Damaged prop leading edge

Two screws from the middle of the propeller hub sheared off and nicked the leading edge of my composite Catto propeller. The plans call for AN526 screws with a nylon washer, however AN515-8R8 screws with a 960L washer were used. The plane (RV-7) & engine (IO-360) has 40 hours on it and the highest RPM reached that day was 2750 RPM.

My question?s are:
1. What caused this and how do I prevent it from happening again?
2. How do I repair the leading edge of the prop? (A call to Catto has already been placed, but no answer yet)

[URL=http://img707.imageshack.us/i/frontleadingedge.jpg/][/URL]

[URL=http://img576.imageshack.us/i/3ofthewayout.jpg/][/URL]

Sorry this happened...

it's also happened to myself and to many others and not just with a Catto Prop. Tape off the areas so not to make a big mess lightly sand and fill with JB Weld. Works great! Then lightly sand to shape, you may need to "Rinse and Repeat" this once or twice to get a nice repair. I would recommend getting the color codes from Catto and having touch up bottles in the hangar. Most likely, there will be another chip in the props future. All props get chipped and nicked. As to the screw issue, I now put a drop of blue loctite in the screws before installing them. So far, no more screwed coming loose.

I do not understand how the screws stay in. I have nutplates. I was having problems with several screws coming lose. I should have used lock washers but did not. One screw came out and nicked my prop.

Used epoxy to fix it. I then removed the spinner and later replaced multiple nutplates.

There is a good video on composite propeller repair in the hints for homebuilders section on the EAA site.

Hi Dave,

I also have a 3 blade Catto on my 9a. On a trip to Big Bend Ranch State Park back in 2007, I got a "ding" on the leading edge of one of my blades--just about 8 inches from the tip. It was from a piece of gravel kicked up while "spinning the plane with power" to position for tie down. I used fast set two part epoxy (get it at any Lowes/Home Depot/etc) along with a womans emory board to sand it flush. From your pics I would say that my ding was slightly deeper than yours. Talked to Craig about it afterward and he told me that as long as the ding did not get down to the wood laminate core of the edge my repair should be just fine. As a result of this experience I installed the tape leading edge protector and have not had an incident since.

Cheers,

db