What is the ICAO code for Reagan National Airport?

Reagan National Airport, located in Arlington, Virginia, uses the ICAO code KDCA. This code follows the International Civil Aviation Organization's (ICAO) convention for airport designations, which assigns a unique four-letter alphanumeric code to each airport worldwide. The "K" denotes that the airport is located in the United States, and "DCA" specifically identifies Reagan National Airport.

The other options represent different airports: KPNS is the ICAO code for Pensacola International Airport in Florida, SWB does not correspond to a specific airport in the United States, and KPHX is the ICAO code for Phoenix Sky Harbor International Airport in Arizona. Understanding the structure of ICAO codes is key, as each code contains information about the geographical location and identity of the airport.