New jet engines

Lachlan

Lachlan

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Lachlan
I think electric airplanes are for rc guys. Real airplanes burn stuff up! Is diesel the future? What about small turboprop power plants like this one? http://www.stuttgart.engineering/specifications/

At a cost of €10,000 it wouldn’t be much more than a new overhauled 4-banger carbureted 1920’s technology tractor engine that we fly behind now.
 
This would be awesome, however: “Last Update 04.November 2017”
 
The idea of small turbine engines propelling small GA aircraft around sounds appealing, I'm sure. Who wouldn't want a similar cost engine with much greater reliability? But I imagine the costs of R&D and certification would be far too prohibitive considering how many pilots/owners would be potential customers.
 
Someone is building a twin Velocity with the little TS100s on it. Can’t wait to see that thing fly.
 
If someone designed a small turboprop system that could be configured and adapted to mount on small 2- and 4-seat airframes I think they could make enough money to stay in business.
 
I think the relevant issue isn't so much the ability to do so on a 2/4-seat air frame, it's that the certification cost and operating cost (fuel burn) don't make it economically feasible for putting around below the flight levels.
 
SoonerAviator said:
I think the relevant issue isn't so much the ability to do so on a 2/4-seat air frame, it's that the certification cost and operating cost (fuel burn) don't make it economically feasible for putting around below the flight levels.
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Yep, they swill fuel down low; any savings in price per gallon are wasted in gallons per hour.
 
RC guys pooh poohed electrics when they first came out.
"Nothing will ever replace the smell of glow fuel".
Then we all started running 2 stroke gas/oil engines.
"Nothing will ever replace gas for large scale aircraft."
Now we have electric motors that will haul real airplanes around the sky, and all the glow fuel/ 2 stroke guys all have electric RC models because it's just so much easier. and a lot less messy.
Any day now, as soon as the electrical generation technology catches up, we will all be flying ion drive airplanes.
 
Shepherd said:
RC guys pooh poohed electrics when they first came out.
"Nothing will ever replace the smell of glow fuel".
Then we all started running 2 stroke gas/oil engines.
"Nothing will ever replace gas for large scale aircraft."
Now we have electric motors that will haul real airplanes around the sky, and all the glow fuel/ 2 stroke guys all have electric RC models because it's just so much easier. and a lot less messy.
Any day now, as soon as the electrical generation technology catches up, we will all be flying ion drive airplanes.
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I was one of those Rc guys. Electric sucks! etc....... Now its all i fly Rc wise because it allows more options and simplicity, No mess etc.... I would definitely dig flying that small turbine around
though if it were practical fuel wise. You never know, These types of things are always under development.

47954884423_5f03f5d4e7_z.jpg
 
Ed Sokol said:
I was one of those Rc guys. Electric sucks! etc....... Now its all i fly Rc wise because it allows more options and simplicity, No mess etc.... I would definitely dig flying that small turbine around
though if it were practical fuel wise. You never know, These types of things are always under development.

47954884423_5f03f5d4e7_z.jpg
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If you get a little bigger Warthog you can stuff a couple turbines in there and have some real fun. ;)
 
Ed Sokol said:
I was one of those Rc guys. Electric sucks! etc....... Now its all i fly Rc wise because it allows more options and simplicity, No mess etc.... I would definitely dig flying that small turbine around
though if it were practical fuel wise. You never know, These types of things are always under development.

47954884423_5f03f5d4e7_z.jpg
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The stuff Freewing is putting out these days is amazing. The days of cheap looking, unreliable Chinese RC jets are over...and it’s killing my wallet! :D

96C7DE7A-561C-476D-9212-D0FF55889AAB.jpeg
 
When we start making aircraft out of styrofoam and plastic, electric “technology” will take off.
 
Velocity173 said:
The stuff Freewing is putting out these days is amazing. The days of cheap looking, unreliable Chinese RC jets are over...and it’s killing my wallet! :D

View attachment 74466
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Mine is an FMS first gen. Fly's awesome. I almost got one of those A-4's and still might after seeing this! Looks awesome!
 
Ed Sokol said:
Mine is an FMS first gen. Fly's awesome. I almost got one of those A-4's and still might after seeing this! Looks awesome!
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Thanks. FMS makes some great planes also. Like their WWII stuff a lot.
 
Lachlan said:
I think electric airplanes are for rc guys. Real airplanes burn stuff up! Is diesel the future? What about small turboprop power plants like this one? http://www.stuttgart.engineering/specifications/

At a cost of €10,000 it wouldn’t be much more than a new overhauled 4-banger carbureted 1920’s technology tractor engine that we fly behind now.
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10,000 Euros is the overhaul cost, not the cost of a new engine.
 
Timbeck2 said:
10,000 Euros is the overhaul cost, not the cost of a new engine.
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Right, overhaul costs are about the same, or slightly in favor of the turbine. I thought that’s what I was implying. I can see how it was a bit vague, though.
 
Lachlan said:
Right, overhaul costs are about the same, or slightly in favor of the turbine. I thought that’s what I was implying. I can see how it was a bit vague, though.
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I read that someone posted $35K for the engine. Not sure if that’s accurate or not. You can get a PBS TS100 for $59K.
 
Lachlan said:
If someone designed a small turboprop system that could be configured and adapted to mount on small 2- and 4-seat airframes I think they could make enough money to stay in business.
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I'd bet against it. Building a small turbine is the easy part. Building a small turbine that can get anywhere close to the efficiency of a similar power/weight piston engine when flown at altitudes that 2-4 seat airframes typically see is the tricky part. Not saying it can't be done but I don't think anyone has done it yet.
 
Juliet Hotel said:
I'd bet against it. Building a small turbine is the easy part. Building a small turbine that can get anywhere close to the efficiency of a similar power/weight piston engine when flown at altitudes that 2-4 seat airframes typically see is the tricky part. Not saying it can't be done but I don't think anyone has done it yet.
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What would the fuel burn be at, say 4,000’ msl be for a small 100hp (shaft, I’m presuming) turbine? It shouldn’t be more than 5-6 gah, but that’s my ignorant guess. Anyone have any real data?
 
Lachlan said:
What would the fuel burn be at, say 4,000’ msl be for a small 100hp (shaft, I’m presuming) turbine? It shouldn’t be more than 5-6 gah, but that’s my ignorant guess. Anyone have any real data?
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Using the Czech PBS as an example:

My back of the envelope math from

https://www.pbs.cz/getmedia/313951f...S_Turboprop-engine_TP100_EN.pdf.aspx?ext=.pdf

Says that you'd get about the same SFC or worse from a smaller turboprop engine. (This one claims 188HP in cruise), but we'll go with "same"

SFC of the PBS TP100 is quoted 0.901lb/HP/hr at cruise (188HP)

188HP x 0.901 = 169.388 pounds per hour

6.7 lbs per gallon = 25.28 gph for 188hp.

So your theoretical 100hp TP should only feature at around 12.5 gph. Or double what a 100LL burner does it in. But you're buying cheaper and more available fuel, so you can make it up in volume. :)
 
Lachlan said:
What would the fuel burn be at, say 4,000’ msl be for a small 100hp (shaft, I’m presuming) turbine? It shouldn’t be more than 5-6 gah, but that’s my ignorant guess. Anyone have any real data?
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No knowledge on that one, but doesn't the RR300 (300 shaft-HP) burn around 29gph? In an aircraft like a PA32-300, that essentially gets you 2.5 hours of usable fuel before you hit IR miminums. All the while you're not likely flying much faster with a turbine than with a piston-powerplant aside from being able to climb to altitude more quickly. You essentially burn 14gph more fuel (albeit at a lower price) in order to have shorter endurance and not much of an increase in speed.
 
An additional consideration is that jet fuel weighs more than 100LL. Not only would you have higher fuel burn, but you're losing payload, as well, with small planes that are payload challenged already. What, an additional 35 lbs for each 50 gals? Double whammy.
 
Fallsrider said:
An additional consideration is that jet fuel weighs more than 100LL. Not only would you have higher fuel burn, but you're losing payload, as well, with small planes that are payload challenged already. What, an additional 35 lbs for each 50 gals? Double whammy.
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It almost sounds like you don’t believe in unicorns or Bigfoot. ;)
 
Fallsrider said:
An additional consideration is that jet fuel weighs more than 100LL. Not only would you have higher fuel burn, but you're losing payload, as well, with small planes that are payload challenged already. What, an additional 35 lbs for each 50 gals? Double whammy.
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I think that a pound of jet fuel weighs the same as a pound of gasoline. Jet fuel is denser, however.
 
You've got a pound of JetA in one jar and a pound of 100LL in another jar. Which weighs more?
 
Kenny Phillips said:
I think that a pound of jet fuel weighs the same as a pound of gasoline. Jet fuel is denser, however.
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If you are joking around, I get it.

Either way, what I said is accurate. With equal pounds of either fuel, you would have less gallons of jet fuel. With equal gallons, you would have more weight of jet fuel.
 
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