Bristell turbine

[toto]

Nice. 

 

Turbotech turbine, who knows. But it looks like it’s actually flying, and doesn’t burn 35gph

 

[midlifeflyer]

Cool!

[GeeBee]

Purchase cost?

[A64Pilot]

57 minutes ago, GeeBee said:

Purchase cost?

If you have to ask 

[A64Pilot]

Starts like a Garrett, so I guess it’s single spool?

[GeeBee]

1 hour ago, A64Pilot said:

If you have to ask 

I'm guessing that heat exchanger is not cheap technology.

 

[toto]

Here’s the manufacturer’s site:

https://www.turbotech-aero.com/solutions/
 

The internet seems to have a $50k price floating around from a couple of years ago for the TP-R90, but I don’t see a price on the manufacturer site. 

Since $50k is for an experimental application, and that’s a couple of years ago, you’ve got to think it would be more expensive now. 

Still, if I’m going to spend $100k on an engine, give me a turbine that burns less than 10gph

 

[Bolter]

54 minutes ago, GeeBee said:

I'm guessing that heat exchanger is not cheap technology.

 

The heat exchanger is typically called a "recuperator" and recuperates waste heat from the exhaust back into the thermodynamic cycle of the gas turbine.  A land based gas turbine of similar size is from Capstone Turbine, and produced by the thousands since 1998, available today.  That recuperator is very effective, doubling the total gas turbine cycle efficiency (from about 15% to about 30%), but very heavy, as it is land based.  It proves the cycle out, but not aerospace ready.  The cost of the recuperator is a major portion of the total system cost, just as it is a major part of the weight, not just an accessory.  

For aircraft, the recuperator effectiveness will depend greatly on size and therefore weight.  Very difficult to make a solution that meets weight and cost targets.  It is also a highly aggressive environment of massive thermal cycles from cold soak to +1000F exhaust temp on the hot side, plus a thermal differential with maybe 400F on the cold side.  The exhaust gas is also highly corrosive at these temperatures, requiring fancier alloys (including Inconel 625 as a popular choice)

Turb-Aero (https://turb.aero/) has a similar solution but with 2 spools like PT6.  Also a long way from being availble for sale.  

-dan

[aviatoreb]

That does seem extremely appealing.  What's the catch?

[GeeBee]

1 hour ago, Bolter said:

The heat exchanger is typically called a "recuperator" and recuperates waste heat from the exhaust back into the thermodynamic cycle of the gas turbine.  A land based gas turbine of similar size is from Capstone Turbine, and produced by the thousands since 1998, available today.  That recuperator is very effective, doubling the total gas turbine cycle efficiency (from about 15% to about 30%), but very heavy, as it is land based.  It proves the cycle out, but not aerospace ready.  The cost of the recuperator is a major portion of the total system cost, just as it is a major part of the weight, not just an accessory.  

For aircraft, the recuperator effectiveness will depend greatly on size and therefore weight.  Very difficult to make a solution that meets weight and cost targets.  It is also a highly aggressive environment of massive thermal cycles from cold soak to +1000F exhaust temp on the hot side, plus a thermal differential with maybe 400F on the cold side.  The exhaust gas is also highly corrosive at these temperatures, requiring fancier alloys (including Inconel 625 as a popular choice)

Turb-Aero (https://turb.aero/) has a similar solution but with 2 spools like PT6.  Also a long way from being availble for sale.  

-dan

So basically you confirm my guess

[AH-1 Cobra Pilot]

This has lots of promise to make turbines cheaper:  

 

[Pinecone]

Based on the data on the Bristell site, the engine produces 130 HP and burns 25 liters per hour at 75% power.  So 3.9 HP per liter per hour.

So, take my 252/Encore at 220 HP, I cruise at about 64% power on 10.1 GPH (38.23 LPH) or about 138 HP.  So should be about 9.4 GPH for that power.   Hmmmm.

Or cruise at 75% power and faster speed on 11.2 GPH.

187 pounds complete.

I am ready.

 

[aviatoreb]

There is an interesting hybrid electric on their website too.  I know what hybrid electric means in car - but in airplanes....  can it be setup differently.  Suppose this engine likes to cruise at 130hp all day long.  But we still want 225hp for short phases of flight like take off and landing - I could see the utility of hybrid electric where the average could be 130hp but electric is there and able to produce that 225hp for take off and landing phases.  Can it do this?

[AH-1 Cobra Pilot]

Just doing the Math gives this engine a Specific Fuel Consumption of 0.345.  That is pretty close to a big Cat diesel.  If it sounds too good to be true...

[Schllc]

Those two engines on a Comanche at 11 gallons an hour would have some range.  Especially if it’s efficient at 25k

plenty of fuel capacity  

how cool would a turbine twinkie be?

[bigmo]

Good golly this is crazy cool. Agree this could rescue all the light twins rotting away as noone wants to feed those beasts. Jet-A is in the $3's here (I saw $3.55 today). Jeeeze this would be nice. 

[M20F]

On 2/26/2025 at 9:04 PM, Schllc said:

Those two engines on a Comanche at 11 gallons an hour would have some range.  Especially if it’s efficient at 25k

plenty of fuel capacity  

how cool would a turbine twinkie be?

You won’t get much more speed than a turbo Twinkie.  Vno is always a problem with a piston going to turbine. 

[Hank]

18 hours ago, bigmo said:

Good golly this is crazy cool. Agree this could rescue all the light twins rotting away as noone wants to feed those beasts. Jet-A is in the $3's here (I saw $3.55 today). Jeeeze this would be nice. 

It would be fun to pop one into my C, it's about the same price as a new O-360.

BUT:

• Need DER to allow use of the engine
• Need DAR to mount to the plane 
• Need new engine mounts and probably cowling
• Need new Performance Tables
• Likely to have longer takeoff roll due to 140 hp vs. 180
• Need new prop

So using this cool new turbine would probably cost 3-4X the value of my plane . . . .

[Hank]

Hmmm . . . .

I wonder if this engine would be suitable for a scaled up, 2-place Subsonex???? It would probably become useful for traveling then.

More thinking need . . .

[Mcstealth]

On 2/26/2025 at 7:29 AM, GeeBee said:

Purchase cost?

 

On 2/26/2025 at 7:29 AM, GeeBee said:

Purchase cost?

It is about double of a 915 Rotax is what I read, so, $105,000 or so? 

Enough to say, Hmmmmmm!!

[Schllc]

On 3/1/2025 at 2:02 PM, M20F said:

You won’t get much more speed than a turbo Twinkie.  Vno is always a problem with a piston going to turbine. 

 Not so quick….

You would save over 300# from the two turbo piston engines, your nacelles and cowlings would be a LOT more aerodynamic simply because the engine is so much smaller.  You would absolutely have to fly in the FL to take advantage of this mod.

i have time in a twin C but am not as familiar with what they did for CG. Is there an equivalent of Charlie weights for the piper?    
There are also a lot of performance benefits to the reduced weight. The TC already has incredible short field performance, the stol kit makes it even better, dropping 300# would probably let it take off in less than 500’. Then there is the turbine reliability…
Lastly, There are not a lot of turbo Comanches around, and there will likely never be a new conversion.  
If nothing else, the cool factor of a turbine TC could only be bested by a twin turbine Mooney!

 

 

[Hank]

44 minutes ago, Schllc said:

 . . . a twin turbine Mooney!

Now there's an STC to price out development on!!  

[Pinecone]

They need to develop a larger one, with a full rated power of around 350 - 400 SHP.  That way they can derate it to run better at higher altitudes.

Hmm, I am thinking turbine Aerostar.

But a turbine 252 would be very cool.

[76Srat]

I'm lamenting that Mooney ownership doesn't have the capital or the prerogative to do a clean sheet with these guys, or someone like them, for a new 4/5 place Mooney, with a 'chute.  They'd sell 800 aircraft a year, if they did.  Instead of wasting time that won't exist for the piston-powered legacy fleet much longer on things like 100UL avgas, we should be pursuing certifications like this for both legacy and clean-sheet certified aircraft.  We Mooney guys shouldn't be happy watching Cirrus take the lead on something like this (they never will push a turboprop equivalent for their legacy piston fleet, for obvious reasons).  We should for our legacy fleet, for equally obvious reasons.

 

[IvanP]

I think this would be sweet in any long body Mooney. It would also solve the impending demise of 100LL problem we are currently facing. If the price of mod would be similar to overhaul of a big bore piston engine, I think many owners would go for it. Unfortunately, the certification challenges would likely make such mod prohibitively expensive for most Mooney owners. If the price for experimental is around 100k, we could probably expect double that or more for certified aircraft.