Which of the following is a valid flight spoiler deflection angle when flaps are full?

• A. 12.5°
• B. 17.5°
• C. 22.5°
• D. 27.5°

Answer: (B)

When the wings are set with full flaps, the spoilers must work in a way that both reduces lift effectively and keeps airplane control within safe limits. The system specifies a maximum flight spoiler deflection of 17.5 degrees in this configuration. That angle hits the sweet spot: it provides enough lift dump and drag to help slow and seat the airplane without overloading the wing structure, interfering with flap mechanisms, or upsetting pitch and roll stability. Angles smaller than this may not give adequate lift reduction, while larger angles could introduce excessive drag, destabilizing moments, or exceed actuator limits. So, 17.5 degrees is the appropriate spoiler deflection when flaps are full.