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120hpTurboprop engine

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Most power limitations on turbines relate to service life. There is always a limit TGT or whatever they wish to call it where you reduce the power to keep under it.. "Sick" engines tend to run hotter. The turbine wheel temp is limiting. Nev



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We aim to rate our engines as follows (at sea level, STP):




Take-off power (5 minutes limit) - 120hp


Maximum Continuous Power (MCP) - 110hp


Optimum Cruise Power (OCP) - 100hp




T/O Pwr - 200hp


MCP - 190hp


OCP - 180hp


We are going to attempt to have a fairly flat SFC curve for the 80-100hp range for the -120, and 150-180hp for the -200. This will allow the pilot to pull the power back from the OCP figure, but still achieve a similar SFC at the lower power. We can’t guarantee this but we will be striving to achieve it.



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Nev, our engineers will determine whether a torque measurement/indication will be required. I cannot say at this point. The display that we anticipate will be an N1/N2 (gas generator shaft speed and power turbine speed) expressed in % of maximum, or possibly an N1/Prop speed display.


Being a constant speed prop system, the power turbine will normally be running steadily at its optimum % while the gas generator % will change to reflect power.


So the pilots primary power reference (for Power + Attitude = Performance) will be a % figure.


As an example for those interested I give the following (figures are only an example and are not true figures):


For a TA120TP powered Lightning Bug with the XXX propellor system fitted, a 250ktas cruise at 10,000’ on an ISA day will require the following:


1 degree nose up and 85% N1 indication.



  • Informative 1

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"We intend for the engine to run on the heavy fuels, JetA, diesel etc. so yes, diesel will be a preferred fuel."


"Yes, that is a little more than the equivalent power pistons, but not a lot."



Avgas, as in many developing countries, is unavailable here. According to Angolan Ministry of Petroleum standards pump petrol here is: Índice de octano Research (RON) 93 - ASTM D2699. A comprehensive analysis of fuel samples taken from a representative sample of petrol stations in Angola along with a 'customer' satisfaction survey conducted by the Universidade Jean Piaget de Angola revealed that 58% of motorists reported fuel related engine problems including pinking, plug fouling and valve/piston damage.


To me, this means that even a low compresion 80hp Rotax would die a horrible death here running on local mogas. I suppose it could be made to run if it were rebuilt to a lower compression ratio and less output. Which is just what you need when you are trying to drag your aircraft off a rough bit of ground in the searing heat of an African day and clear those trees at the end.


We can, however, get diesel. They sell diesel everywhere. Run out of diesel miles in the bush and it won't be long before a kid turns up with a plastic one and half litre mineral water bottle filled with the stuff which he'll sell to you.


The point I seem to be taking a long time to make is that it is all very well having the very latest in fuel injected piston aero engine technology that will only sip an egg cup full of super mogas an hour but it is bugger all use to us who can't get the egg cup full of even middling octane fuel in the first place.


I've read all through this thread and visited the Turbine Areonautics site to pick out all the features and benefits of this engine and nowhere have I seen mention of what to me is the most compelling feature of this engine. It isn't something that this engine does almost as good as the traditional engines, or even does as well as or better. This engine does something that no other lightweight 120/200 hp engine can do here, it can run on the same fuel I sling in my pick up and my generator. For those of us who want a bush hopper to get in and out of tight and isolated places, this engine ticks all the boxes. Think how useful such an aircraft would be, especially in the humanitarian/emergency role. It could provide affordable, no, bloody cheap by comparison, access to hitherto unreachable places. A flying doctor service, a medevac service, anti poaching patrols, all the things that would be nice to have if only there was an affordable alternative to the Cessna Caravans or Beechcrafts, the usual fare lining the light aircraft apron of the international airport and which are restricted to at the very least prepared strips. Add to that this engine has 'KISS'. You need that out in the bush. Anything complicated WILL break. You need Keep It Simple Stupid out here and nothing could be simpler than a turbine with single lever control. So who cares if it is 8 US gallons or twenty child's mineral water bottles full of cheap diesel an hour, it's perfect for here.


"Here’s a question for you guys, what airframe would you like to see a 120hp or 200hp turboprop in?"



The Zenith Super-Duty STOL CH 801-SD and (please!) the Searey.



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AAK Hornet.. With "ordinary" diesel you can get wax clogging filters at fairly frequent when you fly, just below zero © temps. You can't rope start or prop swing a turbine to start it and you need a C/S prop. If you cover all that you are on the money. Nev



  • Agree 1

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