Has Cessna Suddenly Grown Cold On Diesel?

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Cessna’s admission this week that it now has no definite timeline for its diesel 182 JT-A invites speculation. Or maybe I’m the only one who can’t resist asking what’s going on in Wichita.

Earlier this week, we got an email from a reader trying to snag some hangar space at Independence, Kansas, where Cessna builds piston singles. None available, he was told. Cessna has them temporarily occupied, breaking down new airplanes and replacing diesel engines with gasoline powerplants. Moreover, the diesels were being shipped back to the manufacturers. 

A check with Cessna yielded no confirmation or denial of that, merely the non-committal statement that the company has no definite timeline for the 182 project. But they are aiming for approvals on the 172 by the first quarter of next year. And by the way, it’s also resurrecting the Lycoming-powered Skylane 182T, which it discontinued in 2012 when it announced the Skylane JT-A diesel at AirVenture.

This is a curious turn of events on multiple accounts. First, while missing promised cert dates by months, if not years, is a grand tradition in aircraft manufacturing, Cessna doesn’t play that game much. If the company pronounces that the newest Citation will fly in the third quarter of next year, it’s a good bet that it will. Multiple queries about the status of the Skylane JT-A always yielded a reply of “in a few months.” Now, it’s no definite timeline. Are we looking at a soft cancellation here? Cessna isn't saying specifically, but after I wrote this blog on Tuesday, the company phoned back to say the 172 has a definite projected schedule of next spring. It insists it's still committed to the idea of diesel piston engines.

Textron is unlikely to favor us with any detail about why this decision was made or, more accurately, why these two projects appear to be in drift mode and what thresholds will trigger more aggressive development and date-certain deliveries. Does Cessna just see market softness that makes the 182 a short-term loser?  Is the erosion in fuel prices, admittedly minimal for avgas, causing them to rethink diesel economics? Are the engines just not robust enough for Cessna’s standards? Or is it some combination of these factors? I invite you to offer your own speculation. I’m quite certain I don’t have these answers.

One concern, however, is the engine choice for the 182 JT-A, the SMA SR-305. I first clapped eyes on this powerplant in a surprise showing at Sun ‘n Fun, probably around 1999 or so. It was then flying on one wing of a Piper Seneca and it looked real enough. Yet 16 years later, the engine still lacks significant industrialization and has nothing like the installed OEM base of Continental’s diesel line originally developed by the now-defunct Thielert. Does this lack of traction indicate a latent developmental snag in this engine that even Cessna can’t solve? It certainly raises doubts.

Whether Cessna is in or out of diesel--and it says it's still in-- the fact that it’s non-committal on timing is not a good thing for the market. It’s kind of a reverse overhang when a major airframer—the major airframer—gets into diesel, cancels it, gets back in and then waffles on deliveries, at least on one model for three years. It’s bound to send a chill into buyers although, in my view, the diesel market will ultimately shrug it off. Diamond Aircraft long ago established the viability of Jet-A piston aircraft and although the market has never shown signs of explosive growth, it has been steady and poised for more solidity now that Continental is investing in new development for existing engines and new higher-horsepower variants. In Austria, Austro just announced delivering its 1000th AE300. Nope, they’re not exactly setting the world on fire, but who in general aviation is? Cessna is still the big dog in new training airplanes, but it’s no longer necessarily the lead dog in the sense that it drives and owns markets.

I know from a source selling new and converted Cessnas that demand for the Skylane JT-A appears to be good, with 50 to 70 orders booked. Almost all of that is offshore business, which confirms what everyone in the diesel segment has learned: Europe, Africa and Asia are the drivers. With relatively cheap avgas, U.S. buyers aren’t feeling much love for diesel yet. I suspect uncertainty at Cessna won’t change that much. Let’s see if the diesel conversion market steps intro the breach.

P.M. Revision: Cessna spokesperson Lindsay Adrian phoned to say that while the diesel Skylane timing is indeterminate, Cessna is still committed to delivering diesel Skyhawks sometime next year. I've rewritten the blog to reflect that statement. 

Comments (33)

Somewhat withdrawing before hitting bottom on the hyped aircraft C182 diesel market (?), IMO appears to be a good business practice. It follows a paralell to the C162 LSA. Both in unviable markets for Textron's Cessna. No surprise here.

Posted by: Rafael Sierra | May 12, 2015 7:56 PM    Report this comment

Diesel is a loser for US airplanes just like it's a loser for US cars, not because of any inherent faults, but simply for one reason: upfront cost.

Automakers have generally only made diesel engines available in cars with the highest (read: most expensive) trim package--you know, the one with surround sound, heated steering wheel, power sunroof, TV for the kids, and other fancy gadgets--and then tacked on additional cost for the diesel option. Then they wonder why nobody wants to buy the diesel version, and discontinue the option because "Americans don't want diesels". Yeah, not at that cost, we don't!

In airplanes, diesel installations cost tens of thousands of dollars more; that buys a lot of gas. Pricing out diesel vs. Lyclone for an RV shows a cost difference of $30k+, which has prompted past comments of "does that price include an airframe to bolt it to?"

Posted by: Bob Martin | May 13, 2015 5:31 AM    Report this comment

Bob - your anti diesel bias is overwhelming.

Diesels are generally more expensive up front, but deliver far bigger savings in fuel costs over the life of the engine (which itself is generally a far longer lifetime for a diesel than a gas engine, whether in cars, trucks, or airplanes). However, the up-front cost differential is not necessarily very big at all. It's a matter of simple economics - pay some now, or pay much more later.

The desirability of diesel engines depends upon the application. For high automobile fuel economy, the VW Tdi diesels do very well and generally far better than most other economy cars including the vaunted hybrids. For extreme load hauling such as in heavy duty pickup trucks, utility trucks, and class A RVs, nothing beats a diesel for power, torque, and long life under heavy loading. For aircraft where lack of 100LL is an issue (everywhere in the world but North America), a diesel or turbo prop is almost essential. And for long range cruising, the economy and range of a diesel can't be beat. The new four-place Flight Design C-4 diesel now undergoing flight testing is said to have a 1,700 nm range at cruise power! That's nearly three times the range of a gas engine C182 Skylane.

Even so, the up front cost differential between aviation diesels and avgas engines is shrinking.

Recall our thread here a couple weeks ago on the new three cylinder 2-cycle Superior diesel engine that only costs about 20% more up front than the equivalent Rotax engine. Superior plans to unveil a full line of similar diesel engines at all the usual horsepower levels in GA. The payback on the minor ($4,000) cost differential on the 3-cyl diesel in terms of fuel savings over a 2,000 hour TBO is calculated to be about an 8:1 benefit:cost ratio. Plus a 2-cycle diesel should provide a much more robust and reliable engine, given that it completely eliminates the valve train parts of a 4-cycle gas engine that are the source of so many aircraft engine failures ... no minor consideration for a single engine aircraft.

The issue with Cessna's backtracking on their two diesel models likely has little to nothing to do with diesel technology in general, but as Paul suggested, with the slow development of their selected SMA engine supplier, and Cessna's overall non-competitive product pricing.

Consider the overall extremely high cost of their 182 Skylane aircraft, which even with a gas engine still costs close to half a million per copy, (with the diesel model running well over half a mil per copy) which is in no way competitive with other new aircraft like the Flight Design C-4 which outclasses the Skylane in virtually every performance measure (speed, range, payload) at a price that is 40% lower than the Cessna product. For what Cessna is asking for a new diesel 182, one can nearly buy a new Cirrus SR22, a far more advanced and capable aircraft.

Cessna seems stuck in the 1960s in their aircraft design and their pricing is simply not competitive.

Posted by: Duane Truitt | May 13, 2015 7:41 AM    Report this comment


I really would be quite happy using a diesel in my car and my airplane. But I am also capable of running cost projections, and those cost projections tell me that the diesel does not make economic sense for my situation. For example, I've compared the costs of my car vs. a coworker's diesel Jetta, and found that the diesel option doesn't actually save any money at all around here because diesel is consistently priced 10-20% higher than 87 unleaded, erasing the benefit from the lower fuel consumption. Plus, requiring the deluxe trim package just to get a diesel further pushes back the payback period if one otherwise would not be getting said deluxe package.

For my airplane (RV-7), I compared the cost of a new Lycoming clone with EFII (~$35k with FWF) to a DeltaHawk diesel ($70k). That $35k could pay for the rest of my airplane (kit, panel, paint)! But if we look at operating costs, assuming the relative prices stay the same and ignoring inflation, best case (burning 100LL) I break even on cost at 2000 hours--20 years away, assuming I fly 100 hours a year. If I run mogas as planned, that interval stretches further, out to about 4-5000 hours depending on octane. If I'm still even flying at that point, I'll be ecstatic. Even playing with the figures in the DH's favor, I'm looking at a payback period measured in decades.

Now, that changes if there are new entrants to the market in the next couple years. If a 180-200hp diesel comes along with only a 20% price premium vs 100%, and it can run Jet-A or diesel from the gas station, I would be very interested--perhaps even interested enough to be an early adopter. Maybe Superior will be the ones to make that engine, but until it exists I can't put it on my airplane.

I know that these numbers are more favorable in my case because I'm talking about a homebuilt--I don't need to use a certified engine, I'm free to use mogas if I want without an STC, I can use electronic injection, and I'm not putting anywhere near the hours on the airplane that a flight school would. I'm also in the US, where gasoline (in all forms) is cheaper than in the rest of the world. But my point is that not all objections are simply "overwhelming anti-diesel bias"--sometimes the numbers really don't work out. In my case, the payback would come many, many years down the road, plus push back my first flight a few more years while I came up with the additional money.

It should also be noted that a fair bit of the Flight Design's performance and cost benefit comes from having a modern, lighter, less draggy airframe. The 172 is heavy, draggy, and labor-intensive to produce, and as great of a classic as it is, it should have been put to pasture a long time ago.

Posted by: Bob Martin | May 13, 2015 10:19 AM    Report this comment

I've discovered that aircraft diesels are not all about saving money on fuel (or avgas un-availability outside N. America).

Mostly because diesel aircraft engines are liquid-cooled and FADEC-controlled, there are many other benefits:
- No need for engine pre-heat in the winter (e.g., Austro diesels can be started down to -30C without damage)
- No concern for shock cooling; "slam-dunk" approached forced by ATC are no big deal.
- The lack of lead in JetA or diesel fuel means that 100% synthetic oil can be used successfully, leading to 100 hour oil change intervals. Experience has shown oil consumption is less than a quart between 100 hour oil changes.
- No mixture, prop, or turbo boost controls are needed; the computer manages all of these automatically.
- The greater energy content of JetA/diesel means that fewer gallons need to be carried for a given flight, permitting a larger payload.
- No such thing as hot starts (often an issue with avgas fuel-injected engines) or cold starts: just turn the key and the engine starts up immediately regardless of temperature.
- Diesel engines tend to be quieter -- the Austro engines on our DA42-VI have mufflers. People complain that we "sneak up to them on the ramp" because all you hear at low RPM is the prop.
- All aviation diesels tend to be turbo-diesels, so you get all of the benefits of turbo-normalized performance including climb rates of over 1000 fpm all the way into the flight levels, the ability to out-climb icing layers and some of the weather, and improved takeoff performance at high field elevations.

Disadvantages include potential mis-fueling by ramp workers who assume that any aircraft with propellers requires avgas, and the worse smell of JetA. But our experience of owning and flying a diesel aircraft for the last 2 years has been terrific.

Posted by: DAVE PASSMORE | May 13, 2015 10:36 AM    Report this comment

"I know that these numbers are more favorable in my case because I'm talking about a homebuilt--I don't need to use a certified engine, I'm free to use mogas if I want without an STC, I can use electronic injection, and I'm not putting anywhere near the hours on the airplane that a flight school would."

The numbers aren't all that different for a flight school, Bob. I've run them a million times. Diesels are competitive across a narrow range of buyer considerations that include apples-to-apples new-vs.-new and high usage applications in areas where there's a bigger delta between avgas price and Jet A.

For owners willing to use mogas, the diesel advantage all but evaporates in the U.S. Also, the cost of manufacturing diesels is not narrowing. They still cost twice as much to build. Favorable exchange rates have helped, but that applies to U.S. buyers only. Superior has proposed a less expensive diesel, but it's not out there yet and you can't make plans based on press release prices. (Ask Diamond about that.)

No widely fielded diesel lasts longer than avgas engines, although they're getting there. the SR305 has a proposed 2400-hour TBO, but it's simply not fielded. So your impression is similar to mine, borne of analysis with real numbers and, I hope, no bias. Diesel is competitive in certain circumstances, has pros and cons, but isn't a killer app yet.

Duane, I have to ask: Do you work a diesel manufacturer? If you do, you ought to declare that. Just curious.

Posted by: Paul Bertorelli | May 13, 2015 10:58 AM    Report this comment

Don't forget to factor in the advantage of combining diesel with the new batteries using Flerovium-Osmium chemistry, which the developer projects to be commercially available within weeks (after a few minor problems are overcome). These will allow you to keep the diesel's starter engaged during flight, adding 32.79% to the fuel economy figures.

Speaking of fuel costs, I just stopped yesterday at L35 & filled up with 100LL at $4.09/gallon, then later in the day drove by our local Chevron which is selling that good California 87 unleaded at $4.08/gallon. We do so love California.

Posted by: John Wilson | May 13, 2015 11:30 AM    Report this comment

Paul - to answer your question, no, unlike you I am not connected in any way professionally or business wise with any aviation company at all. Touche, I believe.

I am just a private aviator, and an engineer who in his professional career has seen the ancient practice of engineering completely revolutionized by technology within the span of a single generation ... and wonders why so many in private aviation are so stuck in an ancient past while the rest of the world embraces change and advancement.

I happen to prefer modern 21st century technology to early 20th century technology in my aircraft - whether airframes, power plants, or avionics. So much of today's private aviation market as well as regulatory system is so frustratingly stuck in the 1930s to 1960s, where virtually everything else in modern life is, well, modern, and not stuck in the past.

I really don't get the massive cynicism and resistance to change, and constant "prove it" attitude on your part, and that of so many others involved with private aviation. Cynicism - which is not the same as skepticism - is a disease, not something to revel in.

Most would call it a "can't do attitude".

If aviators (and regulators) want to pin the real culprit on private aviation's failure to modernize with the rest of the world - just look in the mirror.

The rest of us are much more interested in focusing on what is being done, and will be done, to make aviation better, safer, and more rewarding, rather than focus on incessant complaining about what hasn't been done, and routinely proclaiming that it (whatever it might be) most likely won't ever get done.

Posted by: Duane Truitt | May 13, 2015 11:37 AM    Report this comment

I think there are two things together. First, is the engines engineering with all the good & bad of self-ignition fuel efficiency, worldwide fuel availability and FADEC electronics (all having benefits, but for the cost of risk) together with the, to the public yet unknown findings of the late certification flight engine breakdown. Second, is the bigger issue - economical circumstances, as the target market outside the US, which is the major demand for diesel engines, can no longer afford buying the plane for a reasonable price. Say a JT-A was calculated to go for 550 grand USD, which was about 400 grand EUR a year ago, but now with US economy up&healthy and eurozone f***ing up, this is 525 grand EUR. A 30 percent crash over one year in expected turnover at one of the, still most important, markets smashes any business case. Until the Chinese market takes over the role of the europeans, there will be little sense in producing such diesel JT-A. Just my two pennies.

Posted by: Mike Meyers | May 13, 2015 11:42 AM    Report this comment

For the moment, there's reduced apprehension that aviation gasoline is going away any time soon. Another 8 years of a democrat administration will renew that apprehension, and diesels once again will draw great interest in the US. If Cirrus produces one, all competitors ( ? ) will follow suite - quickly.

Absent that fuel-availability concern, the prevailing attitude - at least at Cessna - seems to be "why bother?" Indeed.

I don't trust our EPA et all at all, so my next aircraft will be a kerosene-burner - turbine or piston. But it won't be a homebuilt. I can afford to wait, or die trying.

Posted by: Tom Yarsley | May 13, 2015 11:59 AM    Report this comment

"I really don't get the massive cynicism and resistance to change, and constant "prove it" attitude on your part..."

Sorry to offend. I just like incorrect facts to be corrected, is all. Goes with the job description.

Posted by: Paul Bertorelli | May 13, 2015 12:27 PM    Report this comment

It's apparent that GA manufacturers in Europe and other countries are looking toward an emerging global market for their products. Successful American companies from Coca-Cola to Apple and beyond have been doing this for decades.

But for some reason, the mainstream American GA manufacturers are content to limit themselves to the dwindling U. S. market, still giving their aging customers the airframes and powerplants they wanted 40 years ago.

Avionics is the odd exception. Glass-cockpit manufacturers have managed to push their products into most new airframes, despite the skepticism of the loudest voices in the GA community. How did that happen?

Posted by: Rollin Olson | May 13, 2015 12:28 PM    Report this comment

Personally I think this is less about the merits of diesel engines and more about the general indifference of Cessna management towards their piston engine airframes. Pelton was an airplane guy, the current president is a bean counter. He is IMO actively moving Cessna away from the production and support of current and legacy piston Cessna's and towards the higher margin jet airframes.

Posted by: DAVID GAGLIARDI | May 13, 2015 1:41 PM    Report this comment

Cessna made a very clear and unmistakable statement about General Aviation with scrapping its 162 Turfcatcher program. I sat at a CPC seminar in San Diego, when the cards and outlook was completely different and people were hyped up beyond reality about piston singles. Dreams, really - hoping some affluent people would pop out of nowhere, buy a 162, then upgrade to 172/182/ 206 prior to the Van. Then, its onwards and upwards to the Citation. Sure thing!

One CPC guy I remember distinctively was selling greeting cards shortly after loosing his Cessna job. The company has set its target on jets and I suppose the turbine market isn't all to shabby these days. Considering that the company has a long standing heritage in General Aviation and has produced some of the most successful airplanes in the world (that used to be the true backbone, once upon a time) any announcement to scale back efforts indicates that the analysts are not sure that the product will sell that much better with a diesel engine.

I am sure the never ending product liability worry plays a part in Cessna's more than careful steps with the 182 Diesels. One doesn't have to be a Diesel Company employee to be a diesel fan. But, its basically still the same rivet bomber, with the same 50 year old engine technology, with fresh paint and a Garmin panel.

Buyers aren't exactly lining up, yet easy solutions (bullet proof and truly doable) are not implementable due to the regulatory issue in getting such engines approved on certified airframes. A catch 22 for anyone trying to come out with a buck in profit. PR wise, I do not think that Cessna improves its stand by scaling back - after all its aggressive innovation and the willingness to gamble that makes other manufacturers successful. I don't even want to imagine what kind of B.S. Cessna's current CEO (I stopped watching after Jack Pelton went) has to put up with from the unions. Its a harsh environment and sometimes that can stifle a company enough to slowly start moving out of a market.

"A gallon of avgas is a dollar in my country, it will always be a dollar!" Words I remember hearing from a Cessna Representative after asking about better, more efficient engine technology back in 1994. That was 21 years ago, folks. Not yesterday! Guess AVGAS isn't a dollar anymore...

Posted by: Jason Baker | May 13, 2015 2:36 PM    Report this comment

Cagliardi, you are correct.

Posted by: Rafael Sierra | May 13, 2015 2:37 PM    Report this comment

Paul B. - There is another, not-so-small factor here: EUROuro to US$ rate has declined a whopping 30% in just the last 3 - 4 months.
That means that depending on how those delivery/payment contracts Cessna is holding are written, someone is going to take a big hit - or not if their canceled ...

Posted by: Michael Chartier | May 14, 2015 5:49 AM    Report this comment


Though I only have a decade or so as an engineer in the aircraft industry vice a generation or two, I share your sentiment about so much of light GA being stuck in the 60s and 70s. Being involved in the ASTM group working on the new proposed certification standards, I've seen plenty of things in the regs explained away with "well, because we've always done it that way". And I've met plenty of pilots--usually older men--resistant to glass, composites, even fuel injection; it frustrates me to no end. But not all objections are equal; not all are simple knee-jerk reactions to scary new technology. Lycomings and Continentals have their shortfalls, but I don't think it's unreasonable to expect that a newer replacement be at least as reliable as the engines it's replacing--and in light of the potential consequences, neither is it unreasonable for the person who would face those consequences to expect some actual evidence of that reliability .

Past that, the problem that remains is cost. The greatest technology in the world does me no good if I can't afford to buy or use it. And even if I *can* afford to pay more, I'd be entirely reasonable in expecting the benefits I receive to be worth the price premium. Diesels for airplanes aren't there, at least not yet. I want one--oh, I really do want one--and all the benefits that come with it, like turbonormalizing, no mixture control, lower fuel burn, and so on. But I just can't afford it right now. I'd love to be driving a Tesla, too, but I can't pay that price premium, either.

Aviation diesels are simply following the early-adopter model, just like computers, cell phones, and electric cars (albeit hampered by the ridiculous "aviation tax" that raises the cost of everything that flies by a factor of 5 to 10). The first users aren't going to be average joes; they're going to be the people who either don't care about cost, or have a particular extreme situation (price/availability of gasoline) to make it worthwhile. They'll fund the next generation, which will sell to a broader market; and that generation will fund the development of the mass-market version that will be widely adopted. You're trying to convince people we're on step 3 when we're somewhere between step 1 and 2.

We can talk about the merits of technology all we want. But in the end, money talks.

"Avionics is the odd exception. Glass-cockpit manufacturers have managed to push their products into most new airframes, despite the skepticism of the loudest voices in the GA community. How did that happen?"
Glass has become largely accepted in the market because enough people were exposed to it for long enough that they could see the benefits, and it became cheap enough relative to steam gauges to make it worth installing. Again, money talks.

Posted by: Bob Martin | May 14, 2015 7:05 AM    Report this comment

The dollar/Euro exchange rate, of course, favors U.S. buyers, but harms U.S. sellers and European buyers. And Cessna definitely sells in Europe, Asia and Africa. Later today, I'll plug the new numbers into my spread sheet and see where the costs come out.

The exchange value deltas are significant, but also somewhat offset by lower fuel prices in the U.S. I don't have a good sense of how much. (But I'm liking' it for my European motorcycle trip next month...)

I don't recall much meaningful skepticism about glass panel, but a lot of bitching about the costs. That's still true. Buyers of new airplanes wanted it and demonstrated they would pay for it. Cirrus, Cessna and Diamond soon found out buyers didn't want steam gauges as an option, so these were discontinued.

Posted by: Paul Bertorelli | May 14, 2015 7:39 AM    Report this comment

The folks who have enough $ to buy a new airplane want the latest and greatest. No one buys a MB or BMW with manual steering, crank windows and no A/C. However, there are still people out there who look for Kias etc. with basic car equipment. So it is with new airplanes. Therefore, the round dials went away and glass is now the only offering. It makes sense from a manufacturing standpoint, especially when you are only building a hundred + or - of a model in any given year.

I am not sure where the diesel will fit into this scenario. Glass was cool and users perceived and received great value for the $. Diesels aren't sexy and not proven. Now come up with a low cost turbine engine and they will sell.

For most of us on this blog and in the bugbasher world, factory new is not an option, so we keep drooling over the newest and greatest but look at the antiques. Even the LSA market is out of reach for many of us as cost exceeds the perceived value.

Sort of reminds me of going to the auto shows as a kid with my dad. We both wanted the newest and greatest but economics meant that there were some years when the bus and friends were our only ride.

Posted by: Leo LeBoeuf | May 14, 2015 9:22 AM    Report this comment

Surely the trouble for Cessna is all the shops selling diesel conversions for half their price?
You can have this brand new aeroplane for $500,000 in maybe a year's time or you can place an order for delivery in three months on a refurbished "as new" one for $200,000.
I know which one will win my wallet (if it was not so light I could take up ballooning for free....)

Posted by: John Patson | May 14, 2015 9:44 AM    Report this comment

Honestly it seems like the biggest issue to me with diesels is that they haven't hit the true utility market yet. Piston GA airplanes that fly the most are the utility type airplanes--Cessna 206's and 207's, Cirrus SR22's, Barons, Bonanza's, etc--there isn't really a good option right now for these airplanes except an Avgas burning engine. Yes--these airplanes are 1 step below a small turbine, and there are even some turbine conversions for them, but both of those are very expensive.

If a 300-400HP diesel were available and viable (Thielert had one, but I haven't heard much about that recently) I think that would really hit the sweet spot in the market. It would give the fuel economy of a piston engine in an airplane, that was big enough to actually do something commercially, with a fuel that is available literally everywhere.

Posted by: Colin Reed | May 14, 2015 11:17 AM    Report this comment

Considering favorable exchange rates, I plugged new numbers into my spreadsheet to estimate hourly engine cost for diesels vs. gas. The economics are complex, not because the calculations are, but because the operating circumstances vary so widely.

With avgas at $5.15 and Jet-A at $4.64 in the U.S., independent of finance costs, the diesel engines run for about $61.85 an hour, the avgas engine for $58.27. This is a closer spread than it ever has been because Continental upped the gearbox intervals and the exchange rates on parts and engines are close to parity. In the U.S., with TBRs of 2000 hours, the diesel gets to a spread of about $6; at 2400 hours, it's close to $12.

Plugging in European fuel prices, the diesel is a slam dunk, which explains why that's where the market demand is: It's about $63 for the diesel, $110 for the avgas engine.

Whether new or conversion, if you calculate the cost of money, the diesel loses the narrow edge it has in the U.S. for the simple fact this has to compete with older airframes with cheaper engines. Even in a conversion, an operator would have to spend $100,000 to convert. To save, at most, $3000 to $4000 a year in fuel costs? Not a good business case. But it remains so in Europe.

Other factors: The diesels are smoother, quieter and more pleasant to fly than the Lycoming and they have electronic diagnostics for maintenance. On the other hand, for the Continental diesels, they're more expensive to build and replace and in conversions, the airplane carries less and climbs and cruises slower at low altitudes because of weight and performance issues.

All those things added up is why, I think, U.S. operators aren't flocking to diesels. The trend line for diesel appears to inching more favorably, but I've been writing that sentence for 12 years and there still isn't a 2000-hour diesel, much less a 2400-hour one. Qualify that: SMA says the SR305 is 2400 hours, but it's simply not fielded in sufficient volume to be a player and there's no certainty that it ever will.

Posted by: Paul Bertorelli | May 14, 2015 11:40 AM    Report this comment

Aha, avgas engines rock.

Posted by: Rafael Sierra | May 14, 2015 12:55 PM    Report this comment

Cessna's decision to focus on the 172 as the launch platform for the diesel makes business sense. It should allow the company to spread development costs over a far greater number of airplanes, and by the same token, it will be able to prove (and improve) the design that much quicker.
Eventually, diesels will win converts. No one pooh-poohed GPS more than me -- and I should have known better, having spent years relying on Loran C as a commercial fisherman. (In my behalf, I was a fledgling CFII when GPS came on the scene, so I thought I already knew it all.) But fly instruments with today's GPS once and the penny drops, even if you're a trog who insists on the old way. The shift may not be so profound with diesels, but diesel's advantages are hard to ignore. Which is to say nothing of the uncertainty around avgas -- other than its price will rise out of proportion to other fuels'.

Posted by: Jerry Fraser | May 15, 2015 8:47 AM    Report this comment

The diesel demand and acceptance is slow in building in the U.S. In my opinion it has not viably gained. The North American market amounts to about half of the world's aircraft deliveries therefore, we set the trend. Europe books about 25% then Asia and other African and Eastern countries. If the market is "soft" here it will then affect production costs and then prices abroad. China has acquired manufacturing assets in the U.S. but has not developed and I believe it won't be a factor in the market, at least in next ten years. Increasing pricing is not the way to increase production, it is separating from the viable buyers declining to a smaller market and possibly to extinction. Any smaller than today's demand and we would need a sizable microscope to detect it.

It don't look good for av-diesels but certainly good for the refurbished, well equipped, Avgas C172 trainers selling from about $60K or $80K. Cessna is closing a chapter on the diesel C182 and I would expect the C172 as well.

Posted by: Rafael Sierra | May 15, 2015 10:43 AM    Report this comment

I meant to post this and it got dumped.


These are the numbers Redbird quoted for its Redhawks diesels. They're very different than mine. I didn't have time to dig into them and find out why.

Worldwide, diesel is about 7 percent marketshare of new piston aircraft during the past decade. For conversions, the growth is modest, but growth nonetheless.

Posted by: Paul Bertorelli | May 15, 2015 2:06 PM    Report this comment

From the beginning I was very enthousastic about the developments of diesel engines.
However, having flown a converted C182 with the SMA Diesel, I can only say that basically the engine is good, but it was not mature all over due to the various operational restrictions.
Unfortunately the SMA company was not willing or able to devellop the engine up to full operational standards we meet at other manufacturers.
On top of that was the convertion cost itself, being about the same as the engine cost, which was for most of the people a no go on financial efficiency.
I have the strong feeling that Continental wasn't also convinced either about the maturity as they changed in the main time a lot of major components and that finally the engine is still not in production yet.
In those circumstances I have not only the full understanding that Cessna has also his doubts on the current edition of that diesel engine, but also salesfigures for this airplane are rather disappointing.

Having also some experience on the Cessna 172 equipped with the 155 Hp diesel, I can only say that I hat the feeling the airplane is rather underpowered.
However the convertion cost and larger maintenance cost of the clutch will avoid a real brake through on short term of that diesel engine either.

Only in case that the convertion cost of the firewall forward kit will drop dramatically (see redhawk)Diesel application will be very limited in my opinion.

Posted by: ludo huybrechts | May 16, 2015 4:28 AM    Report this comment

"Glass has become largely accepted in the market because enough people were exposed to it for long enough that they could see the benefits, and it became cheap enough relative to steam gauges to make it worth installing."

Bob -

The basic question is how the market got exposed to GPS and glass cockpits in the first place. There was no chorus of demand that forced the manufacturers to install the new avionics in new airplanes. And there was plenty of bad press in the early years. When I was earning my PPL in the early 2000's the old-timers warned me against that newfangled GPS that had questionable reliability and would stunt my navigation skills, a complaint you still hear today. In the early years there were plenty of complaints about the complicated buttons and screens on the glass cockpit devices, and how they would crash in mid-flight. New Skyhawks still come with backup steam gauges - apparently the glass panels still aren't reliable enough. Just recently, Sporty's has earned enthusiastic praise for not including ANY glass in their 172LITE, because all those screens are so confusing to pilots.

And still the airframe manufacturers installed these newfangled contraptions in their new deliveries, and pilots have come to accept them. There were no multi-decade market studies, no endless years of development, no endless complaints about FAA regulations. They just did it.

As for cost of glass, it seems that new-airplane buyers just accept it. No complicated calculations of the cost of various glass options vs steam gauges, no side-tracks about costs of retrofitting.

What's the big difference? Garmin, Avidyne et al are forward-looking companies that actively create a "cool" image for their products, push, not drag their feet, in improving their products, actively market their latest innovations, and don't wait for years for pilots to demand their products. Unlike e.g. Lycoming, which looks for every excuse to drag their feet on even modest innovations.

Posted by: Rollin Olson | May 16, 2015 10:43 AM    Report this comment

In conclusion???

Posted by: Rafael Sierra | May 17, 2015 9:42 AM    Report this comment

Seems to me that comparing the acceptance of power-plant options (diesel, battery, etc.) with cockpit electronics is very much apples-and-oranges, a meaningless exercise.

The glass cockpit revolution took hold because for navigation & AHRS duties electronics provides clearly demonstrated major advantages over "the old way" and does it with very little downside. Couple that with the equally well demonstrated ability of the electronics industry to provide vast improvements in performance & reliability year after year seemingly without limit, and how could the technology not be accepted?

Contrast this with the struggles of "alternative" power-plant developers. On top of an inability to actually demonstrate from the outset any clearly significant overall advantage for their chosen mode of energy conversion, they must deal with the reality that simple physics dictates there will be no revolutionary leaps in performance. At best they can only continue attempts to eke out a few percentage points of improvement in the various aspects of their systems while hoping for some help from changing external factors.

Posted by: John Wilson | May 17, 2015 11:22 AM    Report this comment

John -

You're very right that avionics manufacturers are constantly pushing improvements for their products, but the mainstream airframe and powerplant manufacturers aren't even trying. They've been dragging their feet for years, and no interest in even modest evolutionary innovation. Any change to decades-old technology goes nowhere with the mainstream mfrs because it's not pushed by a chorus of customer demand and backed by years and years of evidence that it makes revolutionary leaps in performance. But even modest improvements in performance add up. Look at the fuel efficiency of today's automobiles compared with 50 years ago.

If Cessna delivered new airplanes with FADEC engines as standard, there would be some grumbling from old-timers who want to fiddle with engine mixtures, but in a few years it would be no big deal, as with automobiles for the past 20+ years.

Posted by: Rollin Olson | May 17, 2015 5:29 PM    Report this comment

I seriously doubt that glass became famous by features, but simply on money. Glass parts are very cheap and you need only few aviation specific parts. As a result these devices run almost from Kellogg conveyors in masses. Say your HSI is gone and you need a new one - these parts are real expensive and glass replacement is maybe half the price and delivers a lot blinkyblinkiness you dont need for basic flying. From long standing experience in aviation I am a strong believer that this industry is only and only governed by profit, nothing else.

Posted by: Mike Meyers | May 18, 2015 5:33 AM    Report this comment

In Conclusion for Raf:

Paul will punch out a new blog article and a different topic will take over. :o)
Whoops. Already happened.

Posted by: Jason Baker | May 18, 2015 7:24 AM    Report this comment

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