Why Pistons Endure

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I took a ride over to Vero Beach on Friday to visit with Piper and fly the new Matrix for a flight review. During the course of that trial, Piper's chief pilot, Bart Jones and I, got to talking about the place of piston engines in the current market and why the technology is so persistent.

It's an easy answer. Nothing works better or more efficiently for small airplanes than piston engines. Jones has been around Piper for more than 20 years and has flown everything from Cheyennes to Meridians to all the piston models. Despite hours of turbine time and often the choice of either, he likes piston-engine aircraft for the same reason most of us do. They're familiar, we know how to make them work and they just get the job done at affordable cost. Much has been made of single-lever control but I noticed in flying the Matrix the prop and mixture are just transparent to me. They're like the clutch in my truck—operated by autonomic muscle memory. Dream as we might about small, fuel-efficient turbines for light aircraft, these aren't likely to happen for the foreseeable future unless the laws of thermodynamics are bent in favor of higher efficiency.

When Piper announced the Matrix in 2007, the aviation press brain trust figured they were nuts. Who was going to buy a non-pressurized Mirage? A lot of owners stepping up from Cirrus SR22s it turned out, once again demonstrating that journalism and marketing exist in separate universes. Matrix buyers saw something the rest of us didn't. Motoring along at 10,000 to 12,000 feet at 180 knots without oxygen in a comfortable cabin is a nice way to travel. With four people, two four-hour legs will put you half way across the continent. The Matrix can overtop weather if it has to, but Jones told me he usually doesn't bother, preferring to avoid the cannulas and masks if possible. I'm not sure I'd drag an airplane into the 20s now either, although there was a time when I felt just the opposite.

If Continental pulls off a 350-HP diesel, it could be somewhat transformational for an airplane like the Matrix. With 30 percent better fuel economy, an owner could tanker a lesser fuel load and pick up more payload or translate that into greater range with the same payload. I suspect more people will opt for the payload rather than the range. Four hours in any light aircraft is more than enough for all but the hardiest souls and they're not likely to be carrying passengers who aren't equally robust. (In any case, the Matrix is one of the few light aircraft with a crew relief tube.)

Gutless in Milwaukee
"Ladies and gentlemen, we're going to need your cooperation today. The flight is completely full and in order for everyone to have room to place their baggage in the overhead bins, we're asking you to place only one item in the overhead and the other under the seat in front of you."

I fear no contradiction in saying that the above is the most widely ignored instruction in all of aviation. It ranks right alongside "the check is in the mail" and "I know I put the gear down," for utter, futile meaninglessness. Yet, knowing full well that it will be profoundly ignored, cabin and flight crews say it a million times a day.

I think I may be among maybe five people on the entire planet who actually follow the requested practice because even though I am ill-tempered, foul-mouthed and fundamentally anti-social, I still like to think of myself as courteous to my fellow man. So I'm the guy that gets on the airplane near the end of the boarding process, only to find the selfish $#@^&#s who boarded before me, have put all their stuff in the overhead so they'll have an expanse of nice comfy footroom and the cabin crew has to disrupt the whole show to find a spot for my roll aboard, probably in the baggage bay.

So on a recent Air Tran flight—I'm starting to like this airline—I was presented with an opportunity to stuff it to the flaming $#@^&#s who have been doing this to me for years. For an extra $10, Air Tran will put you in Zone 2 boarding which these days is really near to the top of the boarding order. It's really a pretty good deal.

There were barely a dozen people on the airplane and when I got to my seat, the overhead was wide open for my two bags. Up goes the roll aboard, up goes the backpack and then…I couldn't do it! Even though there would be no consequences for hogging more than my share of space and inconveniencing my fellow travelers, I couldn't muster the will to do it. Even little wrongs are still wrongs. Taking only a little more than you deserve is still taking too much.

Sigh. All I can say is thanks Mom and Dad. You musta wired me right.

Comments (39)

Right on! Turbines are not the answer for light GA. The efficieny at our altitudes in very poor and the cost of manufacture is high. My hope has long been for a 250 - 300 HP diesel to replace the 100LL guzzlers in the fleet. Althought the FAA will probably make the STC for a change out impossibe or prohibitaley expensive.

On you othersubject, many years ago when I was a road warrior a common occurance was to find that those in the back of the plane, that boarded first, would fill the bins in the front of the plane to avoid carring their bags all the way to the back. It was "just more efficient". When I got to my seat in the front I would ask everyone around if any of them owned the bags over my seat. When no one calimed them I would remove them and place mine in the bin. The flight attendent would come by, see my bags, and since the bins were all full graciously offer to check them for me.

Posted by: James Hiatt | August 6, 2012 7:10 AM    Report this comment

There was a running 350 Hp Diesel Engine at Oshkosh that most people missed. this is because guys developing it focus more on making it work than bragging about what they haven't done. see www.EPS.aero

It is weight, size and shape interchangeable with existing 100LL technology. It weighs firewall forward with everything ready to run only 27 Lbs heavier than the TIO 540 installation in my Aerostar and will fit in the Aerostar nacelle.

Posted by: BILL LAWSON | August 6, 2012 7:28 AM    Report this comment

The turbine market is a total oligopoly. A turbine has fewer parts and is easier to manufacture compared to a piston, yet special interests have made sure the prices are kept high. In the end, I don't think it matters as two things will slowly kill off them both - electric propulsion and higher gas prices. Diesel? Yes, that's the near future for piston engines and I will most certainly switch over to it on my aircraft as soon as a good engine/STC arrives.

Posted by: Adam Frisch | August 6, 2012 7:35 AM    Report this comment

Paul, please try to avoid airline travel commentary, yes, it is aviation but it's the root canal of aviation. It is too depressing for discussion and is best left in the closet. Airlines are technology run amok, something to be avoided if at all possible. However I do applaud your stand for courtesy and common decency, your parents are to be commended.

Posted by: Richard Montague | August 6, 2012 7:45 AM    Report this comment

Paul: The EPS engine lecture at Oshkosh was inspiring. I hope you will get a chance to visit with this outfit. That means another trip to Milwaukee however...

Posted by: Peter Kuhns | August 6, 2012 7:59 AM    Report this comment

If even the least bit of lead in avgas is banned, the highest practical octane rating will be ~93. That may be good enough for motorcycles whose engines are designed for premium gas, but not aircraft like a sleek, fast Mooney retractible. So the gap between turbine and piston will become narrower. As there is unfortunately a carbon dioxide (as well as cost) issue owing to a turbine engine's higher specific fuel consumption, I would like to see the following: First, practical Diesel engines for aircraft like the Cessna 182, Beechcraft Bonanza & Baron and so forth. Second, while this is obviously dangerous if you don't know exactly what you're doing, we should have experimentation (The "E" part of EAA) with novel lead-free high-antiknock piston aviation fuels. One possibility is combinations of 93 octane gasoline, ethanol and butanol. The latter helps cover up ethanol's issues by acting as a cosolvent between gasoline and ethanol, and is a good fuel in its own right.

In the most recent edition of Plane & Pilot magazine, we read about a small twin-engine jet aircraft whose gross takeoff weight is not much over 6000 lb. Its fuel burn is ~60 gallons of JetA per hour, which is roughly twice as much as what one would have with a Beechcraft Baron. But said jet aircraft can hold 400 miles per hour, and the Baron obviously cannot. So if you like twin-engine safety, one can see how the gap between piston and turbine is narrowing even with continued availability of 100LL.

Posted by: Alex Kovnat | August 6, 2012 8:15 AM    Report this comment

Good article on pistons. We four partners find a 1985 182RG is a great traveling machine -- reliable, more than adequate load, great range and relatively cheap to operate. Would love to have the extra power, speed and reliability of a turbine, but no turbine new or used can compare to the economics of our plane (and yes, we are quite proud of her).

I've slowly come to the conclusion you need to have a business that can finance a turbine, or be so extraordinarily wealthy you can sustain the habit indefinitely. If the number of pilots with a few dollars allocated to flying is large, and that number of pilots declines as personal dollars available rises, makes you wonder why several GA mags have such extensive turbine sections each month (other than general education and "gee wiz" ;-). At least three of we partners are interested in diesels, but the replacement cost and what it does to operating expenses is too high.

Posted by: DANIEL DEDONA | August 6, 2012 8:33 AM    Report this comment


Got stuck east of a line of t-storms yesterday at PHL. Everything from heavies to biz-jets (and a lone 182RG ;-) ran to safe harbor, squeezed between the storms and the Atlantic. In the end, technology got leveled by nature anyway. It would be interesting to see an analysis or spreadsheet ranking planes by the key variables driving their economics -- fuel burn, recurring maintenance, annuals, overhauls, insurance, financing -- as an aid to selecting the aircraft suitable to each pilot's long term financial circumstances. Maybe you know of one (I made an approximation but for only one aircraft at a time). Anyway, if turbines or some other technology are going to displace pistons, it will have to pass this economic test or it's likely to be just another profitable opportunity for business or the "very" wealthy. It seems the rest of us who can stay in the game have have found a home with pistons.

Posted by: DANIEL DEDONA | August 6, 2012 8:34 AM    Report this comment

Sounds like a good Catholic upbringing! You did the right thing...

Posted by: Charlie Gibbs | August 6, 2012 9:08 AM    Report this comment

I'm in the camp that thinks diesels hold more of a future for the private pilot sector than turbines.
Responding to your airline rant, I'm in league with you, Paul. The only time I ever put my computer bag overhead with my roller bag are those very rare occasions when the aircraft has plenty of seats empty. I have, and will in the future, confront those morons who ignore the pleadings from the crew when said morons are preventing my from storing my bag. And I think nothing of taking that perfectly laid flat suit jacket and wading it in a ball to make room for my stuff.

Posted by: Phillip Potter | August 6, 2012 9:25 AM    Report this comment

Continental A65: 4 gal/hour. Hand prop. No mixture control. No electrical. No Radios. MPG... Who knows? Fun/Gallon... priceless.

Posted by: Andre Abreu | August 6, 2012 9:36 AM    Report this comment

In fact, don't the same economics hold for short-haul airline flights? Isn't that why DC-3s are still popular airliners and freight haulers in out-of-the-way places? Another plus for pistons is that they aren't burning up the ozone layer and putting pollutants into the upper atmosphere. As for the baggage issue - simple solution is to start charging for carry-on baggage. I bet you airlines are working on that...

Posted by: COLIN SMITH | August 6, 2012 10:13 AM    Report this comment

I agree with what you said, but... What happened to Williams and his small turbines-remember them a Oshkosh a few years ago hinting that they might come out? A small efficient turbine that could be dialed up from 100 hp up to 350 hp all at less than 100 pounds. Obviously if that happened essentially all small GA aircraft could use them and making them cheaper to buy in large numbers. What happened - liability? Too small a market? Wouldn't work? Remember when Walter made a cheap(er) turbine, then recently I believe P&W bought them and "improved" them so they too will now also be too expensive. If we had turbines we could run diesel instead of Jet A, as I understand crop duster guys do. Hard to believe in 50 years of turbines this still can't be done! Till then I too want that diesel - running diesel fuel, nearly $6 a gallon for Jet A and 100LL - its killing GA!

Posted by: Craig Schwab | August 6, 2012 10:48 AM    Report this comment

> What happened to Williams and his small turbines-remember them a Oshkosh a few years ago hinting that they might come out?

Possibly, the technology underlying the Williams small turbine is currently being used in the latest small jets, like the one described in the latest Plane & Pilot magazine that I referred to above. And also, according to an article in a recent edition of Flying magazine, there's a bizjet from Brazil that has a fuel burn of 80 gallons an hour, which again is not bad for a jet aircraft of its size and performance.

Unfortunately when its not cheap to own and operate a J-3 (Happy 75th Birthday to Mr. Walter Jamouneau's great design!), with a A65 Continental that drinks only 4 gallons of (originally 80 octane) avgas/hr, I don't realistically expect to see all that many jets flying over my neighborhood.

Posted by: Alex Kovnat | August 6, 2012 11:11 AM    Report this comment

The only thing I (and many of the public) have against piston is the noise. The piston has a quicker response to inputs against jet.

In UK the airliners have introduced a luggage charge. You can carry on a single bag and it must fit into a small box at check in. Too big and its classified as cargo and has to go into the hold plus you pay extra for it. More than one bag (even handbags) and you again pay. There is nothing more focusing than being charged for your luggage.

Posted by: Bruce Savage | August 6, 2012 11:32 AM    Report this comment

After returning last Saturday from scuba diving in a coat and tie in Cleveland for five days and listening to a symposium titled 'Strategies for implimentation of organizational processes in military....zzzzz huh? I reviewed that the highlight of my trip were the flights. The 'root canal' was the symposium. On the plane I usually get some work done in my dreams while nodding off, and coming back to/thru Vegas I sat next to a couple who claim to actually make a living at playing poker. They fly around to gambling hot spots to keep 'fresh' as they put it. I suggested the PPL and aircraft ownership to make it even more fun and practical, but the look on their faces was exactly like the look on the seminar attendees faces, so I dropped the subject.

Anyway, I noticed most people don't face the rollers out like we're supposed to in the overheads, and if some are too tall they put them in lengthwise, hogging others' room. One woman's purse/handbag could have been used as a canopy cover for a Navion, but she crammed it under the forward seat somehow. I'll gladly pay extra like Paul did if I get the chance.

They're a public stress point, the airlines are. But considering the superlative safety record, hard-working crews, time savings and comedy review opportunities, they're a great part of our aviation and social fabric to me. I had breakfast in Cleveland, late lunch in Vegas, and dinner at home. Awesome.

Bruce, are you a pilot? No airplane noise? Say it ain't so!

Posted by: David Miller | August 6, 2012 3:11 PM    Report this comment

Living in Sweden a couple of times, I ran into the custom of "lagom." It has no corresponding english word but "the correct amount" is often used as a definition. For example if you're eating family style with five friends and the potatoes are passed around, you don't help your self to more than 1/6 of the potatoes. It permeates the culture. I often think back fondly to those days when I'm staring at the full overhead bin (and many other unfortunate examples of the "me first' culture we seem to have descended into.)

Posted by: ROB WYDER | August 6, 2012 3:30 PM    Report this comment

My reasons for liking piston powered aircraft;
You can see the prop turning.
You can feel the engine and its vibrations. People with much piston history can "feel" the health of their engine.
Your ears, hands, feet and backside can become "tuned" after time to feel the quality of the combustion process.
My training was with 28 cylinder, R-4360 Radials--nay sayers will just have to trust me that you can feel the difference !
This dosen't happen overnight but you can train yourself.

Posted by: Louis Sell | August 6, 2012 4:04 PM    Report this comment

"Nothing works better or more efficiently for small airplanes than piston engines." Amen. Of course, they all want to burn fuel, and the environmentalists are irrational regarding lead in anything (sure wish they had felt that way about mercury BEFORE we got hit over the heads with CF light bulbs), so I'm thrilled to see a series of piston engines that burn kerosene.

Jets make sense at altitudes above FL300, regardless of occupant count. Down low, pistons and propellers are a winning combination. Since the G-men seem intent on turning auto gas into a cocktail without olives, diesels seem like our only salvation.

Posted by: Tom Yarsley | August 6, 2012 4:17 PM    Report this comment

Dave Yea still fly and loving it but for some unknown reason there is one helluva noise out front and I just can't hear anything. If it weren't for those new fangled things I put over my ears I would not be able to hear the radio. Can't get the latest tobacco prices these days the guys on the radio tell me I must stop asking for it.

Posted by: Bruce Savage | August 6, 2012 4:24 PM    Report this comment

Thanks for your inciting insight.
BTW,"...from Cheyenne's to Meridians."
Cheyennes you mean, right?
With your exceptional writing skills, "Even little wrongs are still wrongs." :-)

Posted by: Wash Phillips | August 6, 2012 5:44 PM    Report this comment

and the environmentalists are irrational regarding lead in anything >

As an environmentalist I'm not, but some are. Pistons, propellers and petrol forever!

Don't be fooled that generalizations are only to be found coming from pilots. Some environmentalists, too, can make the same errors in judgement.

Posted by: David Miller | August 6, 2012 5:46 PM    Report this comment

There is an alternative to employing the airlines for long distance travel....build and fly a high performance kit plane equipped with a piston engine.

My Questair Venture cruises at 275 mph @13 US gallons per hour and can cross the continent in a single day. It also climbs at 2500 fpm and performs effortlessly above 20,000 feet (the Venture set a world altitude record above 35,000 feet back in the 90's), all without benefit of a turbo charger. Other high performance kit aircraft such as the Lancair Legacy and the SX-300 perform in (almost) similar fashion.

Larry Woods

Posted by: Larry Woods | August 6, 2012 6:27 PM    Report this comment

Thomas, if you think the enviro-nuts (and the ones I'm referring to are the fringe, TR was a hunter and environmentalist) are the only problem, you're being shortsighted. The next / current battle will be with the semi-wealthy / wealthy jerkoffs screaming NIMBY if turboprops and turbines became "the" GA engine. By me, they've already started crying about a regional airport that's been around far longer than any if their McMansions and gold course. The real problem is human behavior, and that self-righteous "I got mine, fark you" attitude. That lady in Arizona? She didn't like the airport at all and bootstrapped her hatred with a "health" claim, even though the airport was there longer than she was.

I think we would, but shouldn't, be surprised if we looked behind FoE and found a few wealthy neighbors (or real estate developers) of airports "helped" point them toward pressing this lawsuit. Call me a cynic, but I've got more than a few friends of means.

Posted by: Joseph Servov | August 6, 2012 8:18 PM    Report this comment

As Diesel engines have been a topic for discussion on the Avweb forums, I would like to share this link with all who are interested:

www. sae. org / mags / AEM / 11241

Posted by: Alex Kovnat | August 7, 2012 6:45 AM    Report this comment


GA faces many issues, enviro-nuts among them. But the current dust-up over 100LL will have existential consequences for the vast majority of non-kerosene-burning aircraft – including my own.

100LL is doomed; that much is clear. Kerosene and auto gas are two fuels that have legs. But the politicians keep diluting gasoline with more and more alcohol, demonstrating that it's easy to buy votes with someone else's money – especially if you never took a high school chemistry course. Thus, for the long haul, kerosene is the aviation fuel of the future. That means re-engining my plane and many/most others. Or retiring them. Anybody who thinks that we have a problem with the active pilot population today, can see where this inexorably is headed. And it ain't pretty.

Posted by: Tom Yarsley | August 7, 2012 6:55 AM    Report this comment


You are a gentleman and a scholar.

Posted by: Tom Yarsley | August 7, 2012 6:57 AM    Report this comment

Alex, that link doesn't work. At least it didn't for me, even after I removed the spaces.

Posted by: Paul Bertorelli | August 7, 2012 7:09 AM    Report this comment

Whoever is interested, drop me an Email to Akovnat on the America On Line system (i.e. Akovnat at aol dot com) with your return E-mail address, and I'll return a copy of that article which I've downlinked and saved as a Word file.

Posted by: Alex Kovnat | August 7, 2012 8:49 AM    Report this comment

"...100LL is doomed; that much is clear. Kerosene and auto gas are two fuels that have legs..."

The FAA is organizing, with others, such as the AOPA, ASTM, etc. to build a pathway to a drop-in replacement for 100LL.

A Continental 350 Hp diesel (I assume you mean JP-4) will not gain traction in undefined market conditions. I'd hate to build a spreadsheet to forecast profit potential over and above certification costs, production tooling costs, a yet-to-be-determined STC path and other issues unknown.

Posted by: Edd Weninger | August 7, 2012 10:24 AM    Report this comment

"The FAA is organizing, with others, such as the AOPA, ASTM, etc. to build a pathway to a drop-in replacement for 100LL."

Right now, their "organizing" and "pathway-building" comprises little more than wishful thinking of the "there's gotta be a way" kind. I'll believe in a fungible drop-in replacement for 100LL as soon as I see it.

Posted by: Tom Yarsley | August 7, 2012 11:34 AM    Report this comment

Piston engines are relatively efficient because they utilize very high cycle temperatures. They are cheap to build because they use simple shapes from cheap materials. Only the exhzaust valve is bathed in high temp gas flow, and only after the work has been extracted from it. Aircraft piston engines are not cheap because they are made in very low volumes to very high quality requirements. Turbines need very high performance materials because they bathe their working parts in the gas flow at their highest cycle temperature, continuously. While they are free from the accelerations and resulting vibrations of reciprocal motion, the critical parts are subject to very high centrifugal loads and stresses. Gas turbines are expensive because the use very expensive materials in complex shapes and they are made in very small low production, again to very high quality standards.
Finally, very expensive engines that have very high performance can only be economically justified if they are used a very high percentage of the time. GA aircraft typically are hardly ever used. (Mine has 4000 hrs in 32 years) I can hardly afford flying pistons, much less a flying turbine!

Posted by: Jack Thompson | August 7, 2012 11:52 AM    Report this comment

Alex That link worked for me thanks

Posted by: Bruce Savage | August 7, 2012 11:59 AM    Report this comment

My recollection, from experts, is that small turbines can never be fuel efficient. Just fundamental physics. Perhaps an expert can provide more.

And for overhead bins: my airline bin container should be marked for my seat only!

Posted by: Bill Berson | August 7, 2012 2:20 PM    Report this comment

GAMI has a fungible replacement for 100LL, and has been running it in a TN Cirrus for probably a year now. They have a local refinery that produces it easily. If the FAA would get out of the way, problem solved.

Posted by: PAUL HEKMAN | August 7, 2012 4:19 PM    Report this comment

Piston aircraft with Lycoming and Conti engines are very efficient and cost effective. The leaded fuel issue is not really a problem - it is about who is going to take the tab and currently no-one wants to do that. The problem in general is costs.
Here a link to a recent presentation I had in California.
http: // www. hjelmco . com/news . asp?r_id=83471
remove the spaces for proper access

Posted by: Lars Hjelmberg Hjelmco Oil Sweden | August 8, 2012 6:24 AM    Report this comment

Pistons will be around for a while because there are so many of them. The international "machine" that builds, supplies, rebuilds and repairs them is as automated as home air conditioning. There are enough Lycoming and Continental cores to build a 4-lane bridge to Mars complete with Sun-Pass. Turbines cost far too much in tooling to justify their physics. Even rotaries which had an outside shot lost when the numbers were crunched. When we come up with an internal lubricant to match lead, pistons will be around for another hundred years.

Posted by: Richard Herbst | August 8, 2012 12:04 PM    Report this comment

The airlines have it backwards. The current practice of charging for checked bags encourages people to bring as much as they can into the cabin which, usually, causes boarding delays and anguish amongst crew and passengers alike. They should allow us to check our bags for free--to help offset the inconvenience of waiting at baggage claim later--and charge for the bag you carry on board. Everyone should still get the "personal item" (purse, laptop) for free but let's buy a ticket for that roll aboard.

Posted by: Unknown | August 8, 2012 1:24 PM    Report this comment

"Why Pistons Endure"

Because what else makes sense?

Posted by: Mark Fraser | August 11, 2012 7:31 PM    Report this comment

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