The rate of climb is approximately equal to what?

The correct answer is that the rate of climb is approximately equal to the still air gradient multiplied by the true airspeed (TAS). This is because the rate of climb in still air conditions can be derived from the vertical component of the aircraft's velocity.

When an aircraft is climbing, its vertical speed (rate of climb) is influenced by how steeply it is ascending (the climb gradient) and how fast it is moving forward through the air (TAS). The still air gradient provides an indication of how much altitude gain is achieved per unit of horizontal distance traveled, and multiplying this gradient by the true airspeed gives the vertical velocity, or rate of climb.

Understanding this relationship is crucial for pilots, as maintaining an appropriate climb rate is vital for ensuring safe operations, especially during takeoff and when avoiding obstacles during ascent.