All sounds for the OpenPilot project are licensed under the Creative Commons Sampling Plus 1.0 License.

http://creativecommons.org/licenses/sampling+/1.0/

Attribution to the OpenPilot project is required if you reuse these sounds. 

OpenPilot wishes to thank Guitar Guy 1985 for his work on the alarms, 3 of his sounds were modified and included as part of the OpenPilot sound set:

alarmsound
beepsound
whoopsound