Final answer:
High gross weights and density altitudes reduce the efficiency of lift and engine performance, resulting in a need for higher true airspeeds and a potential reduction in climb capacity during a go-around.
Step-by-step explanation:
High gross weights and high density altitudes can significantly affect the performance of an airplane during a go-around. At higher gross weights, the aircraft requires more power and a longer distance to achieve the same rate of climb compared to when it is lighter. The lift created by the wings is less efficient at higher gross weights, meaning the aircraft must fly at higher angles of attack to maintain the same lift, which in turn increases drag and reduces climb performance.
Similarly, higher density altitudes, which occur at higher altitudes where the air is thinner or on warm days, reduce the engine's power output and the wings' ability to generate lift. Since the air is less dense, the plane requires a higher true airspeed to generate the same amount of lift it would at lower altitudes with denser air. Consequently, in conditions of high density altitude, the aircraft may not be able to climb as quickly or may require a greater distance to clear obstacles during a go-around, especially at higher airspeeds where the engine may already be operating near its performance limits.