At what speed should one climb with one engine inoperative?

The correct speed to climb with one engine inoperative is V2. This speed is crucial during takeoff and initial climb phases as it represents the minimum takeoff safety speed.

When an aircraft experiences an engine failure shortly after takeoff, maintaining a speed of V2 ensures that the aircraft has sufficient lift and control. At V2, the aircraft can safely climb with one engine out, providing the necessary performance margin for a controlled ascent. It allows for a balanced climb rate and helps avoid stall conditions, creating a safer environment for the aircraft and its occupants.

V1, while important for the takeoff decision point, is more about the decision to continue the takeoff rather than the climb performance after an engine failure. V3 and Vf do not have established roles in this specific context, making V2 the critical speed for handling an in-flight engine failure.