Stephen Poole
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And you're only one person who apparently has very bad luck with Rotax engines and LSAs. Thousands of other people seem to do just fine with them ...
Cessna 150 Rotax Conversion
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And you're only one person who apparently has very bad luck with Rotax engines and LSAs. Thousands of other people seem to do just fine with them ...
bluesideup
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Hi.
You cannot separate the engine from any other components that make / keep the engine operational. When the engine overheats the engine is at fault, unless you can run it without the component that you claim that does not cause the problem.
You cannot separate the engine from any other components that make / keep the engine operational. When the engine overheats the engine is at fault, unless you can run it without the component that you claim that does not cause the problem.
I would like to know the N number of those acft. because I know for sure they do not exist.
DaleB
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You absolutely can. Guy lets baffle seals deteriorate on a Lycoming O360. It overheats. Does that mean all O360s overheat? No. It’s an installation or maintenance problem.
And if you’re looking for tail numbers, N980KM regularly flies in high temps, 3500-plus DA, and has been from NC to NE and a trip down to Key West. Never overheated. And it was built with the oil cooler closer to the muffler than it should be, so it runs hotter than most.
RyanShort1
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But you actually c... wait a minute.
I've been down this road before. Stopping now.
C-1 PILOT
Pre-takeoff checklist
Both the CT and Remos were brandie new aircraft. I took an extended demo flight in both, years ago after an AOPA expo, when AOPA expo’s were actually yearly events, not the crap fly-ins they have nowadays. They were nice aircraft, but not as stable as I thought they would be. I found the CT very squirrelly, IMO. Mechanically, I was very impressed with the 912. I had only flown the Sky Arrow prior to that, which was the first certified standard category Sky Arrow 650 TCNS, N271SA. I have just over 10 hours in it and it was an 80 hp 912. I had zero issues with it and believe me, I was looking for its weak points, as it was to be used for a special purpose role.
MBDiagMan
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Sorry, but the airflow of the installation has everything to do with the temperature range of the engine. If you had a 1/4” diameter air intake opening it would be quite different from having a 12” diameter air intake opening. The airflow design of the installation is paramount in any installation. With an air cooled engine, it’s everything. With a liquid cooled engine, radiator flow is just as important.
The installation can make or break the temperature range of any engine installation regardless of engine make.
Tantalum
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If Rotax decides to *today* to completely stop innovating and in 90 years are turning out the exact same product then yes, I'll be just as miffed at them. My whole point is Lyco / Conti / Piper, Cessna (Beech) also all stopped innovating decades ago. You (third person you, not *you* specifically) can blame it on whatever you want (low demand, FAA, etc.) but the facts are that some manufacturers, like Rotax, Diamond, Cirrus, etc., did continue to innovate and modernize, instead of taking the same design from 1940 and just renaming it dozens of times
Tantalum
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This is also a good time to remind people of a few statistical "gotchas" - because there have been several fallacies raised in this, and other Rotax-centric threads, but they all revolve around:
-I knew someone who crashed and their plane had a Rotax, I don't trust them
-My continental/Lycoming has never given me a problem
**Remember, that you alone are just one sample, a statistically irrelevant entity by itself.. so to claim that you don't trust X because of that is just bananas. Real data has proven that Lyco / Conti / Rotax are about equivalent in reliability: https://www.atsb.gov.au/publications/2013/ar-2013-107_research/ .. so given the choice of me having a plane that is similarly reliable as a Conti / Lyco but lighter, smaller, more efficient, has an ECU, etc., is a huge plus to me. The fact that we have to play science chemist with our engines is absurd
Keep in mind that Rotax has been building engines since 1920... they are not some millennial fantasy tech that "I can't trust because I have been using my 9 liter rich running Lyco beast my whole life, and it's the evil I know"
-I knew someone who crashed and their plane had a Rotax, I don't trust them
-My continental/Lycoming has never given me a problem
**Remember, that you alone are just one sample, a statistically irrelevant entity by itself.. so to claim that you don't trust X because of that is just bananas. Real data has proven that Lyco / Conti / Rotax are about equivalent in reliability: https://www.atsb.gov.au/publications/2013/ar-2013-107_research/ .. so given the choice of me having a plane that is similarly reliable as a Conti / Lyco but lighter, smaller, more efficient, has an ECU, etc., is a huge plus to me. The fact that we have to play science chemist with our engines is absurd
Keep in mind that Rotax has been building engines since 1920... they are not some millennial fantasy tech that "I can't trust because I have been using my 9 liter rich running Lyco beast my whole life, and it's the evil I know"
What bothers me more is that when I get in a rental C172 if I don't prime it exactly right and do a prayer dance to the gods it won't start and my passengers are wondering how safe the plane really is. If I can get modern ECU control and my only cost is turning the prop through then I'm fine with that
Mike Blackburn
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WRT overheating - I operate my Sling hot and high - never seen it overheat. Sure, if you turn away from the wind and run it up with the nose away from the wind it will get hot. But you can’t do that in a Cirrus either. And yes, if you idle at 2250 RPM it idles cooler than at 1800RPM.
Some models will run hotter or cooler than others but that is physics based on cowling design. The early Slings did run hot, they improved the cowling and now they are ok.
The only concern I have with my engine currently is the inverse relationship between oil temperature and oil pressure which nobody seems to be able to solve at the moment.
Some models will run hotter or cooler than others but that is physics based on cowling design. The early Slings did run hot, they improved the cowling and now they are ok.
The only concern I have with my engine currently is the inverse relationship between oil temperature and oil pressure which nobody seems to be able to solve at the moment.
Tantalum
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Wow, that's peculiar indeed?!
bluesideup
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I see that many have decided that Rotax is Not at fault if something goes wrong in the engine compartment and the engine overheats, that logic is incorrect in my opinion.
If Rotax approves an installation in a vehicle, they are responsible for it, and if they do their job right and disseminate specs that are not adhered to they need to take action and make sure the issue is resolved by the installer.
If Rotax approves an installation in a vehicle, they are responsible for it, and if they do their job right and disseminate specs that are not adhered to they need to take action and make sure the issue is resolved by the installer.
Mike Blackburn
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Very. And somewhat worrying.
Weeellllll, yes and no... Remember these are uncertified engines. They don’t have to control how they are used and what mods people do to them after installation..
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dmspilot
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Why does it concern you and why is it special to your engine?
Mike Blackburn
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Thread drift here but I should have mentioned that the pressure drops to the low end of the caution range as oil temp increases over 90C.
It wouldn't be concerning or something to take notice of if it did this at the upper middle range of pressures. It is something that has been discussed at length and without resolution on the Rotax owner forum - and seems to be oil brand related - Rotax stipulates AeroShell plus4 sport for all their engines currently and according to my AMO who build and maintain the majority of Sling aircraft in my country this was never a problem on the 914 until we started using the Shell oil. Again though.. this is an airframe:engine combination specific problem from what I can determine
Grum.Man
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Rotax does not approve any airframe installations. In fact neither do the legacy engine providers. It's up to the manufacturer of the airplane to design around the engine requirements.
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So in your world, Rotax is responsible for decisions made by people who are not associated with them in any way and whom they have zero control over. K thanks bye.
DaleB
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I'm with @RyanShort1 on this one.
genna
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Stephen Poole
Pre-takeoff checklist
That xkcd cartoon pretty well sums it up. I'm wasting my time now. You've obviously decided that Rotax LSA engines, as a class, are prone to overheat. But just for the record ...
Then I guess the FAA and EASA issued special airworthiness directives about this for nothing. Rotax addressed with a service bulletin in 2006. Rotax not only recommends certain coolants, the bulletin specifies a new radiator cap that will prevent loss of coolant.
From the FAA's directive, of note ...
I didn't pull that statement about coolant out of thin air. I got it from a Van's forum post in the RV-12 section. Note also that the FAA acknowledges that installation and operating conditions must be considered, too. Not all planes are the same.
But anyway. Don't fly Rotax, that's fine. We're still friends. I plan to, and as I said, there are thousands of other people worldwide who fly them daily without overheating problems.
Then I guess the FAA and EASA issued special airworthiness directives about this for nothing. Rotax addressed with a service bulletin in 2006. Rotax not only recommends certain coolants, the bulletin specifies a new radiator cap that will prevent loss of coolant.
From the FAA's directive, of note ...
I didn't pull that statement about coolant out of thin air. I got it from a Van's forum post in the RV-12 section. Note also that the FAA acknowledges that installation and operating conditions must be considered, too. Not all planes are the same.
But anyway. Don't fly Rotax, that's fine. We're still friends. I plan to, and as I said, there are thousands of other people worldwide who fly them daily without overheating problems.
Tantalum
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This is absolutely bonkers. Even a tiny bit of logical deduction would indicate that this is incorrect. If I buy a Lycoming, stick it in my plywood home-built airplane and keep it in my living room and it catches fire, is that Lyco's fault
You will notice that the poh for the aircraft you fly has a specific power plant section, it doesn't simply tell you to f off and refer to the manufacturer
remember that one Rolls-Royce, GE, Pratt Whitney, really anybody cause issues for the manufacturer it still ends up being boeing and airbus' responsibilities problem, they are ultimately the ones building the aircraft and choosing what goes in it and how those parts will be utilized
if I buy a pair of Icon windshield wipers at AutoZone, go home, and snap them in half, with my hands, is that the windshield wiper company's fault?
sorry to pile on, but this line of thinking is borderline troll level and I couldn't resist
MBDiagMan
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I got the impression in this thread that Rotax engines can not be certified in FAA certified aircraft. Is this or some variation of this true?
dmspilot
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https://rgl.faa.gov/Regulatory_and_...8b66b86258050006bb696/$FILE/E00051EN_Rev6.pdf
"Engines of models described herein conforming with this data sheet (which is part of Type Certificate Number E00051EN) and other approved data on file with the Federal Aviation Administration, meet the minimum standards for use in certificated aircraft"
Diamond DA-20-A1 Katana and Tecnam Twin are the two certified aircraft I know of offhand with Rotaxes.
Speaking up which, that brings up an interesting question. Why is the Contentinal powered Diamond DA-20 more popular than the Rotax version? The Rotax was first but isn't even produced any longer. Kind of hurts some of the "theory" put forth so far in the thread.
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Who the heck wants a snowmobile engine when you can have a car (or sewing machine) engine?
dmspilot
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I think you're trying to say that the market maybe did not evaluate them fairly. Touché.
Could be analogous to what happened with the geared engine on the Cessna Skylark. Apparently issues arising mainly due to user error caused it to develop a bad reputation.
But it does show the reason we don't see more Rotaxes is not completely due to the FAA or to a lack of trying on the manufacturer's part.
I've wondered about that as well. My suspicion is that the DA20-C1 is more common than the older A1 model because it has been produced a lot longer and because it has more power. With 125hp power seems about right but I'd expect an 80hp one to be anemic. I've never flown an A1 to compare though.
SoonerAviator
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Possibly because many of the buyers were flight schools where mechanics were already familiar with Contis and they didn't want to worry about a mixed fleet.
C-1 PILOT
Pre-takeoff checklist
The Diamond Da-20 A-1, was originally powered by the 80hp Rotax. They were one of the first standard category a/c or any category a/c for that matter to use a Rotax, well before they became popular in the US. That was part of the problem, no one in the US embraced them and the DA-20 was reborn with the Conti. I owned a new 2004, great plane, wish it has a Lycoming, enough said.
So, what did Diamond do? Well most all A-1 airframes were bought up and shipped back overseas, where they were upgraded to the 100hp, 912 ULS, re-born to successfully fly another day, with Europeans who love the Rotax.
C-1 PILOT
Pre-takeoff checklist
Answer above...
Considering the Continental IO-240 is somewhat of an odd engine, I'm not certain that was the major concern there. But I guess it could have been a rationalization that was made.
bluesideup
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If some of you think that after Rotax sells an engine they are no longer responsible for it, and or have control, think about who issues Installation instructions, SBs...
If an engine fails in an acft the first people that get looked at are the engine manufacturers. Why?
If an engine fails in an acft the first people that get looked at are the engine manufacturers. Why?
schmookeeg
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Deep pockets. Plaintiff lawyers who work on contingency?
bluesideup
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Hi.
My intent is to give constructive feedback only, and hopefully have the issue resolved. At this point it's difficult to say who needs to take action and resolve it, but I still think that the liability will likely be pointing more towards Rotax than any one else. An attempt was made to increase the size of the radiator, in Sport versions, but that does not , did not, fix the problem.
It can be fixed, fix it, and then we don't have to discuss it any more.
That does Not apply to what I am talking about, I replied to what is require and approved in the acft after 2009 / to present, different makes / brands that are presently approved.
Exactly my point, they will be held responsible.
My intent is to give constructive feedback only, and hopefully have the issue resolved. At this point it's difficult to say who needs to take action and resolve it, but I still think that the liability will likely be pointing more towards Rotax than any one else. An attempt was made to increase the size of the radiator, in Sport versions, but that does not , did not, fix the problem.
It can be fixed, fix it, and then we don't have to discuss it any more.
Silvaire
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I saw a video of a guy hand propping a Rotax 912. Looked pretty sketchy. Also why do they run the fuel lines on top of the engine? The whole thing looks rather busy and cluttered if you ask me. If you want to turn a propeller at 2300 rpm why build an engine that runs at 5200? Finally, there's nothing inherintly wrong with the O-200 so why bother with this?
Lachlan
En-Route
Because you must innovate or die! If you're flying around in a bombproof design like an old O-200, which is about as simple as you can make 100hp, then you're flying around behind 1940s technology and the school children and puppies are all in danger, because you failed to demand aeronautical innovation from your powerplant! (Or so I've been told.)
LoLPilot
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Running a significance test for Wanttaja's numbers shows no statistically significant difference in the proportion of crashes due to engine failure between traditional engines and rotax engines. It would be interesting to try and get a proportion for failures divided by engines in service from traditional vs. Rotax.
wanttaja
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It's difficult to determine, as the FAA records for homebuilt aircraft aren't very consistent as far as engine types. About 13% of the homebuilts in the FAA registry merely give "AMAT/EXP" as their engine type. Another 9% merely say "Bombardier" (or "Rotax") without identifying the model; we cannot tell if it's a two-stroke 582 or a four-stroke 912. When you add in the entries that are merely blank, you end up with
I have taken a stab at estimating the percentage of the AMAT/EXP engines that fall into certain gross categories...
Traditional Certified
Aftermarket Traditional
Foreign Engine
Auto Conversion
Non-Cert 4 Stroke
Two-Stroke
Turbine
....and estimating how many of the model-less "Rotax" entries fall into given models. I have taken the unknown models, compared them to the NTSB database (which usually has precise engine identification) and used those ratios to predict how many of the AMAT/EXP engines fall into the above categories, and how the Rotax unknowns parcel out.
From that, I compute the "Fleet Accident Rate"...what percentage aircraft with each type of engine suffer a crash in a given year.
Here's the cut:
_________Overall_________|_0.76%_|
__Traditional Certified__|_0.65%_|
_Aftermarket Traditional_|_0.45%_|
______Foreign Engine_____|_0.72%_|
_____Auto Conversion_____|_1.19%_|
____Non-Cert 4 Stroke____|_0.77%_|
________Two-Stroke_______|_0.97%_|
_________Turbine_________|_1.57%_|
(Note to Mods: Please enable the Xenforo table functions....)
Anyway, as you can see, the overall Fleet Rate for EAB aircraft is about .76%/year, while the rate for Traditional Engines is 0.65%.
Rotax 912s fall in what I call the "Non-Cert 4 Stroke" category. As you can see, this category has a 0.77% rate, a bit above the "Traditional Certified" rate.
However... the "Non-Cert 4 Stroke" category is more than the Rotax 912s. It include Jabiru engines, the Rotec engines, etc. In my previous analyses, the Rotax 912s actually come out better than most of the other engines in that category. It is, of course, a lower sample size, so they'll be some inaccuracies there.
Ron Wanttaja
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LoLPilot
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Fun talking with another stats guy about this!!
What sticks out to me in your table is the turbines.
Mike Blackburn
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2 things. There is a certified version of the 914 available. It carries the F designation and a 100% premium on the price tag (give or take)
Wrt hand propping a Rotax, I wouldn't even consider it. The way the ignition works, you need a high nominal rpm to start it (around 2000rpm) and then it starts on all cylinders immediately unlike a "traditional" engine which will generally start slower. The high rpm needed means you'll have to do a BIG pull of the prop which is likely to mean your head ends up in the prop path when it starts at 2000rpm.
Not the best plan. So yes, it will look very sketchy!
Wrt hand propping a Rotax, I wouldn't even consider it. The way the ignition works, you need a high nominal rpm to start it (around 2000rpm) and then it starts on all cylinders immediately unlike a "traditional" engine which will generally start slower. The high rpm needed means you'll have to do a BIG pull of the prop which is likely to mean your head ends up in the prop path when it starts at 2000rpm.
Not the best plan. So yes, it will look very sketchy!
wanttaja
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Small sample size...there are only 108 EAB in the registry with turbine engines, although my analysis/prediction process doubled that.
I've got 78 turbine-powered EAB accidents in my 20-year database.
Ron Wanttaja
Warmi
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Been flying with a rotax engine for a while ... no issues with over-heating or anything of that sort.
I did have one incident of partial power loss on takeoff related to debris in one of the carbs , which I was told ( during Rotax training ) is the most common reason behind partial power loss on carbureted a Rotax power plants - in my case I suspect it was related to maintenance since it happened after carbs were opened for some routine service but i can’t prove it one way or another.
All in all, like the engine a lot - been having tons of fun with it and looking forward to new Rotax 915is equipped planes ...
I did have one incident of partial power loss on takeoff related to debris in one of the carbs , which I was told ( during Rotax training ) is the most common reason behind partial power loss on carbureted a Rotax power plants - in my case I suspect it was related to maintenance since it happened after carbs were opened for some routine service but i can’t prove it one way or another.
All in all, like the engine a lot - been having tons of fun with it and looking forward to new Rotax 915is equipped planes ...