Fly America Act list of Airlines

Major U.S. Flag Air Carriers:

Airtran Airways
Alaska Airlines
America West Airlines
American Airlines
American Trans Air
Continental Airlines
Delta Airlines
Frontier Airlines
Hawaiian Airlines
Midwest Express
Northwest Airlines
Southwest Airlines
Trans World Airlines
United Airlines
US Airways

Some Major Airlines That Are NOT U.S. Flag Carriers (unless they have a U.S. Code Share):
Aer Lingus
Air France
El-Al
Lufthansa
Olympic Airways
Singapore Airlines
Air Canada
British Airways
KLM Royal Dutch Airlines
Mexicana
Qantas
Virgin Atlantic

For the complete details of the Fly America Act, please see http://www.fic.nih.gov/funding/grants_info/travel.htm