Garrett JFS 100-13A Turboshaft engine in homebuilt aircraft?

Discussion in 'Firewall Forward / Props / Fuel system' started by whiteknight, Apr 27, 2012.

Help Support HomeBuiltAirplanes Forum by donating:

  1. Apr 27, 2012 #1

    whiteknight

    whiteknight

    whiteknight

    Active Member

    Joined:
    Jan 20, 2011
    Messages:
    36
    Likes Received:
    0
    Location:
    Medford, Oregon/USA
  2. Apr 28, 2012 #2

    Topaz

    Topaz

    Topaz

    Moderator

    Joined:
    Jul 30, 2005
    Messages:
    13,436
    Likes Received:
    5,132
    Location:
    Orange County, California
    Well, you could write Scott Ehni and ask him, since he's done it. His e-mail address is on the site you link.
     
  3. Jul 16, 2014 #3

    DefiantSix

    DefiantSix

    DefiantSix

    Member

    Joined:
    Aug 3, 2013
    Messages:
    20
    Likes Received:
    10
    Location:
    Sandy, Utah
  4. Jul 16, 2014 #4

    Aviator168

    Aviator168

    Aviator168

    Well-Known Member

    Joined:
    Sep 21, 2012
    Messages:
    2,196
    Likes Received:
    245
    Location:
    Brookville, NY. USA
    Wait. That's an APU. Are you sure you want to put your life on an APU?
     
  5. Jul 16, 2014 #5

    bmcj

    bmcj

    bmcj

    Well-Known Member HBA Supporter

    Joined:
    Apr 10, 2007
    Messages:
    12,563
    Likes Received:
    4,587
    Location:
    Fresno, California
    Oft times, the difference between a propulsion engine and an APU engine is only the way it is housed and used. The core may be identical. That said, I cannot say if that is the case for this particular engine/APU. Someone with specific knowledge of this engine will have to answer that.
     
  6. Jul 16, 2014 #6

    TFF

    TFF

    TFF

    Well-Known Member

    Joined:
    Apr 28, 2010
    Messages:
    11,138
    Likes Received:
    3,017
    Location:
    Memphis, TN
    All the baby turbine helicopters run on APU engines; they are much safer than the small piston versions. A small turbine is cool, but 12 gallons an hour cruse is not too good for 100 hp when a 0-200 is 5 gal an hour. 12 gal an hour cruse is 200-250 hp certified engine.
     
    henryk likes this.
  7. Jul 16, 2014 #7

    Aviator168

    Aviator168

    Aviator168

    Well-Known Member

    Joined:
    Sep 21, 2012
    Messages:
    2,196
    Likes Received:
    245
    Location:
    Brookville, NY. USA
    The parts inside an APU is only guaranteed to run at one speed - WOT.
    Turbine pros and cons in Homebuilts
     
  8. Jul 16, 2014 #8

    DefiantSix

    DefiantSix

    DefiantSix

    Member

    Joined:
    Aug 3, 2013
    Messages:
    20
    Likes Received:
    10
    Location:
    Sandy, Utah
    Reading the article I linked to carefully, it says that the power plant in question isn't an APU - intended for use on the ground, primarily - but a STARTER. The difference is that the JFS-100 was tested at altitudes up to 30,000 feet. The article also describes the choice of the CH-701 as the testbed vehicle for the engine was something of a safety measure, and not intended to be a demonstration of the "best use" application of the engine.

    All in all, it sounds as if Scott Enhi is feeling his way through the applicability of the technology as much as the rest of us.
     
  9. Jul 17, 2014 #9

    TFF

    TFF

    TFF

    Well-Known Member

    Joined:
    Apr 28, 2010
    Messages:
    11,138
    Likes Received:
    3,017
    Location:
    Memphis, TN
    APUs and Starter/GPUs are generally the same engine units. One mounts in an airplane and one mounts on a cart. We had one GPU/Starter at the airline that had big compressor stalls as it started. Always the new guy got that one to watch him jump.
     
  10. Jul 17, 2014 #10

    fredoyster

    fredoyster

    fredoyster

    Well-Known Member

    Joined:
    Mar 21, 2012
    Messages:
    333
    Likes Received:
    103
    Location:
    Monterey Bay, CA
    I have had a lot of good talks with Scott. He said that if he couldn't talk me out of doing one of these turbines in a CH750 that he'd help me any way he could. He is both an impeccable craftsman and a gentleman, but he did talk me out of it. The level of analysis and workmanship needed to do this sort of thing successfully is extremely rare in experimental aviation these days, and Scott is up to the task. I'm not, and I doubt that most of us are. But, talk with him and see for yourself.
     
  11. Jul 19, 2014 #11

    Aviator168

    Aviator168

    Aviator168

    Well-Known Member

    Joined:
    Sep 21, 2012
    Messages:
    2,196
    Likes Received:
    245
    Location:
    Brookville, NY. USA
    I took a second look. It would probably be safe to use an APU IF a constant speed prop is used and it is directly geared to the shaft.
     
  12. Jul 19, 2014 #12

    TFF

    TFF

    TFF

    Well-Known Member

    Joined:
    Apr 28, 2010
    Messages:
    11,138
    Likes Received:
    3,017
    Location:
    Memphis, TN
    These things throttle, but jet engines do not throttle like a piston. You throttle the governor, but the governor is in control. Constant speed is a must because all jets have narrow powerbands. Turboprops really throttle by changing blade pitch and the gov keeps RPM constant.
     
  13. Jul 19, 2014 #13

    Aviator168

    Aviator168

    Aviator168

    Well-Known Member

    Joined:
    Sep 21, 2012
    Messages:
    2,196
    Likes Received:
    245
    Location:
    Brookville, NY. USA
    This trick is to have the prop directly gear to the primary shaft unlike a normal turbo prop which is driven by a separate multistage turbine.
     
  14. Mar 30, 2015 #14

    henryk

    henryk

    henryk

    Well-Known Member

    Joined:
    Mar 8, 2010
    Messages:
    4,547
    Likes Received:
    417
    Location:
    krakow,poland
    Silnik turbinowy z detonacyjn┬▒ komora spalania

    -DTR-350 with rotating detonation chamber...circa 10% moore economic.
     
  15. Mar 31, 2015 #15

    TFF

    TFF

    TFF

    Well-Known Member

    Joined:
    Apr 28, 2010
    Messages:
    11,138
    Likes Received:
    3,017
    Location:
    Memphis, TN
    Can you afford it?
     
  16. Mar 31, 2015 #16

    Aviator168

    Aviator168

    Aviator168

    Well-Known Member

    Joined:
    Sep 21, 2012
    Messages:
    2,196
    Likes Received:
    245
    Location:
    Brookville, NY. USA
  17. Mar 31, 2015 #17

    henryk

    henryk

    henryk

    Well-Known Member

    Joined:
    Mar 8, 2010
    Messages:
    4,547
    Likes Received:
    417
    Location:
    krakow,poland
    Gun-Engine

    =0.5 l gasoline + 4 l water/ 100 km!
     

Share This Page

arrow_white