Aircraft engine

As of 2025, five European and American manufacturers dominate the global market for aircraft engines: The market for aircraft engines, especially jet engines, has very high barriers to entry. These barriers to entry make the market very lucrative for existing manufacturers. As of 2025, the leading jet engine manufacturers reported shareholder returns from between 100 and 1,000 percent over the last five years, compared to small or negative returns for their principal clients, Airbus and Boeing. The engines themselves are typically sold at a loss, but manufacturers derive their profits from the sale of maintenance services and spare parts over the roughly thirty-year lifespan of an engine, following the razor and blades business model. This creates a perverse incentive for manufacturers to slow the production or delay the delivery of new engines, because they profit most from the use of old engines, which need more service and spare parts than new ones. This contributed to the unavailability of new engines, creating a bottleneck for Airbus and Boeing's efforts to ramp up aircraft production in the post-COVID resurgence of aviation after 2023. ==Development history==

• 1903: Manly–Balzer engine sets standards for later radial engines. • 1910: Coandă-1910, an unsuccessful ducted fan aircraft exhibited at Paris Aero Salon, powered by a piston engine. The aircraft never flew, but a patent was filed for routing exhaust gases into the duct to augment thrust. • 1914: Auguste Rateau suggests using exhaust-powered compressor – a turbocharger – to improve high-altitude performance; • 1918: Sanford Alexander Moss picks up Rateau's idea and creates the first successful turbocharger • 1926: Armstrong Siddeley Jaguar IV (S), the first series-produced supercharged engine for aircraft use. • 2020: Pipistrel E-811 is the first electric aircraft engine to be awarded a type certificate by EASA. It powers the Pipistrel Velis Electro, the first fully electric EASA type-certified aeroplane. ==Shaft engines==

Reciprocating (piston) engines In-line engine For other configurations of aviation inline engine, such as X-engines, U-engines, H-engines, etc., see inline engine (aeronautics). V-type engine Horizontally opposed engine 350iS horizontally opposed air-cooled aero engine H configuration engine Radial engine engine A radial engine has the cylinders placed in a circle around the crankshaft. The engine is air-cooled, which can be a problem since they may overheat. Compared to liquid-cooled engines, radial engines have the advantage of being more rugged and capable of absorbing damage. Rotating Radial engine Rotating radial engines have the cylinders in a circle around the crankcase, as in a radial engine, (see above), but the crankshaft is fixed to the airframe and the propeller is fixed to the engine case, so that the crankcase and cylinders rotate. The advantage of this arrangement is that a satisfactory flow of cooling air is maintained even at low airspeeds, retaining the weight advantage and simplicity of a conventional air-cooled engine without one of their major drawbacks. The first practical rotary engine was the Gnome Omega designed by the Seguin brothers and first flown in 1909. Its relative reliability and good power to weight ratio changed aviation dramatically. Wankel engine e self-launching motor glider, removed from the glider and mounted on a test stand for maintenance at the Alexander Schleicher GmbH & Co in Poppenhausen, Germany. Counter-clockwise from top left: propeller hub, mast with belt guide, radiator, Wankel engine, muffler shroud. The Wankel is a type of rotary engine. The Wankel engine is about one half the weight and size of a traditional four-stroke cycle piston engine of equal power output, and much lower in complexity. In an aircraft application, the power-to-weight ratio is very important, making the Wankel engine a good choice. Because the engine is typically constructed with an aluminium housing and a steel rotor, and aluminium expands more than steel when heated, a Wankel engine does not seize when overheated, unlike a piston engine. This is an important safety factor for aeronautical use. Considerable development of these designs started after World War II, but at the time the aircraft industry favored the use of turbine engines. It was believed that turbojet or turboprop engines could power all aircraft, from the largest to smallest designs. The Wankel engine did not find many applications in aircraft, but was used by Mazda in a popular line of sports cars. The French company Citroën had developed Wankel powered helicopter in 1970's. In modern times the Wankel engine has been used in motor gliders where the compactness, light weight, and smoothness are crucially important. Power turbines Turboprop turboprop engine showing the gearbox at the front of the engine A turboprop consists of an intake, reduction gearbox, compressor, combustor, turbine, and a propelling nozzle. Air enters the intake and is compressed by the compressor. Jet fuel is then added to the compressed air in the combustor, where it then combusts. The hot combustion gases expand through the turbine stages, generating power at the point of exhaust. Some of the power generated by the turbine is used to drive the compressor and electric generator. The gases are then exhausted from the turbine, but do not provide enough power to create a major portion of the total thrust, since almost all of the engine's power is used to drive the propeller. Turboshaft is shown in green and the free/power spool (turbine) in purple. A turboshaft engine is a form of gas turbine that is optimized to produce shaft horsepower rather than jet thrust. The engine has two major parts assemblies: the 'gas generator' and the 'power section'. The gas generator consists of the compressor, combustion chambers with ignitors and fuel nozzles, and one or more stages of turbine. The power section consists of additional stages of turbines, a gear reduction system, and the shaft output. The gas generator creates the hot expanding gases to drive the power section; the engine accessories may be driven either by the gas generator or by the power section. Electric power A number of electrically powered aircraft, such as the QinetiQ Zephyr, have been designed since the 1960s. Some are used as military drones. In France in late 2007, a conventional light aircraft powered by an 18 kW electric motor using lithium polymer batteries was flown, covering more than , the first electric airplane to receive a certificate of airworthiness. On 18 May 2020, the Pipistrel E-811 was the first electric aircraft engine to be awarded a type certificate by EASA for use in general aviation. The E-811 powers the Pipistrel Velis Electro. Many big companies, such as Siemens, are developing high-performance electric engines for aircraft use; also, SAE shows new developments in elements as pure Copper core electric motors with a better efficiency. A hybrid system as emergency back-up and for added power in take-off is offered for sale by Axter Aerospace, Madrid, Spain. ==Reaction engines==

Jet turbines Turbojet -GE-17A turbojet engine. This cutaway clearly shows the 8 stages of axial compressor at the front (left side of the picture), the combustion chambers in the middle, and the two stages of turbines at the rear of the engine. Turbofan turbofan engine Advanced technology engine The term advanced technology engine refers to the modern generation of jet engines. Pulsejets Gluhareff Pressure Jet Rocket Rocket turbine engine A rocket turbine engine is a combination of two types of propulsion engines: a liquid-propellant rocket and a turbine jet engine. Its power-to-weight ratio is a little higher than a regular jet engine, and it works at higher altitudes. Precooled jet engines Piston-turbofan hybrid At the April 2018 ILA Berlin Air Show, Munich-based research institute :de:Bauhaus Luftfahrt presented a high-efficiency composite cycle engine for 2050, combining a geared turbofan with a piston engine core.