Very interesting challenge
The issues of operating an RC aircraft at such distances are surely not trivial, not to mention the material resistance, stress loads, navigation, etc. There's a chap in New Zealand called Bruce Simpson that could be helpful. He's also an inventor and RC tinkerer that is currently developing a "sense and avoid" system for aircraft and claims to have developed a cruise missile off standard parts sourced from eBay.
Biting the hand that feeds IT
