An Engine Failure a day...

Challenged

Challenged

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Challenged
April 25th: Cessna 152 in Alabama
April 26th: Yak52 in Oregon (Serious)
April 27th: Kitfox V in Michigan (Fatal)
April 28th: Piper PA28R in Georgia (Fatal)
April 29th: Grumman G164C in California

As much as we post accidents here, I guess I didn't anticipate there to be an engine failure every day (at least that's how it seems from looking at the past week). It seems like a lot, but if there are actually 27,178 GA flights per day, the chance of one of these planes having an engine failure on any given flight would be 0.0036%. I also find it interesting that according to that site, GA has nearly as many flights per day as commercial and regional airlines.
 
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Keep in mind most of the time an engine failure on a Twin is unreported since it doesn’t end in an NTSB report.
 
27,178? I never would have thought that. Wonder when that data was collected?
 
Let'sgoflying! said:
jeez I thought you were having one per day.
I was going to suggest taking up soaring.
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I'd say that if Challenged was personally having one engine failure a day, he was already a fully qualified glider pilot.
And he should by a lottery ticket, if for no other reason than to pay his "luck tax".
 
Topper said:
I would bet the odds are even lower for those of us that properly maintain our engines, get it checked when it sounds/acts funny and keep a little extra fuel in the tank.
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I shut down an engine that had less than 10 hours on it due to loss of oil pressure.
 
Shepherd said:
I'd say that if Challenged was personally having one engine failure a day, he was already a fully qualified glider pilot.
And he should by a lottery ticket, if for no other reason than to pay his "luck tax".
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Hoover had some stories of having multiple per day when he was flying freshly “assembled” aircraft shipped over for the war effort.

YMMV on how embellished that may have been or not, but he certainly understood energy management and crash management.
 
I've had a lot of engine failures over the years, but that's due to ferrying some really sketchy aircraft.
My record is five engine failures on one plane on a single 2 hour "flight". I never made it out of the pattern, and after two additional trips around the patch, never going below 1200 rpm, we parked the plane for the winter.
It's still in the hanger, and they are still working on it to get it to run reliably.
 
Ted DuPuis said:
Keep in mind most of the time an engine failure on a Twin is unreported since it doesn’t end in an NTSB report.
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There are also unreported single failures too. If it doesn't end in a crash, or declared emergency, no report. I don't think anybody should kid themselves. These "dirt simple tractor motors" fail a lot and I don't think the rates will be going down until we stop using the piston engine for flight.
 
Challenged said:
April 25th: Cessna 152 in Alabama
April 26th: Yak52 in Oregon (Serious)
April 27th: Kitfox V in Michigan (Fatal)
April 28th: Piper PA28R in Georgia (Fatal)
April 29th: Grumman G164C in California

As much as we post accidents here, I guess I didn't anticipate there to be an engine failure every day (at least that's how it seems from looking at the past week). It seems like a lot, but if there are actually 27,178 GA flights per day, the chance of one of these planes having an engine failure on any given flight would be 0.00003%. I also find it interesting that according to that site, GA has nearly as many flights per day as commercial and regional airlines.
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Bad math! 1 in 27,178 would round to 0.0004, which is 0.04%

FAA’s Part 91, roughly, standard for reliability is 1 in a million, or 0.000001, or 0.0001%. There are of course aggregate exposures in an engine system...

Paul
 
Nice catch Paul, I was testing you..you passed. Wait. 1/27178 = 0.000036794, would be 0.004%, no? Honestly I sort of question these percentages. Has there been a poll on PoA about how many of us have suffered an engine failure?
 
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Dav8or said:
There are also unreported single failures too. If it doesn't end in a crash, or declared emergency, no report. I don't think anybody should kid themselves. These "dirt simple tractor motors" fail a lot and I don't think the rates will be going down until we stop using the piston engine for flight.
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The reality is all motors fail. That's why Part 25 requires a minimum of two engines. You would probably be surprised at how often turbine engines fail on airliners.
 
Challenged said:
Nice catch Paul, I was testing you..you passed. Wait. 1/27178 = 0.000036794, would be 0.004%, no? Honestly I sort of question these percentages. Has there been a poll on PoA about how many of us have suffered an engine failure?
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The important thing to add to that was an engine failure not caused by failure to put fuel in the tanks.
 
Ted DuPuis said:
The reality is all motors fail. That's why Part 25 requires a minimum of two engines. You would probably be surprised at how often turbine engines fail on airliners.
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Agreed. All motors fail, just some more than others. Unfortunately, for most of us GA pilots, it's piston or stay on the ground for the foreseeable future, but I do hope to live long enough to see the ICE retired from day to day service.
 
I wonder if that spate of failures is related to the sudden onset of Spring weather over much the country.
 
Topper said:
I would bet the odds are even lower for those of us that properly maintain our engines, get it checked when it sounds/acts funny and keep a little extra fuel in the tank.
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Yep. There is the engine failure rate, then there is the well-maintained engine failure rate.
 
Dav8or said:
Agreed. All motors fail, just some more than others. Unfortunately, for most of us GA pilots, it's piston or stay on the ground for the foreseeable future, but I do hope to live long enough to see the ICE retired from day to day service.
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I'm curious as to why you feel that way (referring to the part that I've bolded).

Piston engines have their place, as do turbine engines. I'm enjoying flying between a pair of turbines these days, don't get me wrong. But they are not the right answer for all applications. The parts are expensive (that's because they're complicated to make, not just because of volume) and the fuel burn at low altitude is exorbitant. The engines themselves are lighter but you have to carry around more fuel because they do burn more, and that requires more weight, and a heavier aircraft. Because they're most efficient at higher altitudes you end up needing a more complex aircraft with pressurization. Yeah, there are exceptions to that like the Caravan, but that's not an airplane most own for personal use. Turbines are most sensitive during starting and a weak battery can cause immense amounts of damage to them. Plus cycles are the hardest on turbines, and most (or at least many) piston aircraft are used on short cycles. Note that Cape Air is committed to pistons.

I don't see miniature turbines getting into the market to replace piston engines anytime soon. From my experience, I believe that so long as you stay naturally aspirated, piston engines really have a lot going for them. To me, the issue becomes when you add turbochargers. The complexity of the turbo system and exhaust (plus the extra weight) is where the scales tip in favor of turbines as the turbocharged pistons lose a lot of reliability, increase a lot of cost, and usually don't give you the performance the plane really needs. You get total engine weights in the range of 550-650 lbs (significantly more than a smaller turboprop) and a lot more parts that can and do break.
 
Ted DuPuis said:
The reality is all motors fail. That's why Part 25 requires a minimum of two engines. You would probably be surprised at how often turbine engines fail on airliners.
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Ted, what is the most common failure mode?

-Skip
 
Skip Miller said:
Ted, what is the most common failure mode?
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That's a hard one for me to answer and it's not universal as all engines have their weaknesses, and then you have just random failures that result in shutdown. Probably low oil pressure caused by high oil consumption is the biggest one that I recall. You could argue that's not a failure, but if you don't shutdown the engine then it will result in one. Ultimately the FAA tracks in-flight shutdowns on 121 ops, at least it was something we had to be concerned with. I worked in bearings and a bearing failure will destroy an engine quickly, I saw plenty of those happen. Sometimes the engine architecture really didn't make it realistic to be able to detect a bearing failure being imminent. I would say that bearing failures (other than fan blade outs) are what result in the most insane damage.

One thing to point out is that whenever there was an engine failure on a big turbine, there was an investigation into the root cause if it wasn't an established issue (although sometimes the root cause would be "unknown" at the end of the investigation). A corrective action was then put into place to get put through the fleet. The specifics of that depended on calculations (which were defined by the FAA) that basically determined what the risk of having both engines fail on a given flight was. Really interesting stuff. However what this would mean was that once a problem was identified, the fix might not make it into the fleet for years, and thus we'd see the same failure happen again at some point.

Perhaps the most successful engine failure investigation I had was a bearing failure that actually involved us catching several bearings before they failed, but the first one did reach a complete failure. The first one split the cage right down the middle, causing the core to no longer be positively located where it was supposed to be. That was destructive and expensive. But because we discovered several of them before failure, we were able to look at the bearings and ultimately tracked it down to an installation issue. Last I talked to some of my friends there, the fix we implemented has worked with 0 failures since.
 
denverpilot said:
Ted answered nicely but I thought...

“**** breaks.”

:)
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Your version is basically the same as mine.

The amazing thing is that, for the first time in the history of PoA, you managed to say something more concisely than me (or any other member). ;)
 
Ted DuPuis said:
Your version is basically the same as mine.

The amazing thing is that, for the first time in the history of PoA, you managed to say something more concisely than me (or any other member). ;)
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I’m half asleep.

I’m on my second Java Monster of the day.

It isn’t helping.
 
denverpilot said:
I’m half asleep.

I’m on my second Java Monster of the day.

It isn’t helping.
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My mom had one of those once, not realizing what it was.

2 days later she finally fell asleep.
 
Ted DuPuis said:
I'm curious as to why you feel that way (referring to the part that I've bolded).

Piston engines have their place, as do turbine engines. I'm enjoying flying between a pair of turbines these days, don't get me wrong. But they are not the right answer for all applications. The parts are expensive (that's because they're complicated to make, not just because of volume) and the fuel burn at low altitude is exorbitant. The engines themselves are lighter but you have to carry around more fuel because they do burn more, and that requires more weight, and a heavier aircraft. Because they're most efficient at higher altitudes you end up needing a more complex aircraft with pressurization. Yeah, there are exceptions to that like the Caravan, but that's not an airplane most own for personal use. Turbines are most sensitive during starting and a weak battery can cause immense amounts of damage to them. Plus cycles are the hardest on turbines, and most (or at least many) piston aircraft are used on short cycles. Note that Cape Air is committed to pistons.

I don't see miniature turbines getting into the market to replace piston engines anytime soon. From my experience, I believe that so long as you stay naturally aspirated, piston engines really have a lot going for them. To me, the issue becomes when you add turbochargers. The complexity of the turbo system and exhaust (plus the extra weight) is where the scales tip in favor of turbines as the turbocharged pistons lose a lot of reliability, increase a lot of cost, and usually don't give you the performance the plane really needs. You get total engine weights in the range of 550-650 lbs (significantly more than a smaller turboprop) and a lot more parts that can and do break.
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I feel that way because I don't want a piston engine or a turbine in my airplane. Pistons need to be retired and turbines need to stay right where they are, pushing heavy airplanes through the flight levels. I want an electric motor. IMO, that is what's needed to move GA forward. That is why I say I hope I will live long enough to see it happen. It is still a ways off, but not as far off as some nay sayers think.
 
Dav8or said:
I feel that way because I don't want a piston engine or a turbine in my airplane. Pistons need to be retired and turbines need to stay right where they are, pushing heavy airplanes through the flight levels. I want an electric motor. IMO, that is what's needed to move GA forward. That is why I say I hope I will live long enough to see it happen. It is still a ways off, but not as far off as some nay sayers think.
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Ahh, ok. Well as a naysayer I hope not. ;)
 
Dav8or said:
I feel that way because I don't want a piston engine or a turbine in my airplane. Pistons need to be retired and turbines need to stay right where they are, pushing heavy airplanes through the flight levels. I want an electric motor. IMO, that is what's needed to move GA forward. That is why I say I hope I will live long enough to see it happen. It is still a ways off, but not as far off as some nay sayers think.
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I don’t disagree that electric may be in our future, but only time will tell if the failure rate will be significantly different than what we are flying behind today. Not saying it won’t be better, just that there will still be failures.

Jim
 
Topper said:
I don’t disagree that electric may be in our future, but only time will tell if the failure rate will be significantly different than what we are flying behind today. Not saying it won’t be better, just that there will still be failures.

Jim
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True. Of course the electric propulsion system will break down too. However it promises to be much, much more reliable. Perhaps more reliable than a turbine, but like you say, only the future will tell us the truth. Based on the performance in cars, it is the battery pack that is the weakest link. The good news is, the cars are busy working out the kinks right now. :cool:
 
Dav8or said:
I feel that way because I don't want a piston engine or a turbine in my airplane. Pistons need to be retired and turbines need to stay right where they are, pushing heavy airplanes through the flight levels. I want an electric motor. IMO, that is what's needed to move GA forward. That is why I say I hope I will live long enough to see it happen. It is still a ways off, but not as far off as some nay sayers think.
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As we know at this point the major issues with electric planes are...

1. weight of the battery
2. Inability to be able to balance fuel vs. payload
3. Charging times and stations
4. Range

Hopefully solving issue one will potentially solve all the other issues.
 
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