For an Overlay approach, is it mandatory to monitor the underlying traditional Navigation Aids?

In the context of an Overlay approach, monitoring the underlying traditional Navigation Aids is not a mandatory requirement, but it is highly recommended for safety and situational awareness. Overlay approaches utilize modern navigation technologies such as GPS, which can enhance precision and efficiency. However, relying solely on these technologies without cross-checking traditional navigational aids can introduce risks, particularly in cases of technical failure or other unexpected issues that may arise during the approach.

Keeping an eye on traditional navigation aids ensures that pilots have a backup method of navigation available. This redundancy can be particularly valuable in maintaining situational awareness, especially when transitioning to visual flight or in conditions where GPS signals may be unreliable.

While it's not a formal requirement, the recommendation to monitor these aids serves to bolster safety and provides an additional layer of assurance that can help prevent navigational errors. Therefore, while not mandatory, monitoring is considered best practice in the aviation community when conducting Overlay approaches.