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A turboprop engine is a type of turbine engine which drives an aircraft propeller to produce thrust (as opposed to a jet engine, where the turbine exhaust provides thrust directly).

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Why do we refer to “power” for turboprop engines and “thrust” for turbojet/fan engines?

In jet engines, I read that thrust is related to the fuel flow rate, whereas in turboprop engines power produced is related to the fuel flow rate. What is the reason and brief math behind this?
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1answer
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How to compare turboprop engines and with which values?

I have found this website that lists a lot of turboprop engines. I would like to compare them with as few values as possible. As an example, there are tons of different values that describe a jet ...
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1answer
191 views

Are turboprops less safe then jets?

On a recent trip to an airport, I noticed a large number of Bombardier Dash 8s. I wanted to know - are turboprops less safe than traditional jets like the 737 or A320? For instance, I would imagine ...
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Why aren't there any widebody propliners for the high-density short-haul markets?

Jetliners come in both narrowbody (one aisle) and widebody (two or more aisles) versions, but all propliners, to the best of my knowledge, are narrowbody aircraft. Now, granted, one of the big ...
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3answers
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Why would a turboprop rev down just before going full throttle during takeoff?

The only turbprop I've travelled is the ATR 72. I've noticed that the props' rev go down (for like a second, the sound also goes down) just before engaging full throttle in order to takeoff. I've ...
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1answer
150 views

How does the load transfer from a prop to the airframe?

I was just watching this video... Restoration and startup of a Wright 1820 Cyclone ...and it got me thinking: a propeller shoves back air, and this creates a forward force on the prop. The prop ...
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1answer
81 views

Where should I find a Pratt & Whitney Canada PT6 operator's manual?

I'm studying the PT6 in detail but the infos I get around the web are sometimes lacking in depth of informations. I'm pretty much interested in the power curve vs RPM of this engine. Where should I be ...
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2answers
274 views

Why is there still a preference for turboprop airliners over the new regional jets? [duplicate]

In the 1950s and in the early 1960s, jets were mostly available as fighter/military or big, long haul aircraft. Regional aviation was based primarily on piston aircraft that could operate in smaller ...
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3answers
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In a pusher configuration with turboprop(s), how is the superhot exhaust avoided?

I actually looked around for turboprops in a pusher configuration, and so far I only found one: P180 Avanti. You can see the propellers are behind the turbine, and in fact it looks like two exhaust ...
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3answers
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Why are turboprop intakes placed below the propeller?

On many turboprop aircraft, such as the A400M and the ATR 72, it seems that the air intake tends to be placed below the propeller (images: Wikipedia): source source Given that mounting the intake ...
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2answers
169 views

How long does it take for a propeller engine to spool-up?

To build further upon the question Why does a turboprop lag?, the following: Assuming a propeller engine is running in idle and the throttle lever is switched to full thrust instantaneously at t = 0 ...
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5answers
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Is it incorrect to refer to a C-130 as a jet?

In this article by CNN, the C-130 involved in the unfortunate crash in Savannah, GA is referred to as a "jet." Is this considered proper usage? I'm not looking for public opinion here but official ...
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1answer
175 views

What do these explanations for propellor RPM increases mean?

I have read in a book that if the engine RPM increases while descending, the probable causes are: Engine transfer bearing leaking excessively Excessive friction in blade bearings I am not able to ...
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0answers
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What could cause an engine shutdown on a Q400 with CDS codes 732, 907, 915 and 938?

A Bombardier Q400 displays error code 938 on the Central Diagnostics System(CDS), which is attributed to turbomachinery chip detector. An examination shows debris in the detector hitch which is ...
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3answers
181 views

Why is the first turbine in a turboprop (or turboshaft) connected to the compressor?

Typically the first turbine after the combustion chamber drives the compressor as shown in this picture. (wikimedia.org) This first turbine spins the fastest and harvests the most energy from the ...
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1answer
399 views

FADEC or EEC for PT6-42A…is it feasible?

In a response to a You-tube clip showcasing Piper's M600 single turbo prop, a viewer dismissed it as an inferior engine compared to a GE (probably an H-80 series) due to lack of FADEC or Electronic ...
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1answer
550 views

Is a turboprop or a turbofan more eco-friendly?

If we compare them, which one wins? Why? And, what about CO2 emissions?
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2answers
215 views

How do the compressor stages keep spinning after start in a free turbine?

In a ‘free’ (or uncoupled) turbine engine (specifically the Rolls Royce C20-250), what is spinning the compressor blades (N1) after start? It can’t be N2, because it’s a free turbine. I don’t think ...
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1answer
154 views

What is NH overspeed test and how it is preformed on DHC Q400 aircraft?

In the Aeroplane Operating Manual of DHC Q400 aircraft it is written that, at the time of normal engine shutdown, the engine system tests the NH overspeed circuitry by using it to shutdown the engine. ...
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2answers
489 views

Why were turbojets the first kind of turbo-engines, instead of turboprops?

During WW2, the first jet engines appeared en mass in combat aircraft. Britain and Germany made the first ones. But why were turbojets first? Why not turboprops, which are easier since the turbo-...
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1answer
157 views

For how long can a single-engine turboprop safely run the engine at idle?

Can a single engine turboprop (such as a Piper Meridian or TBM) allow idling long enough to drop off a passenger or package without shutting down the engine? If so, would the prop be feathered but ...
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1answer
284 views

What happens when changing the throttle on a PT-6 engine?

Imagine a PT-6 in cruise flight. What would pushing the throttle forward for increased power show on the engine instruments? We know (I assume!) the prop RPM remains constant by varying the pitch, but ...
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1answer
601 views

How does a turboprop engine keep running during thrust reversal?

For thrust reversal after landing, a turboprop engine reverses blade pitch and blows air forward. But the engine itself requires air flow for the turbine. How can a turboprop engine keep running when ...
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1answer
360 views

Does the DC-3 have a prop sync?

I'd like to ask if the DC-3 has a prop sync. I found nothing about prop sync in the DC-3 operations manual, in the running specs, design features, or in the chapters about its engine and propeller. I'...
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1answer
414 views

What prevents miltiary jets and turbo-props from being refitted with a turbofan?

What prevents military jets and turbo-props (such as P-3 Orion) from being refitted with a high bypass turbofan?
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3answers
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What are the effects of an increase in altitude upon ESHP of a turboprop engine?

This is one of the questions in the ATP material: What effect will an increase in altitude have upon the available equivalent shaft horsepower (ESPH) of a turboprop engine? A) Lower air ...
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1answer
416 views

How much runway is needed for comfortable operations in a PC-9?

I am familiar with simple single engine props and twins and am thinking of moving up to turboprops like a Soccata TBM 700 or Pilatus PC-9. How much runway do aircraft like these need to operate ...
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4answers
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Which engine type requires the shortest take-off run: a turboprop or a turbofan?

If two fixed-wing aircraft almost identical except for the engines, one turbofan and one turboprop, which one would need less runway to take off?
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1answer
396 views

Is the Cirrus SR22T a turbo-prop? Or does in just have a turbocharger?

Is the Cirrus SR22T a turbo-prop? Or does in just have a turbocharger like in a car?
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1answer
156 views

Could low pressure compressor blades be made of aluminum?

With the compressor blades on a gas turbine, could the low pressure blades be made of aluminum, or would it be catastrophic? Edit: Like the 6061 alloy.
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2answers
250 views

Is turboshaft fuel efficiency affected by N2 loading?

When using a free power turbine turboshaft, does fuel burn get affected by N2 loading? I am asking as I want to in the future bench test a turboshaft for fuel burn, but I don't know if the loading ...
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2answers
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What is this on the starboard engine of the Dash 8?

On the inside of the starboard engine of the Bombardier Dash 8 Q400 there is a small aerofoil shaped object* protruding from the casing. There also appears to be pipes protruding from the end of it. ...
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1answer
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What is the purpose of a reverse-flow orientation for turbo-prop aircraft?

If I decide to utilize a PT6 (ignoring for now the cornucopia of variants) as the turbine engine I will be using on my newly designed turbo-prop aircraft, do I then decide how I will orient the engine ...
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3answers
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Why are the top speeds for jet engines higher than for propellers?

I realize turbines are more efficient than piston engines, but if that were true, then why don't turbo-props reach jet speeds?
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1answer
2k views

How does a turboprop engine work? [duplicate]

I don't understand how it works, can someone provide me with details?
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1answer
906 views

How does this fuel pump work?

This question is about the fuel pump controlled by the hydro-mechanical fuel control unit. This is part of a fuel system for a turboprop engine, described on this page which actually comes from a ...
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1answer
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How do blade cuffs help cool the engine?

How does the blade cuff (a fairing of suitable airfoil shape used to cover the shanks of propeller blades in order to reduce the aerodynamic losses) help cool the engine?
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1answer
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What happens when a propeller is placed in beta while feathered?

Could someone explain beta range to me? What happens when we set the throttle control lever to the beta range (reverse thrust) while the propeller blades are in the feathered position? Will the ...
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2answers
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Why is the bypass ratio of a turboprop higher than turbofan?

Whenever, I come across turboprop, the author always mentions that they have higher bypass ratio than turbofan but no one explains the reason for this. So, is the bypass ratio higher due to higher ...
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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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1answer
1k views

What is autofeather for?

What is autofeather and when is it used?
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1answer
491 views

Is there a modern single-seat turboprop?

There seem to be a number of tandem seat turboprop trainers like the PC-9/Texan and the Super Tucano. Are there any single-seat turboprops? I am asking about modern production planes.
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Has the Beechcraft company considered building a single-engine turboprop?

I was passing a stack of magazines at a friend's office and I could have sworn I saw a cover article about a single-engine King Air. I went looking for that article and haven't been able to find it, ...
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1answer
272 views

How does the GE H75 eliminate the need for hot section inspections?

Operators of the Pratt & Whitney Canada PT6 will be familiar with the need for hot section inspections half way to TBO. General Electric is touting the lack of hot section inspection requirements ...
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1answer
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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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2answers
908 views

Why does a turboprop lag?

Compared to a [modern] turbofan/turbojet, why is the throttle response slow in a turboprop? A constant speed propeller mounted on a piston engine responds much quicker. Is the underlying reason ...
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0answers
72 views

Twin otter engine starting procedure [duplicate]

Could you please give me the steps or procedure to start the a/c twin otter gas turbine engine?
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1answer
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Which are typical rpm values for aeronautical turbines?

I wonder which of these has higher or lower rotational speed: turboshaft turbofan turbojet turboprop Does anybody know the typical speeds for these kind of engines?
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Is it possible to drive a prop directly from a jet engine without a gearbox?

I'm studying turbojets, turbofans, and turboprops. I can see that, for the latter engine configuration, a gearbox is necessary so that the propeller rotates at a lower velocity than the main ...
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1answer
873 views

What is the highest service ceiling for turboprop airplane like a Cessna 425? [closed]

What is the highest service ceiling turboprop airplane, that is fairly small, like maximum of 8 seats, and fairly cheap as well, not going over a million dollars. I looked at Cessna 425, and this ...