In a car, you buckle your child into a car seat or booster. But on a plane, guidelines are hazier, since airlines let parents keep kids under age 2 on their laps free of charge. Yet according to the American Academy of Pediatrics, a child is much safer in a car seat than on your lap. If you hit turbulence, you'll be glad he's buckled in.
On a plane, kids under 40 pounds do fine in car seats (those no wider than 16 inches fit best on airplane seats). But skip booster seats, as they don't meet safety requirements on planes. One new option on the horizon: For kids 22 to 44 pounds, the Federal Aviation Administration just certified AmSafe CAReS (Child Aviation Restraint System), a web-buckle device that takes the place of a front-facing car seat; airlines may offer it in the future. For now, ask if they provide loaners for each leg of the flight. You'll still pay for a seat (kids under 2 fly at half-price or less), but you won't have to haul a car seat onboard.