According to Australia's version of the FAA; the Civil Aviation Safety Authority the laws that govern the non-commercial use of a Phantom include: 1. Not flying within 30 meters of people 1a. Except those involved in the operation 1b. And people behind the aircraft when it takes off 2. Not flying above 120 meters 2a. Unless an area is specifically authorised 2b. The pilot is licences and communicating with Air Traffic Control 3. Not to fly within populous areas 3a. Areas that if the aircraft had a failure it could not clear without causing injury or damage to property This is very much a summary, and for anyone curious of the source; see section 101 What I am very curious to know is the extent to which a Phantom moves when a part or component fails. I want to act well within the legislation, but I don't want to restrict my flying based on true unknowns. Many types of failures would result in the same behaviour for various quad-rotors. For example; simultaneously losing 2 engines can cause uncontrolled spin or yaw. Losing power while travelling at high speed would result in a arced trajectory. Losing GPS on a windy day can cause significant drift before control is regained. If you haven't experienced a failure; what area do you prefer to keep free for your Phantom? If you have experienced a failure; how much room did you need for it to fail safely; ie to clear a populous area?