FSX YE-ZB Navigation System. YE-ZB was a Top Secret WW2 US Navy system developed by Frank Akers for homing aircraft to their carriers. This bundle includes two aircraft equipped with the necessary gauges to simulate the YE-ZB system. It is similar to the US Radio Range system, but with changes to make the system usable only by the US, while not increasing the vulnerability of the carriers to detection and direction finding. At the start of WW2 all US carriers were equipped with a UHF device called the "YE" which transmitted a Morse code letter denoting a 15 degree arc of a circle with the carrier at its center. Navy aircraft used the AN/ARR-2 UHF homing receiver (sometimes called "ZB"). Pilots were given daily information so they would know which direction corresponded to each Morse letter. By Dave Bitzer.