[DPline]

There should be a sticker on the side of the seat saying if it is FAA approved for use on planes.

I did a quick Google search and it does seem to be (do double check the sticker as there may be different models) but someone on Car-seat.org did mention using a belt extender to install it. Though others said they didn't need to.

If you want to read more, I Googled 'triumph advance airplane' and got quite a few hits.

Happy travels!