Which instrument is part of the navigation flight instruments?

The Distance Measuring Equipment (DME) is an essential component of navigation flight instruments as it provides information on the aircraft's distance from a specific ground-based navigational aid, such as a VOR (VHF Omnidirectional Range) station. This distance information is crucial for pilots during navigation, especially in en route and approach phases, allowing them to accurately determine their position relative to their flight path and destination.

DME works in conjunction with other navigational aids, enhancing situational awareness and enabling pilots to make informed decisions about course corrections and distance management. Its ability to provide real-time distance information makes it an indispensable tool for effective navigation, particularly in instrument flight conditions.

In contrast, other instruments listed serve different purposes: the fuel flow gauge tracks fuel consumption rather than navigation, the vertical speed indicator measures the rate of ascent or descent, and the attitude indicator indicates the aircraft's orientation relative to the horizon. While all these instruments are important for overall flight operations, DME is distinctly categorized under navigation instruments due to its specific function in helping pilots determine their position and distance from navigational aids.