[ericpauley]

This has a lot of physical issues, not least of which is air resistance (drag). Simply launching a plane off the ground does not impart enough energy to make the full trip at high speed, and airplanes must continually burn fuel to counteract drag and gravity.

Gliders are able to bypass this limitation in certain scenarios (such as updrafts) but this only works in specific cases. It also usually takes more than a launch to bring them to sustainable altitude, and they are slow.