SD Jr first flew in a light aeroplane with me at 2 years old. First flight was a 10-15 minute extended circuit/joyride with another adult (his Grandad) to see how he liked it......and he loved it!! He wears a normal Headset so he can talk and hear me easily, yet it protects his ears from noise. As for Altitude/Ear considerations, would you fly commercial with him, as we all know the cabin altitude isnt kept at sea level is it?
Due to where we and his French grandparents live, it takes 30mins to visit them by aeroplane and about 2.5hrs in the car, and so a regular trip is to go and visit them. Despite Mrs SD really hating to fly, we've done a couple of trips there all together as a Family, but generally he flys quite happily with me all by himself, though we have not done a flight longer than an hour or so, so far.
He is now 6 (wow, doesnt time fly!!) and we are contemplating flying to the UK this summer holidays to visit his UK Grandparents - just me and him. This will be a biggie for me/us as its at least 4 hours flying and includes a channel crossing...
Regards, SD..