PC-12 Crash In South Dakota, 9 dead, 3 survivors (CFIBlizzard?)

Discussion in 'Aviation Mishaps' started by FlyingElvii, Nov 30, 2019.

  1. Omalley1537

    Omalley1537 Line Up and Wait

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    sure doesn’t to me.
     
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  2. benyflyguy

    benyflyguy En-Route

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    Fuel contamination? We always say that right.
     
  3. Tarheelpilot

    Tarheelpilot En-Route

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    no. Not even a little bit. Also doesn’t look to be feathered, Just at the pitch stops.
     
  4. sourdough44

    sourdough44 Pattern Altitude

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    The report mentioned the plane sat out in the weather for the 27 hours it was in the ground. Besides the usual surface contamination, snow gets blown in various places.
     
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  5. hindsight2020

    hindsight2020 En-Route

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    Buh buh huh turbine singles don't fail on takeoff.
     
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  6. Bill

    Bill Touchdown! Greaser! PoA Supporter

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    Does the PC-12 inlet have bleed air heat, or some other type of heat?
     
  7. TipTanks

    TipTanks Pre-takeoff checklist

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    They have a bleed air heated intake, and of course inertial separator.
     
  8. Jamie Kirk

    Jamie Kirk Line Up and Wait

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    What would cause the turbine motor to quit? And that field looks pretty flat, you would think the pilot could have landed it when the engine quit.

    The report also says it sat outside overnight and someone else said there are no services there. With that heavy snow could it have been iced up before it even took off?
     
  9. sourdough44

    sourdough44 Pattern Altitude

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    CBCD5C3C-1784-4B2E-8472-6F427F2A9EB1.png
    500 OVC isn’t a lot of time to land under control in a cornfield. The time may be slightly off, not by much.
     
  10. dbahn

    dbahn Pre-takeoff checklist

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  11. hindsight2020

    hindsight2020 En-Route

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    seems legit.
     
  12. airdale

    airdale Pattern Altitude

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    100LL?
     
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  13. Htaylor

    Htaylor Pre-takeoff checklist

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    Intake does not use bleed air from the engine. The intake is heated with exhaust heat and is always on. Cabin is heated with turbine bleed air.
     
  14. hindsight2020

    hindsight2020 En-Route

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    Not so. The inverse case is true however.
     
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  15. Bell206

    Bell206 En-Route

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    FYI: Most PT-6s can run on avgas up to 150 hours between O/Hs with some Ag apps allowed to use diesel for a select time. So don't think 100LL an issue.
     
  16. Kritchlow

    Kritchlow Final Approach

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    And that’s approved...
    In all honesty most turbine engines will likely run on just about anything flammable.
     
  17. weilke

    weilke Touchdown! Greaser!

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    There have been fatals due to fuel contamination, but those involved waterous contaminants such as cleaning solution and diesel exhaust fluid.
     
  18. Omalley1537

    Omalley1537 Line Up and Wait

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  19. Tantalum

    Tantalum Final Approach

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    The media is trash. Dangerously misinformative.
     
  20. 47PILOT

    47PILOT Pre-takeoff checklist

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    Couldn’t agree more !!
    And then tell you “it was the lottery’s fault”
     
  21. Z06_Mir

    Z06_Mir Pattern Altitude

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    Full disclosure: I don't fly the NG, just the older ones.

    Not having the inertial separator on could do it. Maybe he wanted the probes and prop on and didn't want pusher ice mode activated? Or maybe it was a true mechanical failure of the PT6.. we don't know yet. We won't for quite awhile. The PC12 glides well, but you're not gonna make it back to the airport taking off into 500 overcast and a half mile.
     
  22. AKBill

    AKBill En-Route

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    What rate of climb would you expect in a PC-12 at max gross weight?
     
  23. Sam D

    Sam D Cleared for Takeoff

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    My understanding of the PT-6 is that there is no mechanical linkage from the engine to the propeller. So, I don’t think you can connect “prop doesn’t look like it was turning” to engine problem as directly as you can on a piston engine.
     
  24. Bill

    Bill Touchdown! Greaser! PoA Supporter

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    Huh? So how then does the prop turn? Last time I checked the prop was connected to the turbine section via a gearbox and shaft.
     
  25. nauga

    nauga Administrator Management Council Member PoA Supporter

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    Unless they support our opinion. Then they are the gospel truth.

    Nauga,
    and a strong BS filter
     
  26. Tarheelpilot

    Tarheelpilot En-Route

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    it’s a free turbine but there is still direct mechanical connection between prop and engine.

    inside the hot section there are multiple gas turbines that extract energy from the gas flow. On set is attached to a shaft that runs the compressor and engine accessory gear box.
    The other set is attached to a different shaft that goes the opposite direction and drives the gearbox and prop. There is no mechanical connection between these two turbine sections.

    if you walk up to an aircraft with a PT-6 and turn the prop the only thing you are turning is the gearbox and power section turbine wheels. The first stage turbine, compressor section and accessory gearbox do not move.

    do the same thing to @Ted DuPuis MU-2 and the entire engine spins because it’s not a free turbine. Everything inside is connected.
     
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  27. Ted

    Ted The pilot formerly known as Twin Engine Ted Management Council Member

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    The above is correct. On the TPE-331 you have a single shaft that connects the gearbox, compressor (2 stages) and turbine (3 stages). In fact, that's part of why you see people (like me) spinning the props on TPE-331 engines after shut down. Doing so spins the compressor, which moves air through the compressor, combustor (that's the important part) and turbine section. That airflow helps to cool off the fuel nozzles and prevent coking.

    Interestingly, the King Air B100 is the only TPE-331 powered aircraft to not recommend that, apparently because Beechcraft found it undignified to tell the pilots to spin their propellers.
     
  28. Tarheelpilot

    Tarheelpilot En-Route

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  29. Tarheelpilot

    Tarheelpilot En-Route

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    Referencing the above picture the prop would be bolted to left hand side of engine and accessory gearbox lives on the right side.

    starting from the intake on right side there are 5 stages of compression then three stages of turbine.

    Continue from right to left the first turbine wheel is driving all the stuff to the right side. There is a small space to make room for bearings and then two wheels driving the gear box/prop to the left.

    if you turn the prop the only thing turning inside would be the gear box and the two turbine wheels on far left of picture. Everything else would be stationary.
     
  30. Tantalum

    Tantalum Final Approach

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    Cool note, thanks! Question though.. do the free turbine planes not have this cooling / coking problem? What about regular turbofan engines? Is this a "problem" unique to the Garrett?

    :rofl:
     
  31. Ted

    Ted The pilot formerly known as Twin Engine Ted Management Council Member

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    To be honest I'm not even sure how much of an issue it truly is on the Garrets, but it's cheap insurance, doesn't hurt anything, and might help. I know that every... I think it's 400 hours I'm supposed to have the fuel nozzles cleaned. Last inspection I had it done on one engine, this coming inspection I'll have it done on the other. Basically what happens is the fuel spray becomes less atomized if they coke up (more of a stream than a spray) and that can produce localized hot spots which can burn through expensive parts like combustors, turbine wheels, stators, etc.

    However to answer your question, yes, every other turbine engine has the potential for this to occur. When I worked at Meatball Aircraft Engines, we did see issues with oil coking up, most notably when airlines did not observe the required cool-down period on the engine. And a lot of them didn't. Land, get off runway, shutdown one engine, taxi in on the other to save fuel. However I don't recall any fuel nozzle coking issues coming up.
     
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  32. Kenny Phillips

    Kenny Phillips En-Route

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    That's generally true. If bad fuel or bad engine operation caused this, it's not a failure of the engine.
     
  33. Kenny Phillips

    Kenny Phillips En-Route

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    Over 1,000 fpm, perhaps more in cold air.
     
  34. benyflyguy

    benyflyguy En-Route

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    That might be one reason. But the MAIN reason you do it is because it looks cool...
     
  35. Ted

    Ted The pilot formerly known as Twin Engine Ted Management Council Member

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    The main reason I do it is because all the instructors I had on TPE-331s have said to do it. I have enough other things to do after landing besides spend time answering "What're you doing, rewinding the rubber band in the engines?"

    The MU-2 is what looks cool. ;)
     
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  36. Rockymountain

    Rockymountain Pre-takeoff checklist

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    This would be, if a true statement by the deceased, a personal interpretation of the Church doctrine. The Church of Jesus Christ of Latter Day Saints has no such formal doctrine. People are quite free to interpret how they honor the Sabbath day, with only very loose guidelines. They may have wished to be back in time for Church, and may have had responsibilities that they felt they needed to honor. But no restriction on flying or traveling. Very sad event, and a very generous and charitable family devastated.
     
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  37. James331

    James331 Ejection Handle Pulled

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    Off the cuff, initially north of 1200

    I see DZ and near zero C, wonder if that turned into some freezing precip, heavy, and with all the area those flaps add at 15 for takeoff to the wing, if your wing wasn’t doing all the work it could do due to contamination, maxed out weight going to flaps 0 shortly after takeoff, thus shrinking your wing, and what lift it is making to counter the weight
     
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  38. Rockymountain

    Rockymountain Pre-takeoff checklist

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    Yes it does look like it hit under power. 2 of the 4 blades are bent, and that is a solid metal prop. It will stop the engine when it hits something hard.

    2.jpg

    Like this Meridian that flew into the ground short of the runway under power in low IFR conditions with 3 bent and one perfect blade. These solid metal Hartzell paddle props are nearly indestructible.

    1.jpg
     
  39. Bill

    Bill Touchdown! Greaser! PoA Supporter

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    Though you'd look cooler in a Duke.
     
    Last edited: Dec 4, 2019
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  40. bobmrg

    bobmrg En-Route PoA Supporter

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    Given what has been said about the height of the T-tail and the lack of deicing at the airport, I'm guessing tailplane stall....not engine related in any way.

    Bob
     
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