry families, low oil prices and overall strong demand for air travel.
That's good news for airlines, yet full planes — and the extra fees many airlines charge for preselecting a seat – means families may have trouble getting seated together on airplanes, making it likely adult travelers may find themselves planted next to cranky children.
As part of the FAA Reauthorization Bill of 2016, airlines were supposed to ensure that families flew together without charging extra fees. However, "the rulemaking for this law has never taken place," said Charles Leocha, co-founder of the consumer advocacy group Travelers United, with the policy tied up in bureaucratic red tape since its passage.
Although some airlines make strides to seat families together, the lack of a regulatory framework means families flying this summer "are still on their own," said Suzanne Kelleher, a family travel expert at Tripsavvy.com.
Southwest Airlines, which doesn't have assigned seats, gives families traveling with children six years or younger a head start in the boarding process, prioritizing them ahead of most other travelers in a way that insures families can get seats together.
American Airlines "checks for families traveling with children 13 and under a few days before the flight, and seats each child with an adult," said airline spokesperson Ross Feinstein. "If the automated system doesn't find adjacent seats for families, our agents will assist families at the gate."
Meanwhile, United Airlines staff works "to keep families seated together and will ask customers onboard to move seats to accommodate families," said United spokesperson Charles Hobart.
If preassigned seats haven't been secured, "Check in online 24 hours before your flight, when you should be able to see your seat assignments," Kelleher said. "If you see that your seats are not together, call your airline's customer service center."
If sitting together as a family is a priority, "It can be worth it to shell out the extra cost for 'premium seats' to make sure to get seats together," she said.
Kids flying solo
During the summer, thousands of kids fly alone to camp, and to visit other family members. While each airline has their own set of rules, rates and programs for unaccompanied minors (Ums), parents should do some research before purchasing a ticket.
"For kids flying on their own as unaccompanied minors, the most important thing is to make sure they are prepared for the trip," said Kelleher, "Take stock of a child's maturity, go over the rules about what to do in various situations…and make sure they have a smartphone so they can communicate with trusted adults at the departure and arrival airports."
For example, some airlines require that UMs fly only direct, or nonstop, flights—and never on a connecting flight at the end of the day. Others limit the number of unaccompanied minors that can be booked on each flight, or they decline to carry UMs during inclement weather, when delays and re-routings are common.
Some airlines provide special meals for kids, while others make a point of reminding parents to pack sandwiches and snacks for their kids.
Alaska Airlines offers mandatory UM service for kids age 5 to 12, and optional service for kids 13 to 17, on both domestic and international flights. The cost is $25 each way for direct flights and $50 each way for a one-way trip with connecting flights.
On Southwest Airlines, the UM fee is $50 each way, while American, Delta Airlines, JetBlue and United charge between $100 and $150 a one-way fee for minors between the ages of 5 and 15. American will allow two more UMs from the same family to fly together for that fee; Delta will charge only one fee for up to four children traveling together.
Avoiding kids on planes
Business flyers traveling without kids know that getting seated next to one is all but certain at some point. However, there are some ways to improve the chances of childproofing the flight.
A few international airlines have designated kid-free zones on their planes. Singapore's Scoot Airlines has a ScootinSilence economy cabin zone that bars passengers under 12 years of age. On AirAsiaX flights, only passengers 10 years of age and older are permitted to be seated in the carrier's Quiet Zone/
"For business travelers who are serious about being productive on flights, it's well worth the cost to upgrade to business or first class," said Karl Rosander, founder and CEO of podcast platform Acast.
If all else fails, "I also [have] never board a plane without noise canceling headphones," Rosander joked.
—Harriet Baskas is the author of seven books, including "Hidden Treasures: What Museums Can't or Won't Show You," and the Stuck at the Airport blog. Follow her on Twitter at @hbaskas. Follow Road Warrior at @CNBCtravel.