Piston versus turbine engines.

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C.W.E.
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Piston versus turbine engines.

Post by C.W.E. » Mon Aug 12, 2019 3:20 pm

Which are the more difficult to operate and why?
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C-GGGQ
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Re: Piston versus turbine engines.

Post by C-GGGQ » Mon Aug 12, 2019 3:39 pm

I think that's all going to come down to the specific turbine and specific piston. Some turbines have temp limiters and torque limiters and a new pilot can't mess much up, or they have neither and more caution has to be used. Piston has a less involved start process (usually) but depending on the model, you can over boost the turbo or crack a cylinder head but chopping the power back too aggressively. Neither generic type piston vs turbine is inherently difficult to operate, but pt-6 or Garret, Lycoming, or wasp radial each has its peculiarities.

Now maybe you mean in a business sense. More difficult to operate as a business. Avgas vs jet, maintenance, tbo, on condition and all the other details involved
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Mapleflt
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Re: Piston versus turbine engines.

Post by Mapleflt » Mon Aug 12, 2019 6:05 pm

I see this as an apples & oranges, no reasonable operational comparison can be between these two forms of propulsion other then possibly the throttle/thrust lever.
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Re: Piston versus turbine engines.

Post by C.W.E. » Mon Aug 12, 2019 6:39 pm

no reasonable operational comparison can be between these two forms of propulsion other then possibly the throttle/thrust lever.
A piston engine has more levers than just a throttle and for sure piston engines have their own throttle controlled issues such as shock cooling and reverse bearing loading that can cause real serious damage if not operated properly.

The engine I found most susceptible to improper handling was the Wright 1820 on the Douglas R4D-8, that sucker was really temper-mental. :mrgreen:

My favourite engine was the Garrets on the Turbo Commander.
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switchflicker
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Re: Piston versus turbine engines.

Post by switchflicker » Mon Aug 12, 2019 6:52 pm

piston engine has more levers than just a throttle and for sure piston engines have their own throttle controlled issues such as shock cooling and reverse bearing loading that can cause real serious damage if not operated properly.

The engine I found most susceptible to improper handling was the Wright 1820 on the Douglas R4D-8, that sucker was really temper-mental. :mrgreen:

My favourite engine was the Garrets on the Turbo Commander.


Why didn't you just say that?
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shimmydampner
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Re: Piston versus turbine engines.

Post by shimmydampner » Mon Aug 12, 2019 9:23 pm

C-GGGQ wrote:
Mon Aug 12, 2019 3:39 pm
Piston has a less involved start process (usually)
That's not been the case for any piston I've flown, whereas every turbine has been about as complicated as throwing a match into a puddle of kerosene. Operationally less involved as well. Keep the needles out of the red. Not exactly rocket appliances. No cowl flaps, cowl shutters, carb heat, carb temps, EGTs, CHTs, mixture, turbos, stage cooling, shock cooling, etc to worry about. Gotta love Pratt.
YMMV
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Re: Piston versus turbine engines.

Post by Schooner69A » Tue Aug 13, 2019 7:01 am

By and large; piston engines are the hardest to operate; jets the easiest.

And I second the motion about the Garrets on the Turbo Commander: turn the switch to initiate the start sequence. A speed switch triggers ignition and the introduction of fuel; another speed switch disconnects the starter. Engine comes up to speed; a little reverse on the throttles to get rid of the locks and you're on you way!

My time was in the Commander 1000: a delightful aircraft. Mostly flown single pilot and I enjoyed every minute of it...
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C-GGGQ
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Re: Piston versus turbine engines.

Post by C-GGGQ » Tue Aug 13, 2019 12:24 pm

shimmydampner wrote:
Mon Aug 12, 2019 9:23 pm
C-GGGQ wrote:
Mon Aug 12, 2019 3:39 pm
Piston has a less involved start process (usually)
That's not been the case for any piston I've flown, whereas every turbine has been about as complicated as throwing a match into a puddle of kerosene. Operationally less involved as well. Keep the needles out of the red. Not exactly rocket appliances. No cowl flaps, cowl shutters, carb heat, carb temps, EGTs, CHTs, mixture, turbos, stage cooling, shock cooling, etc to worry about. Gotta love Pratt.
YMMV
Fair enough, I've never personally started a turbine. I guess what I was trying to get at was in a fuel injected piston like the Navajo. Prime a couple of seconds mixtures rich. Throttle cracked and it fires up if it was hot mixtures back throttles up. Vs spooling up waiting the gauges for a hot start or hung start, adding the fuel once you're up to speed. That seems more involved to me.
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Re: Piston versus turbine engines.

Post by digits_ » Tue Aug 13, 2019 12:36 pm

C-GGGQ wrote:
Tue Aug 13, 2019 12:24 pm
shimmydampner wrote:
Mon Aug 12, 2019 9:23 pm
C-GGGQ wrote:
Mon Aug 12, 2019 3:39 pm
Piston has a less involved start process (usually)
That's not been the case for any piston I've flown, whereas every turbine has been about as complicated as throwing a match into a puddle of kerosene. Operationally less involved as well. Keep the needles out of the red. Not exactly rocket appliances. No cowl flaps, cowl shutters, carb heat, carb temps, EGTs, CHTs, mixture, turbos, stage cooling, shock cooling, etc to worry about. Gotta love Pratt.
YMMV
Fair enough, I've never personally started a turbine. I guess what I was trying to get at was in a fuel injected piston like the Navajo. Prime a couple of seconds mixtures rich. Throttle cracked and it fires up if it was hot mixtures back throttles up. Vs spooling up waiting the gauges for a hot start or hung start, adding the fuel once you're up to speed. That seems more involved to me.
If all goes well, a turbine is easier to start.
If you screw up or something breaks in a turbine, it will most likely be a very expensive bill.
A piston engine can be more sensitive to exact duration of priming, throttle position, mixture position, mag timing etc. Lots of these things can work "ok" on piston engines, and you can get old engines going, but they might require a bit of an adjustment to the starting procedure. I'm sure you've noticed that some piston engines require more priming than others or require a different throttle setting, even amongst the same airplane type or even the same airplane.

For a turbine engine, generally, you could write out a script that will always start the engine (unless something breaks).
For a piston engine, you would have to change some details on the script depending on engine condition, temperature, has the plane flown before etc, and even then, you might not get it started right away.

That said, starting a piston engine isn't rocket science either. A turbine is just generally easier and more reliable for starting.
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goingnowherefast
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Re: Piston versus turbine engines.

Post by goingnowherefast » Tue Aug 13, 2019 8:44 pm

Turbines are easier to start when everything works properly. Gotta watch for malfunctions or it could be very expensive.

Pistons are harder to start normally, but malfunctions generally mean it just won't start and the battery dies.

As for flying the engine, turbines are brain dead simple. Keep it in the green and you're good to go. Plus they're super reliable, then when they do fail, there's generally ample reserve power. Pistons have shock cooling, mixtures, turbos have their own fun games, some even have horrible propeller gear boxes. Pistons fail much more often, and are under powered when you need the power the most.
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Re: Piston versus turbine engines.

Post by P-40 » Tue Aug 13, 2019 11:20 pm

Schooner69A wrote:
Tue Aug 13, 2019 7:01 am
By and large; piston engines are the hardest to operate; jets the easiest.

And I second the motion about the Garrets on the Turbo Commander: turn the switch to initiate the start sequence. A speed switch triggers ignition and the introduction of fuel; another speed switch disconnects the starter. Engine comes up to speed; a little reverse on the throttles to get rid of the locks and you're on you way!

My time was in the Commander 1000: a delightful aircraft. Mostly flown single pilot and I enjoyed every minute of it...
Dash 10 equipped Commander's are fantastic!
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Re: Piston versus turbine engines.

Post by valleyboy » Wed Aug 14, 2019 8:40 am

Flying a piston engine, especially big round ones is an art form/intuitive while turbine/jet engines are by the numbers.
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Re: Piston versus turbine engines.

Post by Meatservo » Wed Aug 14, 2019 9:26 am

I don't think operating ANY engine is an "art form". The act of flying itself may be referred to as an art in some circumstances, but I can't think of any creativity or non-linear thinking ("outside the box" as it were) that helps one operate an engine. You either do it right or you don't. A modern turbine engine tolerates more carelessness and requires less knowledge of how the engine actually works in order to operate it safely. Note that by "carelessness" I don't mean "negligence"- I just mean less worry or "care".

In the past when small turbine engines were less ubiquitous a lot of pilots objected to "turbine time" requirements in employment adverts. They moaned that operating a piston engine properly took more knowledge and experience than operating a turbine, therefore the requirement was unfair. I think that generally the requirement existed because of the performance differences between turbine-powered aircraft and a typical piston-driven one. In the past, turbine-powered ships were extremely high-performance compared to their piston-driven counterparts. Additionally, it was inconceivable at the time that anyone with a good amount of turbine experience wouldn't ALSO have loads of piston experience anyway. Nowadays this little discussion over the merits of one type of experience over another is almost anachronistic.

I compare this to the more recent "weeding out" requirement of "glass time". I consider navigating using the cartoons on EFIS-equipped aircraft to be easier and to require less experience than maintaining situational awareness using needles. I mean the needles are perfectly adequate once you have lots of experience, but experience is expensive.

Commercial aviation is all about making the aircraft safely useable by a crew with the lowest skill, lowest training, and lowest experience-level possible. This allows the aircraft to be operated with the lowest salary possible. Advancements in technology are made initially in an attempt to create a higher level of safety for crews of a given skill level, but overall, the commercial effect is to allow an equivalent level of safety with a crew of a lower skill level.

Sorry this ended up being a bit of a stream-of-consciousness didn't it.

Anyway, yes, safely operating a piston-engine requires more attention, and knowledge, than operating a turbine engine. This shouldn't be used as an excuse not to know as much as you can about your turbine engines, nor to pay less attention to them. But that's what happens.
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Re: Piston versus turbine engines.

Post by co-joe » Wed Aug 14, 2019 5:16 pm

Non turbo pistons are pretty easy to operate, but if you compare 300+ hose turbo'd piston engines vs pt6's, the Pratts are way easier to operate. Expensive to fix if you wreck them though.
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