Whirlwind GA200 failure

[chrishalfman]

Anybody else had this issue? It's a Whirlwind GA200L (ground adjustable). The first flight was Sunday and the plane has 15.1 hours on the Hobbs. After the test pilot came back today, he did nothing but rave about the prop and it's performance. After pushing it back into the hangar, I noticed a ripple on the one blade. The other blade shows stress in the coating, but not a complete issue, like in the blade photos shown. There is no nicks or imperfections in the leading edges, but the blade shown does have a hairline crack in the backside of the leading edge. Just glad it didn't depart the plane.





Have a message in to Whirlwind. I'll let you know what they say. I guess I needed something to go wrong, as everything else has been pretty darn good so far.

[cln1owner]

Chris, I've got a GA200 on my IO-320 powered 9A. I'm interested to know what engine you have and what you're static RPM is?

[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.

[Neal@F14]

Kinda hard to tell from the pics, but am I seeing that crack also extending into the metal leading edge strip? If so, then there must be some kind of bad harmonic mode thing happening with that specific engine and prop combo and very lucky that the blade didn't break away in flight.

Your test pilot probably should go and buy himself a lotto ticket

[blackbeard10]

I'll be checking mine as well. I have 120 hrs on my prop and 0 360 A1A 9:1 pistons. Please be sure to post results and info from Whirlwind. The prop is smooth. My only gripe is that the clear coat on the back side of the prop began to peel at about 70 hrs. I called Whirlwind and tech guy's response was not exactly first class. "Get a little 600 wet and dry smooth it down and then shoot some flat black on the back of the prop" Really? By the way Chris, what angle are set at? I believe I am at 22 degrees and I think I'll go to 23 as I have some throttle left.
Mark Wyss

[chrishalfman]

He is lucky the blade didn't decide to leave while he was in the air! Whirlwind has been very responsive. They have new blades coming to me and sent a label to return the ones from the plane. Bad thing-I didn't get these blades in the overnight shipment for UPS and I think they said the person that needed to see them is on vacation next week. That's ok. Millard (KMLE) is down starting next week for runway repaving anyway. Really would like to see what the issue is before going in the air again. We've (I've) come to two conclusions-as mentioned above I'm making some kind of harmonic it does not like or two-manufacturing defect. If it's the first, I am no expert on how to fix it. If it's the latter-I would be disappointed, but put the new blades on and fly. The only complaint I've seen from people is having to adjust them multiple times to get them set.

[chrishalfman]

Oh, to answer the question-we ended up at about 24?. Gives nice RPM at takeoff, but max'es out the motor before hitting 2700 RPM. The guy flying commented again while talking to him tonight he really likes the performance of it. I keep hoping it's something simple. I'm a mechanical engineer by schooling, but forgotten most of what I learned and was never good with vibrations and differential equations. Hopefully it doesn't become a science project as we like to call them at work (guessing on the cause and having multiple failures _guessing_ on what's wrong) and there's a simple reason or fix.

[Neal@F14]

Use a fresh set of Nordlock washers with the new blades. If not sourced from WW, I've found pretty good deals for Nordlock washers from Zoro Tools for my Sensenich GA prop. I had to Google for them by Nordlock part number since Zoro's website search engine didn't find them directly by size.

[danny]

Just wondering g how deep those cracks are. I'm really hoping they are just surface cracks since I have a new Whirlwind in the box waiting to go on an IO-360. My fingers are definitely crossed for you.

[MS19087]

Albeit I'm am flying behind an I0-320 rated at 165hp. Dual p-mags and 8.5:1 cylinders. I have seen no issues in 200+ hours.