What is the maximum flap setting when boots are inoperative?

The maximum flap setting when the boots are inoperative is Flaps 0º because, without the functioning de-ice or anti-ice systems, which may include the boots on the wings, the aircraft is at risk of ice accumulation. Ice on the wings can significantly alter the aerodynamic characteristics of the aircraft, reducing lift and increasing stall speed. Therefore, operating with flaps extended without proper ice protection could lead to dangerous flight conditions, such as increased risk of stall. Keeping the flaps at 0º ensures that the aircraft maintains optimal performance and control under these conditions. This understanding highlights the importance of ice management and maintaining safety limits in flight operations.