Channel 9 is avalible, at the captains discretion, on all United mainline aircraft.
: A319/320, B737-300/500, B-767 ect..
I'ts not avalible on the RJ
's or turbos because well....there no IFE on those planes, unless your flight atendant is doing cartwheels if there so inclined.
I know the voices in my head aren't real but sometimes their ideas are just awesome!!!