The FAA has a thoughtful rule: they haven't banned flying with a baby on your lap because the extra cost would make many parents drive, which is less safe. I'd love to see this "all things considered" thinking applied to babywearing carriers on planes. Carriers are helpful, but for takeoff and landing, the FAA requires you to take the baby out. The rule (14CFR 121.311.b.1) says babies must not "occupy or use any restraining device." This goes back to a 1995 notice proposing to withdraw approval for booster seats and harness-type restraints, based on a 1994 study. That study tested car seats and belly belts, not babywearing carriers. The real problem is they didn't test the most common alternative: holding the baby in your lap. So saying the banned devices "may put children in a potentially worse situation than the allowable alternatives" seems wrong.

The FAA's 1996 final rule acknowledges lap-holding has risks but avoids the obvious comparison. They predict parents will buy a second seat but don't want to require one because people will drive. I expect modern babywearing carriers would prove much safer than arms during turbulence and crashes. In 2024, a bill (Rep Bill Posey's HR8972) proposed something like this but died without a vote. Most harm is inconvenience, but it's a clear example of incoherent rulemaking: the FAA sensibly considered substitution behavior for lap infants but failed to balance it for carriers.