OT: Trans-Atlantic Model Airplane

[Jack Simth]

Actually, you could have a computer controlling it.
The controls would take:
1) Electronic Altimeter
2) Electronic Level Monitor
3) Electronic Compass
4) GPS
5) A processor (A simple Z80 would suffice), RAM, flashed ROM, a battery
6) Override control (for landing/takeoff)

Then just code things to follow a few simple rules:
1) If not on line towards destination (determined by GPS and Compass), turn approprietly.
2) If below a particular altitude, go up.
3) If above a particular altitude, level out.
4) If not within a particular margin of level, level out.
5) If Radio Control is on, follow that, suspending the above rules.

You'd want it to fly fairly high to avoid boats and waves, but low enough to avoid other aircraft. You'd also want to plan it for when the weather would be good. Or you could control it via satelite and camera, as Fyron suggested.