Like, they couldn't use a shell company to just buy one....

This will likely be scaled up, not big enough for GA applications though. Looking for UAV’s, engine is designed for limited life and low cost. Low enough cost that we can build a significant number of aircraft.

Not sure if we’ll ever design and build a turbo shaft in the 300-500 hp class.

I feel like the PBS TP100 is about the best choice out there at the moment. 241 SHP, weighs 157 pounds installed and costs $120K. Fuel consumption 18-20 GPH. Not too bad to have reliable turbine power.

Except that the TBO is just 300 hours, so the per hour engine reserve alone makes it expensive to run, plus the fuel burn.

Fuel consumption is much more than that:

Take-off (5 min) 0.847 lb/HP/hr
Maximum continuous 0.863 lb/HP/hr
Normal cruise 0.901 lb/HP/hr

.901 lb * 188 (hp) = 169.4 lbs/hr = ~25 gal/hour for cruise.
.847 * 241 = 204 lbs/hour = ~30 gal/hour for takeoff
.863 * 214 = 185 lbs/hour = ~27 gal/hour max continuous.

The only way to get piston like fuel/power efficiency with a turbine is with a Regenerative Turbine .

I've already posted on this before, https://www.beechtalk.com/forums/viewtopic.php?f=37&t=166768&hilit=turbotech

I always wondered if there are 15K of these in service, why is the price is so high? Not low cost :( but a great engine:
https://en.wikipedia.org/wiki/Allison_Model_250
A friend of mine has one and it is an amazing machine, albeit pricey:
https://www.soloy.com/uploads/9/0/6/9/9 ... iew_r5.pdf
Maybe what was Walther could copy the Allison 250 like they did the PT6? Oh wait, GE saw that too...

Because the greedy Corporate owner did not make it Open Source !

I've often wondered about the work Rover, the British car company, did on regerative gas turbines for cars in the late 50s to latish 60s. They were trying to win the Inedex of Efficiency at Le Mans.

They were very serious about the possibility of gas turbine powered passenger cars. If any of you were ever familiar with the Rover 2000 the front suspension design was quite complex in order to leave the space for a propose turbine powered variant.

I certainly want to see innovation, and the rolls Royce M250-B17F/2 is a 200 lb turbine Turbo prop that burns 25 gph for flight planning purposes (about 22 in cruise) (in the p210n silver eagle) ... has 450-500Hp takeoff power (at sea level) and 380hp continuous... it is sensitive to temperature and altitude.... but still falls squarely in the performance envelope of the 15-21k’ flight levels for GA... and for those who want higher and faster, there are variants that go to 650hp.. so they could be flat rated to higher critical altitudes..

Rolls even has a FADEC module for the m250 series...

It is used in the silver eagle conversion and a bonanza a36 conversion, soloy 206 conversion.. and a few other fixed wing planes...

Now the problem is it is very expensive... a new one lists around $700k?

I don’t know how to get that price down or why it is that expensive... is it a function of cost of production? Monopoly? Scale of sheer number (or lack thereof)?

If someone committed to converting 1000 airplanes would the cost be radically different? I don’t know..., but there already is an engine in existence since the 1950’s that is suited to the job..

Rolls had a new model RR500 version, specifically designed for GA that they were going to make that they shelved in 2012.. flat rated to 325hp at 15K’

https://youtu.be/j2nD7Nqh7B4

I don’t know why, perhaps the price tag and the fact that there are virtually zero
Pressurized ga aircraft currently made (except the piper M class and they are dedicated to the pt6)...

Boggles my mind that cirrus and diamond are not pressurized... even 3psi would be a game changer for those aircraft...and open up the world of turbine potential to them...

I mean who really wants an engine that is designed for 15-20’ and have to wear O2 all the time... not me...

Guys, we're gonna see electric motors as the main propulsion unit long before we'll ever see mass market or low cost turbines. Ship has sailed. And I'm not talking about electric aircraft.

The main problem I see for electric aircraft over even electric cars is the fuel loading issue. Now it is possible to trade fuel and therefore range for cargo capacity. When the fuel is a battery that can’t be easily removed you won’t be able to do that. You’ll have to move to aircraft designs where it is possible to fill the tanks and the seats for the seats to be of any use.

Then what are you talking about? Please elaborate...

The only way I see electric propulsion entering the mainstream is it will be tied to a motor generator or fuel cell. Batteries have become much more efficient in the last 20 years, but they would have to get even better by a couple orders of magnitude. Having a very efficient generator feeding the electric motor, with a small battery pack, could work. The generator could run at a constant power output with the batteries making up for takeoff. This would allow for a more efficient generator design.

Vince