Final answer:
During the departure of an aircraft, the VVI can be reduced and acceleration can occur once the aircraft reaches a certain point of altitude and speed.
Step-by-step explanation:
During the departure of an aircraft, the Vertical Velocity Indicator (VVI) can be reduced and the aircraft can accelerate after reaching a certain point. This point is generally when the aircraft has gained enough altitude and speed to safely transition from the initial climb phase to a more efficient cruising phase. At this point, the aircraft can reduce its rate of climb (VVI) and increase its speed.
For example, during takeoff, an aircraft initially climbs at a steep angle to gain altitude quickly. But once it reaches a certain altitude and speed, typically referred to as the climbout point, the aircraft can start reducing its rate of climb and accelerating to a faster speed for more efficient flying.
It's important to note that the exact point at which the VVI can be reduced and acceleration can occur may vary depending on factors such as aircraft performance, air traffic control instructions, and specific flight procedures.