Engine Design: No Talent

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I've been spending the past couple of days sorting through the results of our avgas replacement survey. The response was overwhelming: more than 3100 respondents completed the survey and perhaps two thirds of them included direct comments. This one, among many, caught my eye:

It is so ridiculous that in this day and age we are designing a fuel to fit an engine whose technology was born in the 1930s. Shame on Continental and Lycoming for not developing their engines at a pace that keeps up with modern technology. Now the industry suffers because we figure out that we should be using something other than Pepsi or Coke. I am an engine engineer working on a new engine that will burn worldwide available aviation fuel. That is simply Jet A and nothing else. This will meet the demands of future markets, and use technology to solve this ridiculous problem. Trying to engineer a fuel for 30 years, you got to be @%&$ing kidding. Meanwhile automotive engines produce more power per liter than ever before, reliably. Tell Conti and Lyco to get off their asses and hire people that know how to design an engine. As a consultant to these companies I can tell you the talent has gone and left. Very little competence there.

I'm sure this sort of sentiment will be received warmly in Williamsport and Mobile. But is it fair and does it reflect the realities of the market?

In the late summer of 1998, I sat at a conference table in Connecticut with the developmental team of what became Aerosance. They whiteboarded the technical specs of the system that eventually evolved into Continental's PowerLink FADEC system. It essentially adapted state-of-the-art automotive-type pulse-injection and variable timing to aircraft engines and by allowing use of lower-octane fuel, it anticipated the demise of 100LL. In fact, that was the major driver. At the time, I didn't particularly think the Aerosance group lacked talent, nor do I think that now. But some people told me that at the time and many of them are the very same people who, while decrying the inadequacy of other engineers, have produced nothing but talk themselves.

So why didn't PowerLink take off? Buyers said they wanted engines with more technological sizzle. Last year, I asked Continental this very question and they couldn't answer it. But I can. There was no need for FADEC. The market timing was premature. As long as there were no definite plans to eliminate leaded fuel, buyers saw no benefit. Single lever wasn't enough.

Neither did the OEMs see much merit. Cirrus tried PowerLink and so did Mooney and Beechcraft. They found the juice not worth the squeezing and customers were not lined up outside the door demanding FADEC. It was just the wrong product at the wrong time. OEMs probably had worries about reliability and performance. Perhaps it just needed a better sales effort. (I've heard that Beech will be offering PowerLink as an option on the G36 and Baron line this year or next.)

During the same period, Lycoming, in conjunction with Unison, proposed its own electronic engine control, the EPiC. It was soon dropped for technical and marketing reasons. General Aviation Modifications Inc. proposed the PRISM system. It may be progressing in the research phase, but is essentially vaporware and GAMI's engineers are as talented as any you'll find anywhere. So are Porche engine teams. Remember the PFM Mooney introduced in 1988? It was a six-cylinder, air-cooled engine with automotive-style electronic ignition, fuel injection, autoleaning, automatic cooling control and--what was supposed to be the irresistible marketing lure--a single power lever. Sunk without a trace.

More recently, in 2003, along came Bombardier with a much hyped pair of V-6s to take on Continental and Lycoming. Electronic ignition, fuel injection, overhead cams, liquid cooling. Bombardier, through its Rotax division, is the largest maker of aircraft piston engines in the world. They know how to apply technology, they know how to do reliable serial production. Cirrus was on the verge of pushing the button to offer the V-6s as an option. Yet, for internal reasons not clear, Bombardier killed the project. And just as well, because it probably would have failed, leaving Cirrus with a service mess and Bombardier with a black eye.

Why would it have failed? See above. Aircraft owners say they want technological innovations in engines, but they are fickle about responding to these by actually buying them unless these products are able to demonstrate clear benefits over the existing offerings and are at least as reliable. Continental's IO-550 series is smooth, efficient and reliable—and simple. Bombardier's proposed V-6 was more complex and had poorer fuel specifics. But it was high tech, the fruit of talented engineers. And don't forget this: The legacy fleet exerts powerful inertia on future development because low manufacturing volumes make clean sheet engines an economic challenge.

The much-vaunted Jet A burning piston engines have done a little better, but not much. Thielert and Diamond had impressive success with the Centurion line…until Thielert went belly-up, likely due to a flawed marketing and business model and a mechanically tender engine. You might argue that this had nothing to do with the engine, but it had everything to do with market perception of the engine.

SMA has few of its SR305s flying. DeltaHawk has been in development for years in one of the longest cert projects we've ever seen. There are a handful of other diesel projects in development whose likelihood of success is minimal. But it's not due to engineers of no talent, but to a low-volume market sharply sensitive to price and composed of buyers who insist on products with real benefits before they'll buy. As Diamond demonstrated with the DA42 twin, diesel acceptance is better outside the U.S., for obvious reasons. But diesel is far from the slam dunk its promoters say it is because it hasn't yet achieved wide market penetration. We will see if the avgas issue pushes the issue. Just saying that's going to happen doesn't mean that it will.

So, if you're one of those people who believe lack of talent has put us where we are now, try this thought exercise: Heave an IO-550 or O-320 up on the bench. Write down the purchase price, fuel specifics, operating costs, overhaul costs and run a life-cycle cost analysis. Put your honest-man hat on, and compare your proposed engine. Can it do five percent better? Ten? Then bring your marketing guy in—that's where you need the real talent—and ask him if he thinks he can sell it. Buyers want what buyers want. The nexus of engineering and marketing just haven't figured that out yet.

My guess is you'll eventually reach the butt scratching stage where someone will finally say, "Gee, I wonder if maybe we shouldn't just try to figure out a fuel that will work in this old engine." Good, bad, indifferent or intellectually bankrupt, that's more or less where we are now.

Comments (150)

Sad but true.

Posted by: David Bunin | March 11, 2011 8:02 AM    Report this comment

Here's an idea: Starting with the 2012 or 2013 AirVenture Oshkosh, EAA and AOPA should offer an award to home tinkerers or, teams (i.e. universities with automotive and aeronautical engineering departments), or even corporate entities, who do the best job of developing and demonstrating an aviation piston engine that 1) can tolerate alcoholized gasoline, 2) develop full power on gasoline, alcoholized and non-, of no more than 92 octane or thereabouts (or alternatively, JetA), 3) offer satisfactory takeoff and cruise power to weight ratio, 4) create as little aerodynamic drag because of cooling considerations as possible (remember how the P-51D Mustang's radiator arrangement was said to offer a little extra thrust instead of just adding to drag?) 5) be immune to lightning strikes, 6) be as reliable as possible, and 7) be manufacturable at reasonable cost.

The above, will be difficult to achieve so another award that EAA and AOPA could present at AirVenture Oshkosh is, for whoever does the best job of modifying an existing piston aircraft, i.e. a vintage Piper or Cessna fixed gear piston single, to tolerate alcoholized motor gasoline of no more than 92 octane or thereabouts, taking into consideration both the engine and the fuel system.

Posted by: Alex Kovnat | March 11, 2011 8:05 AM    Report this comment

That "engine consultant" you quoted exemplifies the difference between intelligence and experience. Intelligent people are extremely sharp and they see a few aspects of a problem very well; experienced people have an understanding of the system as a whole.

75hp to 250hp engines simply don't benefit enough to offset the complexities of adding FADEC. How many modern auto racing engines (required to run at 75-100% continuously) do you expect to see still running in 40years!? 60 years?

Posted by: Mark Fraser | March 11, 2011 8:36 AM    Report this comment

Between the challenges of getting an STC to retrofit an engine onto a forty year old aircraft and the economic situation of the average pilot, where's the market for a new engine? New GA aircraft sales are a tiny fraction of the overall size of the fleet (and still will require an STC or re-certification); not much opportunity there either.

Posted by: Brad Koehn | March 11, 2011 8:38 AM    Report this comment

So why isn't the collective GA community scratching it's butt wondering why to even eliminate 100ll in the first place? Prediction - 100LL is here to stay for a few more decades. If not, say goodbye to 30% of the market. A new fuel is a mistake.

Posted by: Brad Vaught | March 11, 2011 10:40 AM    Report this comment

@Brad: You may have a point. How many grams of heavy metal (for piston engine aircraft using 100LL, that means lead) is added to our environment every year, in proportion to the number of grams of mercury (also a very toxic heavy metal) added to our environment by coal-burning utility power plants?

Posted by: Alex Kovnat | March 11, 2011 11:25 AM    Report this comment

I don't know that you'll get any real help from the Oshkosh crowd. They're already perfectly content to bolt a Chevy V-8 onto the front of an RV.

Posted by: David Bunin | March 11, 2011 12:19 PM    Report this comment

David, you nailed it. Freedom from regulation and the problem is solved in the least expensive and most efficient manner. The Oshkosh crowd is the future of GA.

Posted by: Mark Fraser | March 11, 2011 12:40 PM    Report this comment

As always interesting comments Paul. It is a shame that all aviation can garner is Lyc/Cont developed decades ago. Just open the bonnet of your car and compare to your airplane. The differences are mind boggling. I had pretty high hopes for the Bombardier V6 only because they clearly were tapping into the European automobile engine technology.

Clearly the technology is avialable for piston engines, evidently plenty of engineers (just all working for auto industry) just no worthy market in aviation. To that point I had hoped that the UAV market might drive more demand for piston engines in air vehicles - but the military long ago went to a single fuel and it didn't seem to take long before General Atomics and others started introducing turbine UAVs.

I'm not sure freedom from regulation will drive the solution. Today you can mount experimental engine on your experimental airplane yet the solution still hasn't surfaced. And even if you found the miracle engine for new airplanes what do you with everything built over the last century?

Posted by: Rob "daSlob" Schaffer | March 11, 2011 3:03 PM    Report this comment

Btw 100ll is compliant with new tech engines too. They can easily be set up to produce more power and greater efficiency using 100ll. So even an imaginary wave of new technology fits in to the keep 100ll equation.

Posted by: Brad Vaught | March 11, 2011 4:19 PM    Report this comment

I recently went through the ordeal of repair/replacing my IO-540. Pretty much every time I got a quote for something, I would get in my car and deeply, sincerely wish that I could simply take my 300hp turbocharged Subaru engine and drop it in my plane. Derate it to 250hp and I'm sure it would run at least as long as the engine it replaced.

But replace the IO-540 with another aviation engine, at aviation prices? New engine prices were quoted almost as high as the total value of the airframe. Not going to happen. It would be cheaper to buy another plane and run it into the ground.

Posted by: Guy Hutchison | March 11, 2011 5:02 PM    Report this comment

I don't see the lack of innovation in the engine market a result of lazy engineering. We only now are seeing a real threat of the total loss of fuel availability, and in this case TCM and Cirrus had a lower octane aircraft ready to go in about a year. I really don't think the environmental issues around 100LL have merit, but it doesn't matter. 100LL is going to either go away or be prohibitively expensive.

Posted by: Josh Johnson | March 11, 2011 6:21 PM    Report this comment

I'm not an engineer but I am an aviation enthusiast that can't help feeling that the reciprocating internal combustion engine had pretty-much peaked in technology just after WW2, with engines like the 8,000 lb. behemoth\240Pratt & Whitney R-4360 "Wasp Major", which was the largest aircraft piston engine in routine use.

I'm also old enough to remember the 1964 NY World Fair, with the\240Chrysler Turbine Car. I'm mentioning this because piston engines were seen as passe by greater minds than mine long, long ago.\240Yet, lightweight turbine engine development was aborted because I think oil company accountants saw greater profits from highly refined gasoline, rather than (literally!) bottom-of-the-barrel kerosene derivatives, and the relatively short TBO of the recip engine. And if you will recall, the oil companies ran repair shops as well, three decades ago\227more opportunity for profit.

It's time to pitch the piston, folks ...

Posted by: Phil Derosier | March 11, 2011 7:58 PM    Report this comment

It's time to pitch the piston, folks ...<<

You might want to do a reality check on that. The Chrysler turbine came close to production, but the company was in trouble in those days and seeking government loan guarantees. At the time, they were involved in the budding M1 tank project. The loan guarantees tanked (so to speak) and so did the turbine car. Not likely the oil companies.

Had it been produced, it likely would have failed for two reasons. It had significant emissions problems and terrible fuel specifics--shortcomings that haven't been addressed 30 years later.

Not to say pistons won't be pitched. Eventually. But not in my lifetime. All-electrics will--and are--making big inroads and so are hybrids and diesels. Pistons are still here for a reason: They're light, cheap to produce and economical.

When something better and more affordable comes along--as it inevitably will--the market will shift. But it'll be awhile.

Posted by: Paul Bertorelli | March 12, 2011 5:55 AM    Report this comment

I should have mentioned this previously. I believe I have mentioned a couple of resources to put some perspective on this: Vaclav Smil's Energy at the Crossroads and The Bottomless Well, by Huber and Mills.

Taken together these two volumes give a good sense of where we are in the age of oil and they encourage thinking beyond the group mentality of the popular press. By that, I mean the press reports about hybrids and plugins and the reader might assume from the number of these reports that these represent a huge wave of demand--a fundamental sea change.

Looking at the larger picture through the prism of primary energy generation, which Smil discusses, you get a different feel for the topic and thus you might see why retiring the piston engine is a long way from reality.

Posted by: Paul Bertorelli | March 12, 2011 9:01 AM    Report this comment

It's interesting question, why hasn't Rotax developed replacements for the O-360 and IO-540 and certify them for use in GA airplanes? Rotax can afford to manufacture aircraft engines because they use the same technology for many different applications and reportedly they use a state of the art product development process and systems. Rotax engines are used in snowmobiles, watercraft, sport boats, ATVs, roadsters and go-karts. Rotax already supplies 75% of the ultralight and lightweight airplane market. Rotax uses state of the art tools for product design, simulation / digital mock-Up, component testing, rapid prototyping, tool design, kinematics, tolerances, wiring and piping harnesses, etc. These tools enable rapid and low cost product development and manufacture. I'm not selling Rotax but they do have the capability. Rotax is also marketing savvy. For example, they stopped selling the 75 HP Rotax 618, which is a derivative of the 65 HP 582 because it competed with the 85 HP 912. Why doesn't Rotax enter the broader GA engine market? It certainly seems like they have the capabilities.

Posted by: Dana Nickerson | March 12, 2011 7:26 PM    Report this comment

In response to Guy, above, I think it would be an interesting experiment to take a factory standard Subaru Turbo and run it through ongoing aircraft-type cycles, including proper maintenance and see how long it lasts. Set up a few different flight profiles for t/o, climb, cruise and descent, as well as circuits. Allow cooling between 'flights', etc, and do the 100 hour maintenance as is would be required by such an engine in actual service. Personally, it's my guess it would fare as well as a Lycoming unit.

Posted by: Peter Buckley | March 12, 2011 8:14 PM    Report this comment

How about this for thinking out of the box: Jaguar showed a concept car powered by electric motors (more efficient than internal combustion engines). The electric power was provided by a small jet engine driving a generator. We would call this an APU in aviation. Similarly the GM Volt car is powered by electric motors, electricity provided by gasoline powered generator.

Posted by: Dirk DeJonghe | March 13, 2011 12:49 AM    Report this comment

why hasn't Rotax developed replacements for the O-360 and IO-540 and certify them for use in GA airplanes?<<

Rotax did enter the market with the V-6 engines. This investment was estimated to be in the $10 million range--hardly chump change for general aviation. These were meant to replace traditional engines.

They withdrew because...? We don't know why. Were there unresolvable technical issues with the engine? Did they not see market potential? Not interested in further investment? These guys:

http://www.avweb.com/news/airventure/EAAAirVenture2010_AdeptAirmotive_V6EngineForum_202976-1.html

Are taking another run at it and some of the same principles are involved. They will face the same challenges of high entry cost, regulatory burdens, small market and the need to get a reasonable service structure in place.

Posted by: Paul Bertorelli | March 13, 2011 5:21 AM    Report this comment

... and in the course of this discussion, are we forgetting the Wankel? My point in an earlier comment is that insufficient R & D is being applied to this problem.

Paul, it's strange that I take exactly your position ... for the electric motor option. Maybe I've got a mental-block, or something, but I just can't get my arms around challenges like the weight of an acceptable battery, recharging times, radius of operation, and overall utility and payload capability of the aircraft.

Shucks ... even the thought of a lightning bolt striking the aircraft and frying delicate control components scares the bejesus outta me ...

And until the "electric advocates" can assuage the concerns of nay-sayers like me, I don't envision electro-motive aero options gaining much 'lift'.

Posted by: Phil Derosier | March 13, 2011 7:10 AM    Report this comment

Let's go back to basics here. The four-stroke recip is the worst possible engine choice for any flying vehicle.

It is heavy for the power it makes, very mechanically complex, and it has a severe thermal limitation with the exhaust poppet valve which is an inevitable failure point.

In the same vein, aviation gasoline is the worst possible choice for fuel. Ninety nine percent of airplanes run on heavy fuel, Jet A etc, which is similar to diesel.

These are the starting points. Now the fact that we are still saddled with these worst possible choices, and the fact that so-called "innovations" have centered on exactly these kinds of engines burning exactly this kind of fuel tells me that light airplane engine designers need to get a clue.

Continued...

Posted by: Gordon Arnaut | March 13, 2011 8:24 AM    Report this comment

The problem is mostly that the light airplane industry is really a rump of what it once was. It has been frozen in time technologically and shrinking steadily, economically.

How can you think about bringing in new engines and airframes that are up to date, when total light airplane production is a couple of hundred units a year? Paul B mentioned previously that recips make up just 4 percent of Cessna's sales revenue. This means they get about 4 percent of the corporate mind share.

Continued...

Posted by: Gordon Arnaut | March 13, 2011 8:33 AM    Report this comment

Now if we look at the boating industry,we see the mirror image. Boating has been growing by leaps and bounds and hundreds of thousands of brand new power boats are sold each year.

Now boats are similar to aircraft in a lot of ways. They need to be light in order to decrease drag and achieve efficiency. And the engines need to run at high power levels continuously.

That is why 2-strokes have been the power choice for outboards since the beginning. When emission concerns and fuel cost began to make carbureted 2-strokes unattractive, the industry developed direct injection which brought efficiency and emissions in line, or better than, 4-strokes.

Some manufacturers, notably the Japanese, brought in lightweight 4-stroke outboards but these are not competitive any more against the direct injection 2-strokes.

Continued...

Posted by: Gordon Arnaut | March 13, 2011 8:40 AM    Report this comment

Now I can go and buy a 300 hp Evinrude for $17,000. The power unit itself weighs less than half of what a Continental IO-550 weighs. It has better emissions (the only engine to achieve highest EPA certification) and comparable fuel burn.

It is mechanically simpler and much more robust. It's crankcase roller bearings can run at full power for several hours without a drop of oil. There are no valves or valve train.

It can run just as well on heavy fuel, spark ignited, with a simple change in the engine computer. Bottom line is if we are looking for an example, we should look to boats not cars.

Continued...

Posted by: Gordon Arnaut | March 13, 2011 8:45 AM    Report this comment

Even better than a spark ignition 2-stroke is a two-stroke compression ignition engine (diesel). Back in the 1930s Junkers built the 205 opposed piston engine which had a power density about double of today's aircraft recips.

A thing of mechanical simplicity with no ignition system of course. Not even cylinder heads, since it is opposed piston. The Wilksch 2-stroke diesel is a pretty good concept but the Junkers is even better.

Continued...

Posted by: Gordon Arnaut | March 13, 2011 8:51 AM    Report this comment

Now look at some of the so-called innovations in lightplane engines. The Thielert is a heavy auto 4-stroke diesel that makes puny power for its weight.

All that mechanical complexity, hundreds of moving parts costs money to manufacture. Plus a gearbox for the prop.

The Rotax-Bombardier V-6? Just as mechanically complex and expensive. Plus it burns gas. A complete non-starter. It's no wonder they pulled the plug.

Rotax and Evinrude are corporate stablemates and the same direct-injection two-strokes are used on snowmobiles. An 800 cc engine that weighs 80 lb is making 150 hp.

The whole snowmobile costs less than half of what a 4-stroke 912 engine alone costs.

Bottom line is if light planes are going to have a future we a heavy fuel engine that costs less than $100 per horsepower. The 2-stroke is the only way this can be achieved. And you get a much more durable engine besides. Every other idea is just plain misguided.

Continued...

Posted by: Gordon Arnaut | March 13, 2011 8:58 AM    Report this comment

And now a word about turbines. Theoretically a turbine is the most efficient internal combustion engine. The very large turbofans live up to this and their fuel burn numbers are better than your car engine.

Small turbines are a different matter. The only way they can achieve this kind of efficiency is with a regenerative cycle where you recoup some of the wasted exhaust heat.

Chrysler's turbine car of the 1960s used this idea, but its wheel type regenerator did not work great. Generally recuperators and regenerators are a difficult nut to crack from an engineering point of view.

Today's small stationary power turbines (microturbines) use heat exchangers to achieve thermal efficiency of about 30 percent, which is about as good as your EFI car engine. Problem is we need a technology breakthrough to shrink these heat exchangers down to a size where they can be used on a propulsion engine.

When this happens, the light turbine with piston fuel efficiency will be a reality. Turboprop or quiet fan, take your pick.

Bottom line is that the 4-stroke recip has been the wrong engine for light planes for at least 50 years. The fact that out of all the people trying to reinvent the lightplane engine, only one (Wilksch) is even on the right track is really puzzling.

Posted by: Gordon Arnaut | March 13, 2011 9:07 AM    Report this comment

I should also mention rotary (Wankel) engines. These are potentially a good aircraft engine. Like a 2-stroke they have a power stroke for every complete revolution of the engine shaft.

They have only two moving parts, the rotor and the engine shaft. (Two stroke recip is almost as good with just crank piston and rods the only moving parts).

This means they can be very light and cheap to make. However they also present some challenges. Sealing the rotor for combustion is not easy and Mazda has been the only one to solve this, with huge infusion of cash over many years.

The geometry of the rotor is not as efficient as the clyndrical shape, and the short stroke of the e-shaft (comparable to a piston crank) means lower mechanical efficiency and high revs to make power.

But it is still a solid possibility. In terms of optimal lightplane engines the 2-stroke diesel is best, followed by the 2-stroke spark ignition engine (heavy fuel) and the rotary, also heavy fuel.

Posted by: Gordon Arnaut | March 13, 2011 12:33 PM    Report this comment

Nice theorizing, Gordon. Two words: Show me.

Posted by: Paul Bertorelli | March 13, 2011 2:03 PM    Report this comment

I will, Paul. Just watch me.

Posted by: Gordon Arnaut | March 13, 2011 2:55 PM    Report this comment

Gordon,

Do you own an airplane? If so, what kind?

Posted by: Brad Vaught | March 13, 2011 3:00 PM    Report this comment

I need to correct myself on the Chrysler turbine. The wheel-type heat exchanger was actually 90 percent effective, which is very high for any heat exchanger.

However, it also allowed some mixing of the intake and exhaust streams which was not good for emissions.

On the plus side it was very compact and allowed for a fairly small engine footprint.

This engine really pushed turbine technology. It used automatically variable turbine vanes to increase throttle response, one of the inherent problems with turbine engines, which have a very narrow power band.

Posted by: Gordon Arnaut | March 13, 2011 3:08 PM    Report this comment

Brad, my experience is in transport category aircraft. Even if I had half a million lying around I would not waste it on a single recip. A used plane can be a decent value, but I am no farther ahead than renting.

Posted by: Gordon Arnaut | March 13, 2011 3:15 PM    Report this comment

Wow, Paul - great editorial. I believe it is solely the inertia of the legacy fleet that keeps us where we are. A&P's are reluctant to learn anything new - look at the LSA owners who can't find a decent Rotax mechanic. Thielert burned the GA population with their entry - a factory overhauled clutch/gearbox at 300 hours at $15,000 ??? Nonsense. Does the memory of the Oldsmobile 350 V-8 diesel sound familiar? Detroit STILL hasn't recovered from that one..... Diesel development will come from overseas; the USA will NOT be a technology leader in this area. We will be a follower and not a leader....sound familiar? The market driver for any of these engine changes will be new fuels that will demand new technology, or government emissions regulations. The market is having a conniption on replacing valve seats for unleaded fuel....why? 1) - Regulations that are inflexible and expensive to comply with; 2) - a reduction in engine power due to the lower octane of the unleaded fuel, mandating the expenditure of a lot of $$$ in rewriting performance specs for every affected airframe out there; and 3) - the horror in the alphabet groups board rooms that predict a reduction in the fleet and pilot community when many of these technologically obsolete airplanes finally hit the boneyard. One would think the A&P community would strongly welcome the new fuel and the technology improvements...it means a lot of work for them in the years to come.

Posted by: Tracy Smith | March 14, 2011 7:16 AM    Report this comment

The reason we are still using engines designed from the 30's is because they don't need to be re-designed. They are perfect just as they are, and the vast majority will operate just fine on premium 93 octane auto-fuel, but the new mandate to blend ethanol in autofuel has ruined that! Ethanol should only be blended with orange juice! There is always room for improvement, but it's hard to improve something that is so bulletproof as the current TCM, and Lycoming engines. Why fix it if it's not broke?

Posted by: Jim Shaw | March 14, 2011 7:30 AM    Report this comment

As one of the (too) few users of a FADEC piston - the TCM IOF 240 in a Liberty XL2, I can assure you, with pushing 1000 hours on the plane, that FADEC delivers. Great fuel economy, ease of operation, turn-the-key simplicity, and dependability (no fouled plugs etc etc). And if 100LL ever disappears, the 'fix' for my engine will be a 40 minute mod - unbolt the ECUs (engine control units) and wire in the new ones. Too bad the market didn't push the airframe and engine makers to modernize. A carb, points, etc are great - in my vintage sports-car, not in my plane! And yes, ultimately manufacturers will follow the market, not the other way around. When innovations are introduced in aviation, all too often everyone takes a 'let the other guy take the risk' approach (often understandable, unfortunately) so no real modernization occurs. But magnetos, in 2011, on a new airplane? Please get real!

Posted by: daniel spitzer | March 14, 2011 7:40 AM    Report this comment

I agree. These engines are wonderful. They are simple by design and have withstood legal and liability scrutiny.

Don't underestimate this. Our litigious society is part of the reason aviation is SO expensive. There are underlying roots to this price problem. The reason my IO-550 costs $50k+ is because of lawyers have extracted enormous amounts of money from power plant manufacturers.

So, not only do you have to have a good marketing guy, but you also have to figure out how to protect yourself and your company when you get whacked with a settlement plus legal fees.

Why would anyone want to take the risk of new engine development? I'm sorry Lyc and Cont are not new and dazzling, but they work, and they work very well.

Besides, I just want to get where I'm going, as safely as possible. They do a great job at that...

Posted by: Kevin Stallard | March 14, 2011 7:42 AM    Report this comment

There is a lot of talent in the aviation industry, including engine technology. Just look at the experimental market. Tons of great engines and electronics that spam-can flyers can only drool over for the price. How about putting the blame where the blame belongs--- with the government. The TSO process is so long and expensive that any innovations get lost unless you have tons of money to throw at getting a TSO for your product or design. Also, the government has allowed the legal system to kill most innovation. I heard somewhere that in 1978, the cost of a new Cessna 172 was $78,000, with about $27,000 of that being for liability coverage for Cessna to cover future exposures. What would happen to the auto manufacturers if the legal system was able to do the same to autos? Instead of $20,000 cars, they would be $50,000 cars. Accidents will happen. Why do we treat the aviation industry different that other modes of transportation?

Posted by: Roger Bocox | March 14, 2011 7:52 AM    Report this comment

Developing new products is an art. If the new product in question is radically different from others on the market then it takes real artists to make it work.

Sadly, most new products are failures. This is not new. It has always been incredibly difficult to develop successful products.

I have seen great new technology fail as a product because there was no market for it. In a similar fashion, just because the marketeers think they can sell something new doesn't mean it can be engineered to work well at a satisfactory price. Even more important is the notion that marketeers who dream up wonder products without good understanding of the customer's point of view are doomed to failure. This whole issue is worse for aviation than other areas because of the painfully low product volumes.

So, diesel aircraft engines, single lever gasoline engines, and other great ideas can't sell. When new ideas are created with wrong thinking (e.g. pilots need single lever controls) they can't hope to be successful even with superb engineering.

I'm afraid America is reaching a real low point when it comes to new product creation and new business creation. The growing economies of China and India seem more likely to produce good new products. I suspect any really good new products will come from places where innovation is the norm rather than ones like the USA where bureaucracy and the lawyers have taken over.

Posted by: Paul Mulwitz | March 14, 2011 8:01 AM    Report this comment

A previous poster hit the nail on the head. For those of us who want to fly leading-edge technology there is a place for us. It's called the experimental/amateur-built category. In this category we're free to have technology as new or as old as we please. You'll see full-blown auto engine conversions, Conti's and Lycs with ancient magnetos, or modern electronic ignition, or one set of each for a "best of the old, best of the new" approach. "Experimental" aviation is leading the way, and sooner or later our regulatory bodies will either catch up or squeeze general aviation out of existence.

BTW, I fly "old" technology - a rock-solid Continental C85 with mags and a carb. It only rarely sees 100LL and doesn't like it much. This aircraft if now 32 years old and has never had a fuel system problem. Luckily here in Canada we can still purchase at least Premium mogas without alcohol in it. I agree with several other posters - for the majority of aircraft, both certificated and homebuilt, the arch-enemy is alcohol.

Posted by: Eddy Riggs | March 14, 2011 8:27 AM    Report this comment

And herein this blog lies the problem: our current stone-age simple engines are 'perfect' and 'wonderful'. No they are not. They are time-tested and robust, but they are far from wonderful. They are full of VERY expensive castings and outdated assembly techniques which help drive the cost to stratospheric heights. They are burdened by stone-age simple dumb magnetos that cannot adapt to changing conditions. But they do run and run and run...just like an old John-Deere tractor from the 1930's...but you don't see these pieces of Old Iron in America's farms working every day. They can, but they have outlived their productive lives - just like out GA powerplants. When the Conti-Zawa IO-550 is redesigned and released with electronic ignition, unleaded-fuel compatible, and single-lever operation, don't be surprised.

Posted by: Tracy Smith | March 14, 2011 8:32 AM    Report this comment

Good piece Paul. Been there seen all that.

I'd add two other design requirements. The engine has to be able to run hard, shut down and sit for days or weeks (or months up North), then start (easily) and get run hard again (maybe the pilot will let it warm up first, but don't count on it).

Finally, when the engine does complain about this treatment, it needs to fail gracefully, providing some useful power so the pilot can return the plane to the ground in one piece.

Been there, seen all that too...and the consequences when the second requirement aren't met.

High tech engines are like thoroughbreds; they have to be handled oh so carefully or bad things happen. IMHO that's why many pilots prefer Lycomings to Continentals. Lycomings may not be beautiful (ugly as a fire hydrant?) but they can take a licking and keep on ticking (apologies to Timex). Love my O-360-A4M.

Jim Grant

Posted by: James Grant | March 14, 2011 8:35 AM    Report this comment

The IO-470s on my baron produce 65% (or more) power for 2,000 hrs reliably. That’s 170 hp for over 400,000 miles. I dare any current high tech automotive engine to do that. Automotive engines 'cruise' on the highway at less than 30hp. Comparing automotive engine technology to aircraft engines just isn't an apples to apples thing. The requirements are completely different.

Posted by: John Memmer | March 14, 2011 8:39 AM    Report this comment

Some people mentioned the lawyers driving good, but risky, technology out. But the FAA is the greatest enemy of aviation progress. They risk their jobs and funding by saying yes, but risk nothing by saying no. I doubt our old fashioned twin magneto carburated engines could be certified today, much less a radial.

If the benefits of FADEC ever get big enough(fuel savings, dependability, and ease of operations) to justify the cost, there will be lots of people ready to convert. Until then, most are wisely taking a wait and see attitude.

Posted by: Roy Zesch | March 14, 2011 8:45 AM    Report this comment

This is a simple economics exercise. Take the current population of piston aircraft. Figure in the development costs for the updated engine. Multiply by MANY orders of magnitude for certification costs. Spread the costs over the new certified piston aircraft that are built (a few hundred annually) plus the current certified population (couple of hundred thousand)and it is now understandable why new technology fails. The numbers just arn't there. It is not a valid comparison to the automotive industry where the sales are in the millions, and the development costs are spread over LOTS of engines. Don't forget how much the STC charges will be to retrofit new technology into ancient airframes.

Posted by: Art Ahrens | March 14, 2011 8:48 AM    Report this comment

High tech engines might be great for your new auto with your AAA free tow card in your wallet. With family onboard, flying at night ,overwater, in the mountains, give me some of the well proven tech(including magnetos). Don't forget the hype of the Tiarra engines of the 70's that was going to bring us to a new age of performance. Thank God it was placed in the Piper Pawness first so that only the pilot would be dissappointed to find out they were not worth a hoot. The double engine failure of the Diamond Twin on takeoff was another eye opener for high tech, at least Lyc and Cont know better than to have the ignition system tied to the electrial system- something they learned back in the 30's I believe. Bill Corbett

Posted by: Unknown | March 14, 2011 8:58 AM    Report this comment

@Roger Bocox:

The legal system HAS gone after the auto industry. Remember the Pinto? Ralph Nader? The difference is volume of production; liability costs are spread out over many more vehicles, so the per-unit cost is less.

What I really want to know is why turbine technology remains so expensive. It's clearly superior to piston tech, and it's been around for years now. Wouldn't a 300HP turboprop solve a lot of issues?

Posted by: Andy Manning | March 14, 2011 8:59 AM    Report this comment

Andy: The innate technological barriers to inexpensive manufacturing is the root cause of the problem. Turbine engine manufacturing pushes the envelope in all aspects; that's why a hot section rebuild is incredibly expensive! However, I do agree: superior technology and reliability.

Posted by: Tracy Smith | March 14, 2011 9:28 AM    Report this comment

@Andy Manning:

Good idea! Retrofitting a turboprop engine to an aircraft originally built or designed for piston power, i.e. Beechcraft Bonanza, Mooney single engine piston retractible, Piper Malibu etc., would immediately solve the 100LL problem since turboprop engines don't care about octane per se.

Unfortunately they tend to eat more fuel, and thus produce more carbon dioxide per passenger-mile (or, per lb-mile of freight). However, the difference in energy consumption (the aviation equivalent of "well to wheels" efficiency) between turboprop and piston engines may well become narrower, because future piston engine aircraft may only have access to avgas with 94 octane, at most.

I hope to be at AirVenture Oshkosh this year. Hopefully there will be some good turbine conversions. Would you believe that Sport Aviation magazine once had an article about a homebuilt pusher-prop aircraft that was converted to JET power to avoid the problems the owner had with attempting to power his aircraft with a Wankel rotary engine?

Posted by: Alex Kovnat | March 14, 2011 9:36 AM    Report this comment

No mention of the Rotax 912? It owns the light sport segment. That's 100's of engines added to the US fleet each year. The Rotax offers electronic ignition, auto leaning and happily runs on 93 octane auto fuel.

Posted by: Tim Fleming | March 14, 2011 9:43 AM    Report this comment

You do not get innovation from customer surveys. Fiat did not ask customers if they wanted a common rail diesel ignition system before introducing it, because customers did not know what it was. When they had the chance to buy though, they were completely won over and all auto and truck diesel engines changed overnight, as did public perceptions of what fuel economy and torque characteristics a car or truck should have. The problem is the factors which stop innovative aero engines from getting to the customer. Government regulations, lawyers and institutional inertia due to makers being small parts of conglomerate companies are high on the list. (Bombardier's decision on the V6 was probably shunted upwards to a boss who had specialized in building trains all his career..)

Posted by: Brian McCulloch | March 14, 2011 9:54 AM    Report this comment

I agree with the poster who mentioned alcohol and orange juice. If only we could could stop the current madness of alcohol being considered a viable eco-fuel (its not) and keep it in mixed drinks only, most of us would be happy campers with Mogas. Corn based elthanol production is a farm subsidy pure and simple. That means its primarily a give away to big agri-business, does little to help save family farms, and is of very dubious energy efficiency to produce.

Posted by: Steve Elder | March 14, 2011 9:59 AM    Report this comment

Andy, a tried and true, mature technology 300 hp turboprop is available for purchase. Charted SFC about .6 to .67 lbs/hp/hr, meaning about 25-30 gph for most operators. How many do you want?

http://www.rolls-royce.com/defence/products/tactical_aircraft/model_250_turboprop.jsp

Posted by: Mickey McCall | March 14, 2011 10:08 AM    Report this comment

Gentlemen, Everyone has great comments and thoughts. I think we can boil all of this down to one word - REGULATIONS. The current state of affairs of the oversight by government has made a very hostile place for innovation and progress. The basic engines are good, but the innovations to make them great and economical are being stifled. The Lycoming EPic was dead upon arrival. Why - the 150+K price tag for the engine. Owners, investors and managers saw that it would not sell because of the cost. I am surprised that it was even announced to the market. We are on the downhill slide of aviation. The government is strangling it slowly and those working for the government will just be reassigned to other duties. The bureaucrats do not and will not loose their empire. It is called job security. A great example of over regulation is the instruments that many of us fly with every day. With new technology we could be flying with much better equipment that would allow us to be safer and with less fuel. But because our aircraft were "certified" with our round dials it takes a huge amount of new "certification" to upgrade our panels. Thus we pay or as many have voted, will not pay for the upgrades and thus the aircraft instruments have remained stagnant for decades. Instruments do not effect how well our airframe flies, but how we fly through the airspace. Work to bring sanity to the FAA and its bureaucrats and we will move forward otherwise enjoy flying while you can.

Posted by: Bobby Picker | March 14, 2011 10:10 AM    Report this comment

I feel that the lack of innovation in aviation in all areas are the result of the FAA. It is nearly impossible to get anything done anymore with the snails pace bureaucracy at work. Getting simple field approvals is near impossible let alone development of a new engine. Engine manufacturers are not going to spend millions and millions of dollars in order to satisfy the requirements of the government if there is not enough demand to recoup those costs. Much of the technology to improve engine design is here and need only be adapted for GA needs. Litigation and government over site is the true death of innovation in our country.

Posted by: David Hutchens | March 14, 2011 10:10 AM    Report this comment

p.s. farmers buy retail and sell wholesale. thus they are frugal. they can make their own ethanol. if ethanol is an economical internal combustion engine fuel, why don't farmers use nothing but ethanol?

Posted by: Mickey McCall | March 14, 2011 10:12 AM    Report this comment

"why don't farmers use nothing but ethanol?"

Because they know ethanol is better for drinking than burning I suppose.

Posted by: Mark Fraser | March 14, 2011 11:02 AM    Report this comment

I agree with Picker and Hutchens above: The largest portion of the cost of aviating, and the largest inhibitor of innovation, is the Federal Gummint, and that will only get worse.

Example - About 10 years ago I needed to replace 4 electroluminescent CB label panels on my '73 C310. None were available, and rebuilding them was going to be expensive. I called the largest EL manufacturer in the US (they do huge numbers of consumer products, and even did some aviation stuff in the past). They could make 25 of each, brand new, for not much more than refurbishing the 4 originals. I sent them the measurements and the old panels. When the new ones arrived they were wonderful! My mechanic installed them, and I sent a set to the Twin Cessna Flyer to show them and let them know in a letter that I'd sell the remaining sets at a very reasonable price to anyone who needed them. I didn't advertise them for sale, however.

A few weeks later, I got a call from the FAA in Washington DC. They informed me I was selling bogus parts (I never sold any, incidentally) and unless I got an STC/PMA I'd be subject to criminal prosecution. I asked them what I needed to do to get an STC/PMA.

(see my next post)

Posted by: John Johnson | March 14, 2011 11:21 AM    Report this comment

(Continued)

They sent me a 20 page document declaring what I had to do, going all the way back to documenting the source of the materials (plastics, wires, connectors, etc.) the manufacturer used and that they met FAA standards, through taking the airplane and EL panels to Wichita, renting a hangar at night, and demonstrating to an FAA approved DER that the color and luminosity of the panels was identical to the originals (which weren't working!). There were 15 pages of requirements in between these steps. I figured it would take about $10,000 and 3 days of time away from my medical practice - not nearly worth it. Again, this wasn't even an innovation,the units were made by an extremely professional an international supplier of EL panels, and drew less than 0.05 amps from the inverter. I said to heck with it.

Anyone out there need a set of perfect CB labels for a '73 310? (The Feds say I can sell labels...just not EL panels wired to the inverter!)Anyway, they looked and worked great in my 310 -illegal or not.

Posted by: John Johnson | March 14, 2011 11:21 AM    Report this comment

Not only that, but the state of Iowa recently voted down some ethanol mandates and the much-vaunted E85 can't find traction even in the corn states because no one wants to invest in infrastructure to deliver it.

Posted by: Paul Bertorelli | March 14, 2011 11:25 AM    Report this comment

I am a mechanical engineer and spent 15 years at General Motors with a lot of that time in power train R&D. I was directly involved in electronic fuel injection and spark control development. Can electronic technology improve aviation engines? Yes, but only slightly. The reason this technology is not used is a financial one. General Motors use to build a million engines per year in a single plant. If that sounds like a lot....think of it this way. That is over 4000 engines per day. Cirrus sold maybe 200 aircraft total last year and they are the big seller.

I have two airplanes. A TNIO550 A36 Bonanza and a TSIO550 IV-P Lancair. Both need 100LL and the octane cannot be compromised. I run a 8.5 CR in the TSIO550. Both are very efficient with a BSFC around 0.39. That is better than any engine I ran on a dyno at GM and both use magnetos.

The solution is a replacement fuel for 100LL not eliminating my airplanes from the GA fleet. George Braly at GAMI has a solution. I flew their Cirrus a few months ago with both 100LL and their "no lead" fuel. The no lead fuel works. Cylinder head temps did not change. Performance did not change. The only down side is the fuel is slightly heavier but the BTU's per pound is nearly identical so it is hard to view this as a negative considering the benefits. The solution is at hand. Now we need to get the politics out of the way and implement the solution.

Posted by: Craig Berland | March 14, 2011 12:15 PM    Report this comment

That is better than any engine I ran on a dyno at GM and both use magnetos.<<

Craig, aren't newer automotive engines doing better than .41 to .40 BSFC? I've been trying to track this data down and one source at a well-known research house told me the last 10 years have brought significant efficiency gains in car engines.

Posted by: Paul Bertorelli | March 14, 2011 12:22 PM    Report this comment

I've enjoyed reading the many comments on this blog. I think the younger "ipad" generations would be more eager to adopt FADEC systems and more trusting in the technology due to having grown up with it, but they're typically the ones with the least amount of money to spend on such things. In a very small way, it's a generational problem. I'm also wondering if Butanol may eventually play a role in the aviation industry - though at this point it's hard to tell due to the fact that it's still very much in its infancy. With several proposed drop-in replacements for 100LL, I also wonder if the engine manufacturers are somewhat content to wait and see what happens. Why spend any more money on R&D/Marketing when there might be an effective replacement on the horizon?

Posted by: Lee Pounds | March 14, 2011 12:35 PM    Report this comment

Paul, I don't know but I will try and find out what is considered a "good" BSFC for today's engines. I can say if auto engines are in the .41 range, then there have indeed been significant improvements in the last 10 years. Remember, BSFC improvements at max power is not a significant priority in a car engine. As you know the duty cycle for an airplane engine is very different from that of a car engine.

Posted by: Craig Berland | March 14, 2011 1:16 PM    Report this comment

I don't think "the market" has anything to do with it beyond the fact that it is too small to support the huge investments "the system" mandates for any innovation within the certified aircraft universe.

The true guilty parties, if that is the right description, have all been enumerated in the previous postings:

    Lawyers/the legal system
    FAA rules/avoid all risk whatever the cost


As noted by others, the fact that innovative products can be successfully and profitably be developed & sold within the much smaller experimental market proves the point beyond question.

Posted by: John Wilson | March 14, 2011 1:21 PM    Report this comment

If you look at the gasoline engines used in the Audi A8 which are direct injected(like a modern European diesel and use high compression ratios like 13 to 1 you can get better fuel specifics than .42 to .44 in a gasoline engine. However this technology will require a complete redesign of our present engines (Many$ required) and you still don't solve the problem of world wide high quality gasoline fuel availability. Currently jet fuel is the only fuel that you can get at almost any airport in the world with a reliable quality. thus the future is diesel. The problem with diesel for most of us is finding a reliable same weight engine that will "fit" in the present engine space and not have a much larger frontal area.

Posted by: william Lawson | March 14, 2011 1:24 PM    Report this comment

post cont The problem with diesel for most of us is finding a reliable same weight engine that will "fit" in the present engine space and not have a much larger frontal area.

At this time Austro seems to be build reliable engines and their new 280 hp engine (based on a 6 cyl Steyr boat engine) may be a good future contender but only for new airplanes that are designed for it. it will be at least 300 lbs heavier than an equivalent power Continental or Lyc. Diesel also offers better fuel economy so depending on which variation of the Cont or lyc you compare it to you can save 30 to 40% in Gal per hr. that will help pay for the engine change and provide greater range etc. the problem is that for this to work the new Diesel needs to be weight, size and shape compatible with present engines. the fuel savings is between 30 and 50 lbs per hour for 280 hp so the new diesel cannot be much more than 70 to 100 lbs heavier and must fit in basically the present space of existing engines for it to be practical.

Posted by: william Lawson | March 14, 2011 1:26 PM    Report this comment

Modern Automotive engines did not develop due to "Market Pressure" they were developed in response to legislation requiring lower emisions and these emisions had to be maintained for 100,000 miles.

Aircraft get their 0.39 specific fuel consumption by running leaner than automotive engines can AND maintain NOx levels within specs.

The only way to get a "Solution" to the lead issue is to set a reasonable deadline and stick to it. If there is no deadline, nothing will change and the industry will remain in limbo as it is now until it dies.

Having gone through the removal of lead from automotive fuels as a mechanic I can say there is very little downside to getting that junk out of the fuel. Plugs will last much longer, the oil will remain clean much longer and there will be less wear to the engine. The only issue that remains is octane. If an unleaded fuel of between 94 and 96 could be introduced and an ignition system that responds to detonation, already done in the auto industry, the we could make some real progress and use current engines.

If the new fuel was marketed and sold at auto stations as "Aircraft Approved" it could have high enough production rates to keep it cost in line.

You see this type of marketing all over the place. Aircraft Grade Aluminum for instance. I see this claim on products from telescope to bathroom scales. Aluminum for aircraft is certified and that costs, but it is the same stuff. Make this type of marketing work for us for a change.

Posted by: Bob Parry | March 14, 2011 2:09 PM    Report this comment

I have a hard time with the notion that a diesel engine weighing 300 pounds more than a gasoline equivalent is a great thing for GA. Unless the operator spends a lot of time in areas where only diesel/jet fuel is available this seems like a huge weight penalty to pay.

I doubt the experimental aircraft sales along with LSA sales are "much smaller" than GA equivalents. This only compares these types to piston single GA sales. Indeed, if you count kit sales, plans sales, and S-LSA I think the numbers would be considerably larger than the ones GAMA publishes.

While I do think turboprop planes can fill a niche in GA for medium distance business travel they don't get much attention in the recreational flying crowd. They just require too much fuel.

There are many engine choices for the light end of experimental designs including new designs from Rotax and Jabiru and many auto conversions. For larger experimentals, most builders choose lycosaurous engines. All of these choices tend to focus on cost above technology. Those who choose factory new engines still lean toward the lower price of Rotax and Jabiru since these engines are not certified.

Posted by: Paul Mulwitz | March 14, 2011 2:16 PM    Report this comment

In order for one technology to replace another there needs to be a real economic advantage to the new technology. A diesel engine if was "fit" compatible with the existing engine space and not too expensive say $100,000 for 300 hp class would offer a real advantage for the heavy singles and cabin class twins that are flown 500 hours per year. most of the engine in this class of airplanes use at cruise, depending if they are high compression or low compression engines, use 19 to 26 Gal per hour @ 75% of 350 hp. an equivalent diesel would use about 14 gal per hour. this means you would have a savings of 5 to 12 gal per hour which probably would save $25 to $60 per hour per engine at an average cost of $5.00 per gal for Jet A or 100LL this means a saving over 2000 hours or$50,000 to $120,000 over a 2000 hour life. with the normal differential between Jet A and 100LL you might save another $1.00 per gallon. This is a characteristic that makes it a reasonable economic decision to change to a Diesel this comes with a lot of provisos like reasonable weight, reasonable purchase and retrofit cost etc. however it does present a reason to change to a diesel.

Posted by: william Lawson | March 14, 2011 2:18 PM    Report this comment

Bob: Good points. I recognize the 'Race Fuel' market is minuscule as compared to even 100LL, but wouldn't that be another avenue to pursue ?

Has anyone noticed there has not yet been ONE comment regarding 'No Talent'? It's not a lack of talent (although I do NOT disagree with the author of the original comment; the talent is gone, but can be substituted with a bevy of contract engineers) but by government regulation, legacy population, and every other reason given above by the the many contributors. Good discussion, all.

Posted by: Tracy Smith | March 14, 2011 2:20 PM    Report this comment

I'm afraid there is no good solution to the two big problems of lawyers and bureaucrats at the FAA.

FAA bureaucrats are just like other bureaucrats in all fields of activity and all countries. They all take any action that will minimize their own risk. It wouldn't help to replace the FAA bureaucrats with ones from another department. To fix this you must de-regulate aviation as much as possible.

For the lawyers, the only possible solution I have ever heard comes from a Robert A. Heinlein (SF) book where he talks about " . . . the day they hung all the lawyers . . ."

Posted by: Paul Mulwitz | March 14, 2011 2:27 PM    Report this comment

Why retrofit to diesel. In my case I own an Aerostar with the low compression 350 Hp engines. at 65% I cruise at 220 knots using 23 gal per hr per side. at 75% I cruise at 240 knots at 26 GPH per side in order to keep the TITs around 1550 deg to provide good engine life. using a diesel, assuming it would "fit" I would use 11.5 GPH at 65% of 350 hp and 14 GPH at 75% to go the same speed. thus I would save 11.5 to 12 GPH. this would save me approximately $60 to $70 per hour per engine or $120,000 to $150,000 over the 2000 hour life of the engine. this will pay for the engine in the firs 200 hours plus allowing me 1 to 2 hours extra range as at 65% 165 gal is good for 3.5 hours using 100 LL while 165 gal of jet A will take me 7.2 hours or for the same weight of fuel I would get about 2 extra hours of range. That that range increase alone would justify the retrofit of Diesel engines if they will "fit" in the Aerostar without too much modification.

Posted by: william Lawson | March 14, 2011 2:43 PM    Report this comment

Why not turboprop? just look at the Malibu for instance. The same airplane with the same capabilities uses lots more fuel and costs a lot more. to buy a 300 hp class turboprop engine by itself costs in the order of $350,000 with propeller. The same power lyc or Cont costs with propeller and accessories in the order of $100,000. The 300 Hp turboprop uses about .55 to .6 lbs per hp hr SPC where the 100LL engine uses much less at .41 to .45 Lbs per hp hr. Thus the fuel usage of a turboprop is much more (30 to 40% more), and the initial and maintenance cost for a turboprop is much more. The main reason small turboprops are selling is in many parts of the world 100LL is not available or very expensive. $14.00 per gal is normal in Europe.

Posted by: william Lawson | March 14, 2011 3:06 PM    Report this comment

There was a company called Innodyne that was making low cost turbines for small planes but failed due to capitalization issues........why can't Lycom/Cont or someone else pick up where they left off. The engines were small and uncomplicated with semi good fuel specs. The idea seems good and I'm sure our talented engineers could improve on their technology. What do you think??

Posted by: Jake Marsh | March 14, 2011 4:27 PM    Report this comment

The IC engine is not a long term solution.. as the availability of fossil fuels diminish. Something else will be required to develop the torque that drives our propellers. I'm thinking high tech batteries and and electric motors. "PROP CLEAR?"

Posted by: Andre Abreu | March 14, 2011 5:12 PM    Report this comment

Regarding the comments about FAA regulation being a big hurdle...

While FAA Certification probably is a huge hurdle for a startup, I doubt it is that much of a factor for Ly-Con. I imagine they know very well how to certify new technology, have the appropriate FAA personnel on speed-dial, and would do most of what the FAA requires just simply as smart R&D. In fact, I would be very surprised if Ly-Con didn't have quite a bit to say, (behind the scenes) about how the rules are written. I've not seen too many large corporations who wanted to make it EASY for some start-up to compete in a legacy market. Think about it.

All you have to do to get a 300 hp electronic ignition, auto-fuel hi-tech engine in your airplane is to build or buy an experimental. Yet, even at Oshkosh or Lakeland, the vast majority of homebuilts are powered by Lycoming or Continental. Just read Van's web site about alternate engines. If any of you have a resume that approaches Dick VanGrunsven's in the experimental market, and a different viewpoint, I'll be happy to listen.

Posted by: Don Tedrow | March 14, 2011 5:40 PM    Report this comment

Turboprops compare very favorably to pure jets for flights of appropriate range. I remember one guy who used to fly from Long Island to Florida several times a month. When he traded his Lear jet for a twin turboprop he saved 90 percent of the fuel and lost 1/2 hour total trip time.

It is different when comparing turboprops to IC engines. The only really good reason for upgrading in this case is to gain airspeed. The power to weight ratio of turboprops is quite favorable compared to pistons. That allows you to put a lot more power in the same weight allowance - so long as you have allowed for the additional fuel to burn.

Posted by: Paul Mulwitz | March 14, 2011 5:44 PM    Report this comment

Don,

Of course Van is a great source of wisdom. However, his planes tend to use 150+ horsepower where the lycosaurous engines rule. For smaller power designs the Rotax clearly leads (as in Van's RV-12) and Jabiru has a big foot in the door.

All of the engines mentioned above were designed as aircraft engines. Where I think Van really loses confidence is not in other purpose built engines but in the numerous auto conversions available in the marketplace. I think the auto conversions offer lower price points but increase the risk of engine problems when used in planes compared to the purpose built ones.

Posted by: Paul Mulwitz | March 14, 2011 5:52 PM    Report this comment

While FAA Certification probably is a huge hurdle for a startup, I doubt it is that much of a factor for Ly-Con<<

Not a hurdle, maybe, but still an expense that's factored into the cost of building and delivering products. Just because you know how to do something, doesn't mean you don't pay for it.

As for the cheap turbine, Rolls Royce has in the R300. But they're not pushing or selling hard, far as I can tell. We have approached them repeatedly to cover the engine, but they have declined. Don't know why.

Posted by: Paul Bertorelli | March 14, 2011 6:08 PM    Report this comment

If you want to read a good book about the state of the art in gasoline engines and what is being done in Europe to provide them with 50% on average better fleet mileage than we get from our US gasoline engines read: "Gasoline Engine with Direct Injection" by Richard van Basshuysen it really describes what is being done in advance cobustion technology using direct injection with FADEC control.

Posted by: william Lawson | March 14, 2011 8:30 PM    Report this comment

It's going to take a lot to get the masses to trade their 0.39 lb/hp/hr engines for an 0.67 turbine (R300)that costs a lot more. No regulatory barrier there, only money and fuel and payload. With regard to auto engines, I think that I saw something in the print media (maybe Kitplanes?) that measured the BSFC of an auto conversion (in a Vans) and it was in the low 0.4s, at least at the power settings used in a conversion (might have been a Subaru). It was not as good as the stock aviation engine it was tested against. At the same airspeeds it had a signficantly higher fuel flow. Now, maybe it could be better, but a lot of the new technology is about high revs and breathing, and that means gearing to turn a prop. It does seem that the airflow for an engine at 2700 was worked out a while ago (mostly) and there are no signficant improvements, especially with reliability a major issue. The only ways you can get the high power to replace the 100LL engines is diesel, turbine, or high revs. All these cost, but diesel may be cheaper in the long haul. High revs (gearing) and turbines seem costly.

Posted by: Tom Lubben | March 14, 2011 8:34 PM    Report this comment

The gasoline piston engine is the RIGHT engine for light aircraft (and not only "light", if you look at the Republic Rainbow, as fast as the 707 on <20% of its fuelburn, but killed by politics & the military) In this age of 100$+ per bbl of crude, this statement is even more true. It has the lightest engine specific weight (except for turbines, but they need to much fuel for our purpose), and the lightest fuel weight vs. energy content, and the lowest specific fuel consumption (with the exception of the large JUMOs, but that is another story), so form the lightest powerpack we can get. Fuel technology exists TODAY to manufacture up to 130 Octane (that is what we need, 100/130 fuel) racing fuel via the GTL (Shell Gas to Liquids) process. What would be GREAT is if the automobile industry adopted such a fuel as well, think ultra lean running high compression ceramic engines. But with the political winds blowing Lithium dust (via all the electric/hybrid mess) and smelling of cheap booze, it is again likely that this engine does not see the light, like the last time when the catalytic converter laws killed lean running engines.

Posted by: Robert Ziegler | March 14, 2011 11:50 PM    Report this comment

Car engines are VERY different in their application from aircraft engines, as normal drivers never run them at constant 75% or more power. So all the electronics and fuel injection in them is MAINLY there to allow operation at 15% power with not too much inefficiency.... At 2400RPM and full throttle you don't need variable ignition timing or fancy multipoint fuel injection controls. You just need a mixture knob to beat the competition on fuel consumption: Look why the Mooney Porsche really died: Aside of excessive cooling drag it did not give any fuel consumption advantage, in spite of all the "technology". So what we need to compare ourselves to are SHIP engines. they run at constant speed and constant power too, and are world champion in specific fuel consumption. And don't come me with the turbines, except for supersonic flight, they have no more justification, after the Concorde was killed. They are simply inefficient, and only have one advantage: you could burn Hamburger grease in them if oil runs out one day in 2678.

Posted by: Robert Ziegler | March 14, 2011 11:51 PM    Report this comment

It's going to take a lot to get the masses to trade their 0.39 lb/hp/hr engines for an 0.67 turbine (R300)that costs a lot more. No regulatory barrier there, only money and fuel and payload.<<

The casual observer has trouble accepting this basic truth. The reasoning is that it must be possible to build a state-of-the-art turbine engine that's both cheaper and with fuel specifics similar to a piston engine. It may be possible. But no one has shown that it is. Not even close.

Rolls was exploring a deal with Mooney in an R300 project. Just penciling it out at .67, where do you put the fuel in that airframe. Never got far enough to ask, I'm afraid. Plus the horsepower gain is not all that much, so the benefits become elusive.

Now where did I put that IO-550 I pulled out of this thing...

Posted by: Paul Bertorelli | March 15, 2011 5:20 AM    Report this comment

Someone mentioned the Rotax 912 series. The North American market initially rejected this engine. Recall that it was introduced in the Diamond Katana. Diamond had issues with Rotax support, repairability in the field was a problem and it lacked power. Diamond converted to the IO-240, which is a much nicer engine to fly.

In Europe, the Rotax did well and, of course, it's the dominant LSA powerplant.

Posted by: Paul Bertorelli | March 15, 2011 5:24 AM    Report this comment

Dick: The first thing we do, let's kill all the lawyers.

Cade: Nay, that I mean to do.

Henry The Sixth, Part 2 Act 4, scene 2, 71–78

Posted by: Mickey McCall | March 15, 2011 6:47 AM    Report this comment

Just curious, Instead of adapting car or marine engines, why not tap into the really small/powerful/light motorcycle engines? At least there is a supply of really good mass produced cylinders being made that would be out-of-the-box perfect for aircraft use. Cheap, reliable, easily replicable.

Posted by: Mark Fraser | March 15, 2011 8:46 AM    Report this comment

Hold on a second. Lots of turbines are way more fuel efficient than any piston engine.

Take a typical turbofan engine, the CFM56 used on B737s and various Airbuses. Cruise thrust is 5,000 lb at a fuel burn of 0.545 lb fuel per lb of thrust per hour. Simple math: two of these engines in cruise are making 10,000 lb of thrust and burning 5,450 lb of fuel per hour.

If we replace these with piston engines how much fuel would we burn? Piston engines are measured in hp not thrust, but hp = thrust x velocity / 550.

Our cruise velocity of M 0.8 is 780 feet per second, so our hp is 780 x 10,000 lb thrust / 550 = 14,200 hp.

That's thrust horsepower coming OUT of the propeller. Since the prop is less than 100 percent efficient, the engine needs to make even more. If we say prop efficiency is 85 percent then our engine power required is 14,200 / 0.85 = 16,700 hp.

If you could even make a piston engine that makes over 8,000 hp (how much would it weigh?) total fuel burn for two of them at 0.45 sfc is 7,500 lb, nearly 50 percent MORE than the turbofan.

The sfc of the turbine is 5450 / 16,700 = 0.33. Show me a piston engine that can do that. The bigger turbofans are even more fuel efficient.

Posted by: Gordon Arnaut | March 15, 2011 10:33 AM    Report this comment

Hold on a second. Lots of turbines are way more fuel efficient than any piston engine.<<

Hold on again. When you say "lots of turbines" you're referring to high output turbofans. You're not going to find a small turbofan doing that...say the 600 series from Pratt, which are pretty efficient engines. Nor will free-turbine or turboshafts do it. These all tend to run in the mid .6s. The R300 appears to be about.55 to .57. That's a long way from the .42 that many aircraft piston engines run at.

The Thielert Centurion 2.0, for all its faults, runs around .35 to .36 and the best Continental gasoline piston engines can manage .39.

Given their cost of purchase, the size of the market and power band, small gasoline pistons are slam dunk better choices against small turbines. That may change eventually, but the technology and market forces that will do that are not in sight now.

Posted by: Paul Bertorelli | March 15, 2011 11:01 AM    Report this comment

And by the way, reference Pratt's 600 series. Even though they are relatively efficient, efficiency was not what Pratt's customers were telling them they wanted.

What they wanted was cheap purchase price and easy maintenance with fewer parts.That's what Pratt delivered. If Pratt set out to achieve efficiency, they probably could. But it's hard to see how they could get much better than the low .5s.

Posted by: Paul Bertorelli | March 15, 2011 11:04 AM    Report this comment

Small turbines are inefficient becasue the volume of the gap between the rotor and the stationary housing of the turbine is large relative to the volume of the turbine. This results in high slipage losses. There is nothing one can do about this. The larger the turbine the lower this ration becomes.

Similar things happen in piston engines as well. The most fuel efficient engine made is one in a Container Ship with operating efficiency of about 60%. No kidding. This is a 2 cycle diesel engine that weighs more than a 747 at take-off, turns at 100 RPM, and is not likely to make it into any aircraft soon.

For aircraft engines that are similar to generators, constant speed, steady load the control systems would be simpler but would benifit from modern developments. Do not confuse dependability by enormous maintenance with true dependability.

BP

Posted by: Bob Parry | March 15, 2011 11:05 AM    Report this comment

Bob you are correct that small engines, piston or turbine, are inherently less efficient mainly due to the fact that they have more surface area for a given volume, hence more friction losses.

Turbine efficiency is a function of pressure ratio and turbine temperature. Big engines can push these high and get great efficiency, but it requires fancy metallurgy and bleed air cooling for the turbine blades. Small turbines do not do this for cost reasons.

But small turbines with exhaust heat recuperation (microturbines) are getting 30 percent thermodynamic efficiency, which is nearly as good as the big turbines (maybe 5 points shy), and as good as a VERY good piston engine.

This is with the simplest possible rotating machinery, basically a turbocharger with a burner can added. Total pressure ratio of about 4.

I am working on a new kind of heat exchanger (patent pending) that is compact enough to be used on a propulsion engine.

Posted by: Gordon Arnaut | March 15, 2011 11:29 AM    Report this comment

Similar things happen in piston engines as well. The most fuel efficient engine made is one in a Container Ship with operating efficiency of about 60%. No kidding. This is a 2 cycle diesel engine that weighs more than a 747 at take-off, turns at 100 RPM, and is not likely to make it into any aircraft soon.<<

And just for reference, I believe you are referring to the Wartsila-Sulzer which, as far as I know, is considered the most efficient piston engine in the world, running at .26.

http://gcaptain.com/emma-maersk-engine?506

Posted by: Paul Bertorelli | March 15, 2011 11:30 AM    Report this comment

As for motorcycle engines in airplanes, this one showed up at Sun 'n Fun a couple of years ago:

http://www.youtube.com/watch?v=vIs45EByKNE

Same problem as car engines. They make their best torque at high RPMs so they require a gear box to carry the thrust and get the prop speed manageable. The Rotax does the same thing, but it doesn't make quite the revs that a motorcycle engine would.

Take my Honda CBR600. It will make about 100-HP at 10,000 RPM. Thrilled to hear it rowing through the gears on the street. No way I'd want to sit behind it in an airplane for even 10 minutes.

Posted by: Paul Bertorelli | March 15, 2011 11:40 AM    Report this comment

There is an old saying in the aircraft industry..."Never buy the "A" model of anything" Unfortunately, all the new and great potential power plant stuff IS always the "A" model. For better or worse that is how it has always been.

Posted by: Dale Rush | March 15, 2011 12:05 PM    Report this comment

No, I did not say use motorcycle engines in airplanes. The Rotax cylinders are almost identical to typical 1200cc motorcycle cylinders in design, bore, stroke, and power. Making use of mass produced precision CYLINDERS is what I was saying. The technology is fantastic and mass production makes it affordable.

Posted by: Mark Fraser | March 15, 2011 12:19 PM    Report this comment

Micro Turbines are getting up there in efficiency but 30% is not going to scare the diesel generator business. They already operate at that or a little better, maybe 33% and are much cheaper.

Thank you Paul for the link to Wartsila-Sulzer engine, I had lost that link.

One of the engineers here used to work on those type of engines, not that one per se. He said they used to re-ring the pistons while in port. Maintenance like that would be difficult on a turbine. Another advantage of piston engines, maintenance is easier even if required somewhat more often.

Posted by: Bob Parry | March 15, 2011 12:23 PM    Report this comment

Making use of mass produced precision CYLINDERS is what I was saying.<<

Go learn more about the details of these processes and tell us what you find, Mark. Motorcycle engines are almost universally purpose made cast blocks, with the exception of Harleys and BMW R-series. For the life of me, I see no connection here.

Posted by: Paul Bertorelli | March 15, 2011 12:42 PM    Report this comment

re-ring the pistons while in port.<<

Geez, imagine the ring compressor for that job! Although, I think the piston may dissemble into three pieces or something.

Posted by: Paul Bertorelli | March 15, 2011 12:44 PM    Report this comment

Bob you are right about the price they are charging for microturbines, outrageous. Something like $1,000 per kW.

That will come down big time. I could build one of these things in my garage using turbocharger for a couple of thousand bucks.

The heat exchanger is the most expensive part. Plus it is big and heavy, no good for a flight engine. There are few people working on this at GE, Rolls, Pratt and Honeywell. Not making great progress though.

The mciroturbine industry is talking 40 percent efficiency in a few years. It should happen. When costs inevitably come down the diesel is history.

Posted by: Gordon Arnaut | March 15, 2011 12:49 PM    Report this comment

When I was at Ballard Power working on a 250 kW fuel cell power plant, one competing system was micro turbines in combined cycle systems. They were expensive but still a lot cheaper than a one off fuel cell power plant. They also were more efficient when balance of plant efficiencies were included. Something the Fuel Cell industry is not good a including. We heard of, but never saw, a combined micro turbine / Rankin cycle that was around 500 kW and about 50% efficient. Again it can not get airborne but relly cool technology.

BP

Posted by: Bob Parry | March 15, 2011 1:07 PM    Report this comment

I understand the Rotax 912 uses a lot of current automotive technology to achieve its nice power to weight ratio and efficiency. This may be a mixed blessing. The dual carburetors are nothing but a huge pain. While this configuration seems to do nice things in cars it causes endless problems in airplanes. I am hopeful future 912s with fuel injection will eliminate this problem.

The Rotax 912 has proven to be very reliable and efficient in LSA. Still, I would prefer a simpler air cooled direct drive engine. The competing engines from Lycoming and Continental are all but worthless in LSA because of their 100 pound weight penalty. I can't imagine how the Cessna 162 will fare with this albatross tied around its neck.

Posted by: Paul Mulwitz | March 15, 2011 1:19 PM    Report this comment

Yep, Honeywell and others in the microturbine game are talking up the combined cycle with fuel cell, using the turbine exhaust heat to power the fuel cell. Haven't heard much about a steam combined cycle, but then I'm not really in this area.

My heat exchanger is small and light enough to use on a flight engine. Plus very straightforward to make at reasonable cost. Also very good flow path. I think I've got the big guys beat.

Am looking to fit a prototype to a Solar T62 but it will need a burner redesign. Also looking into picking up an Isotov GT350, which is about the same size and layout as the Allison 250. I've actually done the numbers on an engine up to 20,000 lb thrust and it will scale up very nicely.

Posted by: Gordon Arnaut | March 15, 2011 1:22 PM    Report this comment

"with the exception of Harleys and BMW"

Correct, big bikes (cylinders with enough displacement to make sense for airplanes). Harley makes hundreds of thousands of new engines per year, BMW makes almost 80,000. Who knows how many custom Harley engines are produced.

In comparison, how many NEW O-200's where made last year? That's why I was curious about not re-creating the wheel when it comes to air cooled cylinders...

Posted by: Mark Fraser | March 15, 2011 1:33 PM    Report this comment

The dual carburetors are nothing but a huge pain.<<

First I've heard that, Paul. Generally, not a lot of service complaints on the Rotax that we hear. We did a survey a couple of years ago and what complaints we did hear related to lead fouling and sprag clutch issues. Nothing on carbs.

Posted by: Paul Bertorelli | March 15, 2011 2:06 PM    Report this comment

It's not for lack of engineering talent that we are flying behind the piston technology we have today. It is not for lack of talent in the marketing, business or FAA regulatory disciplines either. All of these challenges can be addressed with the appropriate investment and a good plan. We still have the best engineers, business people, and regulators in the world. An airline will turn it's whole fleet over for single digit efficiency improvements in fuel burn (think winglet retrofits on 757 & 767's, block point improvement updates on engines, or even new aircraft introductions). These are non-trivial engineering, business, and regulatory undertakings. The commercial aviation market can generate the money to make these improvements a reality just like the automotive industry can-there is a market there that makes those investments possible. I don't know the (small) numbers, but the piston GA industry is what, flight schools, charter operations, and people that fly for fun right? How much money can that community generate to fund a new piston engine family? GA piston engine technology developed when the aviation "business" was flying pistons back in the 30's, 40's and 50's. The money in aviation has since moved on to jets and turbo props which (as others have said here) are not well suited to our purposes. If we are lucky, some technology will spill over from another industrial sector (like what happened with our avionics) and we will make a step forward.

Posted by: Robert Young | March 15, 2011 2:19 PM    Report this comment

Let's look at the Io-550. It costs what about $60,000? Well, it's no wonder. How many of these are turned out by the factory? A few hundred a year? Maybe?

Then look at the pieces that go into it. It has six each of cylinders, rods, pistons; 12 each of valves, lifters, valve springs, pushrods, etc. That is a whole lot of parts, each of which costs a fair bit of money to make.

Now look at a 2-stroke outboard engine, same 300 hp. It costs about one quarter of the IO-550. And that includes gearbox, prop, tilt and trim motors, the motor chassis, etc. Just the engine itself probably costs less than $10,000. that's about $30 per hp, compared to $200 per hp for the Conti.

It has six cylinders. Zero valves or any valvetrain. Direct cylinder injection for unbeatuable fuel efficiency and emissions. Can run on heavy fuel. First scheduled service at 300 hours!

And here is the big one. It weighs half as much. But is designed to run at full power continuously, not 75 percent!

Posted by: Gordon Arnaut | March 15, 2011 2:31 PM    Report this comment

Well said, Robert. Pretty much GA has to "scrounge" for what we can make use of. That's why (on this subject of engine tech) that it might make more sense for GA to forage for engine tech parts instead of develop something new or unique. Adapt instead of develop, raid instead of create. Face it, we're bottom feeders at this point.

Posted by: Mark Fraser | March 15, 2011 2:40 PM    Report this comment

I looked at outboards a little while ago and I was truly shocked at the price. A 300 HP 4 stroke Yamaha was over $30,000. It looked to almost identical to the engine in my Nissan Titan which cost me $36,000 for the entire truck. It was also 900 lbs. with gear box.

I'm not sure 2 stroke is the way to go, bad emisions and poor fuel economy. Probably better if that direct injection is actually fuel and not Lub oil. 2 strokes talk more about oil injection rather than fuel injection. Could be wrong as I have kept up on the advances there.

BP

Posted by: Bob Parry | March 15, 2011 3:38 PM    Report this comment

Bob, the 2-stroke direct injection is high pressure fuel injected directly into the cylinder, just like a diesel.

The fuel specifics are on a par with 4-strokes, or slightly better. The emissions are better by a good deal. The Evinrude engine is the ONLY engine to date to achieve the highest EPA rating.

The 300 hp Evinrude costs $17,000 complete and weighs about 500 lbs. The engine itself is about half of that, 250 lb.

The 4-strokes cost more because, well, they have about 10 times as many moving parts. But they cannot compete with the DI 2-strokes in power, economy, or weight.

Evinrude likes to show its boat in a tug of war with a 4-stroke, where it literally pulls the opponent under the water with ease. It's on youtube.

With DI technology now refined watch for 2-strokes to make a comeback in cars too. For light prop planes it is the ideal engine cycle.

Posted by: Gordon Arnaut | March 15, 2011 4:22 PM    Report this comment

Just for interest folks. Here in Australia, we have two engine manufacturers that are doing well. Jabiru make a range of 4 stroke engines, also the Jabiru aircraft. Most common engines are the 2200cc and 3300cc versions. Air cooled boxer engines. Also Rotec, who build their own design radials, a 7 and 9 cylinder motor. These guys haven't talked about it, they have done it.

Posted by: Jim Williams | March 15, 2011 5:50 PM    Report this comment

Wow. Reading this feels like listening to a couple dozen people commenting on what they see when looking at one spot in the world through a long, 1" diameter tube. Lots of fun, but hard to find that central nugget of truth. That nugget clearly has to include the fact that coming up with a low cost, compact, light, powerful, smooth, quiet, efficient, certified, multi-fuel engine isn't easy.

I really enjoyed the video of the Harley-powered airplane. Thanks Paul. Hope it didn't shake itself to bits too soon.

Regarding small, efficient turbines, one of the tragically under-appreciated developments in recent years is the work of Gerry Merrill at API. After he talked to Cirrus and Piper, they copied his airplane concept, but ignored his even-better engine. Read it all here and at the links on this page: http://apiengr.com/Aviation_Propulsion.html

Posted by: S. Lanchester | March 15, 2011 10:17 PM    Report this comment

Reading this feels like listening to a couple dozen people commenting on what they see when looking at one spot in the world through a long, 1" diameter tube.<<

Much smaller. Maybe 1/4 inch. I like to think my viewing portal can expand to at least 3/8ths. Thanks for the reminder on Merrill. I remember reading that when it was published. (I know Dave Noland.)

One thing reported in the article that doesn't jibe is that investors are afraid of anything other than the incremental. Regardless of how you might view it in reality, the Eclipse project was pitched as the disruptive technology great leap forward. In terms of it expectations--if not performance--it was that. And it, evidently, had little trouble finding investors.

Probably what Merrill most needed/needs is a salesman like Vern Raburn.

Posted by: Paul Bertorelli | March 16, 2011 5:26 AM    Report this comment

This is the Evinrude E-TEC video, by the way.

http://www.youtube.com/watch?v=_-7I00cZUE0

Posted by: Paul Bertorelli | March 16, 2011 5:27 AM    Report this comment

Gerry Merrill's idea can work. He is basically talking about a very high-bypass, very small turbofan. Engine pressure ratio would probably be in the teens, which is higher than small turboprops like PT6 and would give pretty good efficiency. But not that high as to be too complex and expensive.

Still not piston territory as far as fuel efficiency. For that you need the recuperative cycle like the microturbines, where you extract heat energy from the exhaust with a heat exchanger.

It's all moot unless you can deliver this powerplant for considerably less money than what a piston costs now. There just aren't enough people who are interested in buying a personal plane if it costs half a million, no matter how good it is.

continued...

Posted by: Gordon Arnaut | March 16, 2011 7:06 AM    Report this comment

As for a "low-cost, compact, light, powerful, smooth, quite, efficient, certified, multi-fuel engine," I don't think you have to look any farther than DI outboards for an engine that could be strapped into any light plane tomorrow or the day after.

It will run on heavy fuel just as well as on gas and Evinrude has a smaller version for the military that does just that.

The direct injection is the key to the high efficiency. It allows very lean running at low power due to stratified charge. The carmakers have been talking about direct injection and stratified charge for years but have produced nothing.

continued...

Posted by: Gordon Arnaut | March 16, 2011 7:13 AM    Report this comment

The Evinrude DI, which they call ETEC, is pretty ingenious. unlike diesel injectors which are engine driven by a cam to plunge a small piston which pressurizes the fuel, etec uses a wire coil wrapped around a magnet, just like an audio speaker.

the whole thing just bolts to the top of the head and when the coil is energized, the magnet pushes the piston down achieving the very high fuel pressure needed. Beautiful. Invented by a German fellow some years ago, but Bombardier bought the rights.

The extremely high pressure results in very fine atomization, plus evaporative cooling (as the fuel mist evaporates it soaks up heat from the hot air in the cylinder).

This means it lends itself very well to boosted applications with very high efficiency. The Evinrude is not boosted but it could be easily.

Bottom line is they are cranking out these engines for peanuts because there is nothing to it. Getting rid of valvetrain is a huge cost saving, plus weight saving.

Two-stroke cycle is a huge plus for smoothness and power. Bombardier could make an air cooled airplane engine like this tomorrow if they wanted to, but they don't want that can of worms. Also you need to simplify airframes the same way in order to make the whole airplane cheaper.

Posted by: Gordon Arnaut | March 16, 2011 7:21 AM    Report this comment

I think it is fun for technocrats to dream about the magic bullet technology that will reduce the price of aircraft to the point that the average laborer can afford one. Such fun is not in itself a problem - so long as the people who can actually do something about the demise of aviation don't get sucked into this day dreaming.

The obvious problem in aviation is the lack of demand. There just aren't enough people who want to fly light planes - at any price - to make this a really popular activity. There are enough to keep it barely alive, but that is all.

I wish the really creative people would devote their efforts to making aviation attractive to a lot more people rather than trying to reduce the price. Maybe some fun activity like spot landing competition or aerial photo contests could work. High performance racing is a step in this direction but the average citizen can't imagine actually participating in this incredibly expensive and dangerous activity.

Aviation always has been more expensive than the average person can afford. I doubt this will ever change. If only we can find a way to get more of the people who can afford to fly interested in doing so . . .

Posted by: Paul Mulwitz | March 16, 2011 7:29 AM    Report this comment

The carmakers have been talking about direct injection and stratified charge for years but have produced nothing.<<

Not exactly, Gordon. The Honda CVCC engine was a stratified charge engine using carburetion instead of DI, for cost. Ditto the Jaguar HE, which did have fuel injection.

Modern diesel direct injection almost reaches the same goal through shaping of the injection pulse. This has allowed OTR diesel engines to almost double their horsepower while achieving better economy.

Link below explains stratified charge:

http://snipurl.com/27gu2l

Posted by: Paul Bertorelli | March 16, 2011 7:33 AM    Report this comment

Basically, we (200hp or less GA) don't need "improvements" that increase the points of failure. Direct Injection and electronic controls are cool, but a simple carburetor with gravity feed is unbeatable for reliability (well, as long as gravity exists).

As an owner, I don't care if my aircraft gets 8gph with a carburetor Vs. 7.5gph with direct injection. I'll take simple any day of the week. the fuel savings of (100hrs X .5gph = 50 gallons/year) just are not worth it. We waste more than that on the latest iPad/ForeFlight gadgets.

Posted by: Mark Fraser | March 16, 2011 7:51 AM    Report this comment

Audi has been building and selling directed injected Gasoline engines for years .On the A8 for instance. There is quite a lot of work being done with direct injection with good success in Europe.

to get a very good overview of the state of the art read a good book about what is being done in Europe to provide them with 50% on average better fleet mileage than we get from our US gasoline engines read: "Gasoline Engine with Direct Injection" by Richard van Basshuysen (you can get it on Amazon)it really describes what is being done in advanced combustion technology using direct injection with FADEC control.

Posted by: william Lawson | March 16, 2011 8:31 AM    Report this comment

Holy smokes. Paul M, I have to wonder where you get the idea that people aren't interested in flying, even if airplane prices were lower.

This goes against all existing data gathered by the industry. On this very forum there was a fellow not long ago involved in airplane partnerships for LSAs. They found HUGE interest among general population, but PRICE is the big stumbling block.

People are and have been fascinated with flight since time immemorial. But even an LSA at $100,000 is just too much money for most folks. Fifty thou for a boat is not.

Private aviation was not an elite institution. Never has been until now.

Posted by: Gordon Arnaut | March 16, 2011 8:43 AM    Report this comment

Mark if you want to talk about points of failure, let's start with the exhaust valve which is the most highly stressed piece in any engine. It is a GUARANTEED point of failure, unless replaced at regular intervals.

There are 12 of these in a six banger. Plus 12 valve springs, plus 12 rocker arms, plus 12 pushrods, plus 12 lifters, plus a cam, plus cam drive, etc. The first thing that will go in an engine that is sitting idle is spalling on the cam lobes and lifters.

Let your engine sit for a couple of years and then see how long it lasts, even if it was brand new to begin with.

Not to mention that manufacturing all of these parts costs a lot of money and doubles the weight of the engine.

Direct injection does not have to be electronic. Rudolf Diesel invented mechanical DI more than 100 years ago and it still works great. Electric version is just lighter and better.

Posted by: Gordon Arnaut | March 16, 2011 8:50 AM    Report this comment

Paul B and William, yes you are right that European carmakers are ahead on DI. It's the American carmakers that need to start doing DI.

Yes there can be no argument that DI is a VERY good thing for any internal combustion engine. I could mention just a few technical strong points, but you could fill a book, like you said.

DI is also the only thing that can make a 2-stroke fuel efficient. Unless you inject the fuel directly into the cylinder after the piston has moved up and closed off the exhaust ports, fuel will simply go out the tailpipe.

Posted by: Gordon Arnaut | March 16, 2011 8:57 AM    Report this comment

Gordon, there are only 6 exhaust valves in a six banger. Routine inspection for "wobble" or "sticking" pretty much eliminates surprises. Many pilots it seem don't want to pay for good maintenance and/or don't care to take the time to understand that air cooled engines are quite different than what's in their Toyota.

Sure mechanical direct injection works. I'm guessing that gasoline works so well with a simple carburetor and low compression engines that DI was just not needed to do the job?

Posted by: Mark Fraser | March 16, 2011 9:07 AM    Report this comment

Mark, the point is that gasoline is not an aviation fuel any longer. Ninety nine percent of fuel used by airplanes is heavy fuel.

The logistics of supplying a special blend of gasoline to airports is headed for extinction. That poses an opportunity to get the kind of engines that light planes really need.

This is a light, cheap 2-stroke with DI. You simply cannot manufacture a 4-stroke inexpensively unless you are making millions of them. Plus it will still be too heavy.

Weight is the NUMBER ONE enemy of airplanes. If you can cut 300 lb on a 3,000 lb airplane just by changing the engine then that is a dream come true. Think what that does for payload and range. Boeing is going to extraordinary lengths to cut 10 percent. (If it even pans out).

Posted by: Gordon Arnaut | March 16, 2011 9:28 AM    Report this comment

Of course most aviation fuel consumption is by commercial and military jet aircraft. They burn a boatload of it!

Gasoline will be around as long as there are cars. Also, hundreds of "special blends" of gasoline are being made right now REGARDLESS of logistics or consumer preference. Making a non-ethanol general aviation gasoline is no harder than making a boutique winter Los Angeles gasoline blend.

Posted by: Mark Fraser | March 16, 2011 9:37 AM    Report this comment

As for motorbikes, a couple of French brothers have been working away. http://www.vija-engines.com . Mainly at 100hp engines for the European microlight regs (lighter than LSA but not by much) but now also a 120 HP for autogires and a 160 HP model. At the moment they are scratching their heads for certification of the latter but given the state of bureaucracy here with the move to Europe from national level I doubt they will make the move - unless of course people pay them upfront....

Posted by: Brian McCulloch | March 16, 2011 9:48 AM    Report this comment

PS the noise problem is solved by fitting an auto-type muffler, and / or a layer of foam (like that found in car hoods) in the engine casing if you really want stealth. Motor bike engines in motorbikes have to be loud or they do not sell.

Posted by: Brian McCulloch | March 16, 2011 9:51 AM    Report this comment

Wow, Light, modern, compact, powerful. Those engines look really good for LSA and smaller experimentals.

Posted by: Mark Fraser | March 16, 2011 10:02 AM    Report this comment

What about rotary (Wankel) engines? The seem even more suitable for airplanes than cars since they have a very narrow power vs. RPM band. Very simple, light weight, bullet proof and small. And you will never burn an exhaust valve, guaranteed. They will need gearing but so did my Model T. We might even be able to use parts from the Mazda RX-8. By stacking rotors you can get as much BHP as you want.

Posted by: ARTHUR THOMPSON | March 16, 2011 10:17 AM    Report this comment

Arthur there are a few people that have tried the rotary engines like Wankel themselves, Mistral and others. I doubt we'll ever see them.

It's not technical problems that hold back all these great ideas. It's not even really certification issues. Those cause problems for small parts or innovations like Mr. Johnson's sad story, no question. But anyone that truly has the horsepower to design, build, **support** an aircraft engine AND convince an OEM to hitch their wagon to it can easily clear the regulatory barriers. Capability is not a website, press release and cad render

Anyway the real issue is like all ga issues, there's just no money to be made. If there was, all those smart engineers over at Evinrude or GE etc would be coming up with those breakthroughs at Ly/Con.

The best thing ga can do is latch on like a ramora to fields where there is money for innovation.

Except the liability concerns guarentee anything "airplane" to be walled off in it's own compound. That's the real damage the lawyers have done. Not the direct cost of lawsuits to *aircraft* companies but the joint and several liability threat that makes them radioactive to anyone with any money that has not-aviation as their primary business....i.e. all those great industries we want to borrow technology from.

Posted by: B Noel | March 16, 2011 2:15 PM    Report this comment

Those motorcycle engines might look good at first glance but if we scratch the surface we find some big question marks.

That 160 hp engine looks good at just under 200 lb, for a power/weight ratio of almost 1. But look at the specific output, 160 hp from 1.2 liters is a red flag. The reason is heat. That much power from that small a cylinder volume is going to be very hard to carry away during continuous operation.

The rotax 912 is 1200 cc also but is only making 80 hp. The Evinrude 150 hp is 2600 cc. Specific power is 60 hp per liter, compared to over 130 hp a liter for the motorcycle.

Motorcycles are not designed to go at full power, like boats or airplanes. The 100 hp moto engine is about 100 hp a liter and that would be about the upper limit. But its weight is almost 200 lb too.

You can't negotiate with the laws of physics. They are what they are. If you want a light, strong and cheap engine a 4-stroke is not going to do it.

continued...

Posted by: Gordon Arnaut | March 16, 2011 2:19 PM    Report this comment

There is also the efficiency issue. Aircraft recips get pretty good efficiency as was pointed out here, low 0.4's sfc is nothing to sneeze at.

The reason is that these are long stroke, low rpm engines. The long stroke imparts a mechanical advantage with its longer moment arm, hence each pound of downforce on the powerstroke makes more torque.

The low rpms mean the engine is operated in the meat of its peak torque range where efficiency is highest. Now a car engine or a motorcycle engine will not match this efficiency. Even the outboards are at a geometry disadvantage here, but they have DI which can more than make up.

Rotaries can be a good aero engine and the Russians actually built a certified engine for small helos, but it never proved popular since there were good small turbines available.

A rotary is similar to a 2-stroke in light weight and simplicity and low parts count. But it suffers a bit in efficiency due to its rotor shape, compared to the more efficient cylinder. Also some other issues, including sealing, rotor cooling, etc.

Posted by: Gordon Arnaut | March 16, 2011 2:28 PM    Report this comment

About there being no money to be made in lightplanes...

Not at the prices they are charging, which limits the market to a few hundred a year. When the industry was cranking out tens of thousands a year, there certainly was money to be made.

Like I said on the other thread, the engine is just part of the solution. We need the same kind of simple, cheap approach to airframes. New designs that can be cranked out economically.

You are right that GE or Bombardier or anyone else is not interested in any of this.

They would become interested pretty quick though, if someone was able to successfully bring out a $50,000 airplane that sold like hotcakes.

The litigation thing is always a drag, but it is what it is. No one will ever change that because there are way more lawyers than light airplane owners.

Posted by: Gordon Arnaut | March 16, 2011 2:36 PM    Report this comment

Oh and I almost forgot...Look at the prices on those moto engine. Twenty thousand euros? That's nearly thirty thousand bucks. You can buy a certified Lycoming for that amount and it's the no-brainer...

Posted by: Gordon Arnaut | March 16, 2011 2:56 PM    Report this comment

Evinrude 150 hp $11,000. 300 hp, $17,000.

http://www.edsmarinesuperstore.com/evinrude.htm

Posted by: Gordon Arnaut | March 16, 2011 2:58 PM    Report this comment

<

Not at the prices they are charging, which limits the market to a few hundred a year. When the industry was cranking out tens of thousands a year, there certainly was money to be made. >>

Gordon that's a nice thought except that anyone with money could care less about selling 10,000 cheap airplanes a year. They only care about making more money.

How are you going to convince them the best way for them to make more money is to pour hundreds of millions into your startup for years until you can turn a profit at x thousand planes/year?? In an industry that is littered with failed companies and lost money.

"If a farsighted capitalist had been present at Kitty Hawk, he would have done his successors a huge favor by shooting Orville down" - Warren Buffet

Posted by: B Noel | March 16, 2011 3:30 PM    Report this comment

Paul,

doesn't jibe that investors are afraid of anything other than the incremental.<<

You have to recall that Gerry tried at first to find investors for a family of both airplanes AND engines. The whole program was so far beyond an "incremental" change, that the word doesn't fit the situation. Later, Gerry did pitch just the engine to airframe companies, but the real issue wasn't just fear of the non-incremental; it was that few airframers are willing to add to the risk of a new airplane program by using an all-new engine from an all-new company.

Pratt's all-new JT15-D nearly sank Cessna and its new Citation back in the 1970s. I remember Dwayne Wallace bitterly chewing out P&WC's VP in front of the Wichita air terminal because of it. William's all-new FJ-44 nearly sank Cessna's CitationJet program 20 years later (it needed two separate engine swap programs involving several hundred airplanes each time!$!$!), and William's EJ22 engine dug a hole for the already under-designed Eclipse that they never recovered from.

So, all-new engines have been a real risk to OEMs, and all-new engine companies are seen as even riskier. In Gerry's case, that's a shame; he is one of the most knowledgeable engine designers in the world, and -- unlike the examples above -- there isn't a single unproven technology in his engine designs.

Posted by: S. Lanchester | March 16, 2011 4:12 PM    Report this comment

Paul,

"doesn't jibe that investors are afraid of anything other than the incremental"<<

You have to recall that Gerry tried at first to find investors for a family of both airplanes AND engines. The whole program was so far beyond an "incremental" change that the word doesn't fit the situation. Later, Gerry did pitch just the engine to airframe companies, but the real issue wasn't exactly fear of the non-incremental; it was that few airframers are willing to add to the risk of a new airplane program by using an all-new engine from an all-new company.

Some history: Pratt's all-new JT15-D nearly sank Cessna and its new Citation back in the 1970s. I remember Dwayne Wallace bitterly chewing out P&WC's VP in front of the Wichita air terminal because of it. William's all-new FJ-44 nearly sank Cessna's CitationJet program 20 years later (it needed two separate engine swap programs involving several hundred airplanes each time!$!$!$), and William's EJ22 engine dug a hole for the already under-designed Eclipse that they never recovered from. So, all-new engines have been a real risk to OEMs, and all-new engine companies are seen as even riskier. In Gerry's case, that's a shame; he is one of the most knowledgeable engine designers in the world, and there isn't a single unproven technology in his engine designs.

Posted by: S. Lanchester | March 16, 2011 4:16 PM    Report this comment

That brings me to your second point: “Regardless of how you might view it in reality, the Eclipse project was pitched as the disruptive technology great leap forward. In terms of it expectations--if not performance--it was that. And it, evidently, had little trouble finding investors. Probably what Merrill most needed/needs is a salesman like Vern Raburn.”

Maybe so, but the problem with the Eclipse, as with the Starship – just to pick two examples – is that when technology has been oversold to investors, it takes 15-20 years for the investment community to forget. And, just as bad, it strongly reinforces to the existing airframers and their suppliers that the risks of new technologies can’t be justified. Consequently, the damage done to General Aviation by the Starship and Eclipse debacles is enormous. I point to these two airplanes as key reasons why the industry is so wary of all-new technologies. By the way, these were upper management debacles. The engineers who pointed out what needed to be done were swept aside. I was there, and survived by keeping busy on other projects that made money.

One of the great mysteries of aviation is that only naked emperors spouting flapdoodle can raise $Billions for all-new GA airplanes.

Posted by: S. Lanchester | March 16, 2011 4:19 PM    Report this comment

"If a farsighted capitalist had been present at Kitty Hawk, he would have done his successors a huge favor by shooting Orville down" - Warren Buffet<<

Thus explaining why Warren is rich and I'm not and raising the legitimate question: has anyone well and truly ever made a dime selling airplanes?

Recall that Toyota looked seriously at the segment 10 years ago. Got a prototype flying; engaged vendors in the U.S. Certified an engine. The either dropped or delayed the project indefinitely.

Maybe they couldn't find a floor mat vendor.

Posted by: Paul Bertorelli | March 16, 2011 4:19 PM    Report this comment

For serious investors, the thing to buy is not what makes you feel good. It is the thing that will make you money. There are lots of opportunities to invest in great businesses that can turn capital into a good return and still manage to hold on to the capital. For Warren Buffet, one of history's greatest investors, the poster child company is Coca Cola. By the time he was interested in them they had proved for a hundred years or so that they had a product that people were willing to pay for and come back for more.

There is no such product in aviation. Any investment in any aspect of aviation is a gamble rather than a "Guaranteed" winner. If you want to gamble, go to Las Vegas and play poker. At least you will have some fun and eat a few good meals while you lose your money. If you want to turn your money into more money buy boring stuff like Coca Cola.

Posted by: Paul Mulwitz | March 16, 2011 5:35 PM    Report this comment

John Johnston, above, commented on how nit-picky the desk pilots at the FAA can be when certifying replacement parts. I find it interesting that none of those detailed source data requirements were met (as far as I know) for the iPad (all ipads, not just a select factory run of them) to be certified as an Electronic Flight Bag. Have the FAA types unwound their nickers in the last few years? Or is it just that no one has crashed due to EFB failure, so they can relax the requirements? Maybe it has something to do with the certification going to a company owned by... Warren Buffet.

Posted by: Peter Buckley | March 16, 2011 6:02 PM    Report this comment

Well it looks like we live in a time when the Money Man is King.

That's too bad. If it was like that back in the day we would have never had a Henry Ford or Walter Beech, or Igor Sikorsky or Glenn Martin or anyone else who figured there was surely a place in the world for a better mousetrap (for less money).

Posted by: Gordon Arnaut | March 16, 2011 6:14 PM    Report this comment

Peter Buckley makes a very good point. Why isn't a full FAA TSO authorization required for using an iPad with a Jepp chart app?

There may be some relaxing of the processes here; but there was still an extensive 3 month evaluation; and the approval is limited to Executive Jet Management for now, but should soon extend to other operators.

So, my question is why we can't now use our iPads on airline flights? And I wonder -- does anyone have information on any consequential effect on airline safety from passengers using Portable Electronic Devices, or are airline PED limitations another bureaucratic power trip?

Posted by: S. Lanchester | March 17, 2011 11:29 AM    Report this comment

There is a difference between pilots using portable computers and passengers doing the same thing. If a defective computer interferes with the aircraft navigation system you would think the pilots would be able to notice this and turn off the computer. If it is a passenger device it might not be possible to locate and disable the device in a timely manner while conducting an instrument approach.

Passengers are allowed to use these devices when the plane is in normal cruise.

Posted by: Paul Mulwitz | March 17, 2011 11:40 AM    Report this comment

Agreed, but that logic, though reasonable, doesn't meet the approval criteria that I'm used to seeing from the FAA.

Posted by: S. Lanchester | March 18, 2011 2:39 PM    Report this comment

Anyone familiar with ULPower engines? They are 4-cylinder FADEC engines for light sport.

Posted by: Patrick Underwood | March 21, 2011 1:27 PM    Report this comment

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