Which suffix signifies that an aircraft has no transponder but is equipped only with TACAN?

The suffix that signifies an aircraft has no transponder but is equipped only with TACAN is the letter that stands for the condition of not having a transponder while being active with TACAN navigation capabilities. The use of this specific suffix helps air traffic controllers and other relevant authorities quickly identify the capabilities of an aircraft in terms of navigation and communication, which is crucial for safety and efficiency in airspace management.

In the context of aviation communication, TACAN (Tactical Air Navigation) provides highly accurate navigation information but does not involve a transponder's capabilities, which can relay altitude, speed, and position data to ground systems. The ability to distinguish these statuses is important for air traffic management, especially when coordinating with various aircraft types, improving safety protocols, and ensuring appropriate separation in the skies.

While the other suffixes represent different aircraft capabilities or statuses, the one selected specifically denotes the absence of a transponder while indicating that the aircraft is still capable of TACAN navigation.