The frequency of 121.5 MHz is designated as the international distress frequency for aviation. It is used by pilots and aircraft in emergencies to communicate their need for assistance. This frequency is monitored by air traffic control and search and rescue organizations worldwide, ensuring a rapid response to distress calls. In addition to aviation, 121.5 MHz is also utilized by emergency beacons, such as Emergency Locator Transmitters (ELTs). These devices automatically transmit distress signals when activated, helping rescuers locate downed aircraft or stranded individuals. The use of this frequency is crucial for enhancing safety in aviation and emergency response efforts.