Wings | Tail | The Engines | Landing Gear | Flight Controls | Helicopters | Vertical Take-off | Specialised Craft | Aerodynamics in Nature
The main structural components of modern aircraft are the fuselage, wings, the tail, the engines and landing gear. The movie below shows all the main parts of the basic light aircraft.
F u s e l a g e
The fuselage is the main body structure to which the wings, tail, landing gear, and power plants are attached. It contains the cockpit or flight deck, passenger compartment, cargo/luggage compartment, the engines and fuel tanks.
The wing is the most important lift-producing part of an aircraft. Wing designs vary, depending on the aircraft type and purpose. Propeller-driven aircraft normally have an all-metal straight wing with a thick curvature (camber). Jet transports have swept-back wings of medium camber that lower drag and improve performance at high airspeeds. Both straight and swept-wing aircraft normally have ailerons attached to the outermost edges of the wing. When one of these ailerons goes up, the other goes down. Their purpose is to to increase or decrease lift on their wing in order to turn the aircraft. The wing also has flaps along the edge of the wing (also known as the trailing edge). Flaps increase aerodynamic lift and drag and are used during takeoff and landing to increase lift at low speeds. Flaps can be used as an airbrake to slow down to aeroplane. Modern swept-wing transport aircraft also have high lift devices called leading-edge slats, which work with the flaps to further increase the lifting capability of the wing. The angle of the wings causes a bank or a turn. When you are flying level, lift is created in an upward direction at right angles (90º) to the wing. When the wings are at an angle the lift is still in an upward direction, BUT the wings are now not at a right angle and the tip of the wing will receive the most lift and the plane will turn.
(Above) The different types of wing shapes according to the purpose of the craft. From left to right : Commercial craft, fighters, and light aircraft. On the last picture notice the flaps on the wing.
An aircraft is only able to fly when the lift, or upward force generated by the wing, is larger than the aircraft's total weight. The most important element in a wing's ability to produce lift is its cross-sectional shape. Early aerodynamic research on kites and gliders showed that a flat plate would produce lift, but even more lift could be produced if the plate was tilted slightly into the wind. If the leading edge (front) of the flat plate was rounded and the trailing edge (back) narrowed to streamline the wing, drag could be reduced. By increasing the curve of the top surface of the wing, while flattening the lower surface, lift could be dramatically improved. The length of a wing is known as its wingspan. As the wingspan increases so does the amount of lift it creates. This is because there is more area over which Bernoulli’s Law can act.
Wind tunnels, which are used extensively in airfoil (shape of the wing) research, have made the collection of a large amount of data on airfoil types and design easy.
The tail provides stability and control for the aircraft and is mounted on the back of the fuselage. It consists of two main parts: the vertical stabilizer, or fin, to which the rudder is attached; and the horizontal stabilizer, to which the elevator is connected. The rudder works with the ailerons to make synchronized turns, while the elevator is used to climb or descend.
The many aircraft propulsion systems include those which use a propeller, turbine (turboprop) engines and propellerless systems that use the energy of rapidly expanding gases as propulsion. The turbojet and the turbofan are the most widely used commercial jet engines, and turbine engines are still used extensively in light aircraft. Jet engines are normally attached to the wing or aft fuselage on pylons (extensions on the wing), but occasionally they are imbedded in the wing next to the fuselage. On many fighter / bomber aircraft they are mounted in the fuselage to reduce drag and improve performance.
(Above) The different types of powerplants. From left to right : Turbofans, jet engines, propeller engines both foward and on the wing.
Engine-propeller combinations on single-engine aircraft are usually found in the nose, or forward-most, part of the fuselage and pull the aircraft through the air. If there are two or more engine-propeller combinations, they are mounted on the wing, but they stick out of the leading edge.
Turbojet engines are the most effecient at high altitudes (above 7,600 m / 25,000 ft); turboprops at mid altitudes (4,500 - 7,600 m/15 - 25,000 ft); and rotor engines at low altitudes (sea level - 4,500m/15,000 ft).
There are two types of landing gear, namely:
Fixed Landing Gear
Retractable Landing Gear
(Above) The two types of landing gear, retractable and fixed landing gear
Fixed gear consists of a simple design of bars, wheels, and brakes that are not retractable (cannot be pulled in) into the wings or fuselage. Fixed gear is usually found on small, light aircraft. Because this gear cannot be retracted it reduces the risk of problems at landing, but it does create extra drag during flight.
Retractable gear is used on more complex aircraft. The landing gear is attached to motors which lower it before landing. Because the landing gear is stored in the belly of the plane during flight, it causes no extra drag. Since it reduces drag, it increases the length of flight significantly.
The controls of a small aircraft move it on the ground and in the air. The control wheel is found in front of the pilots chair and may be pushed forward or pulled back to move the tail elevators. Pushing forward causes the nose of the plane to point down and pulling back causes it to point upwards. The control wheel also changes the position of the ailerons. The movements of the rudder are controlled from foot pedals in front of the pilot's seat. The pedals activate the wheel brakes when the plane is on the ground. The flaps are controlled by either hydraulics (system of pistons) or by electric motors. A throttle controls engine thrust, which gives the aeroplane speed.
(Above) The cockpit of a light aircraft
"
In the space age, man will be able to go around the world in two hours -- one hour for
flying and one hour to get to the airport.
Neil McElroy