Figure 3-6.  Monoplane (left) and biplane (right).  Figure 3-7.  Wing components.  3-5  Attached to the rear, or trailing edges, of the wings are two  types of control surfaces referred to as ailerons and flaps.  Ailerons extend from about the midpoint of each wing  outward toward the tip, and move in opposite directions to  create aerodynamic forces that cause the airplane to roll.  Flaps extend outward from the fuselage to near the midpoint  of each wing. The flaps are normally flush with the wing’s  surface during cruising flight. When extended, the flaps move  simultaneously downward to increase the lifting force of the  wing for takeoffs and landings.  [Figure 3-8]  operation for which an aircraft is intended and is tailored  to specific types of flying. These design variations are  discussed in Chapter 5, Aerodynamics of Flight, which  provides information on the effect controls have on lifting  surfaces from traditional wings to wings that use both flexing  (due to billowing) and shifting (through the change of the  aircraft’s CG). For example, the wing of the weight-shift  control aircraft is highly swept in an effort to reduce drag  and allow for the shifting of weight to provide controlled  flight.  [Figure 3-9]  Handbooks specific to most categories  of aircraft are available for the interested pilot and can be  found on the Federal Aviation Administration (FAA) website  at www.faa.gov.  Alternate types of wings are often found on aircraft. The  shape and design of a wing is dependent upon the type of  Alternate Types of Wings  Aileron  Fuel tank  Wing tip  Wing flap  Ribs  Stringers  Spar  Skin 