The spoiler surfaces prevent lift when the aircraft is on the ground, for ground lift dumping, roll aid, and speed braking. The spoilers include the ground spoilers and the multi-function spoilers.

There are six spoilers on each side of the aircraft. They are installed on the top trailing edge of the wing from inboard to outboard.

Two ground spoilers are installed on the top surface of the trailing edge of each wing above the inboard flap. They are used for ground lift dumping when the aircraft touches the ground or during a rejected takeoff. The ground spoilers include the inboard ground spoiler and the outboard ground spoiler. Each ground spoiler is made of a phenolic sheet, three support fittings, and a honeycomb core. The top and bottom skin panels, made of graphite laminations, are the covers for the ground spoilers.

There are four multifunction spoilers on each wing. Two multifunction spoilers are installed on the top surface of the trailing edge of each wing above the middle flap. Two more multifunction spoilers are installed on the top surface of the trailing edge of each wing above the outboard flap. The multifunction spoilers supply roll control to help the ailerons during landing of the aircraft. They are also used to prevent lift when the aircraft is in flight. When the aircraft is on the ground, the multifunction spoilers are used like the ground spoilers to prevent lift. The multifunction spoilers can also be used as speed brakes.

The multifunction spoilers help the ailerons to control roll, especially during crosswind landings. They are also used as an alternative to the ailerons if the ailerons do not operate correctly. The multifunction spoilers can also be symmetrically controlled by the pilot, to be used as the speed brakes, through the flight-spoiler control lever. The spoilers supply ground lift dumping when the aircraft is on the ground; they are automatically retracted/extended at the same time as the ground spoilers.

Support Fittings

The spoilers are made of a phenolic sheet, three support fittings, and a honeycomb core. The top and bottom skin panels are made of graphite laminations. Each spoiler has three support fittings that are attached to the auxiliary or rear spar of each wing. All the support fittings are made from aluminum alloy. The outboard support fittings of each spoiler has bushings installed in the hinge pivot points. The center and inboard support fittings of each spoiler and the outboard support fittings of the inboard ground spoiler have spherical bearings. The center support fittings are also the attachment points for the power control units (PCUs).