An Emergency Locator Transmitter (ELT) is a device used in aircraft to help locate them in case of an emergency. When activated, it emits a distress signal that can be detected by search and rescue teams. ELTs are designed to automatically activate upon impact or can be manually turned on by the pilot. These devices operate on specific frequencies, typically 406 MHz and 121.5 MHz, allowing them to communicate with satellites and ground stations. The signals help rescuers pinpoint the location of the aircraft, increasing the chances of a successful recovery and ensuring the safety of those on board.