Converting an ICAO (International Civil Aviation Organization) four-letter identifier to an FAA (Federal Aviation Administration) three-letter location identifier for airports in the contiguous United States is generally straightforward but follows specific regional rules. For the lower 48 states, the FAA three-letter code is simply the ICAO code with the leading "K" removed; for example, KLAX (Los Angeles) becomes LAX. However, this "K" prefix rule does not apply to Alaska, Hawaii, or U.S. territories. In Alaska, ICAO codes start with "PA" (e.g., PANC for Anchorage), which corresponds to the FAA identifier ANC. In Hawaii, they start with "PH" (e.g., PHNL for Honolulu), which maps to HNL. Outside of the U.S., ICAO codes often bear no direct alphanumeric relationship to local domestic identifiers. It is important to note that the FAA uses three-letter identifiers for public-use airports, but some private or small airfields use alphanumeric codes (like 1O2) that do not have a corresponding ICAO equivalent. Pilots in 2026 primarily rely on digital flight bags (EFBs) like ForeFlight, which automatically handle these cross-references, but understanding the "K-prefix" logic remains a fundamental requirement for private pilot ground school and flight planning.