What should the flaps be set to during an engine failure after rotation?

During an engine failure after rotation, it is important to minimize drag while maintaining sufficient lift for controlled flight. Setting the flaps to 40 degrees is typically recommended because this configuration strikes a balance between providing adequate lift for a safe approach and landing without risking stalling the aircraft.

When flaps are set to the landing configuration (often around 40 degrees), the aircraft can maintain a better climb gradient or glide performance, which is crucial for managing the emergency situation. This aids in achieving an optimal airspeed for control while allowing for the possibility of reaching a suitable landing area or returning to the runway.

The other flap settings, such as 20, 30, or 50 degrees, may either not provide enough lift to sustain flight under these circumstances or could create excessive drag, making it more challenging to control the aircraft. Hence, selecting 40 degrees offers the most effective solution in response to an engine failure after rotation.