The tanks in the plane are lighter and smaller, but you refill them the same way you refill a lighter. They can run for a long time, and you can even throttle them. How long they run depends on how much fuel you can lift or want to carry. They are very simple of incredibly intricate. There are v-8s, radials, rotaries, in-line, opposed motors. See the Gasparin site for more info: http://gasparin.cz/?show=main&lng=en and Sam's Models' web site 'Gasparin CO2' page for pictures of some of the motors they make.