What frequency does the ELT operate on for emergencies?

The correct frequency for Emergency Locator Transmitters (ELTs) is 121.5 MHz and 406 MHz. This is because ELTs are designed to transmit distress signals that can be detected by search and rescue satellites, as well as by aircraft and ground stations. The 121.5 MHz frequency was traditionally used for emergency calls and can still be used for local search and rescue efforts. The addition of the 406 MHz frequency provides a more reliable and accurate method for locating downed aircraft, as signals on this frequency can be processed by satellites, which allows for quicker rescue operations.

The other options do not encompass the frequencies that ELTs utilize for emergency situations. While 78.5 MHz and 243 MHz both serve various purposes in aviation and military communications respectively, they are not used by ELTs. The frequency of 960 MHz does not pertain to ELTs at all and is used in different applications, such as satellite communications, rather than emergency distress signaling.