What data should be utilized to issue clearances?

The correct choice for issuing clearances is based on the utilization of FDIO data. FDIO, or Flight Data Input/Output, serves as a vital tool for air traffic controllers, providing them with real-time data about aircraft that are operating in controlled airspace. This data includes essential information needed to issue flight clearances, such as current flight plans, route information, and sometimes even amendments to those plans.

Utilizing FDIO data ensures controllers have immediate access to the most up-to-date information, which is critical for safe and efficient flight operations. It allows for seamless communication with pilots regarding their clearances, including aspects like departure and arrival procedures, which need to be precise and timely.

While AIRAC data is also important for the operational environment by ensuring that navigational and procedural updates are current, it does not directly provide the real-time information necessary for issuing specific clearances. Flight planning data is typically used by pilots and flight planners before a flight commences, and while it may inform controllers, it is not the primary source of information for issuing clearances. ATC routing data can also be utilized for understanding traffic flows and available routes but is part of a broader decision-making process rather than the specific source used for clearance issuance.