Which of the following is NOT a common navigation aid used in aviation?

The correct answer is that a High-Speed Connection (HSC) is not a common navigation aid used in aviation. Navigation aids are systems or technologies that assist pilots in determining their position, course, and direction during flight.

VOR, or VHF Omnidirectional Range, is a type of ground-based radio navigation system that provides pilots with azimuth information by transmitting signals in all directions. It helps aircraft to determine their position relative to the VOR station and is widely utilized in both general aviation and commercial flight operations.

GPS, or Global Positioning System, is a satellite-based navigation system that delivers precise location and timing information to users anywhere on Earth. It is an essential tool in modern aviation for route planning, navigation, and situational awareness.

NDB, or Non-Directional Beacon, is another long-established navigation aid that emits radio waves, allowing aircraft to navigate using a simple receiver that determines the bearing to the beacon, which is helpful for both en route navigation and approaches.

In contrast, a High-Speed Connection does not serve the same navigational purpose and is not classified as a navigation aid; rather, it may refer to a type of communication technology—not directly relevant to flight navigation.