Whirl Wind PIREP loss of shim

[dmattmul]

First, I've loved my WW 3 blade 300 series prop for its smoothness and power both climb and cruise. No issues removing lower cowling and have not split the bottom cowling.

Recently I was doing the normal walk around inspecting and pulling on the tips of the blades and noticed one that seemed "a little sloppy". Not remembering the exact play allowed I looked it up and seemed to be greater than the tolerance. After a call to WW Ohio (They do not exist any longer) called California and they had me inspect the blade root for possible loss of shim. Sure, enough it had departed the propellor. It fits under the heavy-duty retaining ring. See pics. I don't think this was a safety of flight issue or at least not immediate but worth checking on the walk-around.

Service and attention to detail was excellent from the factory!!

 

[airguy]

I don't think this was a safety of flight issue or at least not immediate but worth checking on the walk-around.

Wait, - was that the the opinion of the WW techs you called? Or your own assessment?

Me personally, parts falling off my prop would most definitely be considered a safety of flight issue. Your mileage may vary....

 

[dmattmul]

Examine the design and engineering

Wait, - was that the the opinion of the WW techs you called? Or your own assessment?

Me personally, parts falling off my prop would most definitely be considered a safety of flight issue. Your mileage may vary....

Greg, please examine the design and engineering. Of course, the techs would side on the caution side. During run-up the prop showed zero vibration issues, but I decided to go back to the hangar to investigate further. Even full prop RPM change at max RPM showed zero vibration issues. The shim is obviously very thin but most likely needed long term. I would have not flown after finding the issue but did investigate. I should have said short term safety of flight (till one lands) but you caught me and worth clarifying, congrats.

 

[Roadjunkie1]

Missing shim on a PROPELLER....

Recently I was doing the normal walk around inspecting and pulling on the tips of the blades and noticed one that seemed "a little sloppy". Not remembering the exact play allowed I looked it up and seemed to be greater than the tolerance. They had me inspect the blade root for possible loss of shim. Sure, enough it had departed the propellor. It fits under the heavy-duty retaining ring. See pics. I don't think this was a safety of flight issue or at least not immediate but worth checking on the walk-around.

Well, not immediately, no. Not until the prop departed company with the engine. Then it would be pretty immediate.

That "little slop" that you found just pulling on it could turn into a "huge slop" when all the amazing torques and pressures that are put on a prop are applied in flight. That shim is there for a reason: to stabilize the prop blade in relation to the hub. That would be an AOG grounding for me. What did the Tech people say? Is this a common occurrence?

Small tolerances can make a big difference when the noise is happening up front. I'm reminded of my friend who had a standard piston in a 10 over cylinder. It became a 'safety of flight' issue after 300 hours; then the piston finally had had just about enough of rattling around in the seemingly small space and disintegrated.....in flight....

IMHO......

 

[Desert Rat]

seems like that shim would have to break into chunks to get out from under the snap ring. How easy or hard was this to see once you started looking? did you have to take the spinner off or is this something you could eyeball on the walk around?

I've got one of these still in the box and just trying to educate myself.

 

[dmattmul]

Shim loss

seems like that shim would have to break into chunks to get out from under the snap ring. How easy or hard was this to see once you started looking? did you have to take the spinner off or is this something you could eyeball on the walk around?

I've got one of these still in the box and just trying to educate myself.

I’m not sure if it broke up. It’s split so it wouldn’t have to break up to come off especially at the kind of centrifugal force it might see. It was not in the spinner when I removed it. It’s not easy to visually see with the spinner on. I used my borescope with a side camera and possible to inspect about 2/3rds of the way around but again not easy. The backside of the prop has the largest gap between prop and spinner but that is where the snap ring sits right on top of the shim with no protrusion. The tolerance is 1/4 inch play at the tip but one needs to insure the play is at the composite blade and the aluminum ferrule which is not acceptable and play at the ferrule and hub is acceptable. Both of these should be fairly tight but if you do get some play (over 1/4 inch) spinner removal I feel would be needed to see where the play is. It’s fairly obvious if the shim comes out but really only after the spinner is removed.

Talking with WW is sounds like there have been other shim loss incidents but I didn’t ask the exact number. I don’t think it is very common but that is just my opinion.

My advice is to set up a routine to shake each tip every walk around. (Which we should be already doing) Once you get a “feel” for the amount of play if you loose a shim you will know something is wrong, I did. There will always be some flexing of the composite blade and that is normal. Again when I did my run up there was not a hint of vibration at full power and cycling of the prop so don’t think you’ll see vibration if a shim is lost.

Hopefully I am not coming across as unsatisfied. The prop is incredibly smooth even before it was balanced and I feel a good value for the money.

 

[Scott Hersha]

On my first RV8 with a 2-blade WW CS prop, after 100 hours or maybe more, the blades felt a little loose to me. I don’t remember measuring the play, but I called WW (up the road in Ohio at the time). They sent me a few shims of varying thickness. I replaced the shims in both blades with a slightly thicker one. It was a tight squeeze but it removed all or most of the play I had before.
It’s hard to imagine how a shim could be lost unless it breaks in two. I know there is a tremendous amount of centrifugal force, but it is basically forcing the blade outward, which should eliminate any play from “looseness” while the engine is running. Seems like that to me anyway. I loved my WW prop(s).

 

[DavidP2020]

dmattmul,

Thanks for the PIREP! I have a WW300 on order for my -10. I'll ensure your tip to check for slop in the prop blade is part of my walk around.

 

[Tandem46]

Dave, what year was your prop purchased? I have a new 300 I bought in April to replace my 18yr old 200RV (long story) but I thought the 300 hub was redesigned? Maybe not. Any way you can post photo that includes entire hub?
Thanks