Some (not all) car seats are also rated for use in aircraft, and they have some notes about that on the label. We planned for it, so both of ours were, even though they were enormous. I humped them into and out of every flight when our two kids were small. The flight crews never complained.

Its basically the difference between seat belts that work, and seat belts that don't work. There's plenty of space in between perfect landings and crashes that kill everyone onboard. Seat belts matter in that in-between space, as today's incident shows. For us, the peace of mind was totally worth it.

Edit: The FAA's pamphlet on the topic. Its quite readable, despite coming from a regulatory agency. https://www.faa.gov/documentLibrary/media/Advisory_Circular/...

Infant in lap is supposed to be secured with a seat belt that attaches to the parents seat belt. They are not unrestrained.

However, an infant is much safer in a car seat strapped to their own seat of course.

We were looking at this this morning. Apparently they (WestJet) will refund you the cost of the seat if you provide proof of age up to a week later. I assume this may only apply if your child is close enough to 2 that they feel a need to verify, and you don't have proof of their age with you.

There is also zero chance of the same situation presenting itself again in our lifetimes. It's much better to invest extra money to protect ourselves from things that are likely to occur, like car accidents.

Not sure why you're getting downvoted. Our kids always flew in their car seats. The airplane's lap belt goes over the car seat in slots that are designed for this purpose, and the kid is strapped into the car seat's 5-point harness. The whole thing works great, aside from having to haul the car seat down the airplane aisle during boarding and deplaning.