For any airplane to fly, you must lift the weight of the airplane itself, the fuel, the passengers, and the cargo. The [?]s generate most of the lift to hold the plane in the air. To generate lift, the airplane must be pushed through the air. The [?] , which are located beneath the [?], provide the thrust to push the airplane forward through the air. The air resists the motion in the form of aerodynamic drag . Some airplanes use propellers for the propulsion system instead of jets.
To control and maneuver the aircraft, smaller [?] are located at the tail of the plane. The tail usually has a fixed horizontal piece (called the [?]) and a fixed vertical piece (called the [?]). The stabilizers' job is to provide stability for the aircraft, to keep it flying straight. The [?] keeps the nose of the plane from swinging from side to side, while the [?] prevents an up-and-down motion of the nose. (On the Wright brother's first aircraft, the [?] was placed in front of the wings. Such a configuration is called a canard after the French word for "duck").
At the rear of the [?] and [?] are small moving sections that are attached to the fixed sections by hinges. In the figure, these moving sections are colored brown. Changing the rear portion of a [?] will change the amount of force that the [?] produces. The ability to change forces gives us a means of controlling and maneuvering the airplane. The hinged part of the [?] is called the [?]; it is used to deflect the tail to the left and right as viewed from the front of the [?]. The hinged part of the [?] is called the [?]; it is used to deflect the tail up and down. The outboard hinged part of the wing is called the [?]; it is used to roll the [?] from side to side. Most airliners can also be rolled from side to side by using the [?]. [?] are small plates that are used to disrupt the flow over the wing and to change the amount of force by decreasing the lift when the [?] is deployed.
The wings have additional hinged, rear sections near the body that are called [?]. [?] are deployed downward on takeoff and landing to increase the amount of force produced by the wing. On some aircraft, the front part of the wing will also deflect. [?] are used at takeoff and landing to produce additional force. The [?] are also used during landing to slow the plane down and to counteract the [?] when the aircraft is on the ground. The next time you fly on an airplane, notice how the wing shape changes during takeoff and landing.
The [?] or body of the airplane, holds all the pieces together. The pilots sit in the [?] at the front of the [?]. Passengers and cargo are carried in the rear of the [?]. Some aircraft carry fuel in the [?]; others carry the fuel in the [?].
As mentioned above, the aircraft configuration in the figure was chosen only as an example. Individual aircraft may be configured quite differently from this airliner. The Wright Brothers 1903 Flyer had pusher propellers and the [?] at the front of the aircraft. Fighter aircraft often have the [?] buried inside the [?] instead of in pods hung beneath the [?]. Many fighter aircraft also combine the [?] and [?] into a single stabilator surface. There are many possible aircraft configurations, but any configuration must provide for the four forces needed for flight.