Which of the following are the aeronautical frequency bands?

The correct answer identifies the aeronautical frequency bands as 108-137 MHz and 225-400 MHz. These frequency ranges are specifically allocated for aviation communications. The 108-137 MHz range is primarily used for VHF air traffic control communications and navigation aids, such as VOR and ILS signals, which are crucial for pilots and air traffic controllers during flights. The 225-400 MHz band is used for military aviation communications, including tactical and operational communications among aircraft and ground stations.

Understanding the allocated frequencies and their specific uses in aviation is key to ensuring safe and effective communication in air traffic management. This knowledge is vital for technicians working with equipment that operates within these bands, as it allows them to optimize installations and maintenance in the context of aviation.