Piston engine reliability (questions for high time pilots and mechanics)

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Electric

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Electric
It seems like everyone that has more than 2000 hours in piston aircraft had at least one engine failure. Is that really the case?

I'm a fairly new pilot (170 hours) and it seems rather discouraging to know that if I plan on flying piston singles for a long time I should expect at least one deadstick landing in the future. Especially, considering that 1 out of 10 NTSB reports due to engine failure involves a fatality.

Would an engine that is well cared for vs the engine on a rental aircraft be significantly more reliable?

How well can you manage the risk of mechanical engine failure (not related to fuel starvation, contamination, vapor lock or induction icing, only talking bout mechanical failures.) during preflight or during maintenance?

Are those "mechanical" failures primarily due to negligence/poor maintenance, or its a truly random occurrence?

How helpful is mutli probe engine monitor in predicting otherwise unexpected power loss?

What can a renter (or perhaps an owner) do to significantly mitigate the risk of mechanical engine failure? (again talking about true mechanical failure, not fuel or induction icing related)

I don't mind taking risk, and I know that weather and stall/spin accidents take way more lives than engine failures. However, unlike stall/spin and weather accidents, engine failures can not be avoided by training; and at least at this point, to me engine failure seems like a random occurrence that is very likely to happen if you fly long enough. Which is why it's one of the very few things that makes me nervous. :)

Please advice, answers to the questions above would be appreciated, sorry for a long post.
 
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Well, I've had more than my fair share of failures, but that's an occupational risk when doing ferry pilot work since the plane typically has known problems which is why I'm being paid to fly it.

I have had 3 engine failures in my first plane due to defective oil hose fittings, a batch of 'black market' products it turned out. None of them resulted in a 'dead stick' landing and I had the engine shut down before loss of oil could do it any damage. I knew there was a reason I bought a twin when I had 60hrs and was looking for a plane, when I came out of the bottom of the clouds on an ILS approach at 90' with the runway right beneath me, I was reminded once again.
 
I have nearly 5000 hours and the closest I have had to a complete engine failure is when the towplane towing me had the throttle disconnect just after I released. The Tow pilot made a nice off airport landing with no damage. Fixed the throttle and flew it back to the airport. Of course nearly 1000 of my hours are in a sailplane. (~4000 hours single engine)
I probably deserve to have more failures I fly a lot of old airplanes and many of them quite old. But can't say that I have done anything in particular that has prevented me from having a serious mechanical failure.

Be prepared for, and practice engine failures. But I think you can fly a long time without an engine failure. But it only takes once to really ruin your day. I do simulated failures almost weekly and seem to average off airport landings in my sailplane about once per year.

Brian
CFIIG/ASEL
 
I've had one engine failure, a few little "snags" like bad alternators etc.

Turbines are a little less likely to have issues as they are (believe it or not) a more simple design.

The engine failure I had was on a babied aircraft, maintained with no cost spared, hangared, waxed etc. It had nothing to do with anything, just one of those things, chits happens.

I have flown piston aircraft across this continent a few times and felt very safe doing it.

In the end of the day you are going to die by getting hit by a bus, becoming a fat tub of lard and having a MI, or drowning in your bathtub, I wouldn't worry about aircraft engine failures in the grand scheme of things.

If you want to check stuff out, go have a beer and a long talk with the A&P IA that works on the plane you are flying, check the logs and the compression, see what was replaced and ask WHY and the big one........ready....USE COMMON SENSE.


ALSO remember this, dont let the age (or lack thereof) fool you, the age of a aircraft is irrelevant, it's the level of maintenance that makes the difference I would fly a 70yr old plane that is loved and cared for by diligent owner and a craftsman of an A&P well before I flew a 2012 plane that was looked after by a cheap owner and a hackjob A&P
 
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Also remember this and remember it well: The VAST majority of engine failures in an airplane are because there wasn't any gas getting to the engine. Most of the time this is due to bad fuel planning and running out of gas.
 
Electric said:
It seems like everyone that has more than 2000 hours in piston aircraft had at least one engine failure.
Click to expand...
I don't think there is a lot of truth in this statement unless one starts qualifying what is meant by a 'failure'.
I know of pilots with around 15,000 hrs in piston airplanes with no engine failures to talk about - and by failure I mean a real failure, not an engine 'failure' due to pilot's mismanagement (lack of fuel, illegal 'repairs', unapproved modifications, disregarding obvious signs of trouble way before, etc.). You are like 50 times more likely to die because of your own shortcomings as a pilot (poor decisions, poor piloting skills, etc.) than due to any mechanical malfunctions.

Those exceedingly rare power-plant failures were usually caused by improper maintenance. I was reading recently of an engine failure due to improperly torqued bolts/nuts holding one of the cylinders during an overhaul.
 
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Original post: The reliability of piston engines in the Robinson fleet almost
matches that of turbines. IIRC; both were in the range of ~425,000 hours
between precautionary landings/shutdowns.
 
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Two failures in 850 hrs, both on the runway on take off. Muffler internals had failed and a piece of the internals intermittently covered the muffler outlet. A mud dauber nest inside the SCAT tube between the carb heat box and the carb came loose and got sucked into the carb throat.
 
Electric:
First, you are the weak link in the plane, not the engine...
Second, I'm not sure you are cut out for being a pilot - that is a whole lot of fear I'm smelling..

Aircraft piston engines are as reliable as we can make them, with a 100 years of experience, detailed record keeping, boards of inquiry when they do fail, and directives from the FAA for correcting identified problems... Maintained by a competent mechanic they are vastly more reliable than the pilot...
 
Without reading the entire thread first noticing everyone already said what I wanted to say, I feel that aircraft piston engines are just as reliable as the one in your car. The same failures that happen in your car can happen in a plane. Granted, the plane is a little more meticulously maintained than your car (in most cases). Just like in a car, rods and bearings can fail, filters can get clogged, fuel lines can break, electrical flukes can happen, sensors can malfunction, etc.

Now, let me read the thread and see how wrong I am.

Edit: The only thing I wanted to add is someone mentioning it's only as reliable as how well the plane is maintained. This is true. My old '88 325is with 235,657 miles on it ran like a top while my Mom's '98 Chevy Lumina with barely 100,xxx on the clock made all sorts of noise. I took super good care of my 325is and only ever had it fail on me once because the fuel pump just couldn't do it anymore. I didn't even see it coming.

I wouldn't sit and worry about if your engine is going to fail. If it happens, it happens and you just have to keep flying the plane.
 
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Never understood pilots that fixate on reading NTSB reports and worrying about flying, yet 50,000 people a year are killed driving and they don't read those accident reports at all. :dunno:

Running out of fuel is the number one cause of "engine failure". Eliminate that issue by not running out of fuel and you have a better than average chance of never having a problem. Don't fly junk and planes with timed out engines.
 
I've had a few mag failures that resulted in very reduced power.

I've had had one catastrophic engine failure (valve froze then broke off and bounced around in the cylinder blowing a hole in the top of the piston).
 
I have a little over 2500 hours and have had a couple engine problems. The one I puckered the most at was a 172 which had a cracked intake manifold runner, this caused a lean situation in one of the cylinders, it eventually froze which destroyed the cylinder and caused me to end my flight early. I've had turbos go out on me, mags, and one precautionary shutdown. I only have around 1500 piston time or so.
 
In 1800 hours flying my aircraft I've had 3 electrical failures, One at night, one in actual IFR, and one in the pattern at my home base. I have also had just about all the gauges and avionics failed over the years. In a rental plane I had a gear failure and an electrical failure. I was flying a friends 182 when the prop seal went out and sprayed oil all over the windshield at night and in actual (had to land looking out the side window). But I've NEVER had an ENGINE FAILURE!
 
Dr. O said:
Electric:
First, you are the weak link in the plane, not the engine...
Second, I'm not sure you are cut out for being a pilot - that is a whole lot of fear I'm smelling..
Click to expand...

I agree. Anyone who is smart enough to ask a question about how to mitigate risk of the mechanical aspects of a plane that is not covered in preflight, is way to smart to be cut out for being a pilot.

P.S. The quoted post might be the stupidest thing I have yet to read on these boards.
 
Dr. O said:
Graueradler's post is a case in point... Both problems were maintenance failures, not engine failures...
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In what normal maintenance activity should they have been discovered? The muffler internals were as brittle as glass. Sticking a broom handle into the exhaust of the removed muffler against the internals and hitting it with a hammer resulted in the internals shattering like glass. Broken condition would not necessarily have existed or been detectable by normal inspection during annual. Mud dauber nests can be built rapidly and the insides of the SCAT hose between the carb heat box and carb are not a normal pre-flight check list item. It would require removal of the cowl and dis-assembly of the carb intake system to discover. Sequence seems to have been that the nest came loose and slid onto the carb heat valve during runup and then got sucked up into the carb on take off roll. Some later Piper Carb heat boxes had a screen installed over the air inlet to keep insects and other foreign object out.

Just about any engine (or other) mechanical or electrical failure is going to result from an undetected maintenance condition. Some are easier to detect than others. Ones that should have been detected and weren't are maintenance failures.

"And that's all I'm going to say about that"
 
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Electric said:
It seems like everyone that has more than 2000 hours in piston aircraft had at least one engine failure. Is that really the case?
Click to expand...

3300 hours. 35 years. No mechanical engine failures. (They won't run when the fuel tanks are full of air) There are no guarantees. Brand new engines can fail too.
 
Dr. O said:
Electric:
First, you are the weak link in the plane, not the engine...
Second, I'm not sure you are cut out for being a pilot - that is a whole lot of fear I'm smelling..

Aircraft piston engines are as reliable as we can make them, with a 100 years of experience, detailed record keeping, boards of inquiry when they do fail, and directives from the FAA for correcting identified problems... Maintained by a competent mechanic they are vastly more reliable than the pilot...
Click to expand...

I'm not so sure I would go that far until we get FADEC (electronic injection and ignition) out in the fleet. We eliminated points and mechanical injection/carbs from autos decades ago. Our fuel economy increased and our maintenance has dropped to next to nothing while the longevity of engines has nearly doubled. This is because the engine now gets exactly the fuel and ignition timing it needs to run exactly as it should at all times. This prevents stuck and burned valves as well as detonation and a half a dozen other issues which lead to failure. With a back up electrical system FADEC will considerably reduce the cost of engine maintenance between overhauls including virtually eliminating cylinder replacements and valve work, extend time between overhauls, and seriously cut down of fuel consumption and CHT related issues.
 
Guys I would take another approach.
The fatalatiy rate per 100,000 miles is ten times that of the automobile. However:
1/3 is ran it out of gas
1/3 is weather that you were not equipped nor qualified for.
~1/4 is cocamamie stuff you can eliminate on preflight.

Do the math. This can be as safe as an automobile, if you make it so.
 
bbchien said:
Guys I would take another approach.
The fatalatiy rate per 100,000 miles is ten times that of the automobile.
Click to expand...

While I am for anything I can do to make it safer, 10X that of an automobile is still pretty damn safe.
 
At one time the industry published statistics showing the interval of engine failure likelihood to be more than 100k hours. I have no idea of the who-what-where origins, but always figured it didn't matter anyway. If it quits, you may have some extra work to do. Or not.

MX may matter, may not. Our bought-new-meticulously-maitained 1987 Malibu suffered a crankshaft failure in flight at FL250. He made a ho-hum dead-stick onto an airport and caught a ride to the FBO on the fire truck.

In ~9k piston hours I've had a few that told me they weren't happy and might quit soon, but none that actually gave me the silent treatment.
 
Geico266 said:
Don't fly junk and planes with timed out engines.
Click to expand...

Hey there. I'm new and often don't understand a lot of abbreviations and lingo. You guys mind if I ask what exactly is meant by "timed out engine"?
 
rainsux said:
Original post: The reliability of piston engines in the Robinson fleet almost
matches that of turbines. IIRC; both were in the range of ~425,000 hours
between precautionary landings/shutdowns.
Click to expand...

Good to bring this up, but Robinson's engines are derated (MP restricted) and under a bit less stress than those installed in fixed wing a/c, believe it or not. The R-22's in particular have had their "moments", but engine reliability is enviable. People who abuse the restriction usually see transmission problems before any engine issues arise (which, unfortunately, is potentially far more serious than an engine problem). Theoretically there would be blade issues as well, but the Robinson blade problems are unrelated to excess power, it seems.

The latest 0-360's and 540's used in R-22's and 44's are specially built and not rated for the same hp as their fixed-wing variants (lighter internals to save weight). Even so, they're derated below this lesser value.
 
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ATL-Steve said:
Hey there. I'm new and often don't understand a lot of abbreviations and lingo. You guys mind if I ask what exactly is meant by "timed out engine"?
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Engines are rated with a TBO or Time Between Overhauls rated in both hours of operation as well as years in service, for example a Lycoming O-320 as is likely in the plane you fly for training has a 2000 hour and/or 12 year TBO.

If one is operating in commercial service such as under Part 135 of the FARs, these numbers are required to be adhered to. Under non commercial rules we typically operate under, Part 91, these are viewed as suggested limits.

For what it's worth, I don't necessarily prescribe my actions on an engine by TBO values, rather I monitor condition through oil analysis and other visual/physical inspections as well as general operating conditions of the engine. I have found engines can run well past TBO and fail far short of TBO. The TBO method was instilled long before modern methods of condition monitoring became generally available.
 
I think I have about 7,000 piston hours and only one complete engine failure, which was in a twin. I was able to get it restarted and no one could figure out what caused it, which was not exactly reassuring. The speculation was that something was caught in the fuel vent and when I turned on the high boost pump it was dislodged somehow. I've had a handful of other instances of partial power loss in piston singles due to things such as bad turbos, fractured rocker arm bracket, collapsed air intake hose, etc.

I've had another 6,000 hours of turbine time and no instances of total engine failure. I've voluntarily reduced the power a couple times. One was due to a thrust reverser unlock warning and another was due to a bleed air leak causing a false fire warning.
 
ATL-Steve said:
Hey there. I'm new and often don't understand a lot of abbreviations and lingo. You guys mind if I ask what exactly is meant by "timed out engine"?
Click to expand...


Welcome to POA. :cheers:

No such thing as a dumb question, just dumb answers! :rofl:
 
I have had one engine problem (not failure) that required shutting down the engine and feathering the prop, and it was related to turbocharger plumbing, not the engine itself...the engine was running, but not getting any boost. In 7500 hours I had never had a piston engine actually fail. So, in my experience, your statement is fallacious.

The most common cause of engine stoppage is fuel exhaustion or fuel starvation...both within the means of the pilot to correct. The number of folks who think that engines will burn air is an embarrassment to us all.

Bob Gardner
 
A couple things. Some are repeats.

A lot of failures were easy to prevent - don't run out of gas.

At least some failures can be attributed to poor / deferred maintenance or airplanes that just shouldn't have been flown (You have seen those - don't be that guy.)

1 out of 10 results in a fatality? That is an absurdly poor result. Look at the fatality rate for engine out landings (even off field landings) in gliders. Purd near zero in comparison. Obviously pilot capability and being prepared makes a difference. So even if engine failures may not be prevented by training, the end result is. And that is what you want to focus on.
 
Geico266 said:
Never understood pilots that fixate on reading NTSB reports and worrying about flying, yet 50,000 people a year are killed driving and they don't read those accident reports at all. :dunno:
Click to expand...

Pilots are VASTLY more likely to be killed in an airplane than a car. Of the people I have known, only one has been killed in a car. I remember at least 30 pilots, who I have met and talked with, who were killed in airplanes.

That's why pilots read NTSB reports.
 
kgruber said:
Pilots are VASTLY more likely to be killed in an airplane than a car. Of the people I know, only one has been killed in a car. I remember at least 30 pilots, who I have met and talked with, who were killed in airplanes.

That's why pilots read NTSB reports.
Click to expand...

Wow, my experience is opposite. I have only one personal aquaintence that was killed in a plane (airshow accident) but I know a couple dozen people that have been killed in car accidents.
 
Graueradler said:
In what normal maintenance activity should they have been discovered? The muffler internals were as brittle as glass. Sticking a broom handle into the exhaust of the removed muffler against the internals and hitting it with a hammer resulted in the internals shattering like glass. Broken condition would not necessarily have existed or been detectable by normal inspection during annual. Mud dauber nests can be built rapidly and the insides of the SCAT hose between the carb heat box and carb are not a normal pre-flight check list item. It would require removal of the cowl and dis-assembly of the carb intake system to discover. Sequence seems to have been that the nest came loose and slid onto the carb heat valve during runup and then got sucked up into the carb on take off roll. Some later Piper Carb heat boxes had a screen installed over the air inlet to keep insects and other foreign object out.

Just about any engine (or other) mechanical or electrical failure is going to result from an undetected maintenance condition. Some are easier to detect than others. Ones that should have been detected and weren't are maintenance failures.

"And that's all I'm going to say about that"
Click to expand...

The SCAT tubing with the mud dauber nest is going to fail the crankshaft at overhaul. If the system has big enough holes for a wasp to enter, it has big enough holes for gritty contamination to enter. That condition should have been caught on previous annuals.
 
rainsux said:
Original post: The reliability of piston engines in the Robinson fleet almost
matches that of turbines. IIRC; both were in the range of ~425,000 hours
between precautionary landings/shutdowns.
Click to expand...

Now lets hear the average maintenance per flight hour.........
 
kgruber said:
Pilots are VASTLY more likely to be killed in an airplane than a car. Of the people I have known, only one has been killed in a car. I remember at least 30 pilots, who I have met and talked with, who were killed in airplanes.

That's why pilots read NTSB reports.
Click to expand...

I haven't lost 30 people I know, and I have 3 tours to afghanistan under my belt. I think either you hang out at the wrong places, or your numbers are growing with your age,
 
kgruber said:
Pilots are VASTLY more likely to be killed in an airplane than a car. Of the people I have known, only one has been killed in a car. I remember at least 30 pilots, who I have met and talked with, who were killed in airplanes.

That's why pilots read NTSB reports.
Click to expand...

Stay on the ground and read all the reports you want. :rolleyes:


Do you really think you are a safer pilot reading those reports? :no:
 
kgruber said:
Pilots are VASTLY more likely to be killed in an airplane than a car. Of the people I have known, only one has been killed in a car. I remember at least 30 pilots, who I have met and talked with, who were killed in airplanes.

That's why pilots read NTSB reports.
Click to expand...

Ticking off the list of instructors from Seattle flight who went west?

Bob Gardner
 
bobmrg said:
Ticking off the list of instructors from Seattle flight who went west?

Bob Gardner
Click to expand...

Yes, they come to mind. Plus, numerous pilots at Kenmore Air Harbor. And, Dr. Callison, my friend and AME.
 
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I haven't lost 30 people I know, and I have 3 tours to afghanistan under my belt. I think either you hang out at the wrong places, or your numbers are growing with your age,
Click to expand...

I've been in Afghanistan (and Iraq) for the past five years, and know a lot more dead pilots than that...not from any action in either of those places.

Numbers certainly grow with age; the longer one is in the business, the more dead pilots one may come to know. The list of just those killed firefighting is long, and I know a number of others from many different segments of the industry who have perished doing what they loved, and some who passed on outside of work, too.

As for engine failures, I believe its ten in light piston airplanes, with about 30 or so over the years in larger radial powered aircraft. One year in heavy tankers saw five engine failures in four months, all catastrophic, requiring a shut down, or shutting themselves down. It happens.

I've had TPE-331 and PT6A turboprops fail as well, and have had to shut down turbojet and turbofan engines, albeit precautionary shutdowns.

Most engine failures that one experiences are not necessarily complete shutdowns. A partial power loss is also an engine failure.

My last engine failure in a piston airplane was in a Skymaster, involving loss of oil pressure in the fear engine (accompanying loss of all oil), and a subsequent shutdown. It resulted in an uneventful return to land.

Most of the engine failures and power losses I've experienced have not resulted in off-field landings, and in many cases, power was recovered prior to landing. In one particular case in a Cessna 182, carburetor ice occurred rapidly, causing a power loss and engine failure. When I applied carburetor heat, the carb heat control failed at the carb air box, and I was unable to restore power. That occurred in instrument conditions, and resulted in a dead stick landing on some gravel. Most other occurrences have been not nearly so interesting, and ranged from fuel flow fluctuation (Cessna 206) to mag failure to lifted cylinder heads, failed governors or loss of oil, etc.

Some environments are more demanding on equipment than others (reflected in lower TBO's for the equipment, and additional inspection requirements or more frequent component/airframe overhaul replacement times). In such cases, one might expect higher incidences of power troubles. It happens.
 
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