Prop Hitting A Plastic Twine During Take Off

[Kafin Noe’man]

My plane hit a plastic twine during the take off and the nose part got tangled by it. It suddenly changed the sound and the behaviour of the engine. It made the engine to sound quieter just like when you put an exhaust deflector or some sort and it lost some of the power. Plane could still fly okay though.

What are the chances that it will damge the engine?

Unfortunately I couldn’t go test run the engine nor flying it because it was raining heavily as soon after I landed.


Best,
Kafin

[Ken Culbertson]

I am guessing that it wrapped around or behind the thrust washer.  I have had that happen in combat with zero damage to the engine.  I can see it possibly hurting electric but not an IC unless it overheated and locked up which you said it didn't. 

Ken 

[Al Ferraro]

My plane hit a plastic twine during the take off and the nose part got tangled by it. It suddenly changed the sound and the behaviour of the engine. It made the engine to sound quieter just like when you put an exhaust deflector or some sort and it lost some of the power. Plane could still fly okay though.

What are the chances that it will damage the engine?


   That happend too me a few times when flying combat and the streamer wraps around the prop and drive washer. I never had a engine get damage from it, just had to remove the drive washer to clean it out to put it back in action.
Al

[Kafin Noe’man]

I am guessing that it wrapped around or behind the thrust washer. 

Yes, that’s exactly where it located.

   That happend too me a few times when flying combat and the streamer wraps around the prop and drive washer. I never had a engine get damage from it, just had to remove the drive washer to clean it out to put it back in action.
Al

Did you experience what I experienced too when it happened, engine sound quiter and lose some power?


Best,
Kafin

[Brett Buck]

Yes, that’s exactly where it located.

Did you experience what I experienced too when it happened, engine sound quiter and lose some power?


Best,
Kafin

   As soon as it gets in there, you are lubricating the front bearing with *molten plastic*, that will slow it down and suck up enormous power.

    As noted, you need to take it apart far enough to get the plastic out, you may have destroyed the front bearing and may show some cosmetic damage on the thrust washer or case.

    Brett

[Dan McEntee]

Yes, that’s exactly where it located.

Did you experience what I experienced too when it happened, engine sound quiter and lose some power?


Best,
Kafin

      The twine is acting like an engine brake. You probably have never flow balloon bust, where the object is to mount a balloon on a stick and try to pop it with the prop of your airplane. More times than I can count, I managed to kit the balloon dead center and then the plane flies through the "opening" and somehow the balloon gets completely over the prop, then get wrapped around the prop drive hub and cranks shaft. It can slow the engine down and most times stops it dead.  If you have a plain bearing engine, you have some end play that is needed and that is plenty of room for balloon debris , or combat streamer string to get in there and get wrapped up. In combat, flying lines can get tangled up in the engine, and stooge lines have been known to do that also  If it was something you wanted to do on purpose you couldn't do it but Murphy's Law always has prominence over specific intent !!
  Type at you later,
  Dan McEntee

[M Spencer]

What was it that used to get wrappe around the shaft on the lawn mower ? .

Should be fine , but Id have a good look at the prop , & check the motors still straight .
Or back off the bolts and pull em down with it straight .

Manadged to take off with the stooge line in tow . stopped using heavy thread , as binding
up your ankles meant you had to snap it , bare hand . Or sit down .

When combat got phycho , pilots started carrying side cutters. But you need good ones .

[Motorman]

With the excessive load for the whole flight, it could have damaged the big end of the connecting rod. If it doesn't run right, it's something you could check.

MM

[Al Ferraro]

Did you experience what I experienced too when it happened, engine sound quiter and lose some power?


Best,
Kafin
[/quote]
  Yes, I had some slowdown from 70 mph to 40 mph. When I had the Fox 25BB on the front of my speed limit combat planes the streamer wrapping around the drive washer happened often.
Al