What does Vy for a jet indicate?

The correct understanding of Vy for a jet aircraft pertains to the velocity for the best rate of climb. Vy is particularly significant because it represents the speed at which the aircraft can achieve the maximum altitude gain over time. This is crucial during takeoff and initial climb phases, as flying at Vy ensures that the jet reaches the desired altitude most efficiently, provided that it is maintaining the optimal climb configuration.

While power available and power required are important concepts in understanding climb performance, they do not define Vy directly. Vy is specifically related to achieving the best climb rate, contrasting with other operational speeds like Vx, which focuses on the best angle of climb. Understanding Vy helps pilots optimize climb performance during critical phases of flight.