Ester,
I have 2 toddlers (aged 2 and 3) and we have used the FreedomRide on our recent trip to Bali. We flew with Eva Air from Taipei and throughout the 5.5 hour flight, the girls stayed put! We just threaded the aircraft's lapbelt behind the FreedomRide. I have heard not all airlines allow it so I'd check before flying. We brought ours anyway but was not stopped by any of the crew members.