motoadve wrote:Is it possible to compare privately owned single engine piston with commercial single engine piston?
To see if the extra requirements pay off?

So wondering if we can compare commercial piston vs private piston reliability record.

That looks like an interesting question. Unfortunately, as configured data from the existing survey won't offer insights on that topic since an unknown and unknowable number of respondents were operating under one or more of the commercial regulations, while an also unknown number of respondents were operating under Part 91 with no commercial purpose whatsoever.

Its been my experience that most flat piston aircraft engines are very reliable. I may have 5K hrs in piston powered aircraft and never experienced a mechanical failure to the point of not making a safe landing at an airport. Have had fuel issues and blown oil cooler gasket but no actual mechanical failures with one BIG exception. That was in the DC-3 which I had at least one shutdown a year over 5 years. That was a different category from the very reliable flat 4's and 6's.

Tom

colopilot wrote:Done.

The only issues I've had relate to pilot-induced intake or fuel management. Aborted T/O in a 172N because of a power dip on the roll which was my fault, but I stopped anyway just to be sure (counted as '0' in the survey because I technically never left the airport). I've also been a pax in a 310 when someone flipped a fuel selector the wrong way and made one side pretty quiet for a minute. And the occasional carb ice, though that's a rare problem here in CO where the air is so dry.

Barring outright manufacturer defect of parts, based on my informal reading of other pilots' experiences it seems like these engines generally run a very long time *provided you manage them appropriately*. Over-temp on the parts is an engine killer, and some people just suck at keeping things in the right temp range. Shock cooling can be a bad thing as well, though you have to try a fair bit harder to accomplish that. Proper periodic maintenance is also absolutely critical. Being smooth on the power and not abusing the thing tends to lead to many cases of engines going well past TBO with nary a glitch in flight.

I don't think the Kia comparison is generally fair either. The car will run 200k miles sure, but how much of that is at maximum horsepower near redline? My guess is a few percent at most. Our engines run in that regime almost all of their life across wide ambient temperature margins, and without the benefits of water cooling. Also if you figure 130kts cruise, 2000 hours is nearly 300k statute miles of distance flown. Of course we need to decrease that for time around an airport but still, say 250k miles for comparison? That's pretty good. You *will* replace something on that Kia motor in that time - alternators, radiators, injectors, these parts just wear out.

Do we accept higher risk in an airplane? Of course - you can't just pull over when something bad happens. Do I have qualms about putting my family in a well-maintained, regularly flown aircraft over the remote chance of a catastrophic engine failure? With proper risk management, not really.

Regarding your observation of my Kia analogy, I agree, and I have looked at the situation from that point of view also.

It also occurs to me that the replacement cost for a new O-360 such as I fly is more than the cost of a new BMW or MB, either of which makes more power and is much better equipped. If the engines were interchangeable, a pilot could buy the brand new high performance luxury car, throw away the car, and still have more power and save money.

This is just my way of saying our engines are too expensive for what they are.

For comparison purposes, you would need to then run an equivalent survey about automobile engines. I personally have never had an aircraft engine fail, but have had multiple failures in cars and motorcycles.

JP256 wrote:For comparison purposes, you would need to then run an equivalent survey about automobile engines. I personally have never had an aircraft engine fail, but have had multiple failures in cars and motorcycles.

I've only had one power failure and it was in the pattern. I think the reliability of our GA engines has room for improvement as with many things, but that doesn't mean they're unreliable per se. In fact, I find the reliability pretty impressive for what our standard engines are.

A tid bit off topic but worth mentioning on the note of auto engines... a couple acquaintances and I talked about auto engine reliability a while back. There are plenty of auto conversion aircraft. Some work great, some don't, but there's one auto conversion that stands out as it's own entity; Mazda rotary engines.

I'll admit, finding/making a good PSRU (prop speed reduction unit) is probably the biggest challenge for rotary conversion aircraft, but tons have done it, few have any major issues. The parts count of a Wankel engine, even including the planetary reduction drive, is immensely lower than that of the piston engines, plus, one of the most popular piston aircraft engine choices, Rotax of course, runs with a gearbox.

Rotaries have been making their way into aviation quietly and slowly, and proponents of the rotary claim it runs smoother, has a much better power to weight ratio, and a fuel consumption rate that has improved immensely over the many decades of research, machining, and material technology. Rotaries got a bad rap a while back especially with the apex seal reliability issue, and the housing chatter/wear problems, plus it's understandable that they're not the best candidate for cars. Although they have weakness on the road, they have strengths that shine in the air. Most of the "stereotypical rotary issues" such as the ones mentioned above have been solved with time over the past couple decades.

There are a couple companies working on rotaries for aircraft such as Mistral in Switzerland and Austro (Diamond aircraft) in Austria. The prices are a bit of a shock for now. I definitely understand those who wish to stick to what they know and love, and that is just fine with me. I've owned three piston powered aircraft and I don't have much to complain about (well, nothing serious/anyone else who owns a piston engine wouldn't also complain about ).

I recommend checking out some of the internet resources for aircraft rotaries if you are looking to kick the pistons and try something different and, believe it or not, relatively proven (compared to some other auto conversions). I know a few guys that have 1000s of hours behind rotaries and they're doing just fine. Care and feeding isn't too dissimilar to what we're used to.

Every engine's got it's pros and cons. I wouldn't hesitate to fly behind (or in front of) most standard GA engines, so long as the maintenance, love, and care is there. Neglect any engine and it's bound to bite you.

Sorry for rambling.

I wonder how the Porsche Mooneys held up?

As I recall by the time the FAA was satisfied with modifications any price/parts availablity advantage was negated.

Pragma wrote:

JP256 wrote:For comparison purposes, you would need to then run an equivalent survey about automobile engines. I personally have never had an aircraft engine fail, but have had multiple failures in cars and motorcycles.

I've only had one power failure and it was in the pattern. I think the reliability of our GA engines has room for improvement as with many things, but that doesn't mean they're unreliable per se. In fact, I find the reliability pretty impressive for what our standard engines are.

A tid bit off topic but worth mentioning on the note of auto engines... a couple acquaintances and I talked about auto engine reliability a while back. There are plenty of auto conversion aircraft. Some work great, some don't, but there's one auto conversion that stands out as it's own entity; Mazda rotary engines.

I'll admit, finding/making a good PSRU (prop speed reduction unit) is probably the biggest challenge for rotary conversion aircraft, but tons have done it, few have any major issues. The parts count of a Wankel engine, even including the planetary reduction drive, is immensely lower than that of the piston engines, plus, one of the most popular piston aircraft engine choices, Rotax of course, runs with a gearbox.

Rotaries have been making their way into aviation quietly and slowly, and proponents of the rotary claim it runs smoother, has a much better power to weight ratio, and a fuel consumption rate that has improved immensely over the many decades of research, machining, and material technology. Rotaries got a bad rap a while back especially with the apex seal reliability issue, and the housing chatter/wear problems, plus it's understandable that they're not the best candidate for cars. Although they have weakness on the road, they have strengths that shine in the air. Most of the "stereotypical rotary issues" such as the ones mentioned above have been solved with time over the past couple decades.

There are a couple companies working on rotaries for aircraft such as Mistral in Switzerland and Austro (Diamond aircraft) in Austria. The prices are a bit of a shock for now. I definitely understand those who wish to stick to what they know and love, and that is just fine with me. I've owned three piston powered aircraft and I don't have much to complain about (well, nothing serious/anyone else who owns a piston engine wouldn't also complain about ).

I recommend checking out some of the internet resources for aircraft rotaries if you are looking to kick the pistons and try something different and, believe it or not, relatively proven (compared to some other auto conversions). I know a few guys that have 1000s of hours behind rotaries and they're doing just fine. Care and feeding isn't too dissimilar to what we're used to.

Every engine's got it's pros and cons. I wouldn't hesitate to fly behind (or in front of) most standard GA engines, so long as the maintenance, love, and care is there. Neglect any engine and it's bound to bite you.

Sorry for rambling.

I had a 13B in a 1984 RX-7 GSL-SE. I LOVED THAT ENGINE! It was very smooth, made great power for the displacement, and was very reliable. I never once had a single problem with that engine (I understand that's a single data point) over the 100k or so miles I put on it. Drove it everywhere. Fuel mileage wasn't great though, and the best power was made at pretty high RPMs (~7k or so). I understand the fuel mileage issue has to do with the greater surface area to combustion chamber volume that a rotary has - something to do with cylinder wall cooling.

I saw a magazine article a long time ago where a guy put one in an RV-something and had great results. I haven't done the math to see what engine cruise RPMs would look like with a properly geared reduction drive and an adjustable prop.

I was curious what kind of power folks were making with them these days so I did a search and found a 13B with a street port, a GT35R turbo, and HKS ignition that made ~406 hp at the wheels at ~7250 RPM. It put down greater than 300 hp from ~5200 RPM, and greater than 200 hp from ~3600 RPM. What I haven't found is an accurate weight. I've seen ~390 lbs for the production twin-turbo engine with all accessories, but I'm sure pulling the heavy cast manifolds and production turbo plumbing for something custom-built would save quite a bit of weight, as well as dropping unneeded things like power steering pumps. But now you have to account for a PSRU. There's no free lunches, but it'd be an interesting analysis to look into as an alternate power-plant if you were considering going that route anyway.

Tried to fill out, keeps saying it wants a positive number. Can't beat it into submission.
Dave

Done,

Just the one, broken crankshaft on Lyc. 0-435 in a Stinson. Engine just made noise while on downwind to landing so I tightened up the turn and landed, rolled off the runway and shut it down.

I have had rough running from carb ice a few times but not that really resulted in power loss so I guess i have been lucky.

I have also had one prop strike but that was not "in flight" so does not count in this survey.

Just as a helpful backdrop, AVWEB published an article a while ago titled:

.
Bulletproof Engines: Are There Any?

Link: http://www.avweb.com/news/maint/best_aircraft_engines_208683-1.html

They loved :
1) Lycoming O-320-E2D
2) Lycoming IO-360-L2A
3) Lycoming O-360-A4M
4) Continental O-470

O-360-A4M

IMO, the reason car engines have more issues is because people keep screwing with designs, and people abuse them.

Some engines were just designed right. We have a few tractors that have over 10,000 hrs on them. Others barely make it out of the factory without issue.

My 172 has an O-320 E2D with 2300 hrs on it. To my knowledge, it has never had any major work done since the plane was made in 1969 (AD stuff was done of course). Compression is good, oil use is fine, and metal-in-oil checks are fine.

When I asked one of the big overhaul shops what they recommend about when to overhaul, they told me, "DON'T SCREW WITH IT. Whatever they did on that engine was done right. Unless it shows sign of wear, leave it alone."

I think GA engines spend more time under the microscope, and are "tweaked" less often, thus leading to a reliable record.

I think the costs are too high, though.

P.S. I am think about getting an EI monitor for my bird (good rebates right now). Gonna keep it even more under the microscope.

EDIT: BTW, I hate piston engines for aircraft and think turbines are a god-send.

ShadowAviator wrote:EDIT: BTW, I hate piston engines for aircraft and think turbines are a god-send.

As long as someone else is paying for the gas... LOL

Done. No loss of power here. When I bought my first 172 I did tons of research on the engine reliability of the different models which led me to purchase one with a Lycoming 0320 E2D. Never had an issue. Current plane has a Lycoming 0360 A1A. Also an engine with very good track record. FWIW I have done a lot of research myself on engine failures in piston powered aircraft and one thing that seems to always be a factor is hours on the engine, and frequency of use. Most engine failures caused by some mechanical breakdown (verses fuel starvation) happen in the first 300 hours of use. After that the failure rate goes way down. Also, it appears that the more you fly the better chances of having longevity in your power plant. Over and over again,...lack of use is not good for these things. The flying school where I got my ratings still has an old fleet of 172's that all have well over 15,000 hours on them with many rebuilds of course. They usually fly many times a week, year round. I have never heard of them experiencing a total engine failure in the 20 years I have been involved with them. Use it, or lose it.

JP256 wrote:

ShadowAviator wrote:EDIT: BTW, I hate piston engines for aircraft and think turbines are a god-send.

As long as someone else is paying for the gas... LOL

Well I am thinking you could rig up some smaller turbines.

What I was thinking of was like the Silver Eagle. It burns more fuel, but costs about the same since Jet A is cheaper (at least, from what I looked up). Amazing performance.

They are very expensive, though. But that may be more of a problem with aviation than the engines.

The new Jet A piston engines look kinda cool, though.

Crank shaft sheared in-half at 14,000' over central Utah in a IO-360-A1A in my Mooney (400 SMOH).

Survived and glided 15+ miles to Green River.

Replaced underwear and engine and flew the Mooney another 400+hours.

Be Safe !

How many 1970's cars do you see on the road?
How many 1970's Cessnas and Pipers do you see?

Thing is with aircraft engines is that when even a small problem happens it's a big deal, because we can't stop and deal with it.
When a car has trouble its rarely a big deal. And you can stop and deal with it.

Or maybe my view is bias because my job is fixing land vehicles, so I see a lot of broken cars.

just my 2 cents.

MountainFlyerN22 wrote:How many 1970's cars do you see on the road?
How many 1970's Cessnas and Pipers do you see?

I agree that GA piston engines are very reliable, but there's another factor to this observation:

there's a much larger market / demand for new cars and they're much more affordable than new airplanes. I think that has a much larger effect on the percentage of old vs. new cars when compared to old vs. new planes.