Types Of an Aircraft #Piston Engine #Turboprop #Jet Engine


Types Of an Aircraft

by Pragati Agrawal MBA

a)  Piston Engine Aircraft

b)  Turboprop Aircraft

c)  Jet Engine Aircraft

a)  Piston Aircraft :- An Aircraft piston engine, also commonly referred to as a reciprocating engine or "recip", is an internal combustion engine that uses one or more reciprocating pistons to convert pressure into 

a rotational motion.The Aircraft piston engine operates on the same principles as the engines found in most automobiles. However, modifications, such as dual ignition systems, to improve redundancy and safety,

and air cooling to reduce weight, have been incorporated into engines designed for aviation use. Turbochargers and, less commonly, superchargers can be added to piston engines to improve performance. 

Aircraft piston engines are most commonly fueled with AVGAS but diesel fueled engines are becoming more common, especially in light Aircraft.

Types of Piston Engine Aircraft :- Engine design has varied tremendously in the century that has passed since the first powered flight. Most engines installed in current generation Aircraft are of the horizontally 

opposed configuration. However, there are examples of virtually all of the following engine types still being flown in production, experimental and vintage Aircraft.

1) In-Line Engines

The earliest Aircraft engines were of the in-line or "straight" variety and had the cylinders in a line, similar to many automotive engines. The main advantage to this engine type is that it is narrow and allows the

 Aircraft to have a narrow front fuselage. However, airflow around this engine type is inadequate to allow air cooling so liquid cooling is required thus reducing the power to weight ratio.

2) Rotary Engines

Rotary piston engines were developed during World War I for military Aircraft. In this design, the entire engine rotates with the propeller, creating additional airflow for cooling.

3) V-Type Engines

A V-type engine is basically the equivalent of two in-line engines joined in a "V" configuration by a common crankshaft. The best known example of a V-type engine is the supercharged Rolls Royce Merlin that 

was used to power both the Supermarine Spitfire and the Avro Lancaster.

4) Radial Engines

A radial piston engine consists of one or more rows of odd-numbered cylinders arranged in a circle around a central crankshaft. Due to the small size of the crankcase, this engine type had a better power to weight 

ratio than most other designs of their day. The cylinder arrangement allowed for good cooling airflow and smooth operation.

5) Horizontally Opposed Engines

Horizontally opposed engines are often referred to as boxer or flat engines. They have two banks of cylinders staggered on opposite sides of a central crankcase. The design is simple, reliable and easy to maintain.

b)  Turboprop Aircraft :-  Turboprop Aircraft have one or more gas-turbine engines connected to a gearbox that turns the propeller(s), to move the Aircraft on the ground and through the air. Turboprop Aircraft burn 

Jet-A fuel, are frequently larger than piston-powered Aircraft, can carry more payload and passengers than their piston-powered counterparts and can typically fly higher than pistons, at altitudes up to 35,000 feet. Turboprop Aircraft have 

lower operating costs than jets because they burn less fuel, but they are also slower than jets. Turboprops are an attractive option for businesses that need to fly missions requiring 600-1,000 miles of travel 

between general aviation airports that often have runways too short to accommodate jets. These Aircraft vary in size, but the interior of a typical turboprop is the size of a large SUV, seats 6-8 people, and is 

often configured similar to a small office, where co-workers can meet and make productive use of time en route to a destination.

Manufacturers of turboprop Aircraft include the following companies:







c) Jet Aircraft :-  A Jet Engine is a reaction engine - that is, an engine which provides propulsion or thrust by expelling a reaction mass - and works in accordance with Newton's third law of motion: 

"For every action (force) there is an equal and opposite reaction (force)".

Most jet engines used in aviation are air breathing, axial flow, gas turbine engines. A gas turbine is a rotary engine that extracts energy from a flow of combustion gases. Ambient air is drawn into the engine 

intake where an axial or a centrifugal compressor (or both) increases both the pressure and temperature of the air before feeding it into the combustion chamber. In the combustion chamber, fuel is added to the 

hot, compressed air and ignited. Once ignition has occurred, it is self sustaining as the constant flow of air and fuel provide for continuous combustion. A high energy exhaust stream (reaction mass), produced by

 burning fuel/air mixture, leaves the combustion chamber passing through one or more turbines which serve to drive the compressor(s). The remaining exhaust gas is ejected through a nozzle providing thrust 

(force) to propel the Aircraft forward.

1. Turboprop Engine :-  The turboprop engine is a turbojet engine that uses a gearing system to connect to the Aircraft propeller. The gearbox of an Aircraft comes with a turbojet that spins the shaft attached to it. 

The gearbox slows down the spinning shafts to allow the gear to connect to the propeller. As with Cessna 172, the propeller rotates through the air to produce thrust.

2. Turbojet Engine :-  The concept of the turbojet Aircraft engine is simple. It entails taking air in from the engine’s rear side and then compressing it in the compressor. But fuel has to be added to the 

combustion chamber and burned to raise the fluid mixture temperature to about 1000 degrees.

The hot Air that is produced is then pushed through a turbine that rotates the compressor. The pressure at the discharge of the turbine should be twice the pressure in the atmosphere. However, that depends on

 the efficiency level of an Aircraft engine. The excessive pressure then moves to the nozzle that then generates gas streams, which are responsible for creating a thrust.

3. Turboshaft Engine :-  The turboshaft engine is a form of gas-powered turbine that operates the same as a turboprop engine. But unlike a turboprop engine, turboshaft engines don’t drive a propeller. Instead,

 it is used in helicopters to provide power to the rotor.

Turboshaft engines are designed in a way that makes the speed of a helicopter rotor to rotate independently of the gas generator’s speed. That allows the speed of a helicopter rotor to remain constant even 

when the gas generator’s speed declines. It also modulates the power that a helicopter produces.

4. Turbofan Engine :-  Turbofan jet engines are equipped with a massive fan at the front for sucking in air. For turbofan jet engines, most of the air flow around the exterior of an Aircraft engine to give the plane

 more thrust even at low speeds and make it quiet.

Turbofan jet engines are powering most of todays airliners. All the air that enters the intake of a turbofan jet engine flows through the generator that produces the hot air. This generator comprises of a turbine, 

combustion chamber, and compressor. Only a small percentage of the air that passes through the turbofan engine reaches all the way to the combustion chamber.

5. Ramjet Engine :-  Unlike other engines, the ramjet does not develop static thrust; instead, it generates little thrust below the speed of the sound. That means an Aircraft running on a ramjet engine requires 

assistance when taking off, which could be in the form of another Aircraft. The ramjet engine has been used in space vehicles and several guided-missile systems.

Pragati Agrawal MBA 

Business Analyst

AirCrews Aviation Pvt. Ltd.