On Sunday, April 27, 2014 3:32:49 PM UTC-7, son_of_flubber wrote:
In the USA, the FAA has a voluntary standard for model aircraft that limits operation to 400 feet AGL.



http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgAdvisoryCircular.nsf/0/1acfc3f689769a56862569e70077c9cc/$FILE/ATTBJMAC/ac91-57.pdf



The new legislation for UAVs picks up that 400 AGL limit as I recall.



That said, there are pirates flying quadcopters much higher (7000 meters?). Search Youtube for 'quadcopter altitude record'.

Actually the FAA has no specific height limit for model aircraft. The Academy of Model Aeronautics (governing and insuring body for model competitions) has a safety rule that limits altitude to 400 feet within 2 miles of an airport, but allows other altitudes elsewhere and also with permission of the airport operator. Many of the model sailplanes are operating at altitudes above 3000 AGL when participating in XC contests, they are required to have a specific observer looking for full-sized aircraft to avoid collision.

If a model is being flow outside of a contest, and not by a member of the AMA, then all bets are off!