The conversion protection system ensures the forward nacelle conversion remains active below which threshold?

The forward nacelle conversion protection system is designed to ensure safe operations by preventing unwanted conversion at higher speeds. The designation 'Low Speed Boundary' signifies the operational threshold below which the nacelle conversion is actively managed to maintain stability and control of the aircraft. By keeping the conversion system engaged below this boundary, it helps avoid excessive aerodynamic stresses and possible airframe damage that can occur during critical flight regimes.

The other options, which represent specific speeds, do not capture the general concept of the 'Low Speed Boundary.' This boundary is a more dynamic and adaptable threshold that accounts for flight conditions rather than a fixed speed limit. It highlights the importance of maintaining appropriate flight characteristics as the aircraft maneuvers, ensuring safety and operational integrity during various phases of flight.