Jet Engine vs Propeller, Turboprop: Comparison

Turboprop engines combine the principles of jet engines and propeller-driven systems: a gas turbine engine drives a propeller, so turboprops use propeller propulsion yet are classified as a type of jet engine. Because they closely resemble a high-bypass turbofan and are sometimes called an ultra-high-bypass jet engine, turboprops deliver greater fuel efficiency at lower speeds and altitudes while incurring lower fuel costs than conventional jet engines.

Jets are faster than propeller planes, but turboprop aircraft require less runway for take-offs and landings and possess a more balanced field than many jets. These characteristics, together with lower operating costs, give turboprops a distinct edge in regional operations where versatility and economy outweigh raw speed.

Expert behind this article

Jim Goodrich

Jim Goodrich is a pilot, aviation expert and founder of Tsunami Air.

What are the differences between a jet engine and a propeller plane?

The differences between a jet engine and a propeller plane are given in the table below.

Propeller planes are smaller than jets and fly lower altitudes, so they meet turbulence more often whereas jets ride above most weather. Propeller planes require a shorter runway for takeoff and landing, yet jets have higher weight capacity, longer range, and can fly nonstop over longer distances. Propeller engines reach maximum efficiency at far lower speeds and altitudes, making the propeller-driven aircraft an efficient choice for flights between seven-hundred and one-thousand kilometers. Jets translate into faster top cruising speeds; a private jet is faster than a propeller plane and offers speed, range, and high-altitude capabilities.

A propeller produces forward force by creating a pressure difference between the front and back of the blades. It moves a large amount of air slowly and causes drag that allows the aircraft to stop more quickly. A piston engine provides power to the spinning propeller, but a piston engine cannot produce thrust on its own. Jets generate propulsion by pulling in air, combining air with fuel, and shooting exhaust gases out of a nozzle and these high-speed exhaust gases generate thrust. A smaller light jet will feature two jet engines, with a single engine on each side, while larger jets carry turbine engines encased with fan blades. The turbofan engine was developed, leading to a great leap in efficiency, because the high-bypass turbofan engine generates a lot of thrust by the leading fan.

Propellers are most fuel-efficient and consume less fuel. Jets consume more fuel and have higher fuel consumption rates. Jet engines are louder due to high-speed exhaust gases, although modern jet engines are quieter than early turbojets. Civil operators therefore choose propeller power for short thin routes, while jets are used for missions that demand higher performance and speeds.

Which is safer: a propeller plane or a jet plane?

There is not a clear statistic that claims either plane to be safer than the other. Statistical summaries show jets experienced 0.51 accidents and 0.09 fatal accidents per 100,000 hours, whereas turboprops logged 1.54 accidents and 0.55 fatal accidents per 100,000 hours. According to the IATA Annual Safety Report 2022, one major jet accident occurs every 7.7 million flights, while one turboprop accident occurs every 560,000 flights. Yet the higher turboprop figures reflect the dirt-strip, single-pilot, freight and commuter missions they usually fly. Transport-category propeller aircraft like the ATR-42/72 or Dash-8 do not show a significantly higher accident rate than transport jets. The difference in accident rate is largely due to differences in types of operations that these aircraft typically perform.

Modern propeller aircraft like turboprops are designed with advanced technology and safety features that make them just as safe and reliable as jet airplanes. Both types of aircraft are powered by turbine engines that are mechanically simple, light, reliable, and easy to operate. They undergo equally rigorous safety testing and maintenance to guarantee safe operation, and reputable charter companies guarantee that the aircraft meets current safety regulations regardless of whether you choose a turboprop or private jet. Propeller airplanes are deemed safe to fly when operated by trained and experienced pilots, maintained properly, and operated in suitable weather conditions. The persistent misconception that propeller planes are inherently less safe than jet-powered counterparts persists only because people have concerns when traveling on an aircraft with propellers.

How is the structure different in a jet engine and propeller plane?

Jets have turbine engines encased with fan blades, positioned in pods on the wings or on the rear of the fuselage, so the long, smooth, sleek fuselage is left free for fuel or payload. Propeller aircraft carry either a piston engine or a gas-turbine core whose power drives the propeller. The engine itself is mounted in the nose or on the wings, while the propeller is at front, spinning in clean air. Because all thrust is generated by props, the fuselage must be shorter and the wing sits higher, as seen in Bombardier turboprops that are high winged and stop more quickly.

Internally, a jet relies on the principle of jet propulsion: air is compressed, burning fuel raises its energy, and high-pressure exhaust gas is expelled through nozzles to create forward thrust. A turboprop uses the same gas-generator core, but the turbine assembly is connected to a propeller, so exhaust gases power the propeller instead of producing jet thrust. The propeller moves a large amount of air slowly, giving prop engines an advantage at lower flight speeds, whereas the ultra-high-bypass jet engine directs most air around the engine core for efficiency at high speed in smooth, sleek jets.

What is a turbocharged engine in aviation?

A turbocharged engine in aviation is a piston engine that carries a turbine-driven forced-induction device called a turbocharger. The turbocharger uses the kinetic energy of the engine's own exhaust gases to spin a turbine wheel. The wheel drives an impeller that collects and compresses ambient air before it reaches the cylinder. By compressing the intake air the device raises the manifold pressure, letting the engine burn more fuel and deliver more power for a given displacement.

Because the compressor keeps the intake pressure at sea-level values, the engine can produce its full rated horsepower up to a selected critical altitude, the highest level at which sea-level manifold pressure can still be maintained. Above that altitude the manifold pressure falls, yet the engine continues to operate efficiently at heights where normally aspirated units lose power. Turbochargers therefore solve the ‘thin-air’ problem that limits piston engines in the upper flight levels.

To control the extra heat created when air is compressed, most installations add an intercooler that cools the charge before it enters the cylinders. A wastegate is fitted to vent excess exhaust when necessary, preventing over-boost. The complete system adds some exhaust back-pressure and normally demands 100-octane avgas to withstand the resulting higher cylinder pressures, but it imposes no direct mechanical load on the crankshaft and lets aircraft cruise at altitudes where the outside air is 100°F (37.8°C) colder than at the surface.

What is a turboprop engine in an airplane?

A turboprop engine is a type of gas turbine engine that uses the internal combustion process to turn a propeller. Air is compressed by a compressor, combusted, and converted into power that spins the propeller. Most of the energy of the core exhaust goes into turning a drive shaft connected to a reduction gearbox, which reduces the high-speed rotation of the turbine to a suitable speed for the propeller shaft. The gearbox turns the propeller, and exhaust velocity contributes little thrust.

A turboprop engine is a hybrid power-plant that mixes the established efficiency of an airscrew with the core economy of a gas-turbine rotor. A big airscrew driven by the turbine motions enormous quantities of atmospheric air, giving huge strength at low speeds and altitudes typical of regional trips. This strength translates into short-field go-and-touch-down capacities, making the configuration suited for operating from lower airstrips and linking smaller neighborhoods. Because the motor is more fuel-efficient than a turbofan, it delivers a cost-effective, dependable result.

What is the difference between a jet engine and a turboprop?

The differences between a jet engine and a turboprop are given in the table below.

Jet engines and turboprop engines use two different approaches to aircraft propulsion. Jets rely on the principle of jet propulsion, accelerating a small mass of air to very high speed, while turboprops rely on propeller propulsion, accelerating a large mass of air at a lower speed.

Jet engines create more thrust than turboprop engines, enabling jets to reach velocities between 500-600 knots and to operate at FL40s (around 40,000 feet). Turboprops, whose core spins a shaft connected to a gearbox that turns a propeller, cap their cruise around FL30 and cruise at lower speeds. The additional expansion in the turbine system of a turboprop extracts shaft power beyond that necessary to drive the compressor, lowering residual energy in the exhaust jet and trading sheer thrust for torque.

Because jets produce more thrust, they carry a higher weight capacity, offer longer range, and have higher altitude capability. Their smooth, sleek fuselages and ability to fly at FL410 generally make them the choice for intercontinental missions. Turboprops burn two-thirds of the fuel per passenger, have lower fuel consumption per passenger, and provide lower operating costs, making them economically attractive on regional routes. They can take off and land in shorter distances, a performance advantage amplified in hot-and-high conditions where jets suffer degraded performance and turboprops suffer less. While jet engines have higher maintenance costs and are perceived as louder than turboprops due to high-speed exhaust gases, turboprops are quieter externally and deemed more reliable because they have fewer moving parts.