Airplanes with propellers were invented a long time ago. After that, jet engines came into existence. My question is: why do we still have propeller engines?

The reasons I can think of are:

  • They are cheaper;
  • They cannot achieve very high speed;
  • They are not very noisy (though not always).

Besides these, are there any other reasons general aviation airplanes built nowadays don't have jet engines?

  • 3
    $\begingroup$ Ok, so in the non-confused sense: Would you like to know why we're still using propellers (rather than jet propulsion), or still using reciprocating engines (rather than turbine engines)? Or both? $\endgroup$
    – falstro
    Jan 28, 2014 at 18:16
  • 1
    $\begingroup$ Basically the former one. $\endgroup$
    – Farhan
    Jan 28, 2014 at 21:32
  • $\begingroup$ Somewhat related question: Rotary-engine planes in commercial flights $\endgroup$ Jan 29, 2014 at 6:26
  • 2
    $\begingroup$ The number one fan of a bypass jet turbine engine is a propeller. $\endgroup$
    – Steve Kuo
    Dec 8, 2014 at 22:30
  • $\begingroup$ Another related question: Why is flight training done in prop planes instead of jets?. $\endgroup$
    – Lnafziger
    Dec 10, 2014 at 19:46

6 Answers 6


Jet engines are only efficient at high altitudes and high speed (25,000+ feet or so and 300+ knots or so true airspeed). The cost of making and operating an airplane capable of flying there is very high, and most general aviation flights have no need of such performance (or expense) hence, propeller airplanes.

Reciprocating engine propeller airplanes are relatively efficient at low altitudes and airspeeds, they are more economical for the average types of general aviation flights. They are also much cheaper to build and operate than a turbine powered airplane.

Turboprops fill the efficiency gap between reciprocating and pure jet engines, being most efficient at mid altitudes and airspeeds. Still more expense and performance than most general aviation flights need though.

  • 16
    $\begingroup$ I'll add that if you put a turbine on a C172 the 40 gallons of jet-A in the wings would probably not get you very far. $\endgroup$
    – casey
    Jan 28, 2014 at 16:28
  • $\begingroup$ Good answer! I'd say that the most important aspects though are that they are a) cheaper to build and b) cheaper to operate. $\endgroup$
    – Lnafziger
    Jan 28, 2014 at 17:05
  • 2
    $\begingroup$ Don't forget the Turbo-fans which bridge the gap between turbo-props and pure jet by using a bit of both :) $\endgroup$
    – falstro
    Jan 28, 2014 at 18:17
  • 1
    $\begingroup$ are there any jets still being manufactured with pure jets? I don't think laymen (including OP) knows that he is even flying in a turbofan. $\endgroup$
    – rbp
    Nov 16, 2014 at 17:04
  • 1
    $\begingroup$ Yes, I know I'm flying a turbofan. They are rarely referred to as such on the line. $\endgroup$
    – Khantahr
    Nov 16, 2014 at 18:53

It is all mission related.

Propeller engines - and I am including turboprops - are much more efficient at lower speeds and altitudes. Example: the C-130 Hercules cargo aircraft. It can get in and out of fields much shorter than a turbojet or turbofan can, while trucking a large load, because it has those huge propellers clawing at the air. Jets, as stated before, have the advantage high and fast. But that is not the mission of the Hercules.


As mentioned they are efficient at lower altitudes (and service the GA mission quite nicely) but in many ways it simply boils down to cost. There are companies out there designing and working on smaller jets like Cirrus with the SF50. Then there are a few jets out there like the Cessna Citation Mustang that are single pilot certified and can be flown with appropriate ratings on a PPL. But the fact remains that it is not cheap nor easy to bring a new airplane to market. Cirrus first flew their jet in 2008 and its still not on the market officially. That puts them at nearly 8 years from prototype to roll out and Im sure the first lines for it were drawn well before 2008.

On the other hand companies like Piper and Cessna have approved designs that are still fast and easy to maintain even by todays standards. Very much the "If it ain't broke don't fix it" issue. It is no mystery that GA sales are down and some of the companies could be doing better.

There is a bit of a safety issue. Propeller planes are nice and easy to fly with fast throttle response and lower speeds they make great trainers. Some may argue that jets are just to much plane to handle for a new pilot.

For what its worth there are some very fast piston singles out there. The Glasair claims a cruise of 252Ktas (although its experimental) and the full production Mooney Acclaim Type S pulls in at 242Ktas both of these planes approach turbo prop speeds to the piston engine while an old design can still deliver performance (and high speeds).

There is also some cross over with automotive piston engines. Through out history there have been a few auto engines certified for aircraft. Once upon a time Ford had some motors that found their way into planes. Mooney has attempted to use car motors at least twice starting with the Crosley engine that was found in early Mites and culminating with the epic (if you are a Porsche fan like me) PFM3200 that featured the Porsche 3.2 engine out of the late 80's Carrera. While the PFM3200 was riddled with issues and Porsche eventually dropped the FAA certification for the motor it was an interesting display of engineering. Parts for the 3.2 were arguably easier to come buy and there were plenty of people who knew how to work on them. Currently Diamond offers a diesel DA42 that runs on modified car motors. Again using a motor that is tried and true on the road. So the costs are not just because the engines are cheaper to make but made in much higher quantities as well as being able to offset some of the engineering costs with this bulk.

  • $\begingroup$ The cruise speed for the Mooney Acclaim Type S is 242Ktas not 424. $\endgroup$ Oct 22, 2017 at 16:48
  • $\begingroup$ @TeasingDart good catch, I have updated. $\endgroup$
    – Dave
    Oct 22, 2017 at 18:52
  • $\begingroup$ Re "fast piston singles", I think you're overlooking the fact that a lot of us who fly single-engine prop planes aren't looking for fast. We might instead want to get in and out of short dirt strips (or no strips), do aerobatics, take a leisurely sightseeing flight... $\endgroup$
    – jamesqf
    Oct 23, 2017 at 5:18

Piston-driven propeller powerplants are:

  • Cheaper. Because the engine is a proven and well-understood design, they're cheaper to design, to make, and to maintain, all of which lower expenses for the pilot. You can pick up an older Piper Cherokee for about \$40k nicely equipped with plenty of hours before its next overhaul. The absolute cheapest Piper turboprop I can find with a quick search is a twin-engine Cheyenne for \$275,000, and it probably needs work as they average closer to \$400k. Other turboprop airframes approach $2 million a pop.

  • Smaller. A four-cylinder air-cooled naturally-aspirated piston engine is not much bigger than the V-twin on a motorcycle. Smaller tends to equal lighter, and it also allows for more cabin room in a fuselage of the same total volume, and less variance of the CG with cabin weight (which is a big deal in small planes).

  • Simpler. There's not as much to go wrong with a fixed-pitch air-cooled piston-engine plane. This again reduces maintenance costs but also increases safety by lengthening "mean time between failures" that would require emergency procedures. Constant-speed props are a little more mechanically complex but not too bad. Turboprops a little more complex still.

  • Better-performing at low altitudes. Most turbofans are designed for operation above 10,000 feet, while most propeller-driven craft are designed to fly at 8,000 or below because their cabin is unpressurized. At lower altitudes where the air is thicker, piston engines run more efficiently and cooler than turbofans and much better than pure jets.

  • $\begingroup$ You're comparing small piston engines with small turbines. Turbine engines are well understood, simple, and light with a higher power/weight ratio than piston engines. Only for small engines are pistons still an option due to small turbines not being very efficient. But the question was about propellers. $\endgroup$
    – Koyovis
    Oct 22, 2017 at 19:12
  • $\begingroup$ At the size of aircraft where propellers are most common, so are reciprocating (piston) engines. Efficiency in smaller engine sizes is a concern, and so is cost; small single turboprops start about three times the cost of small single pistons, brand new off the factory line, and well-maintained turboprops hold more value partially due to lower used supply. $\endgroup$
    – KeithS
    Jan 11, 2018 at 14:28

Ultra-light jets were all the craze a decade ago, and never took off: they were too fuel inefficient. Propellers do a much better job at converting fuel chemical energy into thrust that propels the aeroplane forward, than jets do.

Aerodynamic thrust can be written as $T = \dot{m} \cdot \Delta V$, with $\dot{m}$ the mass stream of air in kg/s and $\Delta V$ the speed increase of the propelled air mass in m/s. To get the highest propulsive efficiency, accelerate the largest amount of air to the smallest $\Delta V$. Propellers have a much higher effective disk area than pure jet engines do, and deliver way more thrust per installed engine power than pure jets do.

The turbofan is much more fuel efficient than a pure jet because the large bypass fan works kind of like a propeller does. However, the turbofan is still less efficient than a turboprop, simply because of the larger blade radius.

The issue of piston engine vs turbine engine for general aviation is a separate one altogether. Piston engines are heavier but have better fuel economy. Weight-wise they scale up very poorly, while this is where the turbines fully come into their own: nothing beats a large turbine in power/weight ratio. Smaller turbines are not very efficient due to lower pressure ratios from blade/shroud gaps.


It's very simple: Prop planes are manufactured because most airports around the world have runways too short for jets.

  • 2
    $\begingroup$ How big a runway do you think you'd need for a small GA aircraft with a big jet engine...? $\endgroup$
    – Dan
    Jan 9, 2015 at 14:18

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .