What is the universal VHF emergency frequency?

The universal VHF emergency frequency is 121.5 MHz. This frequency is designated for emergency communications by aircraft in distress, allowing them to reach air traffic control and other aircraft in the vicinity. It is used globally and recognized by all aviation authorities.

When a pilot encounters an emergency situation, they can transmit on 121.5 MHz to signal for assistance, making it a critical frequency for safety in aviation. This frequency is monitored by air traffic control and also by search and rescue operations.

Additionally, while other frequencies listed serve specific purposes—like 121.4 MHz, which is often used for unrehearsed communications or a variety of purposes, 122.9 MHz, typically a common traffic advisory frequency, and 123.0 MHz, which is frequently used for non-towered airport operations—none serve the universal emergency communication function that 121.5 MHz does. This reinforces why 121.5 MHz is recognized specifically for emergency situations across the aviation community.