What's that doohickey over there?

Discussion in 'Maintenance Bay' started by Jaybird180, Sep 25, 2020.

  1. Jaybird180

    Jaybird180 Final Approach

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    As a pilot transitioning to a new airplane, it occurred to me that I don't know enough about what's underneath the cowling. I don't really know what can be deferred during preflight and what is an airworthiness concern on any particular parts. TBH, I have mostly flown well-maintained machines, so my reference point is based on that.

    Case in point: on a plane that I'm gaining some familiarity with, I noticed a flexible air hose that seemed like it's wearing out. It's the type of hose with a wire coil on the inside for structural strength. But I don't really know the purpose of the hose so I can't make an informed decision about to fly or not.

    Where can I find a diagram or something that gives some helpful information about what's forward of the firewall and maybe something on the general airframe?
     
  2. Timbeck2

    Timbeck2 Final Approach

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    That is a SCAT hose and is used for air transfer for cabin heating, engine accessory cooling or engine intake air from the cowl to the carb. What makes you think it is "wearing out"?

    You don't need a "diagram", you need an experienced mechanic or a pilot who knows how to work on airplanes to tell you what's what.
     
  3. flyingron

    flyingron Touchdown! Greaser! PoA Supporter

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    The orangish hoses with the spiral wire are commonly called SCAT hoses. SCAT refers to a specific type of silicone impregnated ducting. There are also CAT (which is just rubber but similar in design and appearance), etc...

    Chafing on it isn't good. As to airworthiness, it would depend what it's used for. If it is your cabin heat, it could pick up CO from the engine compartment and put it in the cabin. Cooling air for something outside the cabin is sort of a yawner.

    Of course, no sane person will fault you for seeking clarification on any airworthiness concern that you are uncertain of.
     
  4. Salty

    Salty Touchdown! Greaser!

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    Google cessna 172m parts manual
    Substituting your aircraft of course
     
  5. Pilot Steve

    Pilot Steve Pre-takeoff checklist

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    I've been a pilot since 1988 and I'm always learning new things as well. Pilot Workshops just put out this new book that is packed full of an unbelievable about of exceptional engine compartment information. I ordered mine. https://pilotworkshop.com/products/airplane-engines/
     
  6. Bell206

    Bell206 Final Approach

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    Get you a copy of the Service Manual and Parts Manual for your model aircraft. If you want more detail on the engine do the same for it. The Service Manual will usually have a "description" paragraph/section at the beginning of every Chapter and in some cases at the beginning of each sub-sections within a chapter that explains the general what, when, where, how of that system. Use the Parts manual for an overall view of the area of interest which will also give you the chapter to look at in the Service manual. Have used this method for my owner-assist customers and new APs to get a basic feel of the aircraft. I still read the description paragraphs on occasion if needed. The ultimate reference for getting to know your aircraft would be to obtain a copy of a maintenance training manual put out by the OEM or OEM certified programs.
     
  7. Jaybird180

    Jaybird180 Final Approach

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    I'd describe it as it had been crushed in the middle 1/3rd of it's run and the outer material was wearing and likely perforated.