What is the change in angle of attack needed to maintain lift as true airspeed decreases?

To maintain lift as true airspeed decreases, it is necessary to increase the angle of attack. Lift generated by an airfoil is directly related to the airspeed and the angle of attack. When the true airspeed drops, the amount of lift generated at a given angle of attack also decreases.

Increasing the angle of attack compensates for the loss of lift due to the lower airspeed. This is because the lift equation demonstrates that lift is a function of air density, velocity squared, surface area, and the coefficient of lift, which is influenced by the angle of attack. By increasing the angle of attack, the pilot can increase the coefficient of lift, thereby maintaining the production of lift despite the reduced airspeed.

It’s important to note that while the true airspeed decreases, the aircraft might encounter stall if the angle of attack becomes too high, but within the safe operational limits, increasing the angle of attack is the correct method for sustaining lift with decreasing airspeed.