Two design objectives among the list of objectives are: (i) maximizing the payload weight and (ii) minimizing the stall speed (Vs). As Equation (5.36) indicates, increasing CLmax tends to increase the payload weight (W) and decrease the stall speed. The lower stall speed is desirable since a safe take-off and landing requires a lower stall speed. In contrast, the higher payload weight will increase the efficiency of the aircraft and reduce the cost of flight. A higher CLmax allows the aircraft to have a smaller wing area that results in a lighter wing. Hence, in a wing design, the designer must find a way to maximize the CLmax. In order to increase the lift coefficient, the only in-flight method is to temporarily vary (increase) the wing camber. This will happen only when the HLD is deflected downward. In the 1970s the maximum lift coefficient at take-off was 2.8, while the record currently belongs to the Airbus A-320 with a magnitude of 3.2.