Is There A Market For A Turboprop Mooney???

[CharlesHuddleston]

OK, so I have read all the reviews and news about air-cooled piston singles, the news about trying to find an alternative for 100LL, and the market availability of fuel in the US compared to Europe. 

I have also read and evaluated the regs and difficulty in building an STC for certified aircraft. 

My big question, with over 10k Mooney M20 models built in the GA fleet, would there be a real market for mating a turboprop engine to a Mooney Short or Mid-body frame? I have been talking with PBS Aerospace about building a proof-of-concept using their TP100 mated to J model or even a C. Yes, the fuel burn rate would be higher, but with long range tanks, and cheaper maintenance, would it be worthwhile? Or am I just chasing a pipe-dream? Serious thoughts, please! After all, it would only take time and money. 

[Oscar Avalle]

Just now, CharlesHuddleston said:

OK, so I have read all the reviews and news about air-cooled piston singles, the news about trying to find an alternative for 100LL, and the market availability of fuel in the US compared to Europe. 

I have also read and evaluated the regs and difficulty in building an STC for certified aircraft. 

My big question, with over 10k Mooney M20 models built in the GA fleet, would there be a real market for mating a turboprop engine to a Mooney Short or Mid-body frame? I have been talking with PBS Aerospace about building a proof-of-concept using their TP100 mated to J model or even a C. Yes, the fuel burn rate would be higher, but with long range tanks, and cheaper maintenance, would it be worthwhile? Or am I just chasing a pipe-dream? Serious thoughts, please! After all, it would only take time and money. 

Everything depends on the cost of the STC and the installation of a turboprop engine. If the cost range for the upgrade (I have no idea about how much such an engine costs) would be more than 40 k, the upgrade would cost more than the many of the 10k M20s that are still around... so do the maths.

[GeeBee]

Short answer. No. A million reasons why, starting with lack of pressurization makes using the potential of a TP come up short, to the cost of the engine itself.

 

 

[Jerry 5TJ]

There is a market for Mooney owners to move to a turboprop, yes.  
 

[Seth]

If the TP was geared for lower altitudes, yes. But otherwise without pressurization, most TP out there don't make sense to run in the low teens or even at 10,000. RR was working on a helicopter engine with the Mooney factory at some point years ago but it never amounted to anything as that TP was created for the low teens.

Now a diesel engine STC that runs on Jet A - that may be an STC that is worthwhile. It basically is a turbocharged engine that continues to produce power at altitude and burns less gas that's less per gallon than 100LL.

If the Mooney were pressurized, it would make sense for a TP conversion STC. So, the next question is . . . how to pressurize the Mooney body . . .I don't see it happening.

What could occur is using the Mooney wing, nose, tail, frame, all of it, and building a composite pressurized vessel including a new cabin (slightly wider). Remove the old cabin, lower the shell, attach the turboprop, and now you have four place turboprop slated below the value of a meridian. If it's not a lower cost than a Jetporp converted Malibu/Mirage, than it won't be economically viable. But if it is, you now may have a winner for those that still only fly 1 or 2 people most of the time. If you fly 3 or 4 often, most will end up in a six seater soon enough anyway (not all).

Heck, use the wings, fowler flaps, gear and tail of the FAA approved M22 and put a carbon fiber body that's pressurized around the center section with a TP. That's another idea. 

But for an M20 - it's got to be pressurized to make it work in my opinion.

The Bonanza TP conversion didn't sell that well as it was unpressurized. 

-Seth

[EricJ]

I'm sure there's a market, it's probably just pretty small.    I don't fly high enough to make a turbine useful, and still wouldn't/couldn't) if I had one (basic med and all that).

 

[N201MKTurbo]

I can turn you on to a beautiful TP A36 for $500K.

It has less payload that a stock A36 because of the extra fuel. It goes a bit faster but not much. It uses about 22GPH of heavier fuel in cruise. Everybody who fly's in it says "It is really smooth!"

[carusoam]

Smooth 

powerful

Increased reliability

More capital, but longer engine life, sort of balances the expense over time, or miles....

If Mooney built it, I would have bought it 15 years old....

MS has a few MSers that have gone turbo...

Jerry (above) is just one of them.... P46T...

Other Brad also went P46T...

Tom included P to make things a touch more comfortable... in his Lanceair IVPT....
 

So engine OHs are a step up... as is insurance... and responsibility...

Go for it!

Best regards,

-a-

 

[Schllc]

With the rolls Royce engine the bonanza uses, which is temperature limited, vs torque so the ceiling is about 23k, it would make an excellent candidate for a long body. 
With Monroy tanks, it would hold more fuel than the bonanza, and the weight savings of the turbine would cancel most of the add for fuel. 
if the bonanza can do 220, the Mooney should do 250. With 130 gallons at 22gph that’s four hours with reserves, about an hour longer than the bonanza. 
the market is small,  but I Suspect more Mooney guys would be interested than bonanza guys. 
after all, they already decided to go slow once...

 

I agree that pressurization would be a game changer, but most mooneys are flying in the FL already, and pressurizing an airframe is not an stc.  It’s a whole new concept. 
But, adding 20-50 knots and the safety of a turbine would make the most sense for the continuity of mooneys mission.  Go Fast!

I would think to be viable it would have to be all in under 200k to even be marketable, and even then only on a long or mid body. 
 

[FloridaMan]

TBM

[Schllc]

27 minutes ago, FloridaMan said:

TBM

Sure, for a million more. 
Btw, I have time in a TBM and a Meridian. 
The TBM, is an incredible machine and in a completely different class than the meridian. 
I would think that the problem with all the turboprop non pressurized conversions isn’t just the cost. 
Its the useful load and fuel capacity. 

[aviatoreb]

The only thing worthwhile of a TP Mooney would be reliability.  Extra speed seems a problem.  Already the Acclaim flies right at the yellow arc doesn't it? (So I am told).  Too much more power would be a problem.

Strengthen the frame to increase the marked speeds?

Too expensive.

I always thought those TP Bonanza conversions are cool - and if I were in the mood and had an extra 300-400k I think that would be the way to go to buy one of those guys used.

If I had a million bucks I would buy a good TBM700.

I think a more clever conversion of a Mooney these days would be a diesel, but also....thinking about the rotax thread on the other thread right now - those are pretty small engines - what would it take to make a twin rotax Mooney - two rotax turbo engines at 140 each - so 280 hp driving a single shaft one prop on the nose?  I bet they would fit the cowl.  Twin reliability on one prop.  They are very efficient and robust little engines and they burn cheaper car fuel don't they?  Sounds less expensive and more practical than a TP.  Heck - how about 3 engines driving a single shaft?  I wonder if you can get a deal if you buy a six pack of 915's?

 

[jetdriven]

also, turbine powered aircraft cannot have a yellow arc. So the top of the green arc becomes the new redline. In my plane its 200 MPH.  But older models its much less.

[larryb]

You need pressurization to get enough altitude to get enough fuel efficiency. Even then you burn a lot more fuel, so you need to carry more, and the Mooney doesn't have the UL for that.  You'll need de-icing because at those altitudes every single cloud you see will be below 0 degrees C. A turboprop really needs to be designed from the ground up.  Fortunately that has been done, it's the TBM, and you can buy a nice used one for around $1 M.

[gsxrpilot]

4 hours ago, Seth said:

The Bonanza TP conversion didn't sell that well as it was unpressurized. 

And has no useful load. There was one for sale on Beechtalk but it only had 185 lbs of payload at full fuel. That was an A36. I also watched one land at Mustang Beach and then talked to the pilot. He said the same thing. Less than 200 lbs payload with full fuel.

[CharlesHuddleston]

Right now the useful load on my M20K is just north of 900#. Full Fuel payload with mains+auxs full is right at 300#. 

Weight of TSIO-360-LB is 396# v/s PBS TP-100 weight of 135.8# So the weight, but changes CG so have to lengthen nose and re-calc CG envelope. 

100LL 6.02lb/gal vs Jet A 6.8lb/gal

TBO of 1800hrs v/s 3000hrs

TSIO-360-LB is rated at 210 HP at 2700 rpm v/s PBS TP-100 rating of 241 HP (5min take-off)/214 HP (Max Continuous)/188 HP (Normal Cruise)

If I cruise at 75% in my K now, that would roughly translate into 157HP. Now, it is obviously much more fuel efficient at +/- 10 gal/hr LOP v/s 18 Gal/hr cruise. That would also shorten the range somewhat, but swapping speed for fuel burn can sometimes be a wash. Then you add in that my wife detests any leg over 3 hours, and that is a whole other conversation. 

So, all in all, if the cost for application can get even close to the cost of an overhaul OR a factory new piston engine, I am imagining faster cruise, longer TBO, and smoother ride. What about noise level at cruise?

A saw a figure showing a factory new TSIO-360 at $65K. 1800 hr TBO = $36.12/hr engine cost. Now, $36.12 x 3000 hrs = $108,360. So, numbers are getting close! Waiting on more info regarding acquisition and install numbers and hourly cost rates. Plus, would want to see overhaul costs as well. 

 

Bottom line is I love aviation, and I would love to diversify my business holdings. Now, if I can get in with Mooney and find out their test info (why they put the red line and yellow arcs where they did), perhaps we can squeeze more speed out of our beautiful airplanes! I mean, we have all heard the stories about how strong they are!

Talk about Mooney Zoom!!!

[Seth]

If you go higher the indicated Airspeed drops so you’ll stay in the Green IAS as your TAS increases. So altitude thus pressurization is required for most TP applications 

[Schllc]

the acclaim cannot fly the advertised speeds for any period of time.
Climb is a little more than half of what a turboprop would do. 
It’s not practical for most, I admit that but for a commuter of 3-4 hours some over water, it is certainly not impractical.
The acclaim reduces my mission by 30+ minutes on average.  That’s worth 3gph more to me than an ovation.  
It would be worth another 5-8 to be another 30 min faster and behind a turbine instead of a piston. 
its noise, safety, speed, dependability, tbo, fuel availability etc. 

Sure, its more money but nothing in ga is rational or cheap. 
 

all that being said, it would take someone like Mike Patey to make this fantasy come to life. 

[CharlesHuddleston]

36 minutes ago, Schllc said:

1. Sure, its more money but nothing in ga is rational or cheap. 
 

2. all that being said, it would take someone like Mike Patey to make this fantasy come to life. 

1. That is certainly the truth!

2. He has done it before. 

I am hopeful to make it happen, or at least start the process!

[carusoam]

Charles,

Are you familiar with STC writing?

We have a couple of STC writers around here...
 

Rocket Engineering has done this exercise a couple of times... both familiar with Mooneys and turbines...

Best regards,

-a-

[Jerry 5TJ]

The Mooney is not a great platform for a turbine because it is too light, IMO. 3400 pounds is about the Mooney wing limit for the 61 knot stall requirement.

If you look at clean-sheet SETP designs they weigh more, a lot more.  

The Evolution is a sleek 4 seater with a gross weight of around 4,500 pounds.  

The Piper M600 is a 6,000 pound airplane and the TBM930 is near 7,400 pounds. Those two will carry four Americans and bags and fuel. 

If you really want to carry 6 people and baggage and a lot of fuel you need a 9,900 pound PC-12. 

The M20 was designed for about 2,500 pounds gross.  It’s a sweet flying plane at that weight. 

[Browncbr1]

The thing that turned me off turboprops are phase inspections.   $$$.   

I would think, after you put a TP in a mooney, you’d have more cost and less utility, certainly way more cost per seat, than a meridian.  Need to deal with ice too

Edited August 19, 2020 by Browncbr1

[Ragsf15e]

I think our fleet could benefit more from a turbo diesel conversion.  I’m actually surprised there aren’t more available.  Piper and Cessna have some basics, but we could use Jet A, maybe keep power up to altitude, Newer engine tech, and fuel burn goes down (although generally balanced by engine weight).  

[aviatoreb]

Sadly the eps turbo 8 cylinder turbo diesel purpose built for GA went bankrupt last week.  That would be a fantastic engine for a high powered mooney.

[Ibra]

11 hours ago, Jerry 5TJ said:

The Mooney is not a great platform for a turbine because it is too light, IMO. 3400 pounds is about the Mooney wing limit for the 61 knot stall requirement.

If you look at clean-sheet SETP designs they weigh more, a lot more.  

Yes before talking type of engine you need high wing loading to get high indicated dive speeds, then enough power to make those dives look straight and level, the other alternative is to fly high but turbo Mooney will make same FL250 as TP Mooney? 

Now putting 200HP TP engine in an M20J will get me interested but I will be happy if it can take a piston Diesel engine, even one at 160hp will make my day !

I am not sure about the sucess of an A36 TP version but Bonanza T34C Mentor will barely make M20K speeds in oxygen altitudes even with big 500hp PT6 engine sitting in front at full power, only the military will have budgets to afford such MPG numbers on sub-10kft flying 

Edited August 19, 2020 by Ibra