Aeroplanes might seem like sleek shells that effortlessly skim through the sky. But, up close, they’re a fascinating, complicated world of perfectly engineered mechanical systems and components that make powered flight a safe and efficient reality.
Understanding the important mechanical components of aeroplanes is a fundamental part of any aviation course or career, and whether you’re studying for a Diploma of Aviation in Australia or just curious about aircraft, you’ll be interested in learning more about how planes are put together.
The Fuselage: The Backbone of the Aircraft
The fuselage is the main body of an aircraft, joining the wings, tail, and landing gear to create the main structure. It also forms the cockpit for the pilot and co-pilot as well as space for passengers, cargo, and sometimes fuel tanks and avionics systems.
On traditional aircraft, the fuselage is built up using a truss-type construction, though most modern commercial and general aviation planes have semi-monocoque fuselages. The fuselage must be strong enough to contain pressurisation, but also hold the control linkages and wiring while remaining stable in flight.
Wings: Generators of Lift and Stability
The wings of an aircraft are among the most important mechanical components in an aeroplane as it is the wings that create lift, enabling the aircraft to take off and stay in the sky. The aerofoil shape of the wings manipulates airflow over and under their surfaces to generate lift.
In addition to lift, the wings also contain moving control surfaces, such as ailerons and flaps. These serve to change the performance of the aeroplane, helping it to bank left and right or increase lift during takeoff and landing. Aircraft designers often install spoilers on the wings, too, which reduce lift as the aircraft descends.
Flight control surfaces on the wings are typically ailerons. These are hinged surfaces, usually near the wingtip, which lower or raise to help the plane turn or roll. Flaps, on the other hand, are found closer to the fuselage and are extended down to increase the surface area of the wing and generate more lift at low speeds.
In addition to their main function of creating lift, the wings can also hold fuel and contain structural spars to keep the wings stable while bearing aerodynamic loads. For commercial pilot training students, understanding wings and how they work is vital to learning the rest of the aircraft systems, as they play a key role in lift, control, and balance throughout all phases of flight.
Empennage: The Tail That Steers and Stabilises
The empennage is the tail of the aircraft and, just like the wings, is a critical mechanical component of aeroplanes, providing both stability and control. It is located at the rear of the fuselage and is usually made up of a vertical stabiliser with a rudder and a horizontal stabiliser with elevators.
The rudder helps the aircraft steer left or right, while the elevators control the pitch (angle of the nose). Some aircraft have a single-piece moving stabilator in place of the elevators to allow for faster pitch response.
In the absence of a tail, airflow disturbance could make the aircraft susceptible to uncontrollable oscillations or other forms of instability.
Landing Gear: Strength on the Ground
The landing gear is another one of the mechanical components of an aeroplane, which, while not involved in the aerodynamics of the flight process, is critical to the aircraft’s operation on the ground. Landing gear is what supports the aircraft on the ground, keeping it steady while taxiing, takeoff and landing.
Most aircraft use a tricycle landing gear arrangement, which means a nosewheel and two main wheels under the fuselage or wings. Landing gear must be able to absorb the high impact forces generated during landing, which is usually achieved through a shock-absorbing mechanism, called an oleo strut.
Oleo struts work using a combination of compressed air and hydraulic fluid to provide a cushion against impact. Larger, faster aircraft use retractable landing gear that folds into bays during flight to improve aerodynamic efficiency.
Landing gear also houses the braking mechanism, which is used to stop the aircraft within the available runway space. Braking systems are a major aircraft safety feature for pilots and ground crew and, in some planes, incorporate anti-skid technology for better control in wet or short runway conditions.
Propulsion: Creating Thrust
The propulsion system of an aircraft is responsible for generating the thrust that powers the aircraft through the air. Light aircraft commonly use piston engines to power a propeller, which drives the plane forward. Propulsion systems work by burning fuel and converting the resulting chemical energy into mechanical energy (rotation of the propeller).
Commercial and high-performance aeroplanes make use of turbine engines, either turboprops (turbine-powered propellers) or turbofans. Turbofans are the most common type of engine on jet airliners. Turbofans compress air and mix it with fuel to create a high-speed stream of exhaust gases for thrust.
Piston and turbine engines both have many components and systems that support their operation, such as fuel pumps, cooling systems, ignition, and instrumentation to monitor temperature, pressure, and RPM.
To the untrained eye, aeroplanes are like beautifully sculpted shells whose business is to cut through the sky at breathtaking speed and power. But when you look beyond their aerodynamic surfaces and roaring engines, there’s a complex mechanical ecosystem at work.
Engineered to precise tolerances and working together in near-perfect harmony, the numerous mechanical components of aeroplanes are as diverse and interesting as they are innumerable. Even just learning about the basics of a few key systems is an essential part of commercial pilot training and builds a strong technical foundation for would-be pilots.