How should true airspeed change to maintain the same angle of attack when air density decreases?

To maintain the same angle of attack in response to decreasing air density, true airspeed must increase. As air density diminishes — for instance, at higher altitudes or in warmer temperatures — the amount of lift generated at a given airspeed decreases.

To compensate for this reduction in lift due to lower air density, the aircraft must fly at a higher true airspeed to achieve the same dynamic pressure on the wings, which is essential for maintaining the desired angle of attack. The angle of attack is a critical factor in producing lift; therefore, increasing the true airspeed counterbalances the decrease in air density and ensures that lift remains consistent at a given angle of attack.

This relationship is critical for flight engineers to understand, as it affects performance calculations and operational parameters, particularly during climbs or when operating at altitudes where air density is notably low.