Editing Biplane (section)

=== Rigging ===
{{main|Bracing (aeronautics)#Rigging}}
Because most biplanes do not have [[cantilever]] structures, they require rigging wires to maintain their rigidity. Early aircraft used simple wire (either braided or plain), however during the First World War, the British [[Royal Aircraft Factory]] developed airfoil section wire named RAFwire in an effort to both increase the strength and reduce the drag. 
Four types of wires are used in the biplane wing structure. Drag wires inside the wings prevent the wings from being folded back against the fuselage, running inside a wing bay from the forward inboard corner to the rear outboard corner.<ref name=GunstonP210>Gunston, 2004, p.210</ref> Anti-drag wires prevent the wings from moving forward when the aircraft stops and run the opposite direction to the drag wires.<ref name=GunstonP51>Gunston, 2004, p.51</ref> Both of these are usually hidden within the wings, and if the structure is sufficiently stiff otherwise, may be omitted in some designs. Indeed many early aircraft relied on the fabric covering of the wing to provide this rigidity, until higher speeds and forces made this inadequate. 
Externally, lift wires prevent the wings from folding up, and run from the underside of the outer wing to the lower wing root.<ref name=GunstonP382>Gunston, 2004, p.382</ref> Conversely, landing wires prevent the wings from sagging, and resist the forces when an aircraft is landing, and run from the upper wing centre section to outboard on the lower wings.<ref name=GunstonP375>Gunston, 2004, p.375</ref> Additional drag and anti-drag wires may be used to brace the cabane struts which connect the fuselage to the wings, and interplane struts, which connect the upper and lower wings together.