# Anyone want a jet?

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#### BBerson

##### Light Plane Philosopher
Although these engines are nice, they won't be viable until we get something in the 400lb-500lb thrust class available.
DGEN 380 575 pounds of thrust
Price Induction

#### Jay Kempf

##### Curmudgeon in Training (CIT)
Any idea of the SFC ?
Price Induction
go to performance section

Anyone have any idea of the price of such an animal. This is truly in the heart of the size that is needed for personal transport single pilot stuff. Single for 2 seat, two engines for more.

#### KC135DELTA

Holy crap. A lot of money. I guess $150K per is not that bad; but we need a cheap jet for the homebuilts. #### Jay Kempf ##### Curmudgeon in Training (CIT) Holy crap. A lot of money. I guess$150K per is not that bad; but we need a cheap jet for the homebuilts.
I was guessing at least 100k per side. That's a bit steep but expected. Maybe if they actually get the thing in production and get enough customers it will be less than that.

#### batesjoe

##### Active Member
If the claimed specifications are accurate, this would be an attractive engine option for the venerable BD-5J. Something like 30 lbs lighter and 50 lbs thrust more than the TRS-18 engine originally installed. Add to that better fuel specifics and better range, I imagine it could be a fun concept for the right person.

#### batesjoe

##### Active Member
Another thought for the pocket rocket BD-5 turboprop is the engine used in the Konner helicopter. The TK-250 engine is 110 lbs in weight and 250 SHP and a SFC of somewhere around 0.72. That would also be quite a flying Lambo.

#### SVSUSteve

##### Well-Known Member
.....and endless amount of a-holes....right ?
If you mean that as a slight at me, you're dead on. Insofar as I am intolerant of Ponzi schemes and delusional thinking that misdirect scarce money and resources, I guess to the true believers I am an a**hole. However, I am proud to be a realist even if it gets me labeled with such pejoratives.

Here is the GE engine guru SUVSteve calls f-cake
Anytime someone gets addressed as a "guru", it makes me think that the person doing the addressing- and probably the person being addressed- has started treating their pet project less like a scientific and engineering endeavor and more like a religious mission with cultish devotion.

#### timberwolf8199

##### Well-Known Member
What it made me think was...I wonder if Steve drives an SUV.

##### Well-Known Member
Price Induction
go to performance section

Anyone have any idea of the price of such an animal. This is truly in the heart of the size that is needed for personal transport single pilot stuff. Single for 2 seat, two engines for more.
I recall about 80K euro's from the Aero.

Let's first wait until it's flying. Until that time, an AMT Titan or similar...

#### Jay Kempf

##### Curmudgeon in Training (CIT)
I recall about 80K euro's from the Aero.

Let's first wait until it's flying. Until that time, an AMT Titan or similar...
80k is probably a marketing number for one part number. I am guessing by the time you add controls, fuel system controls, electronic package, then you would be near 100k by the time you had an installable thrust system in your shop ready to install. But still for those fuel consumption and thrust numbers that is the best thing that has ever been built in that size. No one has ever built a higher bypass system for that thrust range that I know of. Not really sure it has a market for large numbers but I hope I am wrong. Jets are just so much simpler than reciprocating engines that they should be available en masse by now.

Another question/observation: they are marketing the thing as fitting into a range of .3 Mach. But the numbers they are talking about in terms of mass flow and tail pipe velocity means that it could power something significantly faster than that. Let's say just for a guess that they have calculated the inlet air velocity at .3 Mach. If so why couldn't a very clever person design an inlet duct that slows air down at some higher airspeed to keep the inlet conditions happy. That way you get high speed and low inlet pressure. Assuming you have managed airframe drag accordingly that could make a pretty efficient cruise machine by better using the turbine at it's design RPM and flow conditions but getting more airspeed out of it. What this is is sort of a subsonic super cruise configuration for that particular condition. Should make 300+ mph cruise quite possible for the right airframe. Cruise for this engine is north of 200 lbs of thrust. That's quite a bit of drag budget for a small airframe.

#### topspeed100

##### Banned
Holy crap. A lot of money. I guess \$150K per is not that bad; but we need a cheap jet for the homebuilts.
How much are the H250s for a pair ?

#### KC135DELTA

##### Well-Known Member
80k is probably a marketing number for one part number. I am guessing by the time you add controls, fuel system controls, electronic package, then you would be near 100k by the time you had an installable thrust system in your shop ready to install. But still for those fuel consumption and thrust numbers that is the best thing that has ever been built in that size. No one has ever built a higher bypass system for that thrust range that I know of. Not really sure it has a market for large numbers but I hope I am wrong. Jets are just so much simpler than reciprocating engines that they should be available en masse by now.

Another question/observation: they are marketing the thing as fitting into a range of .3 Mach. But the numbers they are talking about in terms of mass flow and tail pipe velocity means that it could power something significantly faster than that. Let's say just for a guess that they have calculated the inlet air velocity at .3 Mach. If so why couldn't a very clever person design an inlet duct that slows air down at some higher airspeed to keep the inlet conditions happy. That way you get high speed and low inlet pressure. Assuming you have managed airframe drag accordingly that could make a pretty efficient cruise machine by better using the turbine at it's design RPM and flow conditions but getting more airspeed out of it. What this is is sort of a subsonic super cruise configuration for that particular condition. Should make 300+ mph cruise quite possible for the right airframe. Cruise for this engine is north of 200 lbs of thrust. That's quite a bit of drag budget for a small airframe.
I talked to them about this specifically. They claimed that there is no real "limit" other than staying subsonic, however for practical application purposes they designed them for mach .338 in terms of exhaust velocity (unmixed turbofan).

In other words the faster you go above .338 the thrust falls off exponentially to the point that they aren't really practical for high speed applications.

#### Aviator168

##### Well-Known Member
I think an efficient mini-turbofan/mini-turboprop is possible. I was looking at JetCat's turboprop addon years ago and did a revisit yesterday. I found the SFC (0.464 not that much more than a piston engine) to be interesting.
JetCat USA Turbines

#### BBerson

##### Light Plane Philosopher
I think an efficient mini-turbofan/mini-turboprop is possible. I was looking at JetCat's turboprop addon years ago and did a revisit yesterday. I found the SFC (0.464 not that much more than a piston engine) to be interesting.
JetCat USA Turbines