Which frequency must an ELT transmit on?

An Emergency Locator Transmitter (ELT) is designed to aid in search and rescue operations following an aircraft accident. The frequencies on which ELTs transmit are critical for ensuring that distress signals can be received by appropriate agencies and rescue services.

The first frequency, 121.5 MHz, is a designated international distress frequency, primarily used for emergency signals in aviation and maritime contexts. It allows private pilots and other non-commercial users to send out distress signals that can be monitored by search and rescue organizations and other aircraft in the vicinity.

The second frequency, 243 MHz, is specifically allocated for military distress communication. Military aircraft are required to operate on this frequency for emergency situations, helping search and rescue teams differentiate between civilian and military emergencies.

An ELT typically transmits on both frequencies. When activated, it sends out signals that can be detected by emergency services and other aircraft, increasing the likelihood of a swift response. By utilizing both frequencies, the ELT maximizes its range and effectiveness in emergencies, making the signal accessible to a wider range of receivers.

This dual capability is essential for enhancing the survival of individuals in distress situations, which makes the answer that ELTs transmit on both 121.5 MHz and 243 MHz accurate.