Whirlwind GA200 failure

[N941WR]

Originally Posted by RV10inOz

...What worries me the most is the PMAG settings and the resulting peak cylinder pressures (read as the extreme forcing frequency amplitude) which when you watch crankshaft torsionals live, it is a scary thing....

Do you have issue with the P-mags or electronic ignitions in general?

At Oshkosh, Craig Catto mentioned the worst engine with regard to harmonics is the (I)O-340 with high compression pistons and electronic ignition. He said he had to redesign his prop just for this engine.

[ColoRv]

Originally Posted by chrishalfman

ECi Titan, OX-360, 185 hp, 8.5:1 pistons, dual E-mags. Static RPM 2250.
Hope it's something easily explained. The guy doing my phase one said it was a super smooth prop (was just ready to dynamically balance it since the pitch seemed to be set right and we weren't going to be messing with adjusting things for the near future) and he liked the performance on takeoff and cruise.
It'll be interesting to see how it all pans out as I have had possession of the prop for more than a year, (about 16 months or so) but just got it installed in June. And, finding out what's wrong with what. With that being said, I did get an after hours response (from a human) to the e-mail I sent them last night. That's a pretty fast response.

There is another possibility that has not been mentioned. Do you have engine data recording capability? Is the setting the prop is at now the first setting? Was it overspeeded while in search of the proper setting? Aerobatic overspeed? I'm sure your test pilot is very qualified and I do not in any way wish to insult anyone, but these things do happen.

[DanH]

Originally Posted by RV10inOz

What worries me the most is the PMAG settings and the resulting peak cylinder pressures (read as the extreme forcing frequency amplitude) which when you watch crankshaft torsionals live, it is a scary thing.

It's a reasonable addition to the suspect list. Sure would be fun to strobe that prop.

I wouldn't get too excited here. The Rusts are entirely qualified to determine what happened, and I think they'll be all over this report.

[chrishalfman]

For those following, here is the response I got form Whirl Wind:

Found non-structural surface flaw in face sheet which allowed epoxy ridge formation that cracked through paint under load. Blades structurally sound. Out of warranty period, courtesy replacement.

I actually feel pretty good about it. Whirl Wind Propellers was very responsive.

Can?t wait to get the new blades on! Now, if they were done with resurfacing the runway (KMLE), that would be even better??

[PCHunt]

Hey Mods: How about changing the title of the thread, since there was no "failure" here. Maybe "Great Customer Service from Whirlwind" or similar?

A blade replacement out of warranty! Nice.

[ColoRv]

Originally Posted by PCHunt

Hey Mods: How about changing the title of the thread, since there was no "failure" here. Maybe "Great Customer Service from Whirlwind" or similar?

A blade replacement out of warranty! Nice.

I love my whirlwind prop, but let's not get carried away. This prop failed. A crack like that is a ground the plane and remove the prop event....that's a failure by anyone's standard.

It was a surface flaw in the face sheet .... Meaning it was a manufacturing defect. The replacement of a brand new prop with 15 hours on it is hardly a stretch of customer service. In fact, it's pretty much a requirement. At 15 hours, if they had called it out of warranty I would have been very disappointed in them.

[Steve Melton]

thanks for the report. it seems the surface fibers may have had a wrinkle in them. wrinkled fibers will fail when loaded. inspect the prop, alum or composite, during the preflight.

[chrishalfman]

I forgot how important it is to follow up on these things. I?m one of those people that did a ton of research on here before purchasing, as it appears others are doing or those with a set of WW blades are concerned how things turned out. No less than 3 people have contacted me in the last couple weeks and a few others prior to that asking if there was more to the story. So??

Well, the good thing is, there really isn?t much more to the story. The new blades came, got installed, and there?s 89+ hours on the Hobbs (74 hours since replacement) now with zero issues. I?m satisfied. Would I buy it again? Yup.