Which statement best describes the relationship between density altitude and lift?

• A. Lower density altitude yields less lift
• B. Higher density altitude yields more lift
• C. Density altitude has no effect on lift
• D. Lower density altitude yields more lift

Answer: (D)

Lift increases with air density, because denser air has more molecules for the wing to push on during each pass. Density altitude is a way to express how dense the air is at a certain altitude and temperature. When density altitude is low, the air is denser, so for the same true airspeed and angle of attack the wing produces more lift. If density altitude is high, the air is thinner, and lift is reduced. That’s why lower density altitude yields more lift is the best description. The other ideas conflict with this fundamental relationship: lift does depend on density, so higher density altitude doesn’t increase lift, and density altitude does affect lift.