An often misunderstood concept is the aircraft maneuvering speed depicted as Va. This limitation is usually taught as the maximum speed which while maneuvering you will ‘stall it before you break it’. As the explanation implies it is really a structural limitation, but since most airplanes don’t have g-meters we must rely on airspeed indications to ensure the limitation is not exceeded. To complicate matters Va changes with the weight of the loaded airplane. Hopefully this article will help you understand the aerodynamic principles behind maneuvering speed and why it is important to us as a pilot.
In straight and level flight the wings produce exactly enough lift to sustain the weight of the airplane. If we bank the airplane the lift is split into two components: vertical and horizontal. As we increase the bank angle the vertical component decreases while the horizontal component increases. The loss of vertical lift will cause the airplane to descend because it is no longer sufficient to suspend the weight of the airplane.