# Non- Biased Engine Reviews -Viking

Discussion in 'General Auto Conversion Discussion' started by flienlow, Jan 22, 2020.

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1. Jan 23, 2020

### Wanttaja

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Are we avoiding the "E-word" for some reason?

I see six accidents involving Eggenfellner engines. One list the engine make as a Subaru/Eggenfellner, another as "Haines" with the model designation of "Eggenfulner". All six use different model designations, and I'm finding no additional hits on those designations. Three were on RV-9As, one on an RV-10, on GlaStar, the last airplane was a Rutan Defiant. Most of the accidents are pre-2010, with one of the RV-9As in 2016.

Of course, some of the other engines designated as "Subaru" are probably Eggenfellner, but it's difficult to tell from the NTSB data. Sometimes the narrative does state the provenance of the engine, but in these cases the NTSB usually lists that in the "Engine Make and Model" columns.

I've mentioned in another auto-engine thread how ambiguous the FAA registry is; the number of "official" registrations with a given auto engine are usually dismayingly small. Looking at just "Ford", for instance, there are only 76 aircraft on the registry with engine makes or models that mention Ford.

Eggenfellner, there's just one in the FAA registry (N81RX), but I'm sure some of the Subaru registrations are Eggenfellner conversions. I get a total of 435 registrations with "Subaru", "Eggenfellner", "NSI", or "Stratus" as a search term. The actual search terms are actually truncated with wild cards (e.g., "*sub*", "*egg*", etc.).

As I mentioned on the other thread, the big bugaboo in this process are the ~6,600 airplanes in the US registry that just list "AMAT/EXP" as the engine. So if someone wants to claim that 6,500 2CV engines are flying in the US, there's no way to prove them wrong.

A couple of years ago, I took a stab at trying to identify these AMAT/EXP engines. I cross-referenced the NTSB accident database (which usually identifies the engine) with the list of AMAT/EXP engines. Got about 250 "hits" out of 3500 AMAT/EXP aircraft (this was counting ONLY aircraft licensed as Experimental Amateur-Built). This is how the AMAT/EXP engines were distributed:
 Traditional Certified 26.0% Aftermarket Traditional 7.3% Foreign Engine 2.8% Auto Conversion 24.8% Non-Cert 4 Stroke 13.4% Two-Stroke 8.9% Turbine 4.1%
So about a quarter of the AMAT/EXP engines are probably auto conversions. Based on that, here's my computed percentage of each engine type vs. the EAB fleet:
 Engine Type % of Fleet Traditional Certified 56.4% Aftermarket Traditional 5.3% Foreign Engine 0.6% Auto Conversion 8.7% Non-Cert 4 Stroke 14.5% Two-Stroke 9.2% Turbine 0.9% AMA/EXPR 1.7% Bombardier 0.9% None or Blank 1.8% Not found 0.1%
"Bombardier" cases are those which identify the engine manufacturer as Rotax or Bombardier, but don't list an engine model. So we don't know if they're two-stroke or four-stroke. Otherwise the Rotax two-strokes and four-stroke engines are included in the appropriate category ("Non-Certified Four Strokes" for the Rotax 912s, for instance).

Ron Wanttaja

Last edited: Jan 23, 2020
2. Jan 23, 2020

### pfarber

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THIS IS THE ONLY CORRECT ANSWER.

How many ADs have Lycoming/Rotax/Cont put out requiring expensive parts (cranks/cams/cases) be thrown away, or expensive inspections be done every X hours ALL AT YOUR COST? How many $5k Lycoming VAR cranks were paid for with a smile because of an AD? The poster of that viking engine web site doesn't strike me as a person who should own an EXPERIMENTAL AIRCRAFT. Really. His uncertified CAR MOTOR is having trouble, and after two failures he continued to fly it. At what point do you not blame the owner? The warped head he spoke about... that's a few hundred dollar fix. Blocks and heads get planed ALL THE TIME. Take your car motor to a shop, have them level the head and tell you what gasket thickness you need to get the proper compression. On a small motor like that I would just get a sheet of glass, some sand paper and level the deck myself. It might take an hour but cost less than$50 and some time.

If you are not willing to walk away from a bad decision, and continue to throw parts are something that breaks, that's more on you than anything else. It cost that one guy his airplane (and luckily not his life) because he would not walk away from a bad decision.

I also commented on some of these motors not being up to aircraft specs. Things like bolts and safety wire... if you are not prepared to know this level of information, then you should not consider and E/AB or a car motor. Go buy a nice Piper or Cessna and let a trained mechanic keep it flying for you.

3. Jan 23, 2020

### Staggermania

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Were all of these accidents caused by engine failure?

Last edited: Jan 23, 2020
4. Jan 23, 2020

### Wanttaja

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No. Just the engine the accident planes were equipped with.

INTERESTING point, though, one that is easily answered.

Here's the same plot, with some additional columns. "Failures" is the number of accidents that involved either mechanical failure of the engine, or a power failure due to undetermined reasons (could be human error). The "Percent" is the percentage of accidents that involved power failures of this type.

 Engine Installed Failures Percent Subaru 183 60 33% Volkswagen 163 64 39% Chevy Non-Corvair 47 22 47% Mazda 21 11 52% Corvair 20 9 45% Ford 16 6 38% Viking 10 2 20%
Notice the lower of the installed base, the less accurate the results are.

My *normal* tally of power failures include human-related ones as well, but not this one.

Ron Wanttaja

5. Jan 23, 2020

### Staggermania

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It would be interesting see how this compares to certified aircraft and certified engines in E/AB

6. Jan 23, 2020

### bmcj

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To borrow a line from J.K. Rowling....

“He who must not be named.”

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7. Jan 24, 2020

### Wanttaja

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Here are the numbers for E/AB:
 . Total Failure Percent Traditional Certified 2002 351 18% Non-Cert 4 Stroke 655 130 20% Auto Conversion 562 214 38% Two-Stroke 475 166 35% Engine Not Categorized 290 71 24% Aftermarket Traditional 140 24 17% Turbine 80 21 26% Foreign Engine 26 7 27%
Again, "Non-Cert 4 Stroke" are engines like the Rotax 912 and Jabiru, "Aftermarket Traditional" are classic-style engines produced by other companies (Superior, etc.).

The failures in this context do not include known operator-induced failures, but do include the undetermined failures which might have been operator induced.

Ron Wanttaja

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8. Jan 24, 2020

### Wanttaja

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And here I thought THAT name started with a "C"....

Ron "Topaz's finger is quivering above the 'cancel' button" Wanttaja

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9. Jan 24, 2020

### Staggermania

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Ok, last question - Fatalities?
Thanks

10. Jan 24, 2020

### Chris Matheny

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Several bank accounts......

11. Jan 24, 2020

### Wanttaja

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Oh, yeah...last for YOU, maybe. I know how this works.

 . Total Failure Percent With Fatalities Traditional Certified 2002 351 18% 70 Non-Cert 4 Stroke 655 130 20% 19 Auto Conversion 562 214 38% 32 Two-Stroke 475 166 35% 21 Engine Not Categorized 290 71 24% 16 Aftermarket Traditional 140 24 17% 8 Turbine 80 21 26% 4 Foreign Engine 26 7 27% 1
The "With Fatalities" column is the number of engine-failure accidents that resulted in at least one fatality. It is not the number of casualties.

Ron Wanttaja

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12. Jan 24, 2020

### cheapracer

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That's scary.

Sod those Luddites who comment in the negative about safety gear.

13. Jan 24, 2020

### Wanttaja

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Indeed. Keep in mind, too, that those statistics are over a twenty-one year period (1998-2018). In that time, I show 562 EAB accidents involving auto-engined airplanes, of which 122 of them involved fatalities. A good percentage of those accidents were due to causes unrelated to the engine.

And while a fairly significant percentage of those involved loss of engine power (45%, when you include pilot-induced failures*), the *fatality* rate of those instances are relatively low. Compared to a lot of emergency problems that can happen to homebuilts, engine failure is one we all train for, and receive recurring training for (in the form of BFRs). Engine failure *is* more survivable.

I don't think there's any question that auto-engined homebuilts have a higher accident rate. I think my last approximation was that their rate was about 23% higher than traditional engines. The ability to do so is a freedom I cherish, though. Just like folks to have their eyes open.

Ron Wanttaja

* Why do I lump in Pilot-induced failures? Because I view homebuilt engine installation AS A PACKAGE. If the engine is (for some reason) more difficult or complex to operate or manage, I see that as part of the issues with the package.

Note that the tables I've been posting on this thread do NOT include the pilot-induced failures...other than the potential ones in the "undetermined" cases.

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14. Jan 24, 2020

### mullacharjak

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It seems the viking engine failures are related to the PSRU.The star shaped coupler on both sides of the rubber disc seems to have failed.Thay are now using a circular coupler between the flex plate and rubber disc.The coupler ahead of the rubber is still a star I think.The drive pins/Lugs were press fit before.Now they are welded.No failures of the shafts/gears/bearings.Looks like the PSRU is now through its testing phase.Only irony being that the customers had to do it.

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15. Jan 24, 2020

### BJC

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BJC

16. Jan 24, 2020

### Staggermania

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Foxworthy?

17. Jan 24, 2020

### BJC

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Foxworthy, Engvall, and probably others.

BJC

18. Jan 24, 2020

### pfarber

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I think if you look up the definition of 'Experimental' you'll see that its not that ironic.

It appears that this is more of an alignment issue, the flex plate/crank flange is not flat enough and vibration caused the connecting part to fail.

Press fit vs welding? I don't know if I believe that looking at the photos. Did Viking ever put out some sort of SB on this?

19. Jan 24, 2020

### Mark Z

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The 750 is the absolute easiest airplane I’ve ever mounted. They are fun to fly. If only the tiniest contour was designed into the tailcone there would be huge improvement from oilcanning. I’m working on my third RV12 and would welcome building a Zenith of any flavor.

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20. Jan 24, 2020

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