At higher altitudes, to produce the same lift, the lift surfaces must be flown faster or at higher angle of attack. The statement is:

At higher altitudes, to produce the same lift, the lift surfaces must be flown faster or at higher angle of attack. The statement is:

• A. True
• B. False
• C. Not sure
• D. Depends on air density

Answer: (A)

When lift is broken down, it depends on air density, speed, wing area, and the lift coefficient. At higher altitudes the air is thinner, so density drops. To keep producing the same lift in thinner air, you have to increase dynamic pressure, which can be done by flying faster or by increasing the lift coefficient, typically by raising the angle of attack (until you approach stall). So the statement is true: to maintain the same lift at higher altitude you must fly faster or increase the angle of attack. In practice, the exact amount you need to increase speed or AoA depends on how much the air density has decreased, and there are limits because entering too high an angle of attack risks stall.

When lift is broken down, it depends on air density, speed, wing area, and the lift coefficient. At higher altitudes the air is thinner, so density drops. To keep producing the same lift in thinner air, you have to increase dynamic pressure, which can be done by flying faster or by increasing the lift coefficient, typically by raising the angle of attack (until you approach stall). So the statement is true: to maintain the same lift at higher altitude you must fly faster or increase the angle of attack.

In practice, the exact amount you need to increase speed or AoA depends on how much the air density has decreased, and there are limits because entering too high an angle of attack risks stall.