- The term "Capital airport" could refer to the main airport located in a country's capital city. For example, in Washington, D.C. the main airport is Washington Dulles International Airport, which could be referred to as the capital airport of the United States since it is located near the capital. Similarly, other countries may have a designated capital airport such as London Heathrow Airport in the United Kingdom or Charles de Gaulle Airport in France. However, it is important to note that not all capital cities have a dedicated airport and in some cases, the main international airport for a country may be located in a different city.