Naval Air Station Patuxent River (NAS Pax River) played a crucial role in forging America's naval air arm. This unique center proved to be vital for flight testing and evaluating naval aircraft and weapons systems destined for operational fleet service. NAS Pax River taught fleet pilots new tactics by conducting aircraft weapons tests, a tradition supplemented today by ground-based simulation. During and after World War II, it served as a primary center for flight testing and evaluating foreign aircraft. Some of the world's best test pilots and eventual astronauts came to NAS Pax River to hone their flight skills and to participate in the testing of naval aviation's premier aircraft. It is also home to the Naval Air Warfare Center Aircraft Division (NAWCAD) and the US Naval Test Pilot School, and it is the headquarters of the Naval Air Systems Command (NAVAIR).