Washout Strut Washout Strut Sprog Figure 3-15.  View inside wing showing top wire coming though  sail that is reinforced, being attached to the crossbar by a tang, an  aircraft bolt, washers, and lock nut. Figure 3-16. Reflex cables. Figure 3-17. Washout struts. Figure 3-18. Sprogs for strutted wing.  Wing Systems  Refl ex Systems   Pitch Control System  As discussed in the aerodynamics section, the trailing edge  near the root and the tips must stay up during unusually low or  negative angles of attack  [Figure 2-29]  to maintain a positive  pitch stability for the aircraft. There are a number of refl ex  systems used to accomplish this in emergency situations.  Reflex cables—most wings with a king post use cables to  hold the trailing edge up at unusually low or negative angles  of attack. These reflex cables are secured to the top of the  king post and attach to several positions on the trailing edge  where the battens are located. Different manufacturers have  different positions where these are attached, depending on  the design of the wing. Reflex cables also provide additional  reflex at high speeds because the drag of the wires pulls up  the trailing edge, creating more reflex at these higher speeds.  [Figure 3-16] Washout struts—tubes near the tips that keep the tip trailing  edge up during very low or negative angles of attack. They  can be inside or outside the double surface of a wing. The  reflex cables may not go to the wingtip, so washout struts  are used to hold up the trailing edge at the tip at very low  and negative angles of attack.  [Figure 3-17] Sprogs—for wings using struts with no king post, sprogs  are used to keep the inboard trailing edge up in place of the  reflex cables. A wire attached to the top of the leading edge  holds the sprog up in place.  [Figure 3-18] The pitch control system is a simple hinge on the keel at the  hang point that allows the pilot to push the control bar out and  3-8