The Current Flight Plan (CPL) is an important concept in aviation. It refers to the flight plan that includes any changes made by air traffic control (ATC). In simpler terms, the CPL is a combination of the original flight plan (FPL) and any updates from ATC. The FPL outlines how the flight is intended to proceed. However, it can be modified through change messages (CHG) submitted by the pilot or another authorized individual. These CHG messages either replace or add information in various sections of the original FPL.
In most cases, the flight operates according to the CPL instead of the initial FPL filed before takeoff. There are several reasons for this. First, a controller may need to intervene. This could involve altering the aircraft’s speed, altitude, or heading to resolve conflicts with other aircraft or to navigate around restricted areas. Additionally, the pilot may request changes to the flight plan to execute maneuvers that avoid bad weather, take a more direct route to minimize delays, or adjust cruising levels based on the aircraft’s current performance.
Once any necessary deviations are completed, returning to the route specified in the original FPL within controlled airspace requires clearance from ATC. This means pilots cannot decide to revert to the FPL on their own. Information regarding the CPL is then passed to the next air traffic service unit. This communication can happen in several ways: through verbal coordination, which includes estimates, revisions, and additional information; using OLDI messages like ABI (preliminary info), ACT (electronic estimate), and REV (electronic revision); or via CPL messages, which are sent when the downstream ATS unit hasn’t received the FPL message for some reason.
