Additional Components.

We've already seen the major parts of a typical plane, but a few important items were left out for simplicity. Let's go back and discuss a few of these items.

1. Flap: Flaps are usually located along the trailing edge of both the left and right wing, typically inboard of the ailerons and close to the fuselage. Flaps are similar to ailerons in that they affect the amount of lift created by the wings. However, flaps only deflect downward to increase the lift produced by both wings simultaneously. Flaps are most often used during takeoff and landing to increase the lift the wings generate at a given speed. This effect allows a plane to takeoff or land at a slower speed than would be possible without the flaps. In addition to flaps on the trailing edge of a wing, a second major category is flaps on the leading edge. These leading-edge flaps, more often called slats, are also used to increase lift.

2. Cabin & cockpit: Sometimes these two terms are used synonymously, but most of the time the term cockpit is applied to a compartment at the front of the fuselage where the pilots and flight crew sit. This compartment contains the control yokes (or sticks) and equipment the crew use to send commands to the control surfaces and engines as well as to monitor the operation of the vehicle. Meanwhile, a cabin is typically a compartment within the fuselage where passengers are seated.

3. Nose & main gear: The landing gear is used during takeoff, landing, and to taxi on the ground. Most planes today use what is called a tricycle landing gear arrangement. This system has two large main gear units located near the middle of the plane and a single smaller nose gear unit near the nose of the aircraft.

4. Trim tab: " Trim tab" is located on the elevator. These control tabs may be located on other surfaces as well, such as a rudder control tab or a balance tab on the aileron. Nonetheless, the purpose of all these tabs is the same. In the previous section, we discussed that the horizontal stabilizer and elevator are used to provide stability and control in pitch. In order to keep a plane in a steady, level orientation, the elevator usually has to be deflected by some small amount. Since it would be very tiring for a pilot to physically hold the control stick in position to keep the elevator at that deflection angle for an entire flight, the elevator is fitted with a small " tab" that creates that elevator deflection automatically. The trim tab can be thought of almost as a " mini-elevator." By deflecting the tab up or down, it increases or decreases the downforce created by the elevator and forces the elevator to a certain position. The pilot can set the deflection of the trim tab which will cause the elevator to remain at the deflection required to remain trimmed.

Slat: A slat is a thin airfoil deployed form the leading edge of the wing. This acts as a new little wing, but it's objective is not to produce lift but to generate the circulation needed for it. Slat circulation will be opposite to wing circulation reducing the highest speed of the boundary layer. This reduces the maximum lift also, making its distribution along the wing softer, but allowing the boundary layer to detach later (by reducing the adverse pressure generated in the trailing edge). Usually, slats are used with flaps during take off and landing operations as both produce extra lift at low speed.

Spoiler: Spoilers are not used for generating lift but for reducing it. They are moving surfaces which are placed vertically across the airfoil. This produces the detachment of the boundary layer before than usual as an adverse pressure is generated. These devices are not very common in piston engine or turboprop airplanes but in turbojet airplanes and gliders. Spoilers are used mainly after touch down (landing) and rarely used during the descend and approach

Landing gear: The landing gear is the principle support of the airplane when parked, taxiing, taking off, or when landing. The most common type of landing gear consists of wheels, but airplanes can also be equipped with floats for water operations, or skis for landing on snow.The landing gear consists of three wheels — two main wheels and a third wheel positioned either at the front or rear of the airplane. Landing gear employing a rear mounted wheel is called conventional landing gear. Airplanes with conventional landing gear are sometimes referred to as tail wheel airplanes. When the third wheel is located on the nose, it is called a nose wheel, and the design is referred to as a tricycle gear. A steerable nose wheel or tail wheel permits the airplane to be controlled throughout all operations while on the ground.

The powerplant: The powerplant usually includes both the engine and the propeller. The primary function of the engine is to provide the power to turn the propeller. It also generates electrical power, provides a vacuum source for some flight instruments, and in most single-engine airplanes, provides a source of heat for the pilot and passengers. The engine is covered by a cowling, or in the case of some airplanes, surrounded by a nacelle.The purpose of the cowling or nacelle is to streamline the flow of air around the engine and to help cool the engine by ducting air around the cylinders. The propeller, mounted on the front of the engine, translates the rotating force of the engine into a forward acting force called thrust that helps move the airplane through the air. The propeller may also be mounted on the rear of the engine as in a pusher-type aircraft. A propeller is a rotating airfoil that produces thrust through aerodynamic action. A low pressure area is formed at the back of the propeller’s airfoil, and high pressure is produced at the face of the propeller, similar to the way lift is generated by an airfoil used as a lifting surface or wing. This pressure differential pulls air through the propeller, which in turn pulls the airplane forward.