What emergency frequency should be contacted when declaring an emergency?

When declaring an emergency, the frequency that should be contacted is 121.5 MHz. This frequency is designated as the international emergency frequency for aviation and is widely monitored by air traffic control, ground stations, and other aircraft. It is specifically set aside to assist pilots in distress and provides a dedicated channel for emergency communication.

Using 121.5 MHz allows pilots to receive immediate attention and assistance in critical situations, ensuring their messages can be heard amidst regular air traffic. In contrast, the other frequencies listed serve different purposes; for instance, 118.0 MHz is commonly used for air traffic control communications at airports, while 123.45 MHz serves as a common traffic advisory frequency for non-towered airports and general aviation. The frequency 119.0 MHz is typically used for approach control in certain areas. Thus, knowing that 121.5 MHz is dedicated to emergencies is crucial for effective communication during critical flight situations.