How many spoiler panels are on each wing and what are their functions?

• A. Two panels: one ground spoiler, one for roll control
• B. Three panels: inboard for ground spoiler only; midboard and outboard for roll control, ground spoiler and speed brake
• C. Four panels: all for speed brake
• D. Three panels: all identical function

Answer: (B)

Spoilers are surface panels that disrupt lift to help slow the airplane, assist in roll control, and provide a deceleration method in flight. On this aircraft, there are three spoiler panels on each wing. The innermost panel is dedicated to ground spoiler function and deploys only when the airplane is on the ground to unload the wing and maximize braking effectiveness. The middle and outer panels are multifunction: they can be used for roll control by deploying differentially, and in flight they can act as a speed brake to slow the aircraft as well as function as lift dumpers during landing. This arrangement gives a dedicated lift-dump capability on touchdown while still providing effective roll control and deceleration in flight.