The $20 an hour Cessna 172 experiment (2020)

https://airfactsjournal.com/2020/11/the-20-an-hour-cessna-172-experiment/

by BWStearns • 3 years ago

485 329 3 years ago

airfactsjournal.com

jaclaz• 3 years ago

[2020]

Seemingly the author is still working at it:

https://corsairpower.com/

Last update (2022):

https://airfactsjournal.com/2022/10/the-20-hour-cessna-172-e...

falcolas• 3 years ago

Very cool. And also a little depressing that the state of the art is still back where it was in 2000 when I last looked at this.

May they drive a revolution.

google234123• 3 years ago

It's annoying how antiquated the engines used on these single engine planes. Continental is selling engines designed in the 60s that are just so inefficient.

nickff• 3 years ago

This is a product of the regulatory process. I am sure Cessna would love to sell new stuff, but it's just not worth it for them or their clients.

mopsi• 3 years ago

The whole small piston-engine plane industry collapsed in 1980s because of excessive liability: https://en.wikipedia.org/wiki/General_Aviation_Revitalizatio...

If I recall correctly, Cessna was found infinitely liable for every plane manufactured, meaning that each new plane off the assembly line increased their potential overall liability without liability over decades-old planes expiring and decreasing it.

Axien3• 3 years ago

Cessna did sell some new stuff. It all failed.

bombcar6• 3 years ago

The market for small planes is basically entirely gone; the entire amount is so small that they can't really get through the cost of certification for the amount they sell.

Even the relatively modern SR20 uses a Lycoming engine: https://cirrusaircraft.com/aircraft/sr20/ - https://en.wikipedia.org/wiki/Lycoming_IO-390

trilbyglens• 3 years ago

Probably because it's so expensive! Cheaper and more modern engines and aircraft could totally make for a new wave of aviators.

flangola7• 3 years ago

Why is the market smaller than in the 60s? There's more people with money than ever.

gnabgib• 3 years ago

SR20 you mean (as you linked, but not written). SR22 uses a Continental https://cirrusaircraft.com/aircraft/sr22/

kevmo314• 3 years ago

Part of the problem is that this V8 engine is a 2x improvement. It's definitely an improvement, but a sub 10x improvement isn't enough to bring on a revolution. The article alludes to investors' lack of appetite for the risk, I suspect a larger improvement would convince them.

yetanotherloser2• 3 years ago

It's not "gone" as if evaporated; it has been murdered by the certification requirements.

The odds of a random stranger dying from a light aircraft falling on them are trivial, several orders of magnitude less than the odds of their being hit by a car or being killed by inactivity; the pilot is free to refuse to take off, so risk appraisal really is on them; it's time to dump safety bureaucrats into your nearest woodchipper and CHANGE. THE. LAW. if you want ANY interesting activities or skills to survive.

jeffbee• 3 years ago

These engines have parts that are interchangeable with pre-WW2 engines. It's pretty generous to say they were designed in the 1960s.

_ph_3• 3 years ago

I think that is one of the reasons why the upcoming electric small planes are such a huge thing - getting rid of not only combustion engines, but very old and inefficient combustion engines. Could be a real game changer.

jacquesm2• 3 years ago

They'll end up with a fraction of the range/payload of the old planes.

outworlder7• 3 years ago

They are probably not going to take off (pun intended) any time soon. Just fuel reserve requirements alone are about the full range they have.

I suspect hybrids will be developed first. Basically an APU sending power to the main motor + a relatively small battery. The 'APU' can be relatively compact and deliver a lot of power, with less engineering requirements (can place it anywhere, doesn't need to interface with a prop). If it fails you have some emergency battery power. Electric motors are incredibly strong and have very few moving parts, so reliability is higher. They are also light.

Net net, there's some complexity and the combined equipment may be heavier (may! existing powerplants are some heavy beasts) but there's probably advantages.

Certification would be horrendous, I imagine.

UniverseHacker4• 3 years ago

Continental sells a range of general aviation engines based on modern Mercedes Benz diesel car engines, initially developed by Thielert as the Centurion. They run on regular Jet-A fuel, and are extremely efficient.

https://www.continental.aero/diesel/engines/cd155.aspx

https://en.wikipedia.org/wiki/Thielert_Centurion

I think these, combined with biofuel based Jet-A are a good solution to this problem, as electric tech is a long ways from having the range needed.

Maybe someone who knows more could chime in why these haven't already completely replaced the ancient air cooled leaded gas motors? My guess is that they're very expensive...

bluGill2• 3 years ago

You need to get the whole airframe certified to change the engine. If the airplane hasn't been in production for 40 years+ who will pay for that? Does the engineering data needed to start that process even exist anymore?

jabl9• 3 years ago

I think this is the $100000 conversion alluded to in the article. Not sure what makes it cost that much. Maybe the same thing that seems to have caused GA to stagnate, very small volumes combined with high certification costs.

(There's also a company called Austro engines that makes aero diesel engines, AFAIU even based on the same MB car engines Continental/Thielert uses. I think Austro is a subsidiary or spinoff of Diamond, so that's where you see these engines used.)

jabl9• 3 years ago

I think if you want to see 'modern' gasoline powered piston aviation engines, you have to look elsewhere than Lycoming or Continental. ULpower and Rotax make fuel injected aero engines with FADEC. I think Rotax has even certified some of their models.

Zak• 3 years ago

The efficiency difference isn't as much as you might think.

Car engines today are much more efficient than they were 50-70 years ago, but that's because the difference between maximum power and cruise power for a car ranges from about 5x to 20x. Much of the efficiency gains come from devising ways to deliver short bursts of power from a small engine, such as variable valve lift and turbocharging.

General aviation aircraft cruise at about 75% power. There's much less to be gained by optimizing the engine to run efficiently at 10%, and running a small engine at high RPM and high boost continuously is a recipe for frequent service intervals.

That's ignoring improvements to transmissions, tires, and aerodynamics in cars that aren't relevant to planes. There's certainly room for improvement, but not to the dramatic degree we've seen with cars.

jabl9• 3 years ago

The efficiency difference isn't as much as you might think.

True, the BSFC numbers of these old school aero engines aren't that bad, actually.

General aviation aircraft cruise at about 75% power. There's much less to be gained by optimizing the engine to run efficiently at 10%

I think the real advantage isn't a small efficiency gain in optimal conditions, but rather that with a modern FADEC there's less pilot workload, with a single lever for selecting the thrust the pilot wants, and the electronics takes care of selecting the optimal parameters (throttle position, amount of fuel, ignition timing etc.) for that thrust setting, taking into account input from a number of sensors (temperatures, pressure, etc.). And all those sensors provide data that can be logged and help with planning maintenance before something goes pear-shaped up in the air.

running a small engine at high RPM and high boost continuously is a recipe for frequent service intervals.

The Rotax aero engines rev to a max of almost 6000 rpm, cruise is ~5000 rpm, and they have a normal(?) TBO of 2000 hours, including the turbocharged 914. (The turbocharged 915iS has a TBO of 1200 hours, but I suspect it's due to the engine being relatively new, probably the interval will be extended when more experience has been gained?). Of course, these engines are designed for that from the ground up, not saying you could take a random car engine off the street and run it at 5000 rpm for 2000 hours.

titanomachy• 3 years ago

He complains that the plane which cost him $45 an hour to rent 30 years ago costs him $125 to rent now. Isn’t that basically just inflation? $45 in 1992 is $104 today.

cjbgkagh• 3 years ago

I think his point was the same planes are much older today and so he expected them to be cheaper after inflation. They were also old when he first flew them so the capital expenditure was likely already a small component of the per hour price.

sowbug2• 3 years ago

The complaint is that it's the exact same plane, but 30 years older. Inflation sucks, but with most durable goods you get the benefit of improved technology. Imagine paying $1,000 for a PC today -- not bad, except what if it were a 60MHz Pentium with a 40MB hard drive?

melling• 3 years ago

I’m pretty sure everyone understands you can’t compare the price drops of electronics with durable goods.

Are cars cheaper today? How about all that construction equipment the Caterpillar sells?

Are the price of tanks and jets getting cheaper?

cholmon• 3 years ago

I did a discovery flight with my son last summer in a C172. We had a blast, but I was pretty surprised how old the plane felt. My recurring thought is that Cessnas are like the TI-85s of airplanes; ubiquitous workhorses frozen in time.

Is it just Cessnas though? Is this the way all small planes are?

kevin_thibedeau2• 3 years ago

You're not paying for a depreciated product. You're paying for the maintenance and operating fees which don't depreciate in value.

wstuartcl2• 3 years ago

imagine the reaction when he finds out what that house that sold for 60k thirty years ago costs now.

ben77993• 3 years ago

He's in a cheap area or something.

Instruction in a 172 is more like $250/hr at the nearest airport to me in Massachusetts, with the plane being at least $200/hr of that. The gotcha is I think they are modern 172s, which are probably more than $500k each to buy at this point.

I took lessons in the early 1990s and it was $125/hr in a 152 which was a much smaller less capable airplane. People are too heavy now, the 152 sized plane is no longer used as much because 2x 200lb adults will put it over it's max takeoff weight if the gas is topped off or something.

Everything about all of it is super wacked. The leaded fuel, the way people cling to old planes cause the new ones are so stratospherically expensive, the ancient technology because the manufacturers need so much money to get anything approved, etc..

grepfru_it2• 3 years ago

People are too heavy now, the 152 sized plane is no longer used as much because 2x 200lb adults will put it over it's max takeoff weight if the gas is topped off or something.

Why would you fly with full fuel tanks while taking lessons? However, your comment is correct that 152 is horribly underpowered

asciimike• 3 years ago

Yeah, prices in CO (where Corsairpower is based) are ~100-150/hr wet for a 172, plus 30-40/hr for an instructor. I think I'm paying ~120/hr plus a varying "fuel surcharge" of ~20/hr for a T41-D.

The main issue right now is that all the flight schools are booked up and you can't get a DPE booked less than two months out.

fijiaarone8• 3 years ago

Other than a slightly nicer looking dash with a digital radio, the brand new $500,000 Cessna 172, is almost exactly the same as the 1950s-1970s era models that make up the overwhelming bulk of the fleet.

ghawk1ns• 3 years ago

That's innovation in my book. Nothing wrong with trying to reduce your costs while improving emissions, especially when we're talking about 30+ year old technology.

ghshephard• 3 years ago

https://www.bls.gov/data/inflation_calculator.htm

According to BLS.GOV - 1970 $45 == 2022 $353.

Makes sense that something like an airplane would drop in price, but I'm surprised that it is (after adjusting for inflation) 1/3 the price that it was in 1970.

AdrianB17• 3 years ago

If 30 years ago you could fly a brand new plane for a price and now you can fly a 30 year old plane for a lot higher price, he is right to complain. It is the same comparing the price of a new car 30 years ago with the price of that used car now, with half a million miles on it, ignoring the potential "vintage, mint condition" surcharge.

xnx• 3 years ago

I can see how the cost and regulation of museum-piece general aviation planes makes battery powered personal VTOL craft (despite their other shortcomings) attractive.

mcculley6• 3 years ago

"Even the largest marine engine manufacturers use mass-produced automotive engines that they modify for the boat mission, an engineering process I was more than familiar with."

This is not true at all, unless one is only talking about small inboard boats.

bluGill2• 3 years ago

The larger boards will use mass produced construction and agriculture engines (I work for John Deere, so while I can't speak for the company I can tell marine engines are important enough of a market that we consider their needs when designing a new engine).

The largest ships get custom built engines.

mcculley6• 3 years ago

I work in the tugboat industry. A quite standard engine there is the EMD 645. That was never a "mass-produced automotive engine" and it is not custom.

Our smallest truckable tug uses John Deere engines. Everything else uses engines that would never fit in any automotive application.

BWStearns3• 3 years ago

90% sure he means "largest manufacturers of marine engines" rather than "manufacturers of the largest marine engines". If I'm right then the largest mfg probably produces smaller engines since there's so many more small boats.

dave78• 3 years ago

Yeah, seems like all you see anymore for I/O engines is Mercruiser and Volvo, which do indeed use automotive engines. I'm not sure if there are even any other manufacturers left.

I'm less familiar with outboard engines, and I don't know what is more common (I/O or outboards) for recreational boating. In the Great Lakes, I/Os appear to dominate, but I've noticed that videos of boating in Florida and the east coast show a lot of outboards even on the bigger boats.

bri3d• 3 years ago

I think they're referring to gasoline "small" boats, like Mercury Marine type stuff, rather than full-sized ships, which generally use industrial / "stationary" diesel engines. I think the point still stands though, as these larger stationary diesels are usually shared with locomotives, gensets, and the like.

mcculley6• 3 years ago

Yes, these engines have other uses. But there is an enormous market of yachts, tugs, etc. smaller than what is considered to be a "ship" and bigger than any automotive engine could power. I argued only with the assertion about "automotive engines". It was true when I was a kid that most engines I was around on commercial boats were special versions of automotive engines. It has not been true in my experience for a couple decades.

blhack• 3 years ago

There is a whole subculture of pilots seemingly trying to run around some of these regulations using "experimental" aircraft like the carbon cub: https://www.youtube.com/@TrentonPalmer/videos

(I'm not saying Trent Palmer is trying to run around any regulations, just that his videos are cool, and seem like a good entry point into experimental bushplanes)

I'd also encourage anyone here to check out Mike Patey: https://www.youtube.com/@MikePatey/videos

His current videos are about a really interesting and unique pool he is building at his house, but most of his stuff is about even cooler and even more unique airplanes he builds. He's an incredible engineer/hacker.

mbustamanter• 3 years ago

Mike is perhaps one the most impressive plane hackers I've seen. His creativity and transparency (he shows all the process!) are much appreciated. He inspired me to try and make some carbon fiber models for RC planes. By the second half of this year I plan to have built an RC delta wing, and use my programming knowledge to automate its flight path.

EDIT: To add to it, and even more remarkable: Mike has apparently got no formal education in engineering. His twin brother also wrote a book about the blessings and curses of ADHD, which both have.

renewiltord2• 3 years ago

Fascinating. They probably have some pretty good coping techniques, since ADHD medication is generally not allowed if you're going to be flying.

madrush20147• 3 years ago

I worked with a flight test engineer at Cessna who spent an hour describing his personal CitationJet RC model plane project. I was a little skeptical, but he said it even had miniature kerosene-powered jet engines.

TylerE3• 3 years ago

Not so much a "runaround" as "established procedure by the FAA". The big restriction is that you really can't use them for commercial purposes.

BWStearns3• 3 years ago

But they're getting rid of the LODA requirement for experimentals at least so flight training can be done again in them at least.

Stevvo• 3 years ago

Mike is the real-life Tony Stark.

edrxty3• 3 years ago

The run around is just "if you built more than half of it, you can be trusted to maintain it" which isn't really all that scandalous. It's actually been a very healthy thing for the GA industry in recent years given the issues outlined in TFA

kayfox• 3 years ago

I like how you talk about a Carbon Cub and then link one of the more famous Cub Killer (Kitfox) Youtubers. ;)

bischofs2• 3 years ago

What the FAA has done to this guy is disgusting, they don't respond to requests and treat him like a little guy despite the impressive engineering here. I'm not a republican but this is a great example of government destroying innovation and progress through bureaucratic nonsense.

matt_morgan• 3 years ago

My heart wants to agree with you but all those regulations must have something to do with how few people die in airplane crashes. It's like the textbook case of when regulations work, and I don't think the FAA has a department of special exceptions. We can wishfor it, but it's not easy to handle someone who wants to do something different.

pdonis• 3 years ago

all those regulations must have something to do with how few people die in airplane crashes

Many of them do, but that certainly doesn't mean all of them do.

It's really hard to see how using decades old engine designs with leaded gas is necessary to prevent crashes, or how updating a proven airframe to newer engine designs that have a lot of operating time in cars needs to be an extremely onerous process to avoid crashes.

ericbarrett• 3 years ago

Commercial aviation, sure. General aviation, e.g. a private pilot flying a Cessna 172 as in the article, is about as deadly per-mile as riding a motorcycle: far more dangerous than driving a car the same distance.

KennyBlanken• 3 years ago

The crash/death rate for piston general aviation is staggeringly high and a lot of it has to do with how unreliable ancient systems in the planes are, and task saturation from pilots still expected to manage stuff like fuel mixture settings by hand.

It's almost entirely about protectionism of a massive industry of rebuilding and servicing companies for ancient engines and electromechanical systems, not safety or reliability.

Compare a modern electronic gyro to its electromechanical cousin. The electromechanical version is unreliable, power-hungry, and extremely expensive to service.

The modern electronic equivalent is ultra-reliable, can self-test, needs no servicing or repair, can contain its own battery to self-power in an emergency, and be networked with other devices in the cockpit.

Want to put the electronic version in your plane? Ooooo, sorry, no can do, Mr. Airplane Owner, says the FAA. Can't hurt the profits of an entire industry dedicated to emptying your wallet of thousands of dollars every time your gyro needs to be rebuilt.

A modern fuel-injected, water-cooled airplane engine can run constant self-diagnostics and logging, and provide highly useful, actionable information to both the pilot and mechanic. It's single-lever, increasing reliability and reducing task loading during the most critical phases of flight, and reducing emissions substantially, too. It doesn't have special considerations in terms of flight profiles; air-cooled piston airplane engines require a gentle descent profile or they will be "shock cooled" and undergo high wear or outright seize. There are no issues with carb freeze. Starting is a breeze, instead of a chore. The list goes on.

We should be encouraging the hell out of EFI conversions and EFI engine options...but instead the FAA buries them all under mountains of paperwork and regulations to protect Lycoming and the like.

tysam_and• 3 years ago

GA is extremely dangerous, piloting runs through part of my family and single-engine aircraft are for the post-midlife/retirement crisis that many pilots go through. It also is their deathbed.

One family member was at breakfast that morning with several other pilots, all of whom had private aircraft except him (he is a voracious pilot, though). Every single one of them apparently had some extremely harrowing stories about engine failure, etc. Every one of them.

It's not a game, and the FAA is really sleeping on the private sector as far as I understand. Its dying under bureaucracy.

To respond to the parent comment as well -- I don't think this is a 'Republican', 'Democrat', or even a 'Libertarian' issue. All three of those parties have weaknesses that tend to screw over this kind of organization -- the first two with extremely bloated processes, and the second with perhaps far-too-little regulation.

This is the kind of org that just needs good leadership with integrity and funding that focuses on getting the little guys up and out there, as well as promoting development and having _very strict_ best practices for safety. It's a very hard blend to do right, I think. Sorta a combination of reducing bloat and inferred/accidental corruption, etc, I think.

(not to get terribly political, I do not like politics at all personally. Just talking through the technical points of the matter as much as I can. Much love! <3 <3 <3 <3 :)))))) :D :D :)))))) )

ineedasername4• 3 years ago

must have something to do with how few people die in airplane crashes

Yes, at least somewhat:

1) The safety record of flying is often cited but that safety record pertains to commercial aircraft, not private aircraft. For hours of travel, private aircraft are significantly more lethal commercial flight and even more than driving [1]

2) The article mentions having to jump through regulatory hoops in the same sentence as literally putting out engine fires. Maybe the two are unrelated but I can see a strong public to regulatory hoops on something that, if done wrong, amounts to a small homemade fuel air bomb with 1,000lb+ of cessna debris added in to the mix if things go wrong.

[1]https://www.wijet.com/private-jet-crash-statistics/#:~:text=....

vkou• 3 years ago

My heart wants to agree with you but all those regulations must have something to do with how few people die in airplane crashes.

Very few people die in large commercial aviation crashes, but the hobbyist pilot space is a graveyard. ~400 deaths/year in the US, ~13 deaths/100M miles traveled. Meanwhile, commercial aviation is closer to 0.002 deaths/100M miles traveled.

Incidentally, the FAA rules around general aviation are a lot more relaxed than they are around commercial aviation. As a landlubber who occasionally spends a week geeking out about planes, but would never own one, their rules don't really seem to be ridiculous.

voldacar2• 3 years ago

You are demonstrating a lot of status-quo bias

rippercushions• 3 years ago

Obligatory link to why the FAA maybe should have a couple of special exceptions.

https://philip.greenspun.com/blog/2011/06/16/revitalizing-th...

rlpb2• 3 years ago

I had an engine failure the other day. Fortunately I managed to land safely. Turns out that the problem had been brewing for a while. A modern engine design would have told me about the failure before it happened. The 1970's engine design did not. Nor did the retrofitted modern engine monitor that was certified and bought at great expense.

The current certification regime makes aircraft more dangerous by preventing modern technology from reaching or replacing the current fleet.

stackedinserter• 3 years ago

There would be fewer crashes if FAA allowed us to fly modern planes instead of those relics from 60's

ck2• 3 years ago

Leaded fuel, leaded fuel fumes and spray.

Adapt the engines or ground them. There's no acceptable middle ground.

It's like secondhand smoke to the rest of the population.

No your "immune system" does not handle lead, it's forever and why it was banned in cars for 25 years

https://www.thedrive.com/news/42218/if-leaded-fuel-is-so-bad...

https://www.nbcnews.com/business/business-news/leaded-gas-wa...

jabl9• 3 years ago

The big news in the past decade or so in this space is the G100UL fuel which now has a STC for almost(?) all prop planes.

Not sure what the next step, regulation-wise, is. An official 100UL spec followed by the sunsetting of 100LL?

sand500• 3 years ago

The later is already happening as cities ban the sale of leaded fuel in their airport.

S2013• 3 years ago

Ah yes, here it is. I was looking for the "but leaded gas is going to kill us all!" comment in this thread.

First, the GA fleet worldwide uses 500 tons of lead per year. Compared to 5,000,000 tons when leaded car gas was in use. That's a 99% reduction in lead pollution, so let's not be so dramatic.

Second, unleaded avgas is here so even that 99% reduction is about to be 100%. G100UL is fully approved for the GA fleet and is in the process of being rolled out this year with more widespread adoption to be seen next year. If you're going to spout unfounded fears at least be up to the date on the facts.

https://gami.com/g100ul/g100ul.php

ahelwer2• 3 years ago

Okay, is unleaded avgas mandated? Is it dramatically more expensive than leaded? For how long should I look up and see a GA aircraft knowing it's some rich idiot spraying my neighborhood with lead?

kylecazar• 3 years ago

There must be something so incredibly gratifying about engineering a thing, and then successfully betting your life on the soundness of its design.

madrush20147• 3 years ago

When I did safety critical engineering, I was more concerned about the other person's life than my own. It's actually more scary than gratifying.

sfeng• 3 years ago

Tiny correction, it's not really true that an experimental can't land at a class bravo airport.

blantonl4• 3 years ago

There's really very little reason for a GA single piston aircraft to land at a Class B airport anyway.

sokoloff2• 3 years ago

I fairly regularly (several times per year) land our A36 at a class B airport: mostly BWI, PIT, and DTW. They are often the most convenient airport to access something downtown (such as a sporting event via public transport or a shorter Uber ride). Even our older 182 could blend in reasonably well speed-wise [though it often meant flying at full cruise power through much of the approach to keep the speed up to 135-140 KTAS].

selectodude3• 3 years ago

Landing at a class B airport is flipping cool, for one.

base6982• 3 years ago

I did it once at KLAS. Way closer to the hotel.

bombcar6• 3 years ago

Landing at a class bravo isn’t really anything special and some bravo airports are pretty small. It’s more about the airspace than the airport. Some bravo airports have heavy general aviation traffic. Others charge large landing fees.

And some airports aren’t technically “bravo” but the most common method of getting there involves transiting bravo airspace.

fijiaarone8• 3 years ago

The main reason someone flies a small single piston airplane anymore is to work towards their commercial rating. And practice in class B airspace is an important part of that.

inamberclad• 3 years ago

This is what we need to make GA an accessible hobby again.

rdl• 3 years ago

One of the biggest markets for small aviation engines which run on something other than 100LL is small drones — running on JP8, Jet A, or Jet A1 would make military logistics far easier and safer. Even road gas would be a reasonable alternative to 100LL, and both diesel/kerosene and gas are easier to find in the bush. Kerosene/diesel are probably better due to risk of water in the fuel at these places, but diesel engines tend to be heavier than gas.

Deltahawk, Thielert, etc are the bigger projects I’ve followed. Getting an actual certified engine is…hard.

sbierwagen• 3 years ago

The updated Predator drone uses a diesel aviation engine: https://en.wikipedia.org/wiki/Lycoming_DEL-120

w10-1• 3 years ago

This person lost a lot of credibility over decades of promoting corsair engines which failed.

Many people are complaining about the ancient technology, but newer ones offer very few advantages.

An piston GA airplane runs basically at two speeds: flat-out for take-off and cruise. For both the fuel/air mixture is easily optimized to optimal, and the slow engines reduce waste. Benefits from EFI are decent but below 10%. Supercharging helps a lot at higher altitudes, but most planes aren't pressurized or carry oxygen, so even that has limited benefit.

The main benefit of the current engines are robustness: I know people who have even flown without oil or with a blown valve. Many experimental builders combine mechanical magnetos with electronic ignitions, partly for fuel efficiency but mainly to lower idle speed on the runway when landing.

The real difficulty is not technology but service. There are very few engine rebuilders, and they are happy with the current limited supply of engines keeping prices up.

And unless you built your own experimental plane, or you get an experimental where the FAA permits owner inspections, the main cost of flying is service on the plane.

Aside 1: many engines have STC's to run car avgas. All require there to be NO ethanol for its impact on the fuel system. The studies I've seen of those engines report bottom rebuild times more like 800-1000 hours rather than 2,000 hours, and of course a higher incidence of valve-related problems.

Aside 2: experimental planes are not a subculture. They form the largest number of new planes. The $200K+ alternates only go to the wealthy. And after 50 years of competing companies, only one has been the overwhelming success, in both popularity and numbers: Van's aircraft. They use old-style, simple designs and construction, and (mostly) old-style engines, preferring the Rotax for their RV-12.

thescriptkiddie2• 3 years ago

One other very big advantage to a more modern engine design is the ability to potentially run on unleaded fuels.

S2013• 3 years ago

Unleaded avgas is now fully approved for the GA fleet with existing engines and is actively being rolled out this year with more widespread adoption next year. https://gami.com/g100ul/g100ul.php

crazygringo• 3 years ago

This person lost a lot of credibility over decades of promoting corsair engines which failed.

As someone not familiar, can you explain? How have those engines failed and how does that impact credibility regarding this, rather than just being something that didn't work out?

...but newer ones offer very few advantages.

From the article, it seems like cost is the biggest advantage (70% cheaper to run), followed by ease of use. And then of course the lack of toxic lead, although I don't know how to quantify that.

What am I missing?

You make a lot of points, but it's not immediately clear to me how they refute the article.

ominous_prime6• 3 years ago

The engines don’t require lead, it was just the only high octane fuel available. We do have a 100LL replacement now, and work is being done to get it into service. Lower compression engines run just fine on mogas where it’s available too.

Axien3• 3 years ago

The issue I have is why should an air cooled engine designed in the 50’s cost 30k to buy?

jcutrell2• 3 years ago

The very short answer is certification and what goes into the overall environment of certified aircraft.

darksaints• 3 years ago

I think that is just the reality of non-mass manufacturing. In the 50's those engines were going into production cars in the tens of thousands, or hundreds of thousands. Now they are produced in numbers of hundreds, maybe thousands, and as such they are hand-built specialty engines, even as primitive as they are.

LastTrain2• 3 years ago

9k for a rebuilt Toyota 2f designed in to 50s & meant for a measly ground vehicle. 30k seems about right for an airplane. What do you do for a living? Why don’t you do it for less?

AdrianB17• 3 years ago

Price gauging. Same for Rotax 912, the most popular small engine on planes that don't need certification (LSA/ULM) and they are 20,000 Euro for a 1.3 liter engine with an 100 HP output.

travisgriggs3• 3 years ago

I'm a fan of the Rotaxes. I fly one in our club's Tecnam. I prefer it over the old tractor engines that run the Piper I fly sometimes.

Curious if you have any thoughs on Sling for kit builds? I'm very serioulsy considering building their new HW (https://slingaircraft.com/aircraft/sling-hw/) that has the new Rotax 915 (turbocharged) in it in the next 12-18 months.

ominous_prime6• 3 years ago

You’ll be waiting longer than that for a Sling HW. It was nearly a 3 year waiting list when I ordered one last summer.

BuckyBeaver2• 3 years ago

Really? Electronic ignition and fuel injection alone are advantageous enough, not to mention the ability of at least one Rotax engine to use true automotive gas (gasohol).

As the article points out, the writing was on the wall for leaded fuel decades ago. The GA industry killed itself by dragging ass on eliminating the need for it, abetted by the burdensome FAA certification process for any aviation advancements.

It may be too late to save GA. BasicMed was a big help, and the increased pace of STC approval has been a boon. But with the FAA derelict in its duty to protect airports (see the sellout of Santa Monica as an example) and corrupt local governments eager to destroy our public airports and sell their land to developers... the future looks grim indeed. Just as electric training aircraft, unleaded fuel, and less-polluting and more-efficient engines render the anti-aviation cabal's excuses moot.

madrush20147• 3 years ago

I worked as a software engineer on the single engine "reboot" at Cessna in the mid '90s. At the time the company would pay for your private pilot's license, up to ATP cert IIRC. I knew a number of people who got their license that way. Cessna had a great ground school and a nice flying club with well-maintained planes. Ultimately, many of the people who got their license ended up not carrying on with flying. It is a very time consuming hobby and not really a practical mode of (even occasional) transportation. I now regret contributing to the single engine program (and the jets) due to the cost to the environment--I can't believe they still use leaded avgas. I read recently that private jets have at least an order of magnitude higher emissions per passenger mile than commercial.

AdrianB17• 3 years ago

Jets have a huge fuel consumption per passenger per mile; airliners have it lower because of the scale. GA is different, in some cases it takes less avgas to fly from A to B than driving a car. In my case, flying a Rotax 912 powered plane to my parents' house takes 2 hours and 30 liters of unleaded gas, driving takes 8-9 hours and 40 liters of Diesel, the environment is happier with me flying than driving.

madrush20147• 3 years ago

It was hard to find emissions data on the Rotax 912, from a Rotax support list [1]:

> I am looking for emissions data for the 912 iSc powerplant. I am in need of data regarding VOC and NO emissions.
I suspect you will have to measure this yourself. I cannot think of a reason why any user outside Rotax would know this, but good luck.

even harder to find emissions on an unknown road vehicle. Lead for autos was phased out in the US starting in the 1980s. I stopped using leaded gas my 1972 VW Beetle (designed to run leaded) in the late 80s. I know some piston A/C are running unleaded, but it is glacial progress compared to cars. Having been in the industry, I am well aware of the reasons (certification/safety requirements, politics and lobbyists). I just regret in my ignorance at the time I contributed to the problem.

(I would also assume you and your parents live next to airstrips, eliminating the need to get to one.)

I think our problem is more systemic. A better question than "Do I fly or drive?" might be "Why don't I live closer to my extended family and friends?"

In fact the computer industry uses more energy than the aviation industry [2]--cryptocurrency and AI are just going to add to it. When I design software, I try to keep efficiency and utility in mind--but the human mind is good at rationalizing what it needs to. Who needs software used to repair broken tech? Hopefully more people than need single engine aircraft or jets.

[1] https://www.rotax-owner.com/en/912is-technical-questions/653...

[2] https://dl.acm.org/doi/pdf/10.1145/3483410

BuckyBeaver2• 3 years ago

Leaded gas is on the (long overdue) way out, now that there's finally an unleaded option approved for the entire piston fleet.

A modern piston plane can get the equivalent of 30 MPG, and fly directly to its destination. So there's no need to rag on it.

madrush20147• 3 years ago

Except that to my knowledge (correct me if I'm wrong) they still have non-closed loop emissions--no catalytic converter or EGR--which would mean a brand new Rotax 912 would emit more NOx, CO, and VOCs than my 20 year old Mazda gas engine car. I feel like it is my right to "rag" on something which doesn't have to follow the same rules as I do.

To be fair, my neighbors probably emit 10X the pollution running their backpack-mounted, gas-powered leaf blowers and open fire pits year round. I rag on them too, and display my rake in protest.

fijiaarone8• 3 years ago

Save a dollar a gallon in gas for north of $100,000 in customization.

cpncrunch• 3 years ago

Is he even saving in gas vs simply paying the $360 for the autogas STC? And privately operated aircraft don't require engine TBOs to be respected. You can go as long as you want over TBO, completely legally. (At least in Canada, and I assume the FAA rules are the same). So, no need for an engine reserve.

nelox• 3 years ago

Would you put your daughter in an experimental aircraft?

dreamcompiler• 3 years ago

Go to Oshkosh some year. You'll see thousands of daughters flying experimental aircraft.

"Experimental" is a legal designation, not an evaluation of an aircraft's safety.

therockspush• 3 years ago

Having trained in some old 172s, I appreciate regulations that require updated weights and balances with a licensed mechanic when the owner does something like upgrading avionics. So I understand the cost of keeping those things airworthy.

But in my case, that same plane has a seat rail lock that fails during takeoff. Luckily I had an instructor with me who grabbed the yoke when I had to let go.

It's a weird world where you're confident to not rent a plane that will stall because of some aftermarket install, but you're on your own if that old seat fails.

watersb• 3 years ago

Impressive! My 1966 Cessna 172G could fly for a bit at $20/hour, but old engine and parts and stuff $65 / hour was more realistic.

concordDance2• 3 years ago

The misregulation of general aviation is absolutely infuriating.

Planes should cost 2-4 years average sallary, but stupid regulations prevent it.

Cardinal7167• 3 years ago

These LS swaps are getting out of hand!

Seriously tho, cool idea. I’m also shocked that leaded gas is still the norm. These LS engines (I’m guessing by the shape of the headers and the hint that it’s an aluminum block) are insanely reliable and I would put my life behind one of those before a lot of other engines. I’ve beat my own into the ground several times now.

doetoe• 3 years ago

I admit questioning the logic of bolting a V8 to a Cessna during that first takeoff, especially without a parachute.

Why wouldn't he just bring a parachute?

silexia• 3 years ago

The FAA and other government regulations mostly serve to inhibit innovation and life improvements and protect entrenched interests. Government regulations need a mechanism equivalent to bankruptcy...

The $20 an hour Cessna 172 experiment (2020)

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