SMA SR460 330+HP JET A retrofit

[Sam Rutherford]

The 4 cylinder (as in the 182 JT-A) engine's big brother, supposed to get certification this year.


Is now the time to buy that tired C206 for 2x nothing, and then fit one of these?


Faster, further for (much) cheaper?

[27/09]

In a word, No.

Two reasons.

One, you'll buy buckets loads of avgas with the money you'll pay for the conversion.

Two, do some research and see what happens on JetA1 piston engines if you have a turbo system failure. Hint: Do some reading on the reasons for the two off field landings Cessna had in their JetA1 C182 during it's certification.

[Sam Rutherford]

Not quite so simple.


1. Depends where you fly. On our C182 SMA we saved over £10K in fuel alone each London-Cape Town-London trip.


2. Any engine is vulnerable to a serious failure (though I do fully accept that this is less likely to happen with an engine design that hasn't really been changed in 50 years).


3. We flew (much) further, (much) faster, carrying more and saving almost 70% in fuel with our C182 (compared to the original AVGAS burner) - and it completely removed huge amounts of fuel planning (though the smaller strips became more complicated).


Have you flown an SMA powered machine? You should give it a go...


Cheers, Sam.

[27/09]

Hi Sam,

As you have shown there is a place for a JetA1 piston aircraft. However I'd suggest regular London-Capetown-London trips are not done by your typical pilot. I would suggest for the average owner a JetA1 conversion would not make economic sense.

A turbo system failure will not result in total engine failure of an Avgas engine like it will on a JetA1 piston engine. There can be a variety of reasons for a turbo system failure, not just the turbo itself.

I haven't had the opportunity to fly an SMA engined aircraft. No doubt they are very good. I hope they're a lot better then the Thielerts were, 300 hour gearbox inspections and all, though I understand that inspection time has now been increased.

[Sam Rutherford]

Like I said, it depends where you fly.


In the US, South Africa, no - stay AVGAS.
In Europe, depends.
Everywhere else, go JET A! It's cheaper, and it's 'everywhere'.


SMA is MUCH better than Thielert (no gearbox as just one advantage).


But it is a very expensive upgrade, I would guess 120-130K EUR (based on the 80-90 they were asking for the 4 cyl). Those (very rough) prices as fully installed and without any credit from resell of old engine.

[A and C]

Your input to this thread is very interesting, I have no experience whatsoever with the SMA engine, the comparitvly simplicity of the engine seems atractive however.

I think that with the doubling of the life in recent times and the ease of changing the gear box on a Theilert engine the disadvantage is somewhat overblown by some critics of the engine.

[AdamFrisch]

Sam - first the engine needs to be certified, then someone needs to certify the STC for your particular aircraft. Hopefully you have an airframe where enough models have been sold to justify the cost of an STC. If not, you're going to be out of luck.

We've had the same discussions over at the Aerostar forum. There is a huge need and interest for a diesel engine for that airframe. With over 1000 models sold and most of them still in service, it's a viable airframe for a conversion. EPS is a company that are pretty far along in the development of their 350hp diesel. It would be a good fit for the Aerostar. There are others - SMA and Continental's developments.

But ultimately, you're looking at at least a 10 year long process certification rules being what they are. Getting FAA and EASA approval might be one thing, but then developing the STC is another. Remember, it's not just the engine that needs certifying for the STC, it's the prop as well. So the question is - can you afford to wait around long enough for this to potentially happen?

I asked myself that question. Had there been a diesel alternative available for me on the Aerostar today or even tomorrow, I would have probably gone down that route. But life is too short - I want to be able to enjoy the freedom of filling up with Jet A1 today, not in 10 years. To travel and not worry about accessibility etc. Can't wait that long. So I've made the decision to go to a turbine.

[27/09]

Everywhere else, go JET A! It's cheaper, and it's 'everywhere'

What about Canada, Australia and New Zealand? Avgas rules in these places too.

I'd say the US, South Africa, Canada, Australia, New Zealand and Europe would pretty well cover 90% of GA operations around the world.

So everywhere else is by my estimation is about 10%.

If you start to factor in Adams comments about numbers of airframes that are likely candidates for conversion then the picture for the engine and or STC developer isn't so rosy.

One other question. Does the SMA use a FADEC? If so how is this powered and what battery back up is there? I'd be very nervous flying out over water for longer than the battery could keep the FADEC (if used) powered for.

[ChickenHouse]

Nice to see this finally reaching a visibility status. Let's see how long it really takes to get it on the market ... anybody remembers how long the Cessna JT-A is reported as "almost ready"? ...

Jet A1 does offer advantages, but - there is no free lunch!
Yes, in certain parts of the world it is mandatory to go this fuel line, as a separate fuel distribution for GA does not make sense right now. Yes, flying Jet or "Diesel" has it's beauty - less fuel burn, cheaper fuel, more range.
But No, it also has disadvantages. Turbo engines quit when turbo quits, when electronic control unit quits engine stopps, unknown influence on environment (one point which WILL come, as common eco terrorists tend to be unreachable by intellect and facts, but jump onto each possible pin point for media coverage).

One open question from us Fraggles croud to the Forum Marjory the Trash Heap: does SMA offer TBO for the 4-cyl. and 6-cyl., or is it TBR?
In my view, that was one of the major drawbacks with Diesel-engine conversion before.

[Sam Rutherford]

Well, almost four years later and still nothing on this... :(

Unless anyone else has heard something?

[Katamarino]

The only activity seems to be Soloy, who expect to certify the next generation SMA 230hp engine next year, followed by a 260hp.

However, asking price for the conversion is $210,000 and $240,000 respectively, which I suspect will make sense for almost nobody. It's a shame, if the price was sensible I'd be first in the queue.

[Sam Rutherford]

Those prices are clearly crazy. Cessna's appetite to take either 'mainstream' is almost certainly zero after the failure of the JET A C182. It's only by going mainstream that the prices can come down to something more useful.

There is a HUGE potential market converting old twins, but the figures (for two engines!) have to make sense.

To add, the SMA (whilst it definitely had issues and limitations) allowed faster, further, cheaper (by hour) flying, carrying more. So, take the installation cost away and it's all good.

[Tay Cough]

There are a couple of companies (Soloy being one) doing turbine conversions of the 206. Is that financially viable given your mission profile?

[Sam Rutherford]

There are a couple of companies (Soloy being one) doing turbine conversions of the 206. Is that financially viable given your mission profile?

I've flown the Soloy C206. Actually I wasn't that impressed.

[nomorecatering]

Another 4 years down the track and diesel engines in Diamond aircraft seem to be going well. The DA62 twin which is a fairly expensive aircraft seems to be selling as fast as they can build them, and most pf the owners on the Diamond forum are from the USA and very happy with the aircraft.

So does anyone have a link to information on the troubles that Cessna had that resulted them dropping the 182 diesel. I have just spent the last hour searching online and....nothing.

[Pilot DAR]

I don't know why Cessna stopped the diesel 182. I don't expect that they are interested in elaborating on the decision. My guess would be perhaps a combination of small teething problems, coupled with less than stellar market demand and simply not needed [yet] then. It would have been a more costly airplane, for little perceived added benefit in the main market (the US), where Avgas is easily available. I had an order in with SMA for their next generation diesel for a 182 client. We waited two years, and though the engine was promised, delivery was a problem. My client gave up, and bought a new O-550. I'm not aware that the SMA diesel is marketed to be a "new" engine these days.

I very much liked the Theilert diesel in the DA-42, though it had its challenges...

At present, I'm working an STC program to approve a RED diesel in the DCH-2 Beaver. It's installed and running, and I expect that the company pilot and I will test fly it in September.