Raising camber improves lift but may increase drag at cruise flight.

• A. False
• B. True
• C. Only at high speed
• D. Only at low speed

Answer: (B)

Raising camber increases the curvature of the wing’s airfoil, which boosts the lift produced at a given angle of attack. A more cambered surface shapes the pressure distribution so the wing achieves a higher lift coefficient without needing as large an angle to fly level. That same extra curvature, however, tends to raise parasite drag because of greater skin friction and a larger wetted area, and it can also slightly worsen form drag if the flow encounters more surface curvature.

At cruise, where speed is high, induced drag falls with speed (since CL needed for weight is smaller) while parasite drag rises with surface area and friction. So even though you may operate at a lower angle of attack due to the increased camber, the added drag from the cambered shape can outweigh the lift-attack benefits, leading to a possible increase in total drag. That’s why the statement is true: raising camber improves lift but may increase drag at cruise.