What is the VHF emergency frequency monitored by most aviation ground facilities?

The VHF emergency frequency that is monitored by most aviation ground facilities is 121.5 MHz. This is designated as the international distress frequency and is used for emergency communications by aircraft. It is critical for pilots in distress to communicate with air traffic control or other aircraft, as it is universally recognized for emergency situations. If a pilot encounters an emergency, they can transmit their situation on this frequency, and it is monitored by air traffic personnel and can be picked up by other aircraft in the vicinity, facilitating timely assistance.

While other frequencies have specific roles—such as 123.45 MHz for general aviation communications and 118.0 MHz primarily for air traffic control communications—none carry the emergency designation that 121.5 MHz does. Thus, pilots are trained to use 121.5 MHz for emergencies, ensuring safety and rapid response in critical situations.