What does the term "vertical navigation" (VNAV) refer to in aviation?

The term "vertical navigation" (VNAV) specifically pertains to the management of altitude and vertical speed throughout a flight. In aviation, VNAV involves the use of electronic systems to effectively guide an aircraft vertically, ensuring that it maintains a designated altitude or follows a predefined vertical profile. This is vital for compliance with air traffic control instructions, safe ascent and descent profiles, efficient fuel usage, and maintaining separation from other air traffic.

VNAV can utilize various technologies, including onboard flight management systems, which can automatically adjust the aircraft's vertical speed to meet the required altitudes at specific waypoints. This capability enhances the overall efficiency of flight operations as pilots can focus more on flying and less on manually calculating and monitoring altitude changes.

While other choices present related concepts, they do not encompass the specific role that VNAV plays in aviation. The process of calculating flight distance pertains more to lateral navigation; coordinating communication with ATC relates to air traffic management, and monitoring lateral navigation solely relates to tracking horizontal position rather than vertical orientation.