Arghhh, WW 200 RV backing plate cracks
 

Pulled my spinner off today to get it ready for paint. Noticed lots of fiberglass
dust on the inside spinner plate. Looked at the back plate and it was shattered
on one half and cracked in two places on the other. Total time 90 hours. It
wasn't like this at 50 hours when I did my conditional. Time to call the factory.
I believe there is a fix but pulling the prop is going to be not so much fun
especially getting the roller pins out. Arghhhh.

Walter

Any ideas as to the cause???

Frank @ sgu and slc RV7A

??
 

Hi Walter,

Why do you need to pull the roll pins? With the help of my neighbor we removed and replaced the prop with the new backplate reinforcements in under an hour. (after I received the new brackets.)

I did send the spinner backplates in for the "fix." The turnaround time was pretty quick from WW. I discovered the brackets cracked at 125 hours.

Walter, Frank,

This is well documented and has already happened to me three separate times. It has to do with the fact that the spinner back plate is in two halves and can flex. There is a fix. For all the background info go to the whirlwind prop yahoo group and for the fix contact Whirlwind aviation. I would go into it all here but I don't feel like typing for an hour.

For the record, I have about 380 flt hrs on my 200RV, a little more counting tach time. Since the latest and hopefully final fix I've got 97 hrs with no cracks.

Tobin

I know there is a fix but was under the assumption that the nuts would have
to come off in order to get a new backing plate installed. I guess that is
not a correct assumption? It's still early here in CA and I'll call WW when I
get into the office.

pics: dayum, look at all that fiberdust. Think that sucker was moving?

http://www.rv7-a.com/Img_1545.jpg
http://www.rv7-a.com/Img_1552.jpg

Looks like mine
 

Walter,

Looks exactly like mine. All there flanges on one side broke and there was some glass dust in there.

You need to send in the backplates for mods. They will send you the new brackets and some additional roll pins incase you shear them off while tightening. While they are fixing your backplates you can get the new brackets and the prop on.

More of an annoyance than anything. 40+ on mine now without issues.

Just got off the phone with WW and aparently the pins do not have to
come out but I just can't see how this is possible.

Parts will be sent out on Wednesday hopefully. Some folks
are on vacation this week and that's slowing down parts manufacturing.

Walter,
I agree with you, I've done this three times....the roll pins have to come out. Someone please enlighten me if I'm wrong. Also make sure you send the spinner back plate in for mod or you'll end up with cracks again.

hmmm. They didn't mention anything about the spinner back plate.
Do you mean the fiberflass spinner back two halves?

Backing plate repairs
 

Walter,

I went through this problem about 50 hours ago with my RV-8 and WW 200. My steel backing plate brackets broke exactly like yours. You need to send your fiberglas spinner backing plate halves back to the factory for a new mod that they do with them. They bond some carbon fiber tabs to one side of each half and you use AN3 bolts to hold the two backing plate halves together. This, in addition to new steel brackets should fix the problem.

You will need to remove the roll pins from the prop bolts (studs) to remove and replace the backing plate brackets. Buy or borrow a roll-pin punch and removing the pins is no big deal. Tapping the new ones back in is also straight forward. I used a bit of locktite on the studs when I installed the nuts and new roll pins. This was suggested by Greg at WW.

Greg at the factory was very helpful with this and turned around my parts very quickly. They did a beautiful job of bonding the new tabs onto the backing plate halves. They sent drawings back with parts to help assemble them correctly. The whole modification really makes the spinner backing plate solid and I don't expect any further problems.

Good luck,

Dan Miller
RV-8 N3TU 130 hours and loving every minute of it.
Aerosport Power IO-360 M1