What altitudes does VNAV capture?

VNAV (Vertical Navigation) capture refers to the ability of the Flight Management System (FMS) to follow the defined vertical flight path in the aircraft’s altitude constraints. When determining which altitudes VNAV captures, it is important to consider both the FMS-generated altitude profiles and the pre-selected altitudes set by the pilots.

The correct answer indicates that VNAV captures the most restrictive altitudes between what is defined in the FMS flight plan and what is set by the crew in the pre-select. This ensures that the aircraft adheres to any altitude constraints imposed by air traffic control, as well as follows the intended flight path established by the flight plan, thereby optimizing safety and compliance with air traffic regulations. The system evaluates both inputs and adopts the stricter altitude to maintain a safe operational profile.

This ensures not just adherence to the planned route, but also compliance with any restrictions that might be applied by air traffic management, thus facilitating safe and efficient flight operations. The focus on combining the FMS and pre-select altitudes is crucial for effective VNAV functionality.