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Questions tagged [piston-engine]

Piston (reciprocating) aircraft engines are internal combustion engines, similar to the type found in most automobiles. They are typically gasoline powered.

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Why are propeller engines uncommon on airliners?

My experience in aviation is essentially zero, but looking at Wikipedia it seems like the Tu-95 Bear offers high subsonic speed and extreme range. I assume that turboprop engines are more fuel ...
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What are the differences between fuel types (comparing with vehicles)?

I find it funny that at gas stations, generally you can purchase "regular" gasoline (in various octane levels) or diesel. At airports, generally you can purchase 100LL avgas or Jet-A. Can you compare ...
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What are some of the differences between piston engines used in aircraft and automobiles?

What are some of the differences between piston engines used in aircraft and automobiles? It seems aircraft engines are much more expensive, I imagine some of that cost must be due to the more ...
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How can reducing power too quickly on a piston engine damage it?

In many places, it's been stated that you should reduce power slowly to prevent engine damage. Depending on who you talk to, some say you should reduce the manifold pressure by 1 inch per minute, ...
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Why are piston engines for aircraft rarely diesel powered?

Why hasn't diesel caught on much for aircraft engines? The list of diesel aircraft engines on Wikipedia is very short. The reason I see mentioned is their poorer power-to-weight ratios. (e.g. What ...
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What is the difference between SMOH and SFOH?

When looking at aircraft for purchase online, a lot of acronyms are used. In particular, the SMOH and SFOH acronyms are thrown around a lot for used aircraft. What are the differences between these ...
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Why are propeller airplanes still made?

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 ...
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How to calculate the thrust of a piston or turboprop engine? [duplicate]

This spawns from a related question. Propeller-drive engines (piston/turboprops) seem to always list their output in horsepower or kilowatts, which are units of power. I want to know the engine's ...
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Why are piston engines so unreliable in airliners?

Before the first jetliners appeared, all airliners used piston (reciprocating) engines, which were astoundingly prone to failing in flight, to the point where an inflight engine failure was an ...
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When is pre-heating a piston engine important, and how does one pre-heat correctly?

As temperatures here in New York plunge toward (and below) freezing it's time for those of us without nice heated hangars to start thinking about pre-heating our aircraft before we turn the key. ...
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How does aircraft design affect carburetor ice?

The Cessna 172 and Piper Warrior are similar in many ways, including their engines: for most of their production history (1968-1998 for the 172; the entire history for the Warrior) both were equipped ...
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In high-altitude piston aircraft, what type of forced induction (boost) is used?

In high-altitude piston aircraft, what type of forced induction (boost) is used? Turbocharger or supercharger?
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Why don't small planes use turbine (turboprop) engines?

Turboprop engines are more fuel efficient1, lighter for the same power, mechanically simpler and consequently more reliable. They are also slightly easier to operate (no need to fiddle with mixture) ...
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9answers
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Why increase the number of cylinders in an engine instead of increasing their volume?

I've been reading about WW2 planes lately. Some of them have 12 or even more pistons in their engines. But if your goal is to increase power, why would you add more pistons instead of simply ...
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Why is water-contaminated fuel bad, but water-injection is not?

A "wet" takeoff of a KC-135 with J57 engines—By USAF Photographer (USAF photo) [Public domain], via Wikimedia Commons Why is water-contaminated fuel bad, but water-injection is not? The way I ...
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Why does manifold pressure increase with power?

Whilst writing an answer to this question, I remembered something I don't really understand. The partial vacuum in the inlet manifold is caused by the piston descending with the inlet valve open ...
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3answers
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Why the lack of faster piston-powered planes?

There aren't very many fast piston airplanes in production. By "fast" I mean, if you look back in the early to mid 20th century, before turbines won out, there were lots of piston airplanes in ...
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What are the advantages/disadvantages of diesel/Jet A-1 piston engine?

Some GA aircraft, notably the DA40/DA42, are equipped with piston engines that use Jet A-1 and/or automotive-grade diesel instead of aviation gas (avgas). An example of such engine is the Austro ...
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Why don't airplane turbo piston engines have boost control?

Why is it possible to over-boost piston aircraft engines? All turbo car engines have a wastegate that just vents pressure back to the intake, whereas in an airplane the pilot has to look at the ...
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3answers
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What is “detonation” in a piston engine?

Recently, I saw this question, which included a rather alarming quote: Full throttle operation with carburetor heat on can cause detonation. Woah! That doesn't sound good. In fact, I would have ...
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Is the Soloy Dual Pac recognised as two engines or one engine?

The Soloy Dual Pac apparently allows two engines to rotate one propeller -- here's a picture of it on an Otter: Is this recognised as a centreline thrust twin engine aircraft, a "standard" twin ...
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1answer
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What is my BHP if I open full throttle and how is it controlled?

In my Cessna 152 POH it is written that the horsepower rating is 110BHP at 2550RPM. My question is: is it 100% of the power of my engine or, as someone told me, if I open full throttle I will get 75% ...
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How reliable are Lycoming and Continental general aviation piston engines?

Statistically speaking, how reliable are Lycoming and Continental general aviation piston engines? What I'd really like to either find or build is a table showing the probability of experiencing ...
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Why would a C150 tachometer bounce so much that the needle fell off?

On a long flight in a C150E, the tachometer started bouncing a little bit and the severity of the bouncing gradually increased until it was extreme: The tachometer was spinning in loops and making a ...
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2answers
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What was the first aircraft that could fly inverted?

I'm taking a guess and assuming the Wright Flyer was incapable of flying upside down. I'm just guessing it probably lacked the power... ;) So what was the first plane that could fly inverted for a ...
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Why does the lack of a magneto affect engine RPM?

So I don't have my pilots licence, but I was part of the Australian Air Force Cadets for nearly 8 years (wonderful organisation). During this time I went on a number of flights in Cessna 172's and ...
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Why is the magneto drop check done at 1700 RPM?

In our Cessna 152, we carry out the mag drop check at 1700 RPM, following the POH. My question is why it is done at 1700 RPM? What will happen If I check it at 2000 RPM or less than 1700 RPM? And if I ...
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3answers
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What does feathering mean and how does it work technically?

Before I ask "What does Feathering mean when it comes to Jet/Propeller Engines" I have to say what I think I know: Feathering jet/prop engines mean achieving a sufficient turbine rotation speed at ...
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4answers
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Why isn't the APU a standard diesel generator?

Why isn't the APU a standard diesel generator? Jet-A and diesel are interchangeable (with the addition of a lubricant). So why not use a cheaper piston engine as opposed to a jet turbine? V.S.
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3answers
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How does the mixture of an engine affect the engine's operation?

I know that in most piston aircraft that there is a mixture control for the engine. My question is, how does the mixture control affect the engine's operation and what type of situations dictate a ...
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1answer
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Why does manifold pressure increase when you turn on carb heat?

So everyone knows that carb heat decreases engine performance. Yet when we check the heat during run-up, the manifold pressure increases. Why is that? Shouldn't adding carb heat cause the intake air ...
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4answers
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Why does carburetor icing require manual attention by the pilot?

Why is it carburetor icing has to be handled manually by the pilot, at least in a helicopter? I am hoping very soon to take my PL/H lessons, I have a little understanding of mechanics and how things ...
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6answers
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Why is full carb heat recommended when reducing power below normal setting?

In my first flight lesson today, my instructor asked me to apply full carburetor heat when we had to reduce power to 1900 RPM in our Cessna 152. I was surprised by this as I didn't remember learning ...
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How does skydiving flight cause shock cooling?

While answering this question (How can reducing power too quickly on a piston engine damage it?), barit1 said that: Skydiving planes see a LOT of shock cooling, and they pay for it at overhaul time ...
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2answers
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Are there any pressurized piston-engine aircraft?

Are there any pressurized piston engine-powered aircraft? Or does pressurization require a turboprop or jet?
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What is a biplane propeller and how efficient is it?

Lazair ultralight series II used biplane props to absorb more power from the engine....so my question is what really is a biplane propeller and are they efficient in comparison to a four bladed prop?
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Why did the manifold pressure gauge on the Ki-61 have negative values?

The manifold pressure gauge of the Japanese Ki-61 has values which go from +40 to -40. I know this has to be relative to something since negative pressure can't exist (you can't get more vacuum than a ...
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Rotax engines have no mixture control, how do they handle less dense air?

Rotax engines have no mixture control, yet they don't seem to have any more problems than other engines at altitude. How do they handle the lower air density in order to not get a too rich a mixture?
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Why is carburetor heat use discouraged on the ground?

I've been reading my private pilot books for when I start in February and Carb Heat has me stuck in a rut. I feel like I need to have a very solid understanding of this being that I live in a very ...
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Should I have carb heat on for landing in a C152?

There is quite a debate about this! I'm a student, have gone solo. My first instructor insists the carb heat goes off/COLD on the approach ('ready for go-around' if needs must! And to prevent dirty ...
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1answer
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What should I look for / check during an oil change?

Piston aircraft engines require regular oil changes, and at least in the US it's something the FARs allow an owner with a private pilot certificate to do. What are some of the things I should look ...
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2answers
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How is horsepower measured for aviation piston engines?

As far as I can tell, aviation piston engine power output is typically measured in HP (horsepower). Automotive engine power output is typically measured by running the host vehicle on a rolling road, ...
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1answer
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Where to find Tach hour and clock hour equivalence rpm?

There is a revolution counter built into the face of the Tachometer in most piston powered GA planes. This counter is calibrated in hours. Most planes also have a Hobbs meter, which is a clock. ...
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0answers
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Will Aerodiesel engines replace Avgas engines? [closed]

I've been following aviation for the last 20 years and have seen particularly since the last 10 a lot of talk of aero-diesel engines for light aircraft. The idea being they're cheaper to run using ...
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1answer
5k views

Is TBO an airworthiness item or just a recommendation?

In browsing Trade-a-Plane for my dream (light GA) ride, I often note the TBO (Time Before Overhaul) for an aircraft in relation to its asking price. Obviously, the more time left before an overhaul ...
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1answer
427 views

Where to find information on the Daimler-Benz 606/610?

There seems to be relatively little information regarding either of these engines on the web. Anyone have an idea where I can find more info?
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3answers
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Is a recoil start (hand propping) allowed if it isn't mentioned in the aircraft manual?

Is a recoil start (hand propping) allowed without it being referenced in the aircraft manual? In a Cessna 150, for example.
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Is there a system where plane/heli auto adjusts prop pitch/mixture?

This one is simple: is there a system that automatically adjusts things such as: Mixture (I Am bored of listening for engine sounds) Prop Pitch (I Hate auto adjusting "gears") So I can ...
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2answers
216 views

Why would a cylinder not work below a certain RPM?

We have an IO 540 Lycoming engine, and cylinder #3 doesn't work below 1900 RPM (cold to the touch; EGT and CHT are zero; no vibration). The engine is new, what could be the cause(s)? We cannot ...