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##  Wing Systems 

##  Refl ex Systems 

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] 

##  Pitch Control System 

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 

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