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Thread: O 200 Crankshaft Rust

  1. #1

    Join Date
    Aug 2023
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    O 200 Crankshaft Rust

    A&P says (In connection with a Continental O200 top overhaul) the crankshaft has too much rust between engine housing and propeller (outside engine).
    I'm thinking the crankshaft diameter reduction and strength reduction from rust is less than 1% and irregular distributed over the length and diameter.
    The design strength of the crankshaft has likely a 50 % safety factor. So there should be no problem.
    Here are the photos:
    http://hc-research.com/Continental.html
    What do you think?

  2. #2

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    May 2012
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    Well ..... Continental service bulletin SB09-14 addresses this subject. Go to Continental Aerospace Technologies, support, service bulletins to read a copy.

  3. #3

    Join Date
    Aug 2023
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    Thanks Eric, I have seen the service bulletin.
    But I am unhappy taking out engine and crankshaft because the 50% safety factor is now a 49% safety factor.

  4. #4

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    Mar 2022
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    Quote Originally Posted by Firefly View Post
    Thanks Eric, I have seen the service bulletin.
    But I am unhappy taking out engine and crankshaft because the 50% safety factor is now a 49% safety factor.
    Where did you come up with the 49% number?
    I don't know how you figured that.
    You asked what do others think.
    I think you've got a area corrosion that circumferences the crank shaft and is a excellent point for cracks to begin. I'm guessing you've got the issue cleared up by now.
    Care to share how it was handled?

  5. #5

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    Mar 2022
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    Quote Originally Posted by Firefly View Post
    A&P says (In connection with a Continental O200 top overhaul) the crankshaft has too much rust between engine housing and propeller (outside engine).
    I'm thinking the crankshaft diameter reduction and strength reduction from rust is less than 1% and irregular distributed over the length and diameter.
    The design strength of the crankshaft has likely a 50 % safety factor. So there should be no problem.
    Here are the photos:
    http://hc-research.com/Continental.html
    What do you think?
    After reading the Service Bulletin, and judging by your pictures, I am in agreement with you A&P. Repair or replacement is in order.

  6. #6
    cub builder's Avatar
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    Nov 2011
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    Your A&P is correct. It isn't the reduction in area of the crankshaft that's the problem, but the rust pitting creates stress risers where the crankshaft has a greater likelihood of cracking and eventually failing all together. As a point of comparison, check the Lycoming service bulletin/FAA AD regarding corrosion pitting on the inside of the crankshaft bore on Lycoming engines (Lycoming SB 505). Those cranks get failed for significantly less corrosion than is shown in your photos. Yours can be reground to remove the pitting and returned to service.

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