Aircraft engine

An aircraft engine, often called an aero engine, is the part that gives an aircraft its power to fly. Aircraft that can fly using their own power are called powered flight. Most aircraft engines are either piston engines or gas turbines, but a few special planes have used rocket powered engines. In recent years, many small flying machines called UAVs have started using electric motors to move through the sky. These engines are very important because they help planes, helicopters, and drones stay in the air and move from one place to another.

Manufacturing industry

See also: List of aircraft engines

As of 2025, five European and American companies are the main makers of aircraft engines. Making these engines is very difficult because it needs special technology and materials, takes a long time, and must meet strict safety rules. Because of this, it is hard for new companies to enter the market.

These engine makers often sell the engines at a lower price but make money by selling parts and services for many years after the engine is made. This can sometimes cause delays in getting new engines ready, which affects airplane makers like Airbus and Boeing when they want to build more planes.

Development history

The development of aircraft engines has seen many important milestones. In 1903, the Manly–Balzer engine set standards for later radial engines. In 1918, Sanford Alexander Moss created the first successful turbocharger. In 2020, the Pipistrel E-811 became the first electric aircraft engine to receive an official certificate, powering the Pipistrel Velis Electro, the first fully electric certified airplane.

See also: Timeline of jet power

Shaft engines

Reciprocating (piston) engines

Main article: reciprocating engine

Reciprocating engines, also known as piston engines, are one of the most common types of aircraft engines. These engines work by using pistons that move up and down inside cylinders to create power. They can be arranged in different ways, such as in a straight line (in-line engine), in a V-shape (V-type engine), or in a circle around the center (radial engine). Radial engines, in particular, are known for being strong and able to handle rough conditions, though they can sometimes get too hot.

Another special type is the rotary engine, where the entire engine spins as it runs. This design helps keep the engine cool even when the airplane is moving slowly. There are also Wankel engines, which are a type of rotary engine that is much lighter and smaller than traditional piston engines. These engines were used in some cars and a few experimental aircraft, but they are not common in airplanes today.

Power turbines

Main article: Turboprop

Main article: Turboshaft

Power turbines are another important type of aircraft engine. Turboprop engines look like jet engines but are designed to turn a propeller instead of creating thrust directly. They mix air with fuel, create a controlled explosion to make heat and power, and use some of that power to spin the propeller.

Turboshaft engines are similar but are built specifically to produce power for things like rotating parts or generating electricity, rather than pushing the airplane forward. These engines have two main sections: one that creates hot gases and another that uses those gases to produce useful power.

Electric power

Since the 1960s, some airplanes have been powered by electricity. These electric airplanes use batteries to power electric motors that turn the propeller. In 2020, the Pipistrel E-811 became the first electric aircraft engine to receive official approval for use in small airplanes. Many companies are now working on improving electric engines for airplanes, which could make flying quieter and cleaner in the future.

Reaction engines

Main article: Jet engine

Aircraft engines are special machines that help airplanes fly. Most airplanes use either piston engines or gas turbines for power. Some small drones today use electric motors, and a few special airplanes have used rocket engines.

Jet turbines

Main article: Turbojet

Main article: Turbofan

Main article: Advanced technology engine

The term advanced technology engine refers to the modern generation of jet engines.

Pulsejets

Main article: Pulsejet

Main article: Gluhareff Pressure Jet

Rocket

Main article: Rocket engine

Rocket turbine engine

Main article: Rocket turbine engine

A rocket turbine engine mixes two types of engines: a liquid-propellant rocket and a turbine jet engine. It can work at very high altitudes and is a bit more powerful than a regular jet engine.

Precooled jet engines

Main article: Precooled jet engine

Piston-turbofan hybrid

At the April 2018 ILA Berlin Air Show, researchers from Munich showed a new engine design for future airplanes. This engine mixes a turbofan with a piston engine to make it more efficient. It could power smaller airplanes with about 50 seats. The design helps save fuel and could make flights cheaper and greener in the future. The project was supported by the European Commission, with help from MTU Aero Engines and GKN Aerospace.

Engine position numbering

On airplanes with more than one engine, the engines are given numbers from left to right, as seen by the pilot looking forward. For example, on a four-engine airplane like the Boeing 747, engine No. 1 is on the left side, farthest from the middle of the plane, while engine No. 3 is on the right side, closest to the middle.

In some airplanes with two engines mounted on the body, such as the English Electric Lightning, engine No. 1 is below and in front of engine No. 2, which is above and behind.

Fuel

Refineries mix a special fuel called Avgas with a chemical to make it work well in airplane engines, but this practice is no longer allowed for car gasoline. Because this special chemical is becoming harder to find and there might be new rules to stop using it, groups of pilots are looking for new fuels for small airplanes.

Small model airplanes often use a special fuel mix that includes methanol and nitromethane, or they can be powered by electricity. Very small flying machines called multicopters usually run on electricity, while some bigger ones are being made to use gasoline.