Turbine Mooney

[aviatoreb]

22 minutes ago, LANCECASPER said:

As I'm sure you already know this has been done a few times with different turbines on Beechcraft Bonanzas. I think someone did one called a Tradewinds conversion.

https://www.controller.com/listings/search?Category=8&Model=A36 BONANZA TURBOPROP&Manufacturer=BEECHCRAFT&ScopeCategoryIDs=13&sort=1

 

https://www.aopa.org/news-and-media/all-news/2015/january/pilot/t_ql

Right. And there is also a well respected conversion of the Cessna P210

https://www.aopa.org/news-and-media/all-news/2012/december/pilot/silver-eagle-golden-performer

[LANCECASPER]

14 minutes ago, aviatoreb said:

Right. And there is also a well respected conversion of the Cessna P210

https://www.aopa.org/news-and-media/all-news/2012/december/pilot/silver-eagle-golden-performer

What makes the P210 turbine conversion a winner and hold its value is the pressurization.

[aviatoreb]

3 minutes ago, LANCECASPER said:

What makes the P210 turbine conversion a winner and hold its value is the pressurization.

The conversion is by "Silver Eagle" a company in PA.  People really like them because at the end of the day, its just a high wing Cessna and supposedly quite easy to fly.  The pressurization is really not up to flying in the 20s without still wearing supplemental o2 but it is up to flying in the upper teens (from my experience flying with a friend in his piston P210).  In my opinion they are valued very highly in the market and you can see the prices are pretty high, so much so that I would sooner buy the more capable piper rocket engineering jetprop if I had that kind of money.

I still think there is some value in a mid-teens cruiser RR M20 (a lot like the RR Beech A36) which is not pressurized since that makes a simpler less expensive platform.  Of course pressurization is lovely.

[Schllc]

2 hours ago, A64Pilot said:

I used to participate in hot section inspections on Ag aircraft (PT-6) and don’t think it cost even a tenth of that unless you found damaged components from over temp operation or clogged fuel injectors. Of course looking for damage was the purpose of an HSI.

A complete overhaul for a smaller Pratt may run $250K or so at TBO or of course may run much more if run until there are problems.

‘I’ve seen a -34 at 10,000 hours, and many run up to 8,000 hours before major work, but they kept up with nozzle inspection / cleanings and HSI’s too, a turbine is truly a pay me now or pay me later thing.

Think about it, if they were phenomenally expensive, you wouldn’t see so many on old Ag planes, yet you do.

Now one is WAY beyond my budget, I couldn’t even afford to feed one, but many have way more money than me.

 

Oh, and I believe the little Allison’s lose power with altitude quite quickly, as they were designed for a Military spotter airplane or a small helicopter, neither requires high altitude, so pressurization may not be much of an asset with one.

My understanding after looking seriously at a turbine bonanza is that the Allison’s have a mid time hot section that requires changing some blades. It’s a non optional 75k process. I know others with pt6’s in meridians and Tbms, and they do not have this so it seems unique to the Allison. 

[exM20K]

18 hours ago, aviatoreb said:

If it goes a little faster great.  Something would need to be done to the airframe structure strengthening i already mentioned if any much more speed than the acclaim would be allowed with 420hp since isn't the acclaim already bumping up against the yellow on 270hp?

Yes, the TN can touch the yellow in straight and level flight at high power and low altitude.  Since turbine conversions do away with the yellow arc, there is little practical use for more cruise power in the TN.

-dan

[aviatoreb]

Just now, exM20K said:

Yes, the TN can touch the yellow in straight and level flight at high power and low altitude.  Since turbine conversions do away with the yellow arc, there is little practical use for more cruise power in the TN.

-dan

The only way then would be as I described that I think that rocket did to the M20L liquid rocket conversion where they put a 350hp TSIO550L engine and they strengthened the frame with gussets.

[LANCECASPER]

1 hour ago, aviatoreb said:

In my opinion they are valued very highly in the market and you can see the prices are pretty high, so much so that I would sooner buy the more capable piper rocket engineering jetprop

The JetProp and Meridian make for a nice airframe/engine combo. But even with the Meridian and the gross weight increase from 2002 the range was still considerably less than the piston Malibu Mirage due to fuel burn. (I was a partner in a 2000 Mirage and later a 2002 Meridian, both very nice capable airplanes. However cost per mile, all things considered, is a lot less in a Mooney. Ramp appeal, no comparison )

[A64Pilot]

1 hour ago, Schllc said:

My understanding after looking seriously at a turbine bonanza is that the Allison’s have a mid time hot section that requires changing some blades. It’s a non optional 75k process. I know others with pt6’s in meridians and Tbms, and they do not have this so it seems unique to the Allison. 

You may be right, but most turbine GA conversions are for those that money isn’t much if a consideration, you know the people who buy new aircraft types.

‘Most but not all, a Friend has done many turbine conversions, name of his company is Turbine Conversions Inc. he specializes in working aircraft and PT-6’s for example he did a PT6 conversion on Cessna 206’s for a jump school, rapid climb and fast descents are the way to make money, and you can set the prop pitch flat on a turbine  and comedown like a rock. -27’s I think, but pretty much anything from a -11 to a -27 may be suitable for a Mooney.

‘Now realize that the -66 in a TBM is roughly a 1700 - 1800 SHP motor. derated to 800 or so for high altitude performance, so while a -27 may sound like a lot for a Mooney, derated for altitude it’s not.

Edited June 30, 2021 by A64Pilot

[A64Pilot]

My mistake it’s a -21

https://turbineconversions.com/conversions/turbine-206-cessna/

[Jerry 5TJ]

On 6/29/2021 at 12:53 PM, donkaye said:

At $250,000 for a Hot Section check at mid-time, all the costs associated with a turbine engine…..

We did a hot section inspection on the PT6A-35 in 2017 as part of a pre-buy.  The engine had 1700TT, nothing was found to replace, cost was $12K.  

[Seth]

What would it take to also pressurize the cabin? I'm kidding. I know that's not really possible. The door itself would have to be reworked, all the windows, the strength, structure, plumbing, everything. But that's what I really want. A pressurized cabin. Aerostar in the future? I remember the Turbine Aerostar.

A small turbine Mooney, the Mooney Wing, Mooney Tail, and a new Carbon Fiber pressurized cabin - 4 seats - I keep coming back to this - and price it less than a M600. That's what I keep thinking may be out there, as it would be a new class of certified aircraft. a 4 place pressurized airplane at the lowest price point for those that really never fly with more than one or two in their Meridians and TBM's. Kind of like the Cirrus Jet - it competes with turboprops as the lowest slowest jet. But this would not be low and slow, it would be fast and the least expensive certified pressurized turboprop.

Rocket did the STC that forced the factory to put big engines on. I'd love to you see your STC cause the factory to get a turbine up there.

-Seth

Edited July 1, 2021 by Seth

[donkaye]

9 hours ago, Jerry 5TJ said:

We did a hot section inspection on the PT6A-35 in 2017 as part of a pre-buy.  The engine had 1700TT, nothing was found to replace, cost was $12K.  

Thanks for the update.  I was basing my number from memory from 2000 on a CJ1.  Must have been replacement of the hot section.  At any rate without pressurization I personally wouldn't be interested in a turbine on the front of my Mooney.

I, also, don't like the change made to MooneySpace yesterday.  I personally like to see all the information about the poster at a glance.

[Raymond J1]

My idea...

I think it was a possible path for Mooney, that tried his luck before without going all the way (M301), that the current Mooney pressurized and mono turbine is the TBM. Given his situation, shouldn't Mooney win back the market by re starting from the bottom ? His M10 three seats has chances (still), but, again, Mooney doesn't pick the good engine.

[Jerry 5TJ]

10 hours ago, Seth said:

A small turbine Mooney, the Mooney Wing, Mooney Tail, and a new Carbon Fiber pressurized cabin - 4 seats - I keep coming back to this - and price it less than a M600…..

I looked hard at the turboprop  Evolution 5 years ago, and flew two of them, before buying my second PA46 JetProp.  The Evolution is a 4 seat composite SETP along the same lines as you propose, about the same dimensions as a Mooney. It is also a 4500 pound aircraft that can’t meet the 61 knot stall requirement.  It weighs that much because it needs to: It has to carry up to 1,100 pounds of fuel along with people and baggage.

It is fun to wish our favorite plane could be born anew, but I don’t think the Mooney design has enough growth left to become a viable turboprop.  One big problem is that 3368 pound gross limit. With an all-new 40+ foot wing and a pressurized fuselage design it would become….a Meridian.  
 

[GeeBee]

If you can get a good trend monitoring program going, you can go a lot longer than mid-time on hot sections. I have had King Airs go the entire TBO without a hot section required. If you treat them right, do assumed temp takeoffs, keep the starter battery wound up tight, you can get a lot of life out of a hot section.

 

[Seth]

36 minutes ago, Jerry 5TJ said:

I looked hard at the turboprop  Evolution 5 years ago, and flew two of them, before buying my second PA46 JetProp.  The Evolution is a 4 seat composite SETP along the same lines as you propose, about the same dimensions as a Mooney. It is also a 4500 pound aircraft that can’t meet the 61 knot stall requirement.  It weighs that much because it needs to: It has to carry up to 1,100 pounds of fuel along with people and baggage.

It is fun to wish our favorite plane could be born anew, but I don’t think the Mooney design has enough growth left to become a viable turboprop.  One big problem is that 3368 pound gross limit. With an all-new 40+ foot wing and a pressurized fuselage design it would become….a Meridian.  
 

Likely correct!

[aviatoreb]

1 hour ago, Jerry 5TJ said:

I looked hard at the turboprop  Evolution 5 years ago, and flew two of them, before buying my second PA46 JetProp.  The Evolution is a 4 seat composite SETP along the same lines as you propose, about the same dimensions as a Mooney. It is also a 4500 pound aircraft that can’t meet the 61 knot stall requirement.  It weighs that much because it needs to: It has to carry up to 1,100 pounds of fuel along with people and baggage.

It is fun to wish our favorite plane could be born anew, but I don’t think the Mooney design has enough growth left to become a viable turboprop.  One big problem is that 3368 pound gross limit. With an all-new 40+ foot wing and a pressurized fuselage design it would become….a Meridian.  
 

It is fun to wish - and I enjoy doing it. I wish there is a turbine in the future for M20 but I doubt there is.

The RR Allison is somehow a quite different engine than a PT6 in terms of where it flies and how much fuel it uses.

But I doubt more horsepower is a good thing for an M20 given the Acclaim is already flying right at the yellow on 270hp, so saying it again, structural strengthening would be needed to do anything with more power. 

And fuel load...  Heavy.

Not speaking certified - just spit balling could it be done - but could a current M20 become pressurized?    Could an inner wall of carbon fiber inside the metal skins, plus new windows, be made to allow it to pressurize?  Kind of a can inside the can.  I have a carbon fiber single scull (rowing shell) I was looking at this am and it is so very strong and light.  It is 28' feet long. 11.25'' beam and weighs about 30lbs including a bunch of metal hardware (the rigging). I think the actual boat separate from the rigging is something like 20lbs.  So its called a shell.  That kind of thin shell would not be strong enough to be the aircraft structure - a lot more material would be needed, but what about as a liner inside the current cabin area simply to be a sealed pressure vessel pushed up against the current al skins and steel tubes, adding a tiny bit of structural strength too?  (Yeah I know it won't get done but again fun to think about).

[pinkiedog64]

1 hour ago, aviatoreb said:

It is fun to wish - and I enjoy doing it. I wish there is a turbine in the future for M20 but I doubt there is.

The RR Allison is somehow a quite different engine than a PT6 in terms of where it flies and how much fuel it uses.

But I doubt more horsepower is a good thing for an M20 given the Acclaim is already flying right at the yellow on 270hp, so saying it again, structural strengthening would be needed to do anything with more power. 

And fuel load...  Heavy.

Not speaking certified - just spit balling could it be done - but could a current M20 become pressurized?    Could an inner wall of carbon fiber inside the metal skins, plus new windows, be made to allow it to pressurize?  Kind of a can inside the can.  I have a carbon fiber single scull (rowing shell) I was looking at this am and it is so very strong and light.  It is 28' feet long. 11.25'' beam and weighs about 30lbs including a bunch of metal hardware (the rigging). I think the actual boat separate from the rigging is something like 20lbs.  So its called a shell.  That kind of thin shell would not be strong enough to be the aircraft structure - a lot more material would be needed, but what about as a liner inside the current cabin area simply to be a sealed pressure vessel pushed up against the current al skins and steel tubes, adding a tiny bit of structural strength too?  (Yeah I know it won't get done but again fun to think about).

Short answer is no.  Long answer is sure, it's possible with enough time (time=money) and more money.  But it wouldn't make sense.  There are aluminum brackets that rivet between the tubular structure and the fuselage skins.  So you couldn't place the pressurize-able carbon "tube" between the tubular structure and aluminum fuselage skins; it would have to go inside in the tubular structure.  Then interior volume would decrease substantially.  And you would add weight.  And you have to worry about things like windows, flight control and wiring penetrations, pressurization source, bleed valves, pressurization control system, etc.  If you went this route you'd end up with a very expensive, heavy, complicated airplane with enough room for 1.3 midgets.  You would be ahead in time, money, and functionality to start over from scratch, at least regarding the fuselage.  You'd be further ahead if you bought a TBM, Epic, or Evolution.  

[aviatoreb]

1 hour ago, pinkiedog64 said:

Short answer is no.  Long answer is sure, it's possible with enough time (time=money) and more money.  But it wouldn't make sense.  There are aluminum brackets that rivet between the tubular structure and the fuselage skins.  So you couldn't place the pressurize-able carbon "tube" between the tubular structure and aluminum fuselage skins; it would have to go inside in the tubular structure.  Then interior volume would decrease substantially.  And you would add weight.  And you have to worry about things like windows, flight control and wiring penetrations, pressurization source, bleed valves, pressurization control system, etc.  If you went this route you'd end up with a very expensive, heavy, complicated airplane with enough room for 1.3 midgets.  You would be ahead in time, money, and functionality to start over from scratch, at least regarding the fuselage.  You'd be further ahead if you bought a TBM, Epic, or Evolution.  

I like your answer - short answer no - long answer sure - that's my kind of internet chat that we all love.

So if at all possible probably the carbon fiber shell would need to replace the metal skins in the current fuselage.

In all truth, this category airplane (not pressurized) its hard to then not notice the bonanza turbine's the allison ones fit the bill and seem to go from 275 to 4 or 500 sometimes nicely equipped.  Impractical as they are, I think they are pretty neat.  I doubt I will ever get one but they are definitely neat.

In a strange mood and with unexpected funds, - I could see myself wanting to convert an airplane I already owned and became attached to, damned the torpedos and the cost.  No one ever rightly accused airplane owners of being financially rational.

[pinkiedog64]

55 minutes ago, aviatoreb said:

I like your answer - short answer no - long answer sure - that's my kind of internet chat that we all love.

So if at all possible probably the carbon fiber shell would need to replace the metal skins in the current fuselage.

In all truth, this category airplane (not pressurized) its hard to then not notice the bonanza turbine's the allison ones fit the bill and seem to go from 275 to 4 or 500 sometimes nicely equipped.  Impractical as they are, I think they are pretty neat.  I doubt I will ever get one but they are definitely neat.

In a strange mood and with unexpected funds, - I could see myself wanting to convert an airplane I already owned and became attached to, damned the torpedos and the cost.  No one ever rightly accused airplane owners of being financially rational.

I almost mentioned that (replacing metal skins with carbon fiber).  The (main) issue there is still the tubular structure.  It wouldn't make sense to have the cabin structure be the tubular structure, then have a structural carbon fiber shell over the outside of that to hold cabin pressure.  At that point you might as well combine the two functions into just a carbon fuselage structure.  None of the composite airplanes with structural exterior skins have an interior steel tube structure.  There's a reason no one does that (Cirrus, Diamond, Lancair, Columbia, Epic, etc).  Then if you are doing that you might as well integrate the aluminum tailcone into the carbon cabin structure.  Then you have a whole new fuselage and it isn't even the same airplane anymore.  Also, the sides of the M20 fuselage are pretty flat which is anti-good for pressurization.  

Note the Glasair Sportsman has a tubular steel fuselage structure with a non-structural fiberglass shell, not unlike the M20U/V.  However, on the Sportman, the structural tailcone is integrated with the non-structural fuselage skin.  An approach like that might make more sense.  But of course the Sportsman isn't pressurized.  Either way, that would require a monumental effort and you'd be better off starting over and optimizing.  

But yes, it is fun to talk about and dream!

Edited July 1, 2021 by pinkiedog64

[ilovecornfields]

2 hours ago, aviatoreb said:

In a strange mood and with unexpected funds, - I could see myself wanting to convert an airplane I already owned and became attached to, damned the torpedos and the cost.  No one ever rightly accused airplane owners of being financially rational.

You go ahead and do that but I’ll just buy one off the shelf when the money comes in. My son already promised me that when he makes his first billion he’s going to buy me a Pilatus and buy himself an R44, paint it like a bumblebee and fly around everywhere instead of driving.

So, essentially, you could say I already own a SETP but I just have to wait a few years to take possession (since he’s still in elementary school).

 

[ChrisH]

A little bit on the small side, but https://www.turbotech-aero.com/solutions/#turbogenerator would be an interesting choice in powerplant if the main concern was fuel availability & reliability (and not speed). 

[EricJ]

49 minutes ago, ChrisH said:

A little bit on the small side, but https://www.turbotech-aero.com/solutions/#turbogenerator would be an interesting choice in powerplant if the main concern was fuel availability & reliability (and not speed). 

That's pretty cool.   I like the idea of slinging one under each wing (or somewhere) and driving the prop with an electric motor.

 

[exM20K]

9 hours ago, Jerry 5TJ said:

I looked hard at the turboprop  Evolution 5 years ago, and flew two of them, before buying my second PA46 JetProp.  The Evolution is a 4 seat composite SETP along the same lines as you propose, about the same dimensions as a Mooney. It is also a 4500 pound aircraft that can’t meet the 61 knot stall requirement.  It weighs that much because it needs to: It has to carry up to 1,100 pounds of fuel along with people and baggage.

It is fun to wish our favorite plane could be born anew, but I don’t think the Mooney design has enough growth left to become a viable turboprop.  One big problem is that 3368 pound gross limit. With an all-new 40+ foot wing and a pressurized fuselage design it would become….a Meridian.  
 

Amen, Jerry.  If a meridian or jetprop fit my mission, I’d buy one.

with another 200# of useful load, I think the Acclaim is about the perfect HPSE plane.  Range, speed, climb rate, operating economics are all excellent. 
-Dan 

[aviatoreb]

3 hours ago, pinkiedog64 said:

I almost mentioned that (replacing metal skins with carbon fiber).  The (main) issue there is still the tubular structure.  It wouldn't make sense to have the cabin structure be the tubular structure, then have a structural carbon fiber shell over the outside of that to hold cabin pressure.  At that point you might as well combine the two functions into just a carbon fuselage structure.  None of the composite airplanes with structural exterior skins have an interior steel tube structure.  There's a reason no one does that (Cirrus, Diamond, Lancair, Columbia, Epic, etc).  Then if you are doing that you might as well integrate the aluminum tailcone into the carbon cabin structure.  Then you have a whole new fuselage and it isn't even the same airplane anymore.  Also, the sides of the M20 fuselage are pretty flat which is anti-good for pressurization.  

Note the Glasair Sportsman has a tubular steel fuselage structure with a non-structural fiberglass shell, not unlike the M20U/V.  However, on the Sportman, the structural tailcone is integrated with the non-structural fuselage skin.  An approach like that might make more sense.  But of course the Sportsman isn't pressurized.  Either way, that would require a monumental effort and you'd be better off starting over and optimizing.  

But yes, it is fun to talk about and dream!

I was trying to imagine if some kind of inner shell to hold the air pressure might be possible - and I am still not convinced it is not, and that would be essentially separate from the metal structural shell that is already there.  Sort of an air pressure version of a fuel bladder which might be retro fitted after the fact to a wet wing that some people do.  Sure that bladder has a weight penalty, but not a lot.  I wonder how much weight penalty a really think air chamber would be.  Remembering this is not high pressure or structural I am not yet convinced this is not possible.  I mean they can make pressure suits for astronauts.  Why not for airplanes?  Still Bs'ing brainstorming - why not carbon fiber sheets, very thin, inside the cromoly frame, in plates, and then some kind of air tight soft material - like an astronaut glove (rubber?) that goes above and around the frame. Those are like sleeves.  Glued to the plates somehow.  How much pressure do we need - the p210 is 3.35psi.  I bet even 2.5 or 3 psi would be appreciated and make a retrofit airplane useful to say 20k even if you might need a little supplemental after the higher altitudes (I don't feel like running those numbers since I don't know how off hand - at what altitude is 2.5psi pressure system becoming like 8 or 10k?).  I mean better than nothing if it could be pulled off.