What is the MULTICOM frequency used for self-announce procedures?

The MULTICOM frequency used for self-announce procedures is 122.900 MHz. This frequency is specifically designated for non-towered airports and allows pilots to communicate their intentions when there is no air traffic control tower present. Operators use this frequency to announce their position, intentions, and any essential information to ensure safe operations in the vicinity of the airport, especially when multiple aircraft might be using the same airspace.

Other frequencies mentioned, such as 121.5 MHz, are primarily reserved for emergency situations and distress calls. Frequencies like 123.0 and 124.5 MHz serve other communication purposes and are not designated for general self-announcement procedures. Therefore, 122.900 MHz is the correct answer as it effectively facilitates the necessary communication for safety at non-towered airports.