What is required when using a "fly-by" waypoint?

When using a "fly-by" waypoint, it is required to make a turn before reaching the waypoint. This type of waypoint is designed to allow the aircraft to commence a turn towards the next segment of the flight path before directly flying over the waypoint itself. By doing so, pilots can maintain optimal flight path efficiency and avoid unnecessary altitude changes or structural stress on the aircraft.

In contrast, passing directly over the waypoint is not necessary with a fly-by configuration; instead, the waypoint serves primarily as a reference point for navigation and transition rather than a mandatory flight point. Additionally, descending before the waypoint is not a requirement, as the aircraft's altitude depends on the specific approach and conditions, and holding position at the waypoint contradicts the seamless transition that a fly-by waypoint promotes. Thus, making the turn before the waypoint is essential for safe and efficient navigation.