I installed our radian on 3 out of 6 flights in a 30 day trip. (2 were international & 3rd I was totally exhausted, wimped out for a 25 minute flight
) I don't know how I could have possibly travelled with anything else.
I have pictures of how I dealt with the 'beast'
Here on a Target luggage cart.
In the airports, I had the wings folded in for space, but when we had dd riding in it the times from our bus to dh's rooms, they needed to be out for extra stability, especially maneuvering curbs.
When I installed it, I leaned the Airline-seat back, then depending on the buckle system, I'd twist down the one end so the fastenings would be on the outside of the seat. Only one time were they in back of her and since it was more of the side, than dead center, she never ever noticed or cared.
Pop the airline seat back up and it would be tight.
Yeah, it's heavy without a decent handle where the head area is, but I fastened a shoulder strap top side & it worked just fine to grab & maneuver.
There is no way I'd want to travel with a carseat with a base. Too much seat for the space, imo. I'm claustrophobic enough. The Radian fit extremely well into the narrow & tight constraints of aircraft we flew on with American. DD was perfectly happy. You can see here. She's listening to her stories on a small cd player tucked in beside her.
She's 5 & 45" tall in the photo. Grew a half inch later on during our trip
I'll be flying again with the Radian in March. (sigh) Yay for flying
But she'll be comfy and safe. So it makes hauling it around worthwhile.
hth & good luck