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Author Topic: Is an engine reliabilty really good, or is it a myth?  (Read 7089 times)

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Al Gilson

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Re: Is an engine reliabilty really good, or is it a myth?
« Reply #15 on: January 27, 2015, 06:26:58 PM »
Done.

Al (Why is it quiet all of a a sudden?) Gilson
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Klaus

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Re: Is an engine reliabilty really good, or is it a myth?
« Reply #16 on: January 28, 2015, 03:00:35 PM »
Avweb just released this video:

How Lycoming Builds Aircraft Engines
Klaus Marx
Juneau, AK (PAJN) & East Wenatchee, WA (KEAT)

will moffitt

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Re: Is an engine reliabilty really good, or is it a myth?
« Reply #17 on: January 28, 2015, 03:13:18 PM »
great vid, thanks

will

HalfFullGlass

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Re: Is an engine reliabilty really good, or is it a myth?
« Reply #18 on: January 29, 2015, 11:11:12 AM »
Avweb just released this video:

How Lycoming Builds Aircraft Engines


This video is really very interesting.  With total volumes of 1500 engines per year, and with some engine runs of exactly ONE product this is an incredible process. 

It would be interesting to look at the reliability and 'manufacturing error stats of the older "large" product runs with these essentially one of a kind products and only slightly larger miniscule builds.  While having the specs in front of operators is helpful, I'm sure, the shear variability inherent in the operation seems like an area rich with opportunity for error.

I guess that's one of the unspoken of hazards of GA...  nearly everything in an airplane (even one that is factory built) has elements of a custom product.

 

HalfFullGlass

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Re: Is an engine reliabilty really good, or is it a myth?
« Reply #19 on: February 08, 2015, 02:26:25 PM »
First, I want to thank the 340 pilots from this and other venues who have shared their experience in the engine failure survey.  The results are starting to firm up.  If anyone on forum hasn't taken 5 minutes to respond to the four simple question, please do!  You might also copy the link and email it to pilot friends who don't participate on this forum.

FWIW, the National Transportation Safety Board reports that in 2012 loss of power was the second highest cause of accidents. Take a look at the part 91 graphic in the 2012 report titled "Defining Event for Personal Flying Accidents" posted under Data and Stats on the National Transportation Safety Board website at   http://www.ntsb.gov/investigations/d...20Summary.aspx 

I think we can agree that accident numbers and rates differ from the number of engine failures and the rate at which they occur. Accidents with a root cause of engine failure are a subset of all loss of power events. The estimate of all power loss events (from any reason) is a more interesting number than the number of reported accidents. Why? Because comparing known accident numbers to the ratio of non-event outcomes indicated by pilots who take the survey suggests how important pilot proficiency AND luck are in the outcome! GA SE FW piston engine events that make it into the NTSB db all involve major damage, serious injuries, or fatalities. This is very serious stuff!! BUT, all hazards considered, what is the real risk of an engine failure? I dunno, and it doesn't appear that anyone else does either. Indications from surveyed pilots pretty clearly suggests that proficiency and a little luck means engine failure does not equate to 'accident'. Now this is useful information, doncha think?!

To participate in the survey, please visit:   https://www.surveymonkey.com/s/CCXT8XF

Keith E Besherse

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Re: Is an engine reliabilty really good, or is it a myth?
« Reply #20 on: February 09, 2015, 11:35:05 AM »
JT,
Yes, the disconnect between incident and accident reporting means that we really don't know what the statistical outcome of most non-planned aviation events.  Some small issue occurs, the pilot responds (appropriately) and everyone's day continues, the outcome is a non-event.  = a good day flying! 
(The holes in the swiss cheese didn't line up.  Or stated more positively, the next layer of cheese prevented the hole from being a passage all the way to impact with a solid object.)
Only when an accident results from the non-planned event do we get reports which are filed and available for statistical analysis.
I did not participate in your survey only because I have no FW time...
Good luck with your analysis.  Very useful stuff indeed.
KeB

114SM

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Re: Is an engine reliabilty really good, or is it a myth?
« Reply #21 on: February 09, 2015, 11:14:31 PM »
Good example is how was the Cirrus ditching off OGG that was so widely publicized categorized? Yes his engine failed, but it wasnt because of his fault or the engine. It ran out of gas because the ferry tank transfer system failed. Yes our wonderful media played the video over and over because they were hoping for doom and gloom and death, but the pilot thankfully survived by his calm demeanor, probably a good BAS system and the coast guard. A $500,000 plane sank to the bottom of the pacific, but the pilot survived.

So was it counted as a engine failure or.........?

BoyScout

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Re: Is an engine reliabilty really good, or is it a myth?
« Reply #22 on: February 22, 2015, 09:34:43 PM »
In February I will speak about engine failures and emergency procedures during a seminar at the Northwest Aviation Conference in Puyallup, WA.  I need your help!  Would you invest just 5 minutes and complete the linked survey?

Great presentation John!  You had quite the crowd!

Sector95

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Re: Is an engine reliabilty really good, or is it a myth?
« Reply #23 on: February 23, 2015, 10:51:33 AM »
I'm curious, what did the results of the survey ultimately indicate?

hotrod180

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Re: Is an engine reliabilty really good, or is it a myth?
« Reply #24 on: February 23, 2015, 07:47:47 PM »
I'm curious, what did the results of the survey ultimately indicate?

Engines fail sometimes.

Sector95

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Re: Is an engine reliabilty really good, or is it a myth?
« Reply #25 on: February 24, 2015, 09:12:21 AM »
Engines fail sometimes.

Good 'ol quantitative analysis... :)

N804RV

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Re: Is an engine reliabilty really good, or is it a myth?
« Reply #26 on: February 25, 2015, 08:24:04 PM »
Engines fail sometimes.

Good 'ol quantitative analysis... :)

Sounds more fundamental than quant. ;)
« Last Edit: February 25, 2015, 08:54:11 PM by N804RV »
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HalfFullGlass

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Re: Is an engine reliabilty really good, or is it a myth?
« Reply #27 on: February 26, 2015, 09:33:14 AM »
I'm curious, what did the results of the survey ultimately indicate?

The survey is still open and accumulating data.  it will remain available to pilots who have not previously responded through March. 

See:  https://www.surveymonkey.com/s/XPYHMYD

When I presented at the NWAC the data set included 407 pilots.  About 20% of survey respondents had experienced 1 or more complete engine failures that required a forced landing on/off airport (N=81 pilots, complete engine failures = 99); about 1/3 of respondents had experienced 1 or more partial engine failures that required a precautionary/forced landing on/off airport (N=120 pilots, partial engine failures = 154). 

Of the complete engine failures, about 18% (N=18) resulted in an accident, and about 15% (N=15) resulted in an incident.  A "complete" engine failure for the purposes of this survey meant any time the engine ceased operation for ANY reason, the problem could not be resolved in the air, and the result was a forced landing on or off an airport.

Of the partial engine failures, about 3% (N=5) resulted in an accident, and about 3% (N=5) resulted in an incident.  A "partial" engine meant any uncommanded reduction in power that resulted in a precautionary or forced landing, either on or off an airport.

Keep in mind this is NOT a random sample of pilots.  The numbers are indications of trends, but they are NOT suitable for statistical inferences!  None-the-less, the numbers suggest that the NTSB accident data base is a very imperfect predictor of the actual number of engine failures in FB FW SE PP aircraft. 

Some of the 'warts' that must be kept in mind are: 
==Dead pilots don't respond to surveys (about 12-14% of engine failures reported by the NTSB involve fatalities... therefore the potential respondent population is understated a bit). 
==Survey respondents are self selected.  This might over represent individuals who have experienced engine failure (it IS something that is a memorable life event) by an unknown amount... conversely persons who have had an engine failure that didn't result in either accident or incident might decline to participate because of any number of concerns.  Pilots who have never experienced an engine failure may or may not be proportionally represented. 
==Respondents may be drawn from regions of the country where engine failures are frequent, or the converse might be true...  So take the numbers with a grain of salt.

The take home messages are these: 

--FB SE FW PP aircraft have more engine issues than the myth of reliability would lead us to believe.
--KNOW your emergency procedures!
--PRACTICE your emergency procedures!
--EXPECT the engine to fail at critical stages (during take off, while on approach or in the pattern, at night, in IMC, over water, over inhospitable terrain, etc.)
--KNOW where you will put the airplane at all times should your powerplant become a house plant.

and enjoy your time in the air...
« Last Edit: February 26, 2015, 09:38:27 AM by jtownsley »

HalfFullGlass

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Re: Is an engine reliabilty really good, or is it a myth?
« Reply #28 on: February 26, 2015, 09:45:48 AM »
Good example is how was the Cirrus ditching off OGG that was so widely publicized categorized? Yes his engine failed, but it wasnt because of his fault or the engine. It ran out of gas because the ferry tank transfer system failed.

So was it counted as a engine failure or.........?

ANY time the engine fails and a precautionary or forced landing ensues it's an emergency that requires pretty much the same pilot performance.  Forced landings are forced landings, regardless of cause.  Ditto for precautionary landings.

HalfFullGlass

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Re: Is an engine reliabilty really good, or is it a myth?
« Reply #29 on: August 30, 2016, 09:27:24 AM »
18 months ago I posted a survey on engine failure that generated quite a bit of interest.  I used that data in several safety seminars, including a talk on emergency procedures at the 2015 Northwest Aviation Conference held in Puyallup, WA.  Ultimately 420 pilots from this and other online forums contributed their experiences. 

I'm preparing for another series of talks so decided to re-release the survey.  Over 500 pilots have now contributed their experiences to the data set.  As the data set has expanded it includes more low time pilots, and some very high time pilots who have never experienced a powerplant malfunction (i.e. engine failure) that required either an off airport landing or an unplanned landing at an airport.

Two important take-away messages from the data set are fairly constant:

1) In most cases even complete loss of power does not result in either an NTSB accident or an FAA 'incident'.  For those pilots who report having experienced a complete engine failure FOR ANY REASON, only about 1/5 reported the outcome was an accident.  About another 1/6 reported the outcome was an FAA 'incident'.  Engine failures were reported by very high time pilots, and by pilots with fewer than 100 hours.  Most pilots probably won't exercise their emergency procedures under the 'real thing'... but then again... We'll lnever know if this flight - or the next - will be "it!"

Bottom line:  Proficient and prepared pilots are well equipped to minimize bad outcomes.  A high percentage, perhaps as many as 2/3 of complete power loss events in SE FW PistonPowered FactoryBuilt aircraft come through with minimal or no damage.

The take home messages: 
==>Powerplant malfunctions (aka "engine failure) can happen to a new pilot or a hoary old veteran with thousands of hours.
==>Know emergency procedures.  Periodically review them. 
==>Listen to your engine.
==>Powerplants fail for a lot of reasons.
==>Know your aircraft's best glide performance.
==>Practice slow flight.
==>Fly the airplane (Stalls are really, really bad medicine!).

2) A relatively high number of pilots (a large minority of respondents) have experienced one or more partial engine failures (resulting FROM MANY REASONS).  Of these pilots, only about 5% reported an NTSB accident, and another 3% or so reported an FAA 'incident'. 

Take home messages: 
==>See No. 1, above. 
==>Plus:  Power (even minimal power) equals options. 
==>AND fly the airplane!!  DO NOT STALL!

If you've not previously responded to the survey send me a PM and I'll send you the link.  I'm not reposting the link here since I need to minimize the potential for double responses.

PM me if you'd like to discuss the survey.
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