Engine Failures w/ Rotary?

[Wylbur]

Does any one know of an experimental that crashed where the crash was caused by a rotary engine failing?

You might wonder why I would ask. It is something one needs to know when looking at using one for an airplane. Why do rotary engines fail, assuming any have?

[FritziAnn]

Rotary engines usually have apex seal failure, but generally that causes only power reduction. The 13B model has only 3 moving parts. Lots of rotary info and video,s on the net !

[Wylbur]

If you run a rotary in an airplane, the engine can fail because the fuel pump fails, or the oil pump fails, or the ignition system fails, etc. Imagine the kind of failure that will take place if you do not have sufficient oil going to the PSRU and it fails. That prop, assuming an RPM at or above 2300, will have significant angular momentum to cause problems. So the idea that the engine only has 3 moving parts is rather simplistic when one looks at possible failure modes.

Take a common engine such as an O-360. They can fail because an oil line springs a leak and the engine seizes. Or, the mags can fail (both within minutes of each other). The basic engine is not what failed, it was a "support" component that failed killing/stopping the engine.

A rotary of the TTC type, has a water pump, radiator, oil pump, etc. More complexity leading to more things that could fail and cause the engine to quit or even fail catastrophically.

These are the things I am looking for so I can research this in the NTSB data base or look for ways to mitigate. I am interested in seeing this engine as the engine of choice for Experimental aircraft and then get them into certificated status.

[FritziAnn]

My mention of 3 moving parts, being a simplistic statement, in reality is in reference to the engine design. A 13B is 1.3 litres, now compare that with your average 1.3L which is a 4cyl, now do the parts count! All auto conversions have the same support systems. What is unique to the 13B is it needs a 3 to 1 psru or more depend on max RPM. This particular rotary group was started by Paul Lamar, a highly knowledgeable rotorhead. I have been involved for over 5 years, until Paul's passing. I have engines and development PSRU,s in my shop, so it's not my first whack at the cat. What history do you have with the Wankel ?

[Wylbur]

The question was "Does any one know of an experimental that crashed where the crash was caused by a rotary engine failing?" Your answer didn't address the question. Let me be direct and blunt: I have not worked on any REs at this point. I have been doing aircraft designs and working toward what will be required to certificate an RE with the Part 23 overhaul.

Now, you have built PSRUs. That's great. How difficult is it to do a 4:1 to get an RE to 10,000 RPM? That was a question that had come up in the old mail group. Paul was also working on an ignition system to solve the spark problems at that RPM and greater. He said he was working on a patent for it. So, yeah, I've been a lurker more than a participant.

[Otter805]

This discussion thread reminds me of a repeated coversation I had with my father over the reliability of the rotary design. His favorite point over and over again was the success the engine had in high performance endurance racing like Le Mans. Auto racing at this level, requires advanced designs in fuel injection, gearbox and apex seals. In fact, you could argue that racing is more technical demanding than aviation. A lot of my father's engineering did indeed come from that field for which he was an expert for over 60 years. It does not take much of a google search to come up with excellent articles on this very subject.
This quote comes from the source listed below it:
"About reliability, not only did the engine withstand 24 hours of pedal to the metal racing, but upon inspection after the race, Mazda engineers said that the R26B was in such a good condition that it could take the start in another 24 hours race with only an oil change."

https://www.autoevolution.com/news/m...ns-139515.html