Here’s a piece of interesting data from a recent Conti press release:
The company has also reported excellent figures regarding the reliability and safety of its engines as a result of continued product improvement over the years.
Over the last 52 weeks the CD-135 only had 1.74 in-flight shut downs per 100,000 flight hours which is far beyond industry standard.
According to the FAA statistics, engines used in general aviation experience an average of 10 engine failures or engine-related “in-flight shutdowns” (IFSDs) in 100,000 flight hours. Since market introduction, the IFSD rate for Continental has always been less than half of the GA average and has steadily decreased year over year. The most recent CD-155 shows only 1.57 IFSD due to improved field quality. The CD-135 and CD-155 are therefore probably proven to be the most reliable piston engines in general aviation
Not entirely fair to compare an engine with an age of anywhere between 0 and 10 years to the GA-wide engine age of 0-50 (or 75?) Nonetheless this is promising, and it’s time to get rid of the bad reputation that still lingers on left and right.. Damn, these Chinese are catching up 
I saw that on the Diamond Aviator Network today too 
This brings me back to the DGAC Thielert safety study that I have referred to on several occasions, which concluded based on numbers provided by Thielert and FAA, that the Thielert rate of IFSD was about half that of the Lycosaurus’. These numbers are even better.
But a bad rep is hard to shake off.
Let me be the devil’s advocate (yeah, again ) and ask whether statistics like this can be skewed not just by the Lyco population being vastly older but by the possibility that an engine which cannot be freelance/field overhauled could have it’s reliability data massaged much more easily? Unfortunately the bad reputation years back was earned on multiple fronts, not directly just in the Thielert department.
Massaging failure records inside a company is totally and completely easy to do and is standard practice everywhere. In addition to that, you tell every customer with a problem that his problem is the first time you have seen it.
Then, the difference between an ethical operator and a crook is that the ethical operator will immediately make good on the situation, at his expense, and as is well known a customer with a problem efficiently solved is more loyal than a customer who never had a problem
I think this is only reasonable. The Lycomings and Continentals were designed 50-60 years ago to be maintained in the field, mostly using military specs. TBO in the military could be 25 hours, certainly not 2500 hours. Replacing the engine is no big deal, so TBO numbers means very little, if anything at all. You simply replace things, check/fix them, and put them back as often as needed to prevent failure in flight. What is strange here is that the Continental CDs aren’t much better considering all the “development” that has been done on them, and considering they are originally MB car engines. Commercial trucks runs for 1M km without anything happening, and the engines used are much more complex, and endure much more abuse.
@Peter you can also be the realist advocate and affirm that Lycosaurus IFSD or loss of power are either not recorded / centrally reported, or are blamed on “inflight icing”, thus making the Lycosaurus stats a lot better than they really are.
10 failures for 100,000 flight hours means an MTBF of 10,000
1.57 failures means MTBF of 63,700
So if TBO is 2000, then the probability of any single (lyco) engine to reach TBO before an in flight shut down is e^-(2000/10000) = 0.819 or 81.9 % This means about 18% of all lyco engines will have an in flight shut down before they have run 2000 hours. Maybe this is right, but it doesn’t sound too assuring
The same for the new continental CDs are 97.7% chance of running to 1500 h (TBO or TBR) without an in flight shutdown.
I think this statistics is skewed. Very few of the new Continental CDs have flown to TBO, but most of the lyco engines have. Even though one can calculate a IFSD per 100,000 hours, this doesn’t really mean much when they on average have flown only 100 hours each for instance. Faults due to old age, wear and tear, continuous abuse and poor maintenance haven’t started to occur. It only shows that a brand new Continental CD is more reliable than the average poorly maintained, 40 year old lycosaur. It doesn’t compare apples to apples.
Could that 10/100,000 figure not also include VW conversions and Gypsy Majors?
I’ve just undertaken a two week trip flying 58hrs through Europe and the Middle East behind two Centurion 2.0 diesels. I’ll do a write up soon but our average TAS was 150kts with a fuel burn of 43.8 l/hr. This aircraft is on its second set of engines (due to TBR) and has never lost a single task due to engine reliability issues. I know it is an extremely small snapshot but, in business, the diesels make sense.
In three weeks time we take delivery of a DA62 which will present better load carrying and speed capabilities.
you can also be the realist advocate and affirm that Lycosaurus IFSD or loss of power are either not recorded / centrally reported, or are blamed on “inflight icing”, thus making the Lycosaurus stats a lot better than they really are.
That’s possible too.
I don’t get your repeated swipes about inflight icing. For me, induction icing is real (two events) and I posted the data proving it. Regarding that “famous” SR22 FL230 engine stoppage, the plane was sold very fast and no info ever came out on it. If it was a turbo failure, surely the prebuy would have picked up a duff turbo. So either it wasn’t the turbo (or anything else mechanical i.e. the engine was working just fine after the event) or the remedial work was done but for some reason remained undisclosed.
So if TBO is 2000, then the probability of any single (lyco) engine to reach TBO before an in flight shut down is e^-(2000/10000) = 0.819 or 81.9 % This means about 18% of all lyco engines will have an in flight shut down before they have run 2000 hours. Maybe this is right, but it doesn’t sound too assuring
It’s also very unlikely to be right, because that would mean that, given the average GA fleet age, a large % of PPLs would experience an engine failure, and that simply isn’t the case. It would also remove those planes from the fleet because many forced landings would write off the plane (and the occupants in many cases).
I think this statistics is skewed. Very few of the new Continental CDs have flown to TBO, but most of the lyco engines have. Even though one can calculate a IFSD per 100,000 hours, this doesn’t really mean much when they on average have flown only 100 hours each for instance. Faults due to old age, wear and tear, continuous abuse and poor maintenance haven’t started to occur. It only shows that a brand new Continental CD is more reliable than the average poorly maintained, 40 year old lycosaur. It doesn’t compare apples to apples.
Indeed.
Another thing is that diesels have the opportunity to avoid bad engine shops – because they go back to the mfg for any work. That will help. And FADEC helps to protect from abuse.
It means that if you manage the engine correctly and don’t use some crappy shop to overhaul it, you won’t see the statistical failure rates
It means that if you manage the engine correctly and don’t use some crappy shop to overhaul it, you won’t see the statistical failure rates
True, but there’s one of the main advantages of Diesels. There is no need to learn how to manage your engines and to invest time to choose to become a member of the LOP or ROP church, become proficient in monitoring EGT, CHT or TIT temps, or to do investigations where to send your engine to for overhaul. If GA is to attract new pilots, it better make it easy for them.
