I want to send data over 3G when my iPhone is connected to my ARDrone. Is it possible?
no, it is not.
iPhone: Internet connection
“When you use these interfaces, you don’t need to choose whether you use Wi-Fi or cellular radio stations yourself.” - Network and Internet access point - it means that you also have no choice.
This is really possible, since the connection is adhoc and apparently tells the iPhone that there is no internet through it, since I piloted it, and MLB broadcast the game in the background.