Fly America Act
Federal travelers are required by 49 U.S.C. 40118, commonly referred to as the "Fly America Act," to use United States air carrier service for all air travel and cargo transportation services funded by the United States Government. One exception to this requirement is transportation provided under a bilateral or multilateral air transport agreement, to which the United States Government and the government of a foreign country are parties, and which the Department of Transportation has determined meets the requirements of the Fly America Act.
The United States Government has entered into several air transport agreements that allow federal funded transportation services for travel and cargo movements to use foreign air carriers under certain circumstances.
There are currently four bilateral/multilateral “Open Skies Agreements” (U.S. Government Procured Transportation) in effect:
http://www.gsa.gov/portal/content/103191?utm_source=OGP&utm_medium=print-radio&utm_term=openskies&utm_campaign=shortcuts
e