What is the optimal rotor RPM during a maximum glide?

The optimal rotor RPM during a maximum glide is recognized to be around 90%. This RPM provides a balance between lift and drag, allowing for optimal aerodynamic efficiency. At this rotor speed, the helicopter is generally able to maintain sufficient lift while minimizing drag, thus extending the glide distance.

In a glide situation, maintaining rotor RPM is crucial for rotor inertia and for ensuring adequate control of the helicopter. Operating at or near optimal RPM enhances lift capabilities, which strengthens the helicopter's ability to maneuver and control during the glide. While some helicopters might have slightly different optimal glide RPM specifications depending on their design, 90% is a commonly referenced figure for many aircraft, making it a good benchmark for pilots to remember in training and operational scenarios.