Questions tagged [turboprop]
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 TBM 850 checklist calls for high idle during taxi
According to the TBM 850 checklist, at 13% NG you introduce LO Idle. But before taxi all TBM 850 pilots select high Idle. I was under the impression that high idle is selected for takeoff. Anybody ...
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Why do only turboprops have ground/flight idle selections?
Why is it that only turboprops have a pilot controlled flight/ground idle and not jets?
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Which engine is more financially economical to operate, a turboprop or gasoline engine?
I've seen a discussion about this somewhere before. I'm aware that there's no real way to calculate this. So rather then comparing weight and volume for efficiency, let's compare prices. Which engine ...
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Are there any twin-engine turboprop airplanes with FADEC and 6 seats?
Are there any twin-engine airplanes with FADEC with 6 seats? Is there nothing equivalent to DA62 in the turboprop world with slightly bigger interior and club seats?
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What is this indication on most turboprops?
What is the small fan I've seen on different turboprops?
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What is the EGT of a turboprop engine?
I am looking for a range of temperature of the exhaust stubs of a turboprop engine, typically a P&W one.
However, I am not able to find such information on P&W's technical documentations ...
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Is there a reason for the difference in turbo prop exhaust placement?
The TBM 940 and Cessna caravan both have the PT6A turbo prop engine. The sister caravan has one single exhaust stack under the engine cowling, and almost all other small turbo props have dual exhaust ...
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Where is the thrust of a turbojet felt? [duplicate]
At a high level, this is simple. Hot gas goes out the back, and Newton's third law says the engine is pushed forwards. But when you look inside the engine, it's less clear which part experiences the ...
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Cessna 208B Caravan various emergencies
looking for help from some experienced Caravan pilots.
So for the 208B Caravan we have our emergency checklist,
which for engine failure tells us to power idle prop feather and fuel lever to idle and ...
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What does the Permanent Magnet Alternator do exactly and how works?
From T6b Naval manual:
A dedicated permanent magnet alternator (PMA), mounted on the reduction gearbox, powers the PMU. The PMA supplies 32 VAC, which the PMU converts to DC. The PMU automatically ...
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where is the centrifugal force the flyweights experience coming from?
The T6b uses a PT6-68 engine which has a variable pitch, constant speed, feather, and non-reversible prop system. There is only one lever in the cockpit which regulates Torque and the Power Management ...
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Evaluating maximum TAS for a given available power
This is the original problem:
A turboprop aircraft with a weight of 162 kN is equipped with a power plant with a power derating model described by $\frac{P_A}{P_{A,0}} = 0.9\sigma^{0.75}$, where $P_{...
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Why is more angle of bank (AOB) at the best gliding speed giving less altitude loss?
Reading the manual for the T6b (turboprop aircraft single engine), it says different altitude losses during a 360 degree turn, holding 125 kts (the best glide for range speed), power is either dead, ...
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Why are spins not allowed below 10k ft msl in the T6b?
Reading through the manual I see that spins are not allowed below 10000 msl in this turboprop aircraft, the t6b, the reason that is written in the manual is as follows, quote:
"Spins below 10k ...
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Why does the gas turbine recuperator hugely increase efficiency but slightly decrease the peak power?
I understand that the heated intake air will burn more efficiently with the fuel and that's why recuperators increase efficiency. The part I don't understand is that if efficiency is going up, why isn'...
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Is this part of the engine intake an aerodynamic component? [duplicate]
Just was seeing this image:
And found out there is a component that split up the intake into two parts. Is this part of the engine intake an aerodynamic component? if so, how does it work?
Edit: I ...
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Could an executive configured ATR 42-600 get 2000nm range?
Say you wanted to outfit an ATR 42-600 for executive transportation like a smaller version of an Airbus ACJ 220. For example, 2 living areas of 4 rows, 1 sleeping area of 3 rows (a double below and a ...
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How come a turboprop can't reach speeds as high as a turbofan?
I understand that turbofan powered aircraft can reach much faster speeds than turboprops like the C130 Hercules, and I can't imagine a turbofan turboprop powered 737 would be of any use really, but as ...
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Why does the torque curve of free shaft gas turbines keep gradually dropping as RPMs increase?
When i look at the output shaft torque curve of a free shaft gas turbine i can see that they are almost like an electric motor. It makes peak torque at very low rpm and then torque keeps gradually ...
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How exactly is the free shaft part of a gas turbines controlled?
As you can see in the picture, the free turbine still gets the same exhaust gas that the main turbine gets.
How can it exactly spin freely from the main turbine?
How can the free shaft even stay ...
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How to compute the mass flow rate for a turboprop at cruise given the static sea level value?
I am trying to obtain the mass flow rate of the Allison T56-A-15 used on the C130H at cruising altitude (so as to solve the Joule-Brayton cycle at cruising altitude). I know from "Turboshaft, ...
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how is ITT peak temperature affected by altitude during an airstart?
another T-6 Texan II (turboprop aircraft) question. When reading the airstart prodedure in the engine failure during flight section of the manual, I found something that Id appreciate the ...
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How does the weight affect the altitude that can be reached by trading speed after a total engine failure?
I recently read in the manual for The Beechcraft T-6 Texan II (a turboprop aircraft) about engine failure during flight at different altitudes and the gains from pitching up after the engine failure ...
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Why do turboprops not have a thrust value in the specifications? [duplicate]
When looking through aircraft engine specifications, turbofans always provide a thrust value, e.g. in JT8D engine: https://prattwhitney.com/products-and-services/products/commercial-engines/jt8d
In ...
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What does the small needle + scale on this turboprop's N1 gauges indicate?
Look at these weird turboprop N1 gauges:
I'm referring to the smaller needle at the top of each PERCENT RPM labelled N1 gauge. What does it display ? I have no ...
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How does the velocity of a turboprop engine relative to the airplane change when a plane is banking?
I saw this YouTube video recently:
And in it, a turboprop engine propeller and gearbox comes out and slashes across the underbelly of the plane, crippling the aircraft....
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What is the meaning of "Contra-Rotating Propeller Increases Efficiency"? How is it calculated?
This picture is taken from here.
In that video is mentioned that contra-rotating propeller increases efficiency up to 6-16%. Regardless of the number that could be vary from one airplane to another, ...
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What is the correct cruise operating temperature for the PT6A-60 in a King Air 350?
Why are King Air 350 PT6 operating temps the way they are? I’ve been taught to cruse at 785 as per Beech/Textron maintenance recommendations. My non typed not really qualified FO claims I am ruining ...
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Why are the cargo doors of the C2 Greyhound open during flight, even when not delivering cargo?
You may find this strange, but I have a love for the C2 Greyhound and E2C Hawkeye. I noticed that when flying, the C2 Greyhound often opens its cargo doors. Is this for a better view, training, or ...
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Why do the replacements for craft like the C2 Greyhound and E2 Hawkeye still use turboprops?
These two airplanes are some of the classics in naval history, but replacements for them exist. When taking a look at them, they do have some improvements, but I still have one question. Why do they ...
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What is the danger in the over-use of reverse thrust during ground operations when operating a turboprop powerplant?
I'm new to turboprops, and everyone I've flown with seems extremely cautious about using only the bare minimum reverse thrust after touchdown and never during forward taxi.
Why might that be?
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Do aircraft engines come with electric generators?
For turbojet/fan/prop engines, do they come with an electric generator when delivered to aircraft manufacturers, or it is something that the aircraft manufacturer has to find or make themselves?
I am ...
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Why have propeller engines never been mounted on the tail in production transport aircraft?
Recently, Embraer teased this concept.
Unlike jet engines, I have never heard of a production airliner or executive aircraft that mounted propellers on the tail like this.
From the source:
the new ...
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Do turbine engines contain engine oil and fire-extinguishing fluid?
When aircraft turbine engine companies sell their engines to aircraft manufacturers, does the product contain the tank and pipe for engine oil and fire extinguishing fluid in the same package? Or is ...
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Can you have a Hybrid Turboprop-Jet engine?
To start things off I am writing this to gain information for vehicles in a story, so I am more so looking for theoretical possibilities, unless there are real world examples.
The background and my ...
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Which popular turboprop engine feathers its propeller blades with each shutdown?
Chapter 12 of the FAA Airplane Flying Handbook, discussing multiengine flying, goes into quite a bit of detail in the propeller section about how most feathering-propeller-equipped engines on ...
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How does a C208B's climate control system that utilizes bleed air for cabin heat work?
I'm studying the systems on my first turbine-engine aircraft, specifically, a C208B.
I know that there is "bleed air heat" that mixes with re-circulated cabin-air. I know that the bleed air ...
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What's up with the long exhaust stack I saw on a Cessna Caravan?
Our local airport is regularly visited by Cessna caravans flying cargo. This week I saw one parked outside the FBO building that had its exhaust stack bent down to lead under the cowling, where it was ...
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Does the engine mount of a turboprop engine in an aircraft experience engine torque?
When the turboprop engine is active, the propeller shaft rotates and causes the propeller to rotate as well, which in turn generates thrust. The propeller shaft rotates because of the torque (or ...
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What would be the advantage of a Puller vs. Pusher configuration on Embraer's new Turboprop?
Embraer recently teased a turboprop aircraft with aft-mounted, open rotor engines. Why would this aircraft not use a pusher configuration?
The reasons that are frequently stated as a benefit for a ...
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What does the "MAX EMR PWR" lever do in a Quest Kodiak?
On a photo of the Quadrant of a Kodiak Quest 100 there was an additional red lever to the left of the throttle (black handle) labeled with "MAX EMR PWR". Can anyone explain what what this ...
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What is "alternate takeoff" in this PT6A performance table?
I am flight mechanic, and I would like to know about this performance limitation:
What is the definition of alternate take off?
Why is the alternate take off temperature limit (ITT) lower than max. ...
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Is it safe to use a propeller plane to fly commercially over the Tibetan Plateau?
I saw this youtube video today: Flying over Mt Everest. A lovely view of stunning nature - quite spectacular. However, I looked up the plane - or at least what I think is the plane - and found that it ...
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How to decide the diameter of a propeller and number of propellers needed in a UAV I am designing? [closed]
I want to design a turboprop aircraft. I know all the design parameters such as lift, thrust, weight etc at a given flight stage. I want to know what the size of the propeller should be.
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What is prop RPM control logic on PC-12?
Pilatus PC-12 has a constant speed propeller, but it does not have a prop control lever in cockpit, just a power lever and small fuel on/off lever.
So how does it determine the prop RPM? Does it ...
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Why do propellors have white markings on their tips? [duplicate]
Why do propellors have white markings on their tips?
Here are a couple of examples:
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What is the difference between RTOP, MTOP, and MCP?
I am currently learning how to fly the SD3-60 (Shorts) Aircraft, and I am trying to gain an understanding of RTOP (reserved take off power), MTOP (max take off power), and MCP (max continuous power). ...
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How does the maintenance cost of turboprops compare to turbofans?
I was initially under the impression that the added complexity of gearing in a turboprop would lead to more maintenance. Then I found out geared turbofans are becoming fairly common so there should be ...
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How does one choose the number of blades and the diameter required for a turboprop propeller?
I am interested in the preliminary design of a regional aircraft that uses turboprops as the propulsion method.
Following considerable research online about propeller design (disk theory, BEM...) I am ...
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Do any regional turboprop aircraft have leading edge high lift devices?
I'm currently working on an aircraft design project for a regional turboprop. I wanted to know if there are any regional TP's with leading-edge devices. It seems that a lot of them have deicing boots ...
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