Some of the most robust CRS for auto use for U2 children indeed won’t work for common carrier use even in economy class, but it mostly comes down to labeling for FAA-approved use (or perhaps near-equivalent foreign institution-approved use, if relevant) in-flight, at least with regard to economy class seating.


For most of the CRS approved for use by U2 children on common carrier flights, they may also work in some premium cabin lie-flat seats but not all even when looking at just one particular carrier, as equipment substitution can be an issue in that regard.

I am generally not an advocate of using the primary at-home car’s CRS for in-flight use, as the more a CRS is moved around and bumped around the more compromised it can become. And given U2 children are far more at risk in a CRS in a car near their home than as a lap child on a common carrier flight, having your primary car seat remain more securely in the primary automobile for U2 child transport near home is better than having the primary CRS repeatedly moved into and out of vehicles, bumped around and perhaps not as securely reinstalled upon return to use it in the primary at-home vehicle for U2 child transport.

Whether or not you have a separate CRS for travels by U2 children taking flights, the most important thing is knowing and followig up with proper installation in cars on then ground. That’s where the greatest risk is.