An autothrottle (AT) mode logics design for the civil aircraft is proposed in this work especially to ensure sufficient thrust in various take off and go around scenarios. Firstly, the AT states and modes are defined for the typical active throttle lever scheme considering the airworthiness requirements. Then, the typical and atypical take off and go around scenarios are analyzed. An AT mode logics design is proposed which can meet conflicting requirements and has great ergonomics. Finally, the effectiveness of the proposal is verified in four scenarios including normal takeoff, normal go around, a low altitude go around and accidentally pressing TO/GA button after touchdown through Simulink Stateflow modeling.