Here are some images i have made with blender , hope you like it.

http://i.imgur.com/WKh77.png
http://i.imgur.com/5f6X9.png
http://i.imgur.com/1yxnu.png
http://i.imgur.com/mhRNw.png
Since the game uses voxels (is blocky) , i think that a helicopter more blocky, would look better, in game :)
Plz, tell me what you think :D
Thank you.
Skaliogon