Which identifier is NOT an airport?

The identifier "SZW" is not associated with an airport, while the other identifiers represent actual airports. In the context of aviation, identifiers typically conform to specific formats such as those defined by the International Civil Aviation Organization (ICAO) or the Federal Aviation Administration (FAA) for U.S. airports, which often begin with specific letters to denote geographical locations.

For instance, the identifiers starting with "K," such as "KDTN" and "KSHV," are FAA codes for airports located in the United States. The identifier "D" in "SHV" indicates an airport in Shreveport, Louisiana. However, "SZW" does not correspond to any known airport, making it the correct choice as the identifier that is not an airport.

The understanding of these codes is essential for recognizing airport locations and operations in the realm of aviation, highlighting the significance of maintaining knowledge about which identifiers are valid representations of airport facilities.