Peter wrote:
They are talking 230HP-420HP. What airframes would that be used on?
C182/C206/C207/C210, R44 etc, to name some obvious candidates.
Peter wrote:
I wonder if these projects are waiting not for certification but for something quite different: some non-GA volume application; probably a drone?
Yep, I think that’s exactly it.
C182/C206/C207/C210, R44 etc, to name some obvious candidates.
What I was getting at is that if you bolt a 420HP motor on the front of something which currently has a 250-300HP one, you will have a whole load of fun with getting the STC – FAA or EASA 
Rocket Engineering did well with the Jetprop STC, many years ago and under an easier regime (accepted more recently by some pre-EASA European CAAs), replacing ~350HP with ~750HP, but there you get a massive benefit, appropriate to an airframe which can do FL170 or so and is pressurised. Putting a turbocharged 420HP in an unpressurised SEP will give you a plane which burns loads of fuel to get dragged through the air at something like 180kt (IAS) and which can achive say 220kt TAS at altitudes at which almost nobody will fly at (with an oxygen mask).
I suppose you could do a 420HP diesel conversion of a PA46?
Yep, I think that’s exactly it.
So, to mix a few idioms, they are pulling our leg when they talk about a 10 year road to GA certification, and they are just floating a baloon to see if anyone bites
Peter wrote:
they are pulling our leg when they talk about a 10 year road to GA certification, and they are just floating a baloon to see if anyone bites
I don’t think so. But if they are selling to a drone manufacturer in large numbers, these numbers would go into the same pot as the civilian application and greatly enhance the number over which the development cost can be split upon.
As a matter of fact i wonder how many of our current piston engines were offspring of initial military technology and had a significant part of it’s development financed there. Maybe that is where we should look for future GA engines….
I have no idea about how big the market may be for this engine in GA but it will certainly help if they can sell a few thousand to the military first before trying to sell hundreds to GA and ending up with tens.
Peter wrote:
What I was getting at is that if you bolt a 420HP motor on the front of something which currently has a 250-300HP one, you will have a whole load of fun with getting the STC – FAA or EASA
Not necessarily, I’m sure this one can also be de-rated (should be relatively easy with FADEC), much like the various IO520/540 versions are.
Derating an engine is indeed easy, a diesel especially. Getting rid of the extra weight is another thing – diesels are instrinsically heavier than petrol engines, they need heavier build to withstand the higher internal pressure – and derating doesn’t make any engine weigh less, either. So the weight & balance might become “interesting”.
what about all those Dukes C421 big Piper twins etc would they get a new lease of life with someting like those engines???
This engine has been well known in the Aerostar community for some years and has had initial investors amongst its ranks, as a potential upgrade path for that airframe. The problem becomes, even if they can sell these engines at, say, $150K/each, then someone will need to develop the STC to install them for each airframe. No way that’s going to cost less than $150K/airframe. So you’re looking at $450K at least to convert any old legacy twin into this. And for that money, I can right now, buy any number of really nice, more modern turboprop twins or singles.
The economics don’t make sense – they’ll cost more than turboprops to run.
AdamFrisch wrote:
So you’re looking at $450K at least to convert any old legacy twin into this. And for that money, I can right now, buy any number of really nice, more modern turboprop twins or singles.
No, you can’t buy any modern turboprop single for $450k at least not with some 2000 hours left on the engine.
The other thing is: would you want to be a beta tester for a totally new engine? Having two of them is only marginally better, especially if there is a nice bug in the FADEC which shuts both of them down if the outside temperature happens to be divisible by 128, or whatever
I wonder how the 150k for the STC was calculated. They must have made a market estimate. My guess is that the STC (for an engine which is already certified for the right sort of operation, say to FL280 for a pressurised twin) would cost of the order of $1M. Are they really planning to sell just 7 of them? It could not be worth doing. I wonder if the certification cost is being mixed-in with the airframe specific STC cost.
Where are these figures from Adam? Is that what they said it would cost? If so, they can stop now. 150k for one engine is rubbish and a further 150k for the STC likewise, if it is for each individual airframe.
To be successful, the engine can not cost significantly more than the engine it’s replacing and the STCs must be done by the company in order to get the market going.
Basically, when an avgas engine runs out and needs to be overhauled, the conversion must be in a price range to make sense, so the engine alone similar or maybe 10% on top of what a new IOxxx would cost plus maybe a one time 20k to convert the airframe. Anything else nobody will go for it.
