What type of training do pilots undergo related to VNAV?

Pilots undergo both simulator and ground training that is essential for effectively operating the Flight Management System (FMS) and understanding VNAV procedures. This training is critical because VNAV involves advanced navigation techniques that utilize data from the aircraft's systems to ensure the correct vertical profile during flight.

Simulator training allows pilots to practice various scenarios, including altitude passage and descent management, in a controlled environment where they can learn how to respond to different conditions and situations. Ground training complements this by providing the theoretical background necessary to understand the principles behind VNAV, including its integration with other flight systems and navigation aids. Together, these training types equip pilots with the skills and knowledge required to safely and effectively use VNAV in real-world operations.

Contrasting this with the other options, theoretical training alone is insufficient when it comes to the complex operation of VNAV systems. Manual navigation skills, while still important, do not encompass the advanced capabilities and automation that VNAV provides, making them a limited focus for training. Lastly, self-study of VNAV manuals lacks the hands-on experience and structured guidance needed to fully grasp VNAV functionalities and procedures.