What is the effect of spoilers on lift in straight-and-level flight when deployed and speed and load factor remain constant?

• A. Lift increases
• B. Lift decreases
• C. Lift remains unchanged
• D. Lift becomes negative

Answer: (C)

Lift in straight-and-level flight is the force balancing weight. If the speed is the same and the load factor (the ratio of lift to weight) remains constant, then the lift must stay equal to weight (L = nW). Spoilers disrupt the wing’s lift-producing capability, but under the specified conditions—constant speed and constant load factor—the amount of lift required to keep the aircraft level does not change. So the lift remains unchanged.