One of the first things you are likely to notice during a visit to your local airport is the wide variety of airplane styles and designs. Although, at first glance, you may think that airplanes look quite different from one another, you will find that their major components are quite similar.
The fuselage serves several functions. Besides being a common attachment point for the other major components, it houses the cabin, or cockpit, which contains seats for the occupants and the controls for the airplane. The fuselage usually has a small baggage compartment and may include additional seats for passengers.
When air flows around the wings of an airplane, it generates a force called “lift” that helps the airplane fly. Wings are contoured to take maximum advantage of this force. Wings may be attached at the top, middle, or lower portion of the fuselage. These designs are referred to as high, mid-and low-wing respectively. The number of wings can also vary. Airplanes with single-set of wing’s are referred to as monoplanes, while those with two sets are called biplanes.
To help you fly the airplane, the wings have two types of control surfaces attached to the rear, or trailing edges. They are referred to as ailerons and flaps. Ailerons extend from about the midpoint of each wing outward to the tip. They move in opposite directions – when one aileron goes up, the other goes down. Flaps extend outwards from the fuselage to the midpoint of each wing. They always move in the same direction. If one flap is down, the other is down.
The empennage consists of the vertical stabilizer, or fin, and the horizontal stabilizer. These two surfaces are stationary and act like feathers on an arrow to steady the airplane and help you maintain a straight path through the air.
The rudder is attached to the back of the vertical stabilizer. You use it to move the airplane’s nose left and right. Actually, you use the rudder and ailerons in combination during flight to initiate a turn.
The elevator is attached to the back of the horizontal stabilizer. During flight, you use it to move the nose up and down so you can direct the airplane to the desired altitude, or height.
Most airplanes have a small, hinged section at the back of the elevator called a trim tab. Its purpose is to relieve the pressure you must hold on the control wheel to keep the nose in the desired position. In most small airplanes, you control the trim tab with a wheel or crank in the cockpit. Your flight instructor will direct you in the proper use of the trim control for the airplane you are flying.
Some empennage designs vary from the type of horizontal stabilizer just discussed. They have a one-piece-horizontal stabilizer that pivots up and down from a central hinge point. This type of design called a stabilator requires no elevator. You move the stabilator using the control wheel just as you would the elevator. When you pull back, the nose moves up; when you push forward, the nose moves down. An antiservo tab is mounted at the back of the stabilator, to provide you with a control “feel” similar to what you experience with an elevator. Without the antiservo tab, control forces from the stabilator would be so light that you might “overcontrol” the airplane or move the control wheel too far to obtain the desired result. The antiservo tab also functions as a trim tab.
The landing gear absorbs landing loads and supports the airplane on the ground. It typically is made up of three wheels. The two main wheels are located on either side of the fuselage. The third may be positioned either at the nose or at the tail. If it is located at the tail, it is called a tailwheel. In this case, the airplane is said to have conventional landing gear.
Conventional gear is common on older airplanes, as well as on some new ones. It is desirable for operation on unimproved fields, because of the added clearances between the propeller and the ground. However, airplanes with this type of gear are more difficult to handle during ground operations.
When the third wheel is located on the nose, it is called a nosewheel. This design is referred to as tricycle gear. An airplane with this type of gear has a steerable nosewheel, which you control through the use of the rudder pedals.
Landing gear can also be classified as either fixed or retractable. Fixed gear always remains extended, while retractable gear can be stowed for flight to reduce resistance and increase airplane performance.
Just as you need shock absorbers on your car, you need some shock absorbing device on the landing gear. Shock struts are designed for this purpose. They absorb bumps and jolts, as well as the downward force of landing.
Airplane brakes operate on the same principle as automobile brakes, but they do have a few significant differences. For example, airplane brakes usually are located on the main wheels, and are applied by separate pedals. Because of this you can operate the brakes on the left independently of the brake on the right, or vice versa. This capability is referred to as differential braking. It is important during ground operations when you need to supplement nosewheel steering by applying brakes on the side towards the direction of turn. In fact, differential braking is extremely important on conventional gear airplanes, since some do not have a steerable wheel. Airplane brakes usually are located only on the main wheels and may be operated independently from one another.
THE POWER PLANT
In small airplanes, the power plant includes both the engines 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. A firewall is located between the engine compartment and the cockpit to protect the occupants. The firewall also serves as a mounting point for the engine.
The engine drives the propeller which, in turn, produces thrust. It also provides electrical power, a vacuum source, and heat for the cabin.
Courtesy of: Private Pilot Manual, Jeppesen Sanderson, CO, USA, 1991