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  #201  
Old 01-25-2020, 11:08 AM
breister breister is offline
 
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Thanks Dave!
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  #202  
Old 02-03-2020, 11:07 AM
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gmcjetpilot gmcjetpilot is offline
 
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Love turbines but if you have to ask how much or fuel burn gives you pause it is not for you. Also these tiny turbo props and turbo jets often have very low TBO.

If you want a turbo-prop a used TBM 700 or Piper Meridian or Cessna Caravan is the way to go. The older ones are now $750,000 or less used. Heck you can get used Mitsubishi MU-2 or Turbo Commander cheap, but care and feeding of two turboprops is expensive. Hard to beat a PT6 or TPE331.

Turbo Jet? A used Lear 24 or early Cessna Citation can be had for $250,000 or less.
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  #203  
Old 02-03-2020, 12:22 PM
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rv6ejguy rv6ejguy is offline
 
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The big deal with this design is the recuperator which is extensively used in stationary gas turbine setups. This can have a significant effect in reducing BSFC figures. Big challenge to make work well on an aircraft application but will be worth it if they can.
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  #204  
Old 02-03-2020, 03:19 PM
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N941WR N941WR is offline
 
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Quote:
Originally Posted by gmcjetpilot View Post
Love turbines but if you have to ask how much or fuel burn gives you pause it is not for you. Also these tiny turbo props and turbo jets often have very low TBO.

...
Spot on!

I was talking to a friend who is a turbine designer for GE and showed him the web page for this turboprop last week.

His first comment was that small turbines don't last very long. I mentioned that the TBO for my Lycoming was around 2400 hours and he said, "Not even that long."
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  #205  
Old 02-03-2020, 09:38 PM
Turbine Aeronautics Turbine Aeronautics is offline
 
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Quote:
Originally Posted by gmcjetpilot View Post
Love turbines but if you have to ask how much or fuel burn gives you pause it is not for you. Also these tiny turbo props and turbo jets often have very low TBO.
"These tiny turboprops and turbojet"engines that I believe you are referring to are generally model aircraft or model aircraft derivative engines. They offer a very simple design and many of them use the fuel itself, or an oil additive to the fuel for lubrication. Consequently, many of them require bearing changes every 25-50 hours. This is not a TBO as such, but folks often equate the bearing change requirement to being a TBO.

Our engine is not one of "these tiny turboprop" engines. It is being designed from the ground up to be a proper, purpose built engine for man-carrying aircraft and it is definitely not a model aircraft engine derivative. We intend to be the PT6/TPE331 equivalent in the sub-300hp power range. Through utilisation of recuperator technology, we should have a significant improvement in fuel efficiency over the larger turbine engines, and be competitive with piston engine fuel efficiency in the 150-200hp power range.


Quote:
Originally Posted by gmcjetpilot View Post
If you want a turbo-prop a used TBM 700 or Piper Meridian or Cessna Caravan is the way to go. The older ones are now $750,000 or less used. Heck you can get used Mitsubishi MU-2 or Turbo Commander cheap...
One of our aims in delivering this engine technology is to offer the experimental aircraft owner the traditional turbine benefits (size/weight/reliability/longer TBO/use JetA etc.) plus fuel efficiency not previously attained by turboprops. Even fitted with our 200hp engine, many builders will be able to build their aircraft on a $200k or less budget. When retrofitted to an existing airframe, there are going to be owners who will be able to own their own turboprop aircraft for under $150k.

Quote:
Originally Posted by N941WR View Post
Spot on!

I was talking to a friend who is a turbine designer for GE and showed him the web page for this turboprop last week.

His first comment was that small turbines don't last very long. I mentioned that the TBO for my Lycoming was around 2400 hours and he said, "Not even that long."
The Allison/RR250 which through its iterations have offered power in the range 250-450+hp has TBOs in the 2000+ hours range. The TBO is a combination of what the engine was designed for and what it can actually achieve. Our engineers have designed for a TBO of 3,000 hours and a life of at least 5,000 hours. Testing and experience in the field will determine what the correct TBO figure will be and what TBO figure we will apply to our engine.

The design of our engine incorporates well proven and well understood turbine technology. However, it also incorporates some technology that has only recently become available thanks to advances in computational capability, materials and manufacturing techniques. There are challenges associated with the development of this technology and it is overcoming these challenges which will result in the advances in turbine technology that we hope to offer. I can't say that we are there yet because we have not yet demonstrated the technology. However, we believe that we are close to being able to do so.

We have the benefit of starting with a clean sheet design. Every single component has been optimised and designed to achieve a specified performance, both as a standalone component and more importantly, as a critical element of an assembly. As we have found during the design phase, the change in performance or geometry of one component generally affects many other components. One reason our design process has taken so long (albeit short by major engine manufacturer standards) is the iterative process that is required to design the whole engine. As of now, the major iterations are completed and we are left with only minor ones.

Traditional perspectives about turbine engines are generally valid in relation to our engine, but we have enough technical differences for some of those traditional perspectives to potentially be incorrect. The architecture of our engine and the technology that is incorporated into it is not like anything that many will have seen, including existing designers of small gas turbine engines for aircraft. There are very few who could speak with authority about our engine, because very few will have the intimate knowledge of the technology that we are developing and incorporating into our engine.

It is definitely not valid to compare our engine to the AMT, JetCat etc, or even the PBS TP100 because our design and technology is so different from those products.

In the not too distant future, I will be able to confirm or otherwise that our technology works as we hope. In the meantime, my team continues the development program with vigour and determination in order to bring affordable turbine power to us enthusiasts, although I think my engineers motivations are more towards having the satisfaction of designing the most innovative small gas turbine aircraft engine out there...
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  #206  
Old 02-04-2020, 08:41 AM
TS Flightlines TS Flightlines is offline
 
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Dave----we are looking forward to the results!!!
Tom
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  #207  
Old 02-04-2020, 09:52 AM
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gmcjetpilot gmcjetpilot is offline
 
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Quote:
Originally Posted by Turbine Aeronautics View Post
"These tiny turboprops .... The Allison/RR250 which through its iterations have offered power in the range 250-450+hp has TBOs in the 2000+ hours range.
No argument but the TBO I am referencing is for the Sonex Jet https://www.sonexaircraft.com/subsonex/. The engine is a TJ-100 turbojet engine https://www.pbs.cz/en/our-business/a...gine-pbs-tj100 made by PBS Velká Bíteš of the Czech Republic. I recall people are also using them in the BD-5J. The TBO is not high, due to bearing replacement I recall. Is this an over sized RC jet engine. I think it more of a drone or cruise missile engine.

Allison Model 250 or now Rolls-Royce M250, (military T63 and T703) have been used in many fixed wing but even more helicopters. For turbo Prop I think they are in production again, but very expensive. As far as TBO on the 250, I assume the number you quote is progressive maintenance, section is "on condition" or IRAN "Inspect, Repair as Necessary". The question is what will wear out or time limited parts cost.

So yes if you can make an inexpensive, reliable turboprop with good BSFC great. Kit Plane or EAA Sport Aviation I recall had a RV-10 with a turbo prop, may be yours. The figures were interesting I recall. It performed about as well as a IO-540 but had more fuel burn or lower MPG...

Quote:
Originally Posted by N941WR View Post
Spot on! I was talking to a friend who is a turbine designer for GE and showed him the web page for this turboprop last week. His first comment was that small turbines don't last very long. I mentioned that the TBO for my Lycoming was around 2400 hours and he said, "Not even that long."
My two Lycomings on my Piper Apache PA-23-160, when I sold the airplane, had 2300 hours since new. The engines were replaced by previous owner with brand new Lycs before I bought it with about 1800 engine total time. They were running strong, had compression all over 75/80 and oil use about 1 qt in 8-10 hours. The secret was plane flow often, not abused and always kept oil at 5.5 Qt, no more. I'd added a little oil every few flights. Anything over 6 qts a Lyc will spit out.
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Last edited by gmcjetpilot : 02-04-2020 at 10:18 AM.
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  #208  
Old 02-04-2020, 09:54 AM
MercFE MercFE is offline
 
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Dave,

Definitely looking forward to the results... And waiting patiently for my deposit number to come around.

I greatly appreciate that you are open and, from what I've seen, honest with your vision and plans.

Heck... Even the website update is something that others have promised and never delivered within their own projects. It might be a small thing for some, but it shows that you are truly trying to develop a whole company around a product that you believe will be a success!

My only dilemma is what to do when my deposit comes up and I have finally decided I might need two of your engines... :P

Victor
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  #209  
Old 02-04-2020, 03:10 PM
Turbine Aeronautics Turbine Aeronautics is offline
 
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Quote:
Originally Posted by TS Flightlines View Post
Dave----we are looking forward to the results!!!
Tom
Thanks Tom.

Quote:
Originally Posted by gmcjetpilot View Post
No argument but the TBO I am referencing is for the Sonex Jet https://www.sonexaircraft.com/subsonex/. The engine is a TJ-100 turbojet engine https://www.pbs.cz/en/our-business/a...gine-pbs-tj100 made by PBS Velká Bíteš of the Czech Republic. I recall people are also using them in the BD-5J. The TBO is not high, due to bearing replacement I recall. Is this an over sized RC jet engine. I think it more of a drone or cruise missile engine.
I understand that the TJ100 is a development of the Auxiliary Power Units that PBS built for many years for Eastern bloc aircraft. As far as I know, it was not a clean sheet design. It was not derived from a model aircraft engine so it is more complex than those simple engines, but you are correct, it's TBO is not impressive.

Quote:
Originally Posted by gmcjetpilot View Post
So yes if you can make an inexpensive, reliable turboprop with good BSFC great. Kit Plane or EAA Sport Aviation I recall had a RV-10 with a turbo prop, may be yours. The figures were interesting I recall. It performed about as well as a IO-540 but had more fuel burn or lower MPG...
The engine installed in the RV10 is a PBS TP100 which is a 240hp turboprop variant of the TJ100 turbojet used in the Subsonex. PBS hit the mark in providing some of the benefits of a turboprop engine (size, weight, runs on JetA), but for the experimental market, they missed the marks in price point (now around $130k for a 240hp engine), specific fuel consumption (cruise SFC from their own literature of 0.90 lbs/hp/hr which is twice that of piston engines - our SFC is targeted to be under 0.50 lbs/hp/hr), and reliability/TBO which have been reported to be both low.

With our engine, we hope to address all the factors that will make a turbine engine an attractive proposition for the experimental aircraft owner. Fairly soon, we will know whether we have achieved our aims or not.

Quote:
Originally Posted by MercFE View Post
Dave,

Definitely looking forward to the results... And waiting patiently for my deposit number to come around.

I greatly appreciate that you are open and, from what I've seen, honest with your vision and plans.

Heck... Even the website update is something that others have promised and never delivered within their own projects. It might be a small thing for some, but it shows that you are truly trying to develop a whole company around a product that you believe will be a success!

My only dilemma is what to do when my deposit comes up and I have finally decided I might need two of your engines... :P

Victor
Thanks for your patience Victor, as well as your ongoing support.

Bringing an engine to the market is not only about solving the technical issues to be able to offer a quality product, it's also about building a solid company around the business.

Our company has (at least) two significant priorities; the happiness and welfare of its employees and the satisfaction of its customers. We are working hard to address both these priorities. We are pretty confident that we have succeeded so far with the first priority with the small team that we have, but we know that we will have a lot of work still to do with the second priority.

I recognise that I have been guilty of not getting enough information out there to the handful of customers that we have and for that I apologise. With the lean team that we have been operating with while we undertake the development program for the engine, I have had to prioritise my time and efforts.

We have now taken steps to address the communications issue with the appointment of a Marketing and Communications Manager (Amanda) who has recently started with us. She is an absolute dynamo and has been responsible for developing our communications and marketing strategy. Hence the new website.

While the new website is currently only a landing page, Amanda is actively pursuing the development of the full website which will offer significantly more information to help a prospective customer make their buy decision. There will also be a dedicated forum which will include aircraft type specific sections for discussion around installation of our engines in specific aircraft models; ordering of engines and accessories will be done through the website; download of technical/installation manuals will be available; and there will be a restricted access dedicated section for registered owners.

We are also busy developing the infrastructure to support the engines in the field. After-sales support is probably more important than the support offered during the purchase process. Consequently, we are placing a high priority on establishing a network of approved service centres who will be able to offer high quality maintenance, repair and overhaul services.

Victor, as a gesture of my appreciation for your support as one of the handful of customers that have reserved a delivery slot, when we confirm whether you wish to accept your first engine, I will offer you the option on a second engine that will be within 10 serial numbers of the one that you have reserved now. That way if you want or need two, you can have two.

Discussing this is reminding me how much I have on my to-do list today so I'd better get on with it.

Dave
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