What is the UHF GUARD frequency used in aviation communications?

The UHF GUARD frequency used in aviation communications is 243.00 MHz. This frequency serves as the emergency frequency for aircraft and is monitored by military and civilian air traffic control. It is important for pilots to be familiar with this frequency, as it facilitates communication during emergencies when normal communication channels may not be available.

The other frequencies listed have specific uses but are not designated as the UHF GUARD frequency. For instance, 121.50 MHz is the VHF emergency frequency used primarily for civil aviation, while 143.00 MHz is typically associated with non-emergency communications within the UHF range. The frequency of 300.00 MHz is not designated for aviation communications and is used for other purposes. Understanding the significance of 243.00 MHz as the UHF GUARD frequency is crucial for ensuring safety and effective communication in aviation.