Final answer:
Coast Guard aircraft are equipped with dual analog frequency ELTs and a single digital frequency ELT, devices that emit distress signals for search and rescue.
Step-by-step explanation:
The question revolves around the equipment used in Coast Guard aircraft and specifically what types of emergency locator transmitters (ELTs) they are equipped with. ELTs are devices designed to transmit a distress signal in case of an emergency, so that search and rescue teams can locate the aircraft. Coast Guard aircraft are typically equipped with dual analog frequency ELTs, which implies they can transmit on two separate frequencies, and also a single digital frequency ELT, which transmits a digital signal that may include additional data such as the aircraft's identification and position.