Which of the following is NOT a component of the PAR signal path?

The PAR (Precision Approach Radar) signal path is primarily concerned with the elements that directly receive, process, and communicate radar signals to assist in the landing of aircraft. Each component within the signal path plays a critical role in ensuring accurate radar information and communication are provided to air traffic controllers.

Radar Control Units (RCUs) are essential as they process the radar signals and provide critical data about the aircraft's position and altitude. Ground communication units are also vital, as they facilitate the communication between the radar system and air traffic control, enabling effective management of aircraft operations. Air Traffic Control systems indeed utilize the information from the PAR to direct aircraft safely and efficiently.

In contrast, aircraft performance data, while important for overall flight operation and safety, does not form part of the PAR signal path itself. This data typically relates to the aircraft's capabilities and performance metrics, such as speed and altitude, but is not involved in the processing or relay of radar signals within the PAR framework. Therefore, identifying aircraft performance data as not a component of the PAR signal path aligns with a clear understanding of the roles of radar systems and their components in air traffic management.