How does altitude affect indications of stall speed?

Indicated stall speed is primarily influenced by the aircraft's weight, configuration, and the density of the air. As altitude increases, the density of the air decreases due to lower atmospheric pressure. However, stall speed is defined in terms of airspeed over the wings, not absolute speed through the air.

At higher altitudes, even though the air density is lower, the indicated airspeed for stall remains the same because it is based on a standard reference for sea level conditions. The stall speed indicated on the airspeed indicator does not change simply because the altitude has increased; rather, it is the actual stall speed that can become affected due to changes in the aircraft's aerodynamic performance as the air gets thinner. Therefore, despite changes in the performance parameters at altitude, the indicated stall speed remains consistent relative to the aircraft's parameters at sea level.

This understanding leads to the conclusion that altitude has no effect on indicated stall speed, making the reasoning behind this choice valid.