If the center of gravity is moved from the aft limit toward the forward limit, how will the cruising speed be affected?

If the center of gravity is moved from the aft limit toward the forward limit, how will the cruising speed be affected?

• A. Decrease the cruising speed and increase the stalling speed
• B. Increase the cruising speed and decrease the stalling speed
• C. No change
• D. Double the cruising speed

Answer: (A)

Shifting the center of gravity toward the forward limit makes the airplane more longitudinally stable but increases the lift the wing must provide for level flight. The tail must push downward more to keep the nose from pitching up, adding to the overall load the wing has to support. To maintain level flight at the same weight, the wing must generate more lift, which means a higher angle of attack and more induced drag. That extra drag slows the airplane at a given power, so cruising speed decreases. At the same time, operating at a higher angle of attack brings you closer to the stall, so the stall speed increases.

Shifting the center of gravity toward the forward limit makes the airplane more longitudinally stable but increases the lift the wing must provide for level flight. The tail must push downward more to keep the nose from pitching up, adding to the overall load the wing has to support. To maintain level flight at the same weight, the wing must generate more lift, which means a higher angle of attack and more induced drag. That extra drag slows the airplane at a given power, so cruising speed decreases. At the same time, operating at a higher angle of attack brings you closer to the stall, so the stall speed increases.