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Thread: GA Turboprop

  1. #1

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    GA Turboprop

    Hi all

    I'm doing some research on turboprop engines for general aviation, and I wonder what people here see as the advantages and disadvantages of a turboprop engine? Or just opinions in general..

    Advantages:
    • ..
    • ..
    Disadvantages:
    • ..
    • ..
    I will really appreciate your input!

    Thank you,
    Kristoffer Jensen

  2. #2

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    It sounds bad and smells worse, and it costs a lot more than a piston engine, and may need to fly high always requiring an IFR flight plan in order to get good fuel economy.

  3. #3

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    Quote Originally Posted by Bill Greenwood View Post
    It sounds bad and smells worse, and it costs a lot more than a piston engine, and may need to fly high always requiring an IFR flight plan in order to get good fuel economy.
    Do you know how much higher fuel consumption a turboprop have compared to a piston engine?

  4. #4

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    Quote Originally Posted by kjensen View Post
    Do you know how much higher fuel consumption a turboprop have compared to a piston engine?
    It's not enough difference to get excited about. Of course a turboprop has numerous advantages, fewer moving parts, more efficient propeller dia/speed, ability to use a wide range of fuels, reliability. The big disadvantage is cost. With current technology, GA is not quite ready to accept the additional expense.

  5. #5

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    I'm shocked in this day and age we don't have a nice IO550 alternative turboprop. Something in the 300-400HP rating that get's comparable fuel burn (probably higher). I think it would be a great seller, but as stated, cost is the big thing. But think about how much you save in MX, reliability, not replacing cylinders all the time, just overall hassle. The TBO on a turboprop could be much higher too. Just do a 2k hr hot section inspection, then fly it to 4k hours easy.

    There's got to be enough smart people that can get together and build something that fits those parameters.

  6. #6

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    [QUOTE=uavmx;14355]I'm shocked in this day and age we don't have a nice IO550 alternative turboprop. Something in the 300-400HP rating that get's comparable fuel burn (probably higher). I think it would be a great seller, but as stated, cost is the big thing. But think about how much you save in MX, reliability, not replacing cylinders all the time, just overall hassle. The TBO on a turboprop could be much higher too. Just do a 2k hr hot section inspection, then fly it to 4k hours easy.

    So in terms of technology, is a turboprop considered better than a piston engine? Who makes the turboprops available today in the 300-400hp range?

  7. #7
    steveinindy's Avatar
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    Quote Originally Posted by kjensen View Post
    Do you know how much higher fuel consumption a turboprop have compared to a piston engine?
    The difference between the fuel consumption of a high-end reciprocating engine and a turboprop aren't that different if you look at them on a pounds of fuel per horsepower per hour ratio. Of course, when you have an engine that produces 800-1000+ horsepower, it's going to consume more fuel than a 150-200 hp engine. The actual fuel consumption is going to vary based on the engine (for example, the Honeywell/Garrett TPE variants tend to get better economy than a PT-6) and the altitude you're flying at.

    Keep in mind that this forum has a distinct lean towards the "low and slow" side of aviation so you're going to get comments like Bill's. A more inclusive forum like http://www.homebuiltairplanes.com/forums might be a better place to ask that. That's normally where I go when I have technical questions about things like turboprops (which is what is the powerplant for my design BTW).


    may need to fly high always requiring an IFR flight
    Which isn't a bad thing in the mind of those of us who are looking for point A to point B travel. One of the major drawbacks to this forum is the general disdain towards talking to ATC so people tend to look at you like you have two heads or make comments like "You know if you want to go above FL180 you have to talk to ATC all the time right?" when you mention things like turboprops or other high altitude cruise.


    I'm shocked in this day and age we don't have a nice IO550 alternative turboprop. Something in the 300-400HP rating that get's comparable fuel burn (probably higher).
    Why do you think people switch out the IO-550 and other similar engines for a more powerful turboprop. The benefits of a turboprop become less clear when you're going slower which is what a 300-400 hp range would entail.
    Unfortunately in science what you believe is irrelevant.

    "I'm an old-fashioned Southern Gentleman. Which means I can be a cast-iron son-of-a-***** when I want to be."- Robert A. Heinlein.



  8. #8
    steveinindy's Avatar
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    Who makes the turboprops available today in the 300-400hp range?
    Rolls-Royce has one but honestly it's not really worth it.

    So in terms of technology, is a turboprop considered better than a piston engine?
    It depends on what you're looking to do and who you ask.
    Unfortunately in science what you believe is irrelevant.

    "I'm an old-fashioned Southern Gentleman. Which means I can be a cast-iron son-of-a-***** when I want to be."- Robert A. Heinlein.



  9. #9
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    Brayton cycle turbines have very high power-to-weight ratios, but suffer from poor thermal efficiency, which is the main reason why many land-based gas turbine plants are going cogeneration or adding a rankine bottoming cycle. (There is even development on magnetohydrodynamic generator bottoming cycles.. although normally MHD is used as a top cycle, with a rankine bottom)
    Last edited by tdm; 04-14-2012 at 02:55 PM.
    學而不思則罔,思而不學則殆。

  10. #10

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    There are three primary advantages of turboprops. First, they are more reliable than piston engines. Second, they are smaller and lighter than piston engines. Third, they can run on a number of more common fuels, including diesel and (for some engines) gasoline.

    Their disadvantages are that they are expensive to purchase, feed (they *typically* use 50% more fuel per hp delivered than a reciprocating engine), and maintain, relative to piston engines. Also, they are loud and their exhaust smells like a BBQ grill gone wrong.

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