The aircraft beacon code assignment after join-up is determined by what?

The correct choice is determined by the formation type because the assignment of aircraft beacon codes during a join-up is closely linked to the specific requirements of the formation being executed. Different formations may have distinct operational needs and communication protocols that dictate how aircraft will identify themselves to air traffic control and to each other. By assigning beacon codes based on formation type, it enhances situational awareness and ensures that all participating aircraft can effectively coordinate their actions within the formation.

For example, when flying in a tactical formation, the lead aircraft might have a specific code that indicates to air traffic control that they are operating in a formation, which can help avoid potential conflicts with other air traffic. This systematic approach to code assignment allows pilots to maintain better control and coordination throughout the mission, thus fostering an efficient operational environment.