As altitude is increased, the stall speed (IAS):

As altitude increases, the stall speed in terms of indicated airspeed (IAS) does indeed behave in a specific manner related to the aircraft's aerodynamic characteristics. Generally, stall speed is influenced by the density of the air, which decreases with altitude. The stall speed is defined as the minimum speed at which an aircraft can maintain level flight and is directly associated with the lift generated by the wings.

As you climb to higher altitudes, the air becomes less dense. However, the stall speed itself is primarily a function of the lift coefficient and the specific weight of the aircraft. The stall speed, in terms of true airspeed (TAS), will increase as altitude increases due to the reduction in air density. However, the indicated airspeed, which is what the pilot reads on the airspeed indicator, may not change initially because the instruments are calibrated to reflect air pressure changes.

The correct understanding is that stall speed increases due to the necessity for the aircraft to fly at a higher true airspeed to achieve the same lift in less dense air. Hence, stall speed in IAS initially remains constant (as pilots typically use indicated airspeed in their operations) but eventually increases as the density diminishes significantly at higher altitudes. Therefore, it is accurate to