Textron Introduces Diesel 172

[Ozgrade3]

Textron Introduces Diesel 172 - AVweb flash Article (http://www.avweb.com/avwebflash/news/Cessna-Introduces-Diesel-172222445-1.html)

Sheesh, $420,000 USD ($60,000 more than AVGAS) that burns 3 USG less per hour than the AVGAS version.

Cant see flying schools lining up for a whole fleet of them.

Will diesel engine prices fall with economies of scale?

[gassed budgie]

Just what the yanks were looking for, a diesel powered 172. It'll probably sell just as well as the diesel powered 182, which means, not a lot.
As OZ3 suggested, all a flying school needs is a 160hp avgas powered 172, with steam driven instrumentation, rubber mats on the floor and cloth covered seats under your backside.

The current Cessna management (accountants, all of them) are not interested in single engine anything, Caravans included. As has been pointed out elsewhere, about all they can see are Citations and government contracts. They seem to be hell bent on running down the single piston sales to the point where they can make excuses about closing down production because of poor sales.

[TTY]

[The current Cessna management (accountants, all of them) are not interested in single engine anything, Caravans included. As has been pointed out elsewhere, about all they can see are Citations and government contracts. They seem to be hell bent on running down the single piston sales to the point where they can make excuses about closing down production because of poor sales.]
Sounds like the same mob that's running Qantas.

[bankrunner]

Do Cessna even sell avgas 182s anymore?

The only 182 shown on their website for the last year has been the vapourware diesel model.

[Kulwin Park]

People, the next biggest thing to sell in Aviation will be engines! And especially fuel efficient and clean burning ones too. Everyone has upgraded their Avionics, the next biggest expense is an engine to improve performance and reliability.

The only other technology to come out that will interest owners and flying schools is better and lighter paint, with easy changeability. And maybe newer lightweight interiors.

Diesel concept technology is the way to go.

To the Future, KP.

[peterc005]

Ditto. Improvements in engine efficiency and emissions are desperately needed.

[currawong]

Great.

There is diesel and diesel.

Curious to know - is the grade of diesel these engines are certified for available in Australia?

Some folks are finding not.

[Horatio Leafblower]

Currawong,

My understanding was that the engine uses the Diesel cycle to ignite JetA1, not Diesel fuel.

...I may be wrong :confused:

[Duck Pilot]

Long term I feel that diesel or JetA1 is the way to go. Avgas can be extremely difficult to get in some remote locations these days, not to mention that you will pay through the nose for it if you can get it. Avgas these days in PNG is basically not available anywhere, even Moresby these days and the large operators who are using piston engined aircraft are having to import their own Avgas into country as the fuel suppliers aren't generally stocking it now.

[Squawk7700]

You won't put Aussie made diesel in an aircraft, you use Jet A1 as noted above.

[Duck Pilot]

Why not, if it meets the specs (production and distribution) what's going to stop suppliers selling it if there is a commercial demand.

[Flying Binghi]

via peterC005:
Improvements in engine efficiency and emissions are desperately needed.

"desperately needed" ?

One always wants to go faster, higher.... though, so did the Wright Brothers.

I've not noticed any emissions concerned desperate flying school operators running around airfields of late...:hmm:










.

[Jabawocky]

Well I saw it this morning, and it is a 172, but the truth is it is not 3 USG better and it is (from memory) 155 HP.

The burn at best BSFC is really more like 2 GPH but the TD will hold HP to higher heights, so it will go a bit quicker too.

[Jenna Talia]

Don't worry about Peter too much. He's also a lover of the carbon tax :rolleyes:

[Rich-Fine-Green]

We should not view the introduction of this airframe/engine from a mature market centric position.

Cessna and other OEMs see the future growth market for sales will be in the regions where Avgas is not available.

The future market for light aircraft sales in the traditional markets is bleak at best.

There is no long-term future in Avgas.

Other OEMs will focus their attention in a similar direction. Such as Gipps Aero with the (future) relatively cheap GA10.

[Pontius]

I get the point of the diesel engine but who on Earth can afford to spend $420,000 on a single-engine, four seat 'spam can'? I like the 172 and agree it is an iconic aircraft but that is just really silly money for what it is.

[bankrunner]

And yet CASA wonders why the GA fleet is so old!

You'd have to fly that 172 for 40 years to pay for it...

[27/09]

People, the next biggest thing to sell in Aviation will be engines! And especially fuel efficient and clean burning ones too. Everyone has upgraded their Avionics, the next biggest expense is an engine to improve performance and reliability.

Do you really believe this?

The current Avgas engines are already very fuel efficient by spark ignition standards. They're also pretty damn reliable unlike the Thielert engines. No gear box issues etc.

"Upgrading" as you call it to a diesel engine isn't just a matter of bolting in another engine. There's the small matter of a new engine mount, and probably new cowls and also I suspect a new prop. The initial conversion cost can be pretty eye watering.

While this new engine may improve performance at high altitude (due to the turbo charger) I don't see much performance gain for most operators and certainly no improvement in reliability. In fact based on the earlier Thielerts I'd expect less reliability. But I do see plenty of up front costs which are not necessarily going to be offset by any fuel burn savings.

Also what happens when the turbo fails especially at altitude? :uhoh:

[yr right]

Aero enterprise at lismore many moons ago had a kit for 172 and 182 for a desiel conversion but it never went any where due to the cost of it. I don't remember which engine it was they where using but

[Walter Atkinson]

There are still major problems with props and diesel engines. Only steel props will work at this point. Very heavy. There are other issues as well that Teledyne nor CMI want to talk about publicly. They want to look like they think the public wants them to look--that diesels are the wave of the future. I am less than convinced. An unleaded AVgas will arrive and the diesel rage will wane.

Diesels in airplanes are like fitting a submarine with an air-cooled engine. I guess you "could" do it, but why would you?

[No Hoper]

clearedtoreenter, from memory you are correct. EPS claims to have overcome the problem and have an aluminium prop on their EPS 350.
It is fitted into a cirrus, as test bed.
Compression ignition using JetA1 is the future for General aviation, the availability of Avgas is a major issue.

[Aviater]

The Austro Diesel engines fitted to Diamond Aircraft use MT composite props and have done right through development. Walter Atkinson, I'm disappointed.

Austro are also working on STC's for other airframes and their 170hp diesel/jetA1 engines.

[27/09]

The rest of the plane was really awful, noisey, vibration, smelly, no guts, slow, although it did use minute amounts of JetA1 and was far cheaper on fuel than a Lycoming. It was of course an aftermarket modification and so it couldn't be expected to be perfect but I hope Cessna are doing better than that.

That's what happens when you try the con of telling everyone that a 135 HP diesel can match a 160 HP avgas engine.

I see Continentals new CD 300 diesel engine is only 17% heavier (it's actually more like 20%) than it's avgas equivalent. That should be a real selling point.

[Walter Atkinson]

Gentlemen:

A lot of testing has been going on concerning the use of composite and aluminum props on diesels. The mounting data is that these applications, while they can hold up in the short term, are not well-suited to the very high combustion pulses transferred to the crank and the prop. More than a few props have been destroyed whilst being tested. Time will show what I am reporting is accurate. Wishful thinking is a poor substitute for hard data. A delaminated prop will make for an interesting ride.

[yr right]

As I've stated before the hymomics of a desiel engine destroys props and airframes. You need to run a Cush drive in the hub. What's need ed is a low cost turbine if you won't to run jet a

[Jabawocky]

Having seen both the 172 and 182, the 172 option is DUMB. The 182 with the SMA engine is the smarter of the two…….BUT.

………………anyone know why they have had two (2) engine failures in the certification test process so far? :ooh:

I have said this before……I would like to try one but it would get the same VFR flight that I would do in a two stroke ultralight.

[Aviater]

Walter. All Austro Diesel Engines use a torsional vibration damper between the crankshaft and the gearbox and vibration levels are monitored by the ECU. Ie:- the prop and the crankshaft are not hard mounted together.

Did I mention it's certified for Jet A1 and all it's aviation equivalents PLUS good ol' pump diesel.

I don't understand why your so anti diesels. Most certified airframe manufacturers are investing in some capacity into this technology. Clearly it is a valid pathway to reducing overall running costs.

Austro believe that after a few years of collecting data from in service engines there's no reason why they're engines couldn't have an 'On Condition TBO". They all have mandated oil analysis as part of the maintenance program.

Have you ever flown one?

[Aviater]

http://s14.postimg.org/5qdk8xjzl/flywheel2.jpg

[Aviater]

2 flywheels attach the crank to the gearbox with a torsional vibration damper inside. Takes care of high frequency vibes as well as rapid changes in power application.

[currawong]

Aviater, is your "good ol' pump diesel" the diesel that is available in Australia?

There are engines here already certified for diesel, are being run on diesel, but the grades certified are not what is available here.

[Aviater]

I've been personally informed by one of the project heads that Australian Pump diesel has been certified for use. Have been looking for supporting documentation but am still waiting to hear back.

During testing one of their DA42 NG aircraft did 2500 hours without teardown on what they called agricultural or farm diesel. That was in Europe though.

[currawong]

You may wish to check out CASA AWB 28-015

[Luke SkyToddler]

How can a b***dy diesel engine be a $60,000 "optional upgrade" over the lycoming?! You can get a complete brand new diesel Hilux for a lot less

[catseye]

Might want to have a look at the BP Diesel site. Specifically said not to be used in aircraft

:= http://www.bp.com/content/dam/bp-country/en_au/products-services/fuels/ultimate-fuels/BP_Ultimate_Diesel.pdf

[27/09]

$60,000, which I presume is USD, buys one hell of a lot of avgas especially when you consider the difference between the avgas cost and the cost of JetA1 for the same flight time.

What TBO are they giving for the diesel engine?

I'd venture to suggest the Lycoming IO540 will have a higher TBO and lower direct operating costs and overhaul costs.

Why anyone in this part of the world would even consider a diesel C182 beats me. As for retro fitting, it ain't going to happen.

Also the elephant in the room is the turbo reliability.

Apparently both engine failures during test flying were turbo related. Turbos have been fitted to aircraft for many many years now and have very good reliability. To have 2 engine failures with this engine suggests to me the turbo on this engine may not have the reliability we are used to in our aircraft. To follow on from that, a turbo failure in a spark ignition engine doesn't usually end in engine failure like it does so often for a compression ignition engine.

[Konev]

that is BP covering their ass due to probable contamination in diesel tanks at fuel stations. most people fit a second fuel filter to new common rail diesels for instance.

[27/09]

I see AvWeb are reporting the probable demise of the diesel C182.

There is now no definite timeline for the C182 diesel according to the article. It also mentions Cessna are taking out the diesel engines from the aircraft already fitted with them, sending these engines back to the manufacturer and re fitting avgas engines.

There's speculation as to why this has happened, suggestions are that it's due to partly economics (avgas being to cheap) and reliability problems with the engines.

See article here Has Cessna Suddenly Grown Cold On Diesel? - AVweb Insider Article (http://www.avweb.com/blogs/insider/Has-Cessna-Suddenly-Grown-Cold-on-Diesel-224068-1.html)

[LeadSled]

I've not noticed any emissions concerned desperate flying school operators running around airfields of late...:hmm:


Sadly, of late even desperate flying schools, or any flying schools, are getting hard to find. Emissions, except from CASA, are way down their order of priorities.

Tootle pip!!

[Jabawocky]

Well bugger me………. :}

I will try not to say it…..

Clearedtoreenter, I could answer that IF there was a sensible comparison to make. The bottom line is this, the STC for a 260HP IO540D4A5 (Comanche & RV10 engine basically) is the best fit for a C182.

It climbs like a love sick angel and LOP produces very good BSFC numbers (yes I do them) and its cost of operation is pretty darned good. The reliability is the best in all of GA and I don't think many will argue that one. It will not flame out with a TC problem or a simple intake leak.

I am not sure what I said previously in this thread but i reckon if you look back the story in avweb (which I also have not read yet) could be very interesting in terms of what is not said.

Cessna would be wise to go back to IO540's but not the 230HP version, the 260. Cost is the same and in cruise the fuel burn is the same as the 230, but you get far more climb. I happen to know the eta on this as a very good friend has one, late model and 260HP. We discussed this at OSH last year and he wrote the cheque, and has not stopped smiling since!


PS: My comment of the smarter of the two, only in terms of a payload capable plane in use in Africa or somewhere….not sure C172's with a TD are the go. But Cessna seem intent on releasing that. Go figure???

[yr right]

Mmmm. Induction leaks can be easily fixed by engineering it out. Please advise what is the critical altitude for a turbo falute in a compression engine.
main thing in this engine will be the lack of pilot management in the set up like a turbine. This will increase reliability of the engine.
And as fuel use age as creamie states is not an issue all will be good in the universe.

[Andy_RR]

Critical altitude is probably sea level, yr right. You will definitely see a performance drop with a sudden disappearance of boost before you leave the ground - that and a load of black smoke!

The issue isn't only critical altitude, but keeping the combustion chamber hot enough to support combustion. When you're at altitude, low temps, low air pressure, the unboosted compression pressure isn't enough for the low CR these engines run at. Add in the SMA/Continental's air-cooling where you have nearly no thermostatic control, if you lose boost at altitude, chances are you can kiss goodbye to all combustion and you'll never get it started again until you reach the bottom.

[yr right]

Do you understand what crictal altitude is.
Next I take it that no combustion engines work at altitude and in cold weather. That's strange I've worked at above 10000feet and we had Diesel engines working.

As for cooling yes they work better in general the hotter they get. This is also overcome with engineering. It's easier to heat an engine than to make it cooler. So still what is the crictal altitude for a complete turbo failure and to loose all performance from the engine. Next what is the crictal altitude for a normal ignition engine for a restart.
Even most turbines can't be started above 10000 feet. Your argument dose not stand up for restarting.

[QFF]

Critical altitude

Turbochargers increase a piston engine's critical altitude, which is the maximum altitude at which an engine can maintain its full, rated horsepower. Because the maximum horsepower of a normally aspirated (nonturbocharged) engine is achieved in standard, sea level conditions, sea level is this engine's critical altitude.

From AOPA (USA) Flight Training magazine website

Quote: "Even most turbines can't be started above 10000 feet."

I would think that the PT6 qualifies as "most turbines" - this is the airstart envelope for a PT6-66D:


http://i103.photobucket.com/albums/m122/nospamphotobucket/Air%20Start%20Env_zpscv27faqh.jpg (http://s103.photobucket.com/user/nospamphotobucket/media/Air%20Start%20Env_zpscv27faqh.jpg.html)

[Jabawocky]

I suspect there are a host of other "unforeseen" issues that include but are not limited to the power plant.

So much so that the massive engineering and certification effort may kill it forever.

Just my guess from joining a few dots……maybe not perfect dots, but better than average dots ;)

[yr right]

Maybe it will not make certifcation and maybe it will. Who knows. The amount of aircraft engines that don't out weighs the ones that do.
How ever time will tell.

But still what is the max crictal alt that this engine will restart at.
Is the engine boosted from sea level or is it just normalized to alt.
you can't just put up a statement if you don't know what it performance is !!!!
Examples of turbine was to show that they can't be started at alt ether. Not many pistion engine aircraft get up of 25000 feet.

[Andy_RR]

Diesel engines run at 2-3Bar (absolute) manifold pressure at sea level, yr right. They need all this air because even at full power, they are running lean. The better the combustion system, the closer they can run to stoichiometric before they reach their smoke limit - i.e. how rich before soot emissions become unacceptable.

If you don't have any boost at all, they will have half or less of their power, even at sea level, therefore the critical altitude of a heavily boosted diesel engine - which is most of them - is sea level.

Highly boosted diesel engines usually run lower compression ratios due to structural limits for the maximum cylinder pressure. Low compression ratios means low peak cylinder temperatures under compression which limits the starting capability. That's why diesel engines run glow plugs and inlet air heaters for starting assistance - these are usually only man enough to start a stationary engine - not one that has it's cooling system running flat out, as it is for air cooled engines in flight. Lower atmospheric pressure at altitude also reduces peak compression temperatures too, with similar results. Combine the two and your diesel engine might be very hard-to-impossible to restart at altitude.

Even low power levels below the turbocharger boost threshold can be enough to let the fire go out. I believe this is why the SMA engines have a minimum power level for descent.

[Jabawocky]

Andy, well said and nicely described. I just hope the effort was not wasted.

And for all the reasons you describe, when the shiny gloss of sex appeal etc are worn off, you end up with a sub optimal piston aircraft engine in my humble opinion. A turbine is another matter, but for low level ops at lower HP these are not practical.

Square pegs in square holes. :ok:

[yr right]

You seam to be comparing automotive to aircraft needs. So why can't you have high comp at sea level and have turbo boost at altitude.
I'm sure that the designers have taken everything into account. I'm not pro or anti. Don't really care. But I'm surprised at all the knockers but then again I'm not supposed about that ever.
When you consider the size of rods and cranks in a 150 hp aero engine to that of good quality automotive racing type rods of around the same stenghy that will take around 700 odd hp.
And like I've said earlier. It easier to make heat than it is to cool it. So is this engine air cooled or liquid ?
Maybe the aircraft is fitted with an emergency system for in flight starting.
Comes with a can of start you bastard tapes to the engine air filter inlet.

[Andy_RR]

You seam to be comparing automotive to aircraft needs.


I don't recall mentioning automotive at all, although most of the (truly) available aero diesels are heavily automotive based.


So why can't you have high comp at sea level and have turbo boost at altitude.


You could, but the engine would be much larger than required to make the power, especially if you're still paying the weight and complication penalty of having a turbocharger hanging off the side of it. A big engine is a heavy engine, especially when the high cylinder pressures of diesel engines are concerned.


So is this engine air cooled or liquid ?


The SMA and Continental CD200/TD300 are air/oil-cooled. The rest tend to be liquid cooled (and thermostatically controlled)

[nomorecatering]

Interesting thread so far, lots of thoughtful arguments/comments. I suspect of this forum had been around in the 1920's, we would have been arguing how will they ever get these new fangled gasoline aero-engines to be reliable.

I'm completely confident that the engineers will ultimately lick the problem. It may take a paradigm shift. My guess is SMA will ultimately make the engine liquid cooled.

However, there is another problem on the horizon for diesels that no one has mentioned. The production of diesel particulates, aka soot. Diesel particulate filters cure this problem at the expense of power and efficiency, then there's the need for active or passive regeneration in the DPF (burning off the soot in the DPF), but periodically you still need to remove the DPF to clean out the accumulated ash plugs. Don't even for a minute think that aero engines will forever escape the EPA who will eventually mandate DPF's for aero-diesels.

I've installed a water/meth injection system on my RAM3500 which keeps the DPF clean as a whistle and almost never have to do a regen.

[yr right]

As for soot well I'm not sure. But anyone that's has work at a large airport will know what their car looks like after a week on shift. It's covered in black soot. It seams pa140 and moneys have now stc for fit ment as well

[Lumps]

Seems like it'd be easier to develop and certify (or is it certificate?:hmm:) an unleaded, 100 octane avgas able to be brewed in auto refineries...

[LeadSled]

Seems like it'd be easier to develop and certify (or is it certificate?:hmm:) an unleaded, 100 octane avgas able to be brewed in auto refineries...

Lumps,
A well timed thought, Continental ( as I recall, not Lycoming) has just announced the certification by FAA of an engine to run on 100LL or 91ULP. It did not mention whether that was motor octane or ASTM octane -- but the intent is to have a engine manufacturer certified to run on mogas, not an STC.

The threat to 100LL is not any shortage of "petrol" but the TEL (lead), which is now produced at one single site only. EPA's of this world are a lesser problem, (except in the minds of rabid greenies) because avgas consumption is sod all % of petrol consumed, the lead is now barely measurable from avgas sources.

With changed refinery processes we are now seeing 100 ULP (motor octane) as common with 105 not far away.

Tootle pip!!

[Ozgrade3]

One reason I want to see all types of AVGAS disappear is that the market in the US, let alone Oz is too small to justify the infrastructure costs of making it available. You have Jet-A, and associated stuff to get it too the bowser, trucks etc. Then you have another fuel, AVGAS, that must be carefuly handled, separated, trucks, tanks, lines etc, duplicated infrastructure. That's not even talking about the refining costs.

Mush better I say to have the one fuel, Jet-A for everything that flies.

I cant work out why we have 3 different grades of fuel for cars. 91, 95 & 98. Why cant they just standardise on 98 and take the advantage of economies of scale.

[Jabawocky]

I cant work out why we have 3 different grades of fuel for cars. 91, 95 & 98. Why cant they just standardise on 98 and take the advantage of economies of scale.

I like your idea, but it just does not work like that.

I want to breed cattle that give 100% eye fillet steak, but instead you get all the other cuts in larger volume. Refining is much the same. Even avgas, the stuff from BP in WA is not the same as the Geelong stuff from what was Shell. The BP has way more lead because of a lower grade alkalyte.

As for all JetA burners……don't hold your breath.