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#22
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Presumably all the pilots who had engine failures believed the same thing.
Mike MU-2 "Captain Wubba" wrote in message om... Andrew Rowley wrote in message . .. studentpilot wrote: Know a bloke well with over 15'000 hours, he has had no engine failures. He has had however 4 self inficted engine failures, these were fuel system failures. Mostly failure to put enough in, failure to check for water contamination properly, failure to know the aircraft fuel system. This blokes expirence is all single engine, going from little Lyc's to Radial's and turbine. Why do you exclude fuel exhaustion, fuel contamination etc? Don't they happen if you're IFR? If you're IFR or at night it doesn't really matter WHY it stops. Because I can control these problems. If I do a proper preflight, the probability of fuel contamination is very, very low. If I do the proper fuel calculations and check the fuel levels and carry proper reserves, I'm not going to run out of gas. This is about risk management. I can manage the risks of fuel contamination or exhaustion very easily, if I exercise diligence and care. If those are no longer concerns, the primary engine-related concern becomes mechanical failure, and that's what I'm looking at. Cap |
#23
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#24
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"Mike Rapoport" wrote in message
link.net... Presumably all the pilots who had engine failures believed the same thing. It's safest to assume that, but I suspect that in reality, only some small subset even bothered to think hard enough about the issues to believe the same thing. |
#25
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Sorry I can't point you to the "harder" data you're looking for, but
here's perhaps a little perspective on the issue: According to one NTSB Study, pilots with fewer than either 500 hours total time, or 100 hours in type, are more likely to encounter an inadvertent stall/spin than to have a genuine engine failure (i.e.: a random-event engine failure, not one attributed to such pilot errors as fuel mismanagement). In my case, over 6,400 hours with 5,600+ hours of instruction given (mostly doing spin, emergency maneuver, aerobatic, and tailwheel training -- the type of flying that might be considered harder on an engine than more routine types of flying), I've had several non-critical engine anomalies that were successfully dealt with, including: Prop stoppages during spins due to a couple of students hanging on so tight to the throttle that it choked off the engine -- we call that "fright idle"; Clogged fuel injectors during take-off that only revealed themselves at full throttle; Primer controls that were not truly "in and locked" which has lead to prop stoppages during idle power landings. In addition, two legitimate engine failures as follows: The first, a fuel injector failure as we entered the traffic pattern (after practicing off field landings, no less!) -- landed without further incident; The second, carb ice in a Champ during a flight review choked off the engine during a touch and go -- touched down on the taxiway abeam the departure end of the runway, hit a parked Porshe, bent the airplane, walked away without so much as a scratch. Rich http://www.richstowell.com (Captain Wubba) wrote in message . com... Indeed. Interesting. But I'd still like to see some hard data. This is the kind of problem I run into...most of your pilot friends report that they have had a failure, but the majority of mine report none. And none of the 2000+ hour CFI types I asked (I asked 4 of them) have ever experienced an engine failure. My dad was a pilot with well over 12,000 hours and never had one. Another relative had fewer than 500 hours total in his flying carrer and lost one on his first solo XC. I asked another A&P I ran into at the airport tonight, and he said he thought it should be at least 40,000 hours per in-flight engine failure, but really wasn't sure. Since a big part of flying is risk management, it would be very helpful to *really* know the risks involved. If the odds of losing an engine are 1 in 50,000 hours, then night/hard-IFR single-engine flying becomes a great deal more appealing than if it is 1 in 10,000 hours. I'll try to go over the NTSB data more thoroughly, I think a reasonable extrapolation would be that at least 1 in 4 in-flight engine failures (probably more) would end up in the NTSB database. But the cursory review I made earlier made me think the numbers were much less negative than I had considered before. And the opinions of these A&Ps are very interesting, because while failure might not require a total overhaul, it will require *something* to be done by a mechanic...and if these guys are seeing 30-40 engines make it to TBO for every one needing repair due to an in-flight failure, that might well support the 40,000 to 50,000 hour hypothesis. Cheers, Cap (Michael) wrote in message om... (Captain Wubba) wrote Howdy. I was discussing with a friend of mine my concerns about flying single-engine planes at night or in hard IFR, due to the possibility of engine failure. My buddy is a CFI/CFII/ATP as well as an A&P, about 3500 hours, and been around airplanes for a long time, so I tend to give credence to his experiences. He asked me how often I thought a piston engine had an in-flight engine failure. I guestimated once every 10,000 hours or so. He said that was *dramatically* over-estimating the failure rate. He said that in his experience it is at least 40,000 to 50,000 hours per in-flight engine failure. The only vaguely official number that I've ever seen came from a UK accident report for a US-built twin. The UK investigators queried the FAA on engine failure rates for the relevant engine, and the only answer they got was that piston engines have failure rates on the order of 1 in 1000 to 1 in 10000 hours. This is consistent with my experience. I've had one non-fuel-related engine failure (partial, but engine could only produce 20-30% power) in 1600+ hrs. Most people I know with over 1500 GA hours have had an engine failure. 50,000 hours is not realistic. Excluding a few airline pilots (who have ALL had engine failures) all my pilot friends together don't have 50,000 hours, and quite a few of them have had engine failures. I've heard the maintenance shop thing before, but you need to realize that most engine failures do not result in a major overhaul. Stuck valves and cracked jugs mean that only a single jug is replaced; failure of the carb or fuel injection system (my problem) affects only that component. And oil loss will often seize an engine and make it not worth overhauling. There are no real stats on engine failures because engine manufacturers and the FAA don't want those stats to exist. The FAA could create those stats simply by requiring pilots to report engine failures for other than fuel exhaustion/contamination reasons, but will not. The truth is, FAA certification requirements have frozen aircraft piston engines in the past, and now they're less reliable than automotive engines (not to mention ridiculously expensive). Michael |
#26
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"Captain Wubba" wrote in message om... This is about risk management. I can manage the risks of fuel contamination or exhaustion very easily, if I exercise diligence and care. If those are no longer concerns, the primary engine-related concern becomes mechanical failure, and that's what I'm looking at. I'm with you. I'm most interested in anything which forces me down. Included in that would be carburetor failure, fuel line breaks, engine fire, as well as the engine deciding to punch a hole in the case... stuff that I could never protect against by a thorough preflight. I'd also be interested in survival statistics for forced landings at night, over mountainous terrain, in cold weather etc. for *any* reason (including self-induced fuel exhaustion). Then it is easy to work out the risks. -- Dr. Tony Cox Citrus Controls Inc. e-mail: http://CitrusControls.com/ |
#27
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"studentpilot" wrote in message ... Know a bloke well with over 15'000 hours, he has had no engine failures. My airplane has about 5500 hours over 50 years on it. It's had two fairly major engine failures to my knowledge. I had the (mis)fortune of having the second one which put an end to this engine (it's sitting in my basement a new zero-time replacement is now installed). |
#28
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Knowing *NOTHING* about turbocharged engines, I was wondering. Would a loss
of the turbocharger still allow the engine to produce the same power as a non-turbo engine of the same size at the same altitude? From the examples I've read in this thread so far, 3 out of 4 are turbocharger failures. Interesting. "Bob Gardner" wrote in message news:G_vwb.294669$Tr4.929561@attbi_s03... In 7000 hours I had one engine "failure," which was just a loose hose between the turbocharger and intake manifold. Engine didn't really fail, it just lost boost on that side. I've had some engine anomalies, but nothing that would meet the definition of failure. I would tend to agree that honest-to-goodness failures are very rare when considered in the context of total operating hours for all powered aircraft. Bob Gardner "Captain Wubba" wrote in message om... Howdy. I was discussing with a friend of mine my concerns about flying single-engine planes at night or in hard IFR, due to the possibility of engine failure. My buddy is a CFI/CFII/ATP as well as an A&P, about 3500 hours, and been around airplanes for a long time, so I tend to give credence to his experiences. He asked me how often I thought a piston engine had an in-flight engine failure. I guestimated once every 10,000 hours or so. He said that was *dramatically* over-estimating the failure rate. He said that in his experience it is at least 40,000 to 50,000 hours per in-flight engine failure. The place where he works sometimes as a mechanic has plenty of planes come in for overhauls and annuals, and he estimates that for every plane that has had an engine failure before TBO, at least 20-30 make it to TBO without any failure (which would extrapolate to a similar figure). The flight school he teaches at has 7 Cessnas used for primary training and rental that have flown at least 40,000 hours total in the six years he has been there, and they have not experienced a single engine failure. I emailed Lycoming, and (unsurprisingly) they told me they did not keep records about engine failure rates. So I'd like to find out if anyone has done any objective analysis of certificated, piston-engine failure rates in light airplanes. I have seen all kinds of 'guesses', but little in the way of objective facts. After analyzing NTSB accident data and comparing to annual GA flight-hours, I'm starting to think my friend is on the right track, but that is a relatively small sample, and has some methodologial flaws. It's funny. I know 20,000 hour CFIs who have never had an engine failure, and I also know 300 hour PP-ASELs who have had engine failures. Just for giggles, I asked 8 pilot friends/relatives if they had ever had an engine failure. The only 'yes' was a relative who lost an engine after takeoff on his first solo cross-country in 1958. And I know one other pilot who had an engine failure, who I wasn't able to talk to. So what is it? If the engine-failure rate is one failure for every 50,000 flight hours, I'll feel much less reticent about night/IFR single-engine flying than if it is one in 10,000 hours. Anybody have any facts or hard data, or have any idea where I might be able to track some down? Thanks, Cap |
#29
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True but I would assume that they thought that they had given the subject
adequate consideration. It is arogant to believe that everyone else is a fool and you are not. My fovorite ezample are those pilots who are confident that they could handle an IMC gyro failure when the record shows that many (most?) cannot. Mike MU-2 "Peter Duniho" wrote in message ... "Mike Rapoport" wrote in message link.net... Presumably all the pilots who had engine failures believed the same thing. It's safest to assume that, but I suspect that in reality, only some small subset even bothered to think hard enough about the issues to believe the same thing. |
#30
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It depends on the type of turbo failure. The typical failure is the bearing
in which case the engine will not make much, if any power. Mike MU-2 "Jeff Franks" wrote in message ... Knowing *NOTHING* about turbocharged engines, I was wondering. Would a loss of the turbocharger still allow the engine to produce the same power as a non-turbo engine of the same size at the same altitude? From the examples I've read in this thread so far, 3 out of 4 are turbocharger failures. Interesting. "Bob Gardner" wrote in message news:G_vwb.294669$Tr4.929561@attbi_s03... In 7000 hours I had one engine "failure," which was just a loose hose between the turbocharger and intake manifold. Engine didn't really fail, it just lost boost on that side. I've had some engine anomalies, but nothing that would meet the definition of failure. I would tend to agree that honest-to-goodness failures are very rare when considered in the context of total operating hours for all powered aircraft. Bob Gardner "Captain Wubba" wrote in message om... Howdy. I was discussing with a friend of mine my concerns about flying single-engine planes at night or in hard IFR, due to the possibility of engine failure. My buddy is a CFI/CFII/ATP as well as an A&P, about 3500 hours, and been around airplanes for a long time, so I tend to give credence to his experiences. He asked me how often I thought a piston engine had an in-flight engine failure. I guestimated once every 10,000 hours or so. He said that was *dramatically* over-estimating the failure rate. He said that in his experience it is at least 40,000 to 50,000 hours per in-flight engine failure. The place where he works sometimes as a mechanic has plenty of planes come in for overhauls and annuals, and he estimates that for every plane that has had an engine failure before TBO, at least 20-30 make it to TBO without any failure (which would extrapolate to a similar figure). The flight school he teaches at has 7 Cessnas used for primary training and rental that have flown at least 40,000 hours total in the six years he has been there, and they have not experienced a single engine failure. I emailed Lycoming, and (unsurprisingly) they told me they did not keep records about engine failure rates. So I'd like to find out if anyone has done any objective analysis of certificated, piston-engine failure rates in light airplanes. I have seen all kinds of 'guesses', but little in the way of objective facts. After analyzing NTSB accident data and comparing to annual GA flight-hours, I'm starting to think my friend is on the right track, but that is a relatively small sample, and has some methodologial flaws. It's funny. I know 20,000 hour CFIs who have never had an engine failure, and I also know 300 hour PP-ASELs who have had engine failures. Just for giggles, I asked 8 pilot friends/relatives if they had ever had an engine failure. The only 'yes' was a relative who lost an engine after takeoff on his first solo cross-country in 1958. And I know one other pilot who had an engine failure, who I wasn't able to talk to. So what is it? If the engine-failure rate is one failure for every 50,000 flight hours, I'll feel much less reticent about night/IFR single-engine flying than if it is one in 10,000 hours. Anybody have any facts or hard data, or have any idea where I might be able to track some down? Thanks, Cap |
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