Flap retracted Flap extended Actuator Hinge point Retractable nose Fore flap Mid flap Aft flap Retracted 1-30 Figure 1-64.  Triple-slotted flap.  Figure 1-65.  Leading edge flaps.  Spoilers are made with similar construction materials and  techniques as the other flight control surfaces on the aircraft.  Often, they are honeycomb-core flat panels. At low speeds,  spoilers are rigged to operate when the ailerons operate to  assist with the lateral movement and stability of the aircraft.  On the wing where the aileron is moved up, the spoilers  also raise thus amplifying the reduction of lift on that wing.  [Figure 1-68]  On the wing with downward aileron deflection,  A spoiler is a device found on the upper surface of many  heavy and high-performance aircraft. It is stowed flush to  the wing’s upper surface. When deployed, it raises up into  the airstream and disrupts the laminar airflow of the wing,  thus reducing lift.  Another leading edge device which extends wing camber is  a slat. Slats can be operated independently of the flaps with  their own switch in the cockpit. Slats not only extend out  of the leading edge of the wing increasing camber and lift,  but most often, when fully deployed leave a slot between  their trailing edges and the leading edge of the wing.  [Figure 1-67]  This increases the angle of attack at which  the wing will maintain its laminar airflow, resulting in the  ability to fly the aircraft slower with a reduced stall speed,  and still maintain control.  Heavy aircraft often have leading edge flaps that are used  in conjunction with the trailing edge flaps.  [Figure 1-65] They can be made of machined magnesium or can have an  aluminum or composite structure. While they are not installed  or operate independently, their use with trailing edge flaps  can greatly increase wing camber and lift. When stowed,  leading edge flaps retract into the leading edge of the wing. An enhanced version of the fowler flap is a set of flaps  that actually contains more than one aerodynamic surface.  Figure 1-64  shows a triple-slotted flap. In this configuration,  the flap consists of a fore flap, a mid flap, and an aft flap.  When deployed, each flap section slides aft on tracks as it  lowers. The flap sections also separate leaving an open slot  between the wing and the fore flap, as well as between each  of the flap sections. Air from the underside of the wing flows  through these slots. The result is that the laminar flow on the  upper surfaces is enhanced. The greater camber and effective  wing area increase overall lift. The differing designs of leading edge flaps essentially  provide the same effect. Activation of the trailing edge  flaps automatically deploys the leading edge flaps, which  are driven out of the leading edge and downward, extending  the camber of the wing.  Figure 1-66  shows a Krueger flap,  recognizable by its flat mid-section. Fowler flaps not only lower the trailing edge of the wing when  deployed but also slide aft, effectively increasing the area of the  wing.  [Figure 1-63C]  This creates more lift via the increased  surface area, as well as the wing camber. When stowed, the  fowler flap typically retracts up under the wing trailing edge  similar to a split flap. The sliding motion of a fowler flap can  be accomplished with a worm drive and flap tracks. A split flap is normally housed under the trailing edge of the  wing.  [Figure 1-63B]  It is usually just a braced flat metal  plate hinged at several places along its leading edge. The  upper surface of the wing extends to the trailing edge of the  flap. When deployed, the split flap trailing edge lowers away  from the trailing edge of the wing. Airflow over the top of the  wing remains the same. Airflow under the wing now follows  the camber created by the lowered split flap, increasing lift. of the flap essentially the trailing edge of the wing. The plain  flap is hinged so that the trailing edge can be lowered. This  increases wing camber and provides greater lift.  Slats  Spoilers and Speed Brakes