What happens to the best rate of climb and angle of climb after an increase in speed from the best rate of climb?

The best rate of climb and the angle of climb are affected by changes in airspeed due to the relationships governing aircraft performance.

When an aircraft is flying at its best rate of climb speed, it is generating the most vertical lift relative to drag; this specific speed allows the aircraft to achieve the highest altitude gain in a given time frame. If the speed is increased beyond this optimal speed for rate of climb, the aircraft enters a regime where induced drag starts to increase more significantly than the increase in overall thrust. As a result, both the rate of climb and angle of climb diminish.

Specifically, the best rate of climb is dependent directly on the excess power available at the best climb speed. Moving to a higher speed usually results in the aircraft needing more power just to maintain level flight, and therefore less power is available for climbing. The angle of climb, which is the vertical speed divided by the horizontal speed, also decreases because while the vertical speed is diminished, the horizontal speed increases.

In tandem, these performance characteristics indicate that an increase in speed beyond the optimal rate of climb speed will lead to a decrease in both the best rate of climb and the angle of climb. Thus, both climb metrics are reduced when flying faster than the best rate of climb