What are the Odds

[Ken Culbertson]

I was able to fly the Southwesterns last weekend and had a very strange experience on my early morning warm up flight.  I had a small, so I thought, prop strike taking off.  Common on that circle, lots of bumps and cracks.  The plane seemed to be fine, no vibration or funny prop noise so I went ahead and flew.  I was on a short battery so I only did a few loops, some inverted a sq8 and an overhead 8.  Figured I could sand the tip and rebalance it when I got home.

This is what I saw when I landed.  I know BadAss props produce a lot of thrust but I never figured that this shape would fly a plane nearly as well as a new prop.  When I got back to the shop I put it on the balancer.  Of all the weird stuff I have seen over the years, this one is up there with the best of them - THE PROP WAS BALANCED.

Ken

Maybe I should send this pix to BadAss.  They could add "In case of a prop strike, our exclusive self-balancing feature will insure a smooth run" to their advertising.

[MikeyPratt]

Ken,
You must be doing something righ, your lucky as all get out, it should have exploded the from end of the model.  I hope you pray to the Stunt Gods for their help, because they were looking out for you.  That being said, You said it’s a BadAss Prop, what type & size?

Large,
Mikey

[Dave_Trible]

The size is a Run Flat whatever you grind it to be.    No joke that could have hurt somebody or vibrated your airplane to pieces.    Glad you got lucky.
Carbon can also do things like that when they get brittle in colder temps.   During the winter off season I seldom get carbon stuff out.   At a fall contest last year two carbon props snapped off while burping the airplanes.   The engines were cranky in the cold and both pilots (I'm one) took to man handling the props.   NO NO.    I'm using muffled engines and wood props much below about 55 degrees.


Dave

[Dan McEntee]

  Did you turn the prop over on the balancer? You have to be careful with those little magnetic rigs. Check the spindle, or armature or whatever you call it to make sure it's not bent. I have gotten a couple of them to keep in various places for convenience and some of mine had threaded rods that were bent slightly, almost un-noticeable. They tweak back into being true pretty easy but that just means that they bend easy either way.
  Type at you later,
    Dan McEntee

[Brett Buck]

   At a fall contest last year two carbon props snapped off while burping the airplanes.   The engines were cranky in the cold and both pilots (I'm one) took to man handling the props.   NO NO.    I'm using muffled engines and wood props much below about 55 degrees.

   I never heard of one breaking in those conditions, but I sure am hesitant to be sticking my fingers in there when it's low 50s or less. When I was running my PA61, it was particularly vicious, kicking back unless you got everything exactly right. It even popped while choking it, just when it rocked back against compression.   The 40VF and Jett 61 are super mellow, but I am still in no hurry to go first when it is cold out.

     Brett