materials have don t corrode and plans for speedier boarding. taking a plane could be as simple as taking the subway. in the future we could think about city center check-in and actually transport little pods to the airport where the passengers are already in, and just get with the pod, slide it into the airplane, in order to have a seamless experience of flight. reporter: cheaper flights have driven the growth, and with air traffic predicted to rise by more than 4% a year, the prospect of free flights is on the horizon. the airlines may not take the money from the passenger directly. it may be from somebody who has an interest of you flying somewhere. medical services, for instance. you are confined in a space sitting on a seat which might be quite technical, might sense body behavior. for quite a while, and somebody might be willing to pay thor this type of thing while you fly. reporter: the final aassembly