Final answer:
The number of presets for NAV radios varies depending on the equipment's model and capabilities, with common models having between 10 to 25 memory slots and advanced systems having 50 to 99 or more.
Step-by-step explanation:
The number of presets available for NAV radios can vary depending on the model and make of the navigation radio being discussed. In aviation, NAV radios are used to receive signals from navigational aids like VOR (VHF omnidirectional range) and ILS (instrument landing system) facilities, which help pilots determine their position and guide them during flight.
Generally, most modern NAV radios come with a certain number of preset channels or memory slots. These presets allow aviators to quickly tune into frequently used or important frequencies without the need to manually dial them in each time. For example, it's common to have 10 to 25 memory slots, but this can vary from one manufacturer to another.
Advanced NAV/COMM (communication) radios, which often also include GPS functionalities, tend to have greater capabilities and more presets. Existing on some advanced models are up to 50 to 99 preset channels. However, in more sophisticated flight decks and FMS (Flight Management Systems), the number could be significantly higher, well into the hundreds, as these systems can integrate with databases that store vast numbers of frequencies.
When selecting a NAV radio, it is crucial to consider your specific needs and the requirements of your aircraft's avionics suite. More complex aircraft and missions will typically require radios with a higher number of presets and additional features.