Hole in Cowling

Discussion in 'Maintenance Bay' started by NealRomeoGolf, Apr 27, 2022.

  1. NealRomeoGolf

    NealRomeoGolf En-Route

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    Is there a rule of thumb for what would deem the breach of a cowling (i.e. a hole) unairworthy? Hole size? Hole placement? Any hole at all?
     
  2. Fearless Tower

    Fearless Tower Touchdown! Greaser!

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    Hole in cowling is kind of ambiguous. Could range from a stop drilled crack (ok) to a gaping hole after cylinder head fails (decidedly NOT ok)…..
     
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  3. Bell206

    Bell206 Final Approach

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    Depends. If you are adding a hole to the cowling some fall under a major alteration per 43 Appx A. If you are repairing a hole in the cowling it follows other requirements.
     
  4. NealRomeoGolf

    NealRomeoGolf En-Route

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    This would be a hole found on preflight that shouldn't be there. About half a cm square, maybe smaller.
     
  5. Capt. Geoffrey Thorpe

    Capt. Geoffrey Thorpe Touchdown! Greaser! PoA Supporter

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    So, something is rubbing against the cowling that shouldn't oughta be rubbing?
    I would be less concerned about the cowl and more concerned about what is rattling around loose under the cowl.

    But, I ain't no A&P.
     
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  6. mondtster

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    How the hole got there would determine my level of concern about the hole itself. It would also be the deciding factor on if I flew the aircraft again before working on it to correct the problems found.
     
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  7. Bell206

    Bell206 Final Approach

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    Technically, its a discrepancy and should be addressed. But as noted above, what caused the hole should be determined to ensure there are no other issues or any hidden damage.
     
  8. Jeff Oslick

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    What caliber hole?
     
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  9. AKBill

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    OP says 1/2 a cm. That makes it about a 50cal..?
     
  10. mondtster

    mondtster En-Route

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    1/2 cm is 5 mm. That’s around 0.2”. So maybe .22 caliber of some type?
     
  11. GaryM

    GaryM Pattern Altitude

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    But it was reported as 1/2 cm square, so I'm assuming a squarish hole. Though I guess it could be round estimated to have an area of 1/2 sq cm.
     
  12. NealRomeoGolf

    NealRomeoGolf En-Route

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    I love you guys.

    Remeasured it at .25mm so it's pretty small. A&P says I'm fine and he will patch it.
     
  13. GaryM

    GaryM Pattern Altitude

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    0.25 mm? That's really small, like 1/10th the diameter of a standard round toothpick.
     
  14. Rgbeard

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    Could have been a .22LR?
     
  15. Rgbeard

    Rgbeard En-Route

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    Cm, mm, inches, caliber. We mess it up with grandeur.

    And the world wonders why the US of A can't handle the metric system.
     
  16. NealRomeoGolf

    NealRomeoGolf En-Route

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    Argh. Centimeters.
     
  17. Unit74

    Unit74 Final Approach

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    **** off, ya blimey wanker!:goofy::lol::rofl:
     
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  18. asicer

    asicer Final Approach

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    Radius? Or diameter? Perimeter?
     
  19. NealRomeoGolf

    NealRomeoGolf En-Route

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    Diameter
     
  20. eman1200

    eman1200 Touchdown! Greaser! PoA Supporter

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    Bro do you even lift
    Can u describe the hole?
     
  21. DaleB

    DaleB Final Approach

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    Not reliably.
     
  22. Jeff Oslick

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    I'd go with "an absence of aluminum".

    Like a hospital, a big building with sick people.
     
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  23. GaryM

    GaryM Pattern Altitude

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    Could be depth.
     
  24. Checkout_my_Six

    Checkout_my_Six Touchdown! Greaser!

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    why are we measuring in cm? o_O
     
  25. Racerx

    Racerx Pattern Altitude

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    I thought you were from Texas? Since when did Texas join the EU?
     
  26. NealRomeoGolf

    NealRomeoGolf En-Route

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    Don't ever accuse me of being from Texas.

    I lived in Germany for 3 years. I had a metric tape measure handy.
     
  27. Racerx

    Racerx Pattern Altitude

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    .25 cm is roughly 3/32 for those from 'Murica...or slightly larger than a c-hair for those that can't read a real tape measure
     
  28. Racerx

    Racerx Pattern Altitude

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    Apologies. Misremembering. I don't even know where I'd go go to purchase a metric tape measure
     
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  29. NealRomeoGolf

    NealRomeoGolf En-Route

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    All good. I went to college in Texas. I currently dont live too far south from you.
     
  30. Albany Tom

    Albany Tom Pattern Altitude

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    I'm not positive, but I think it's OK to use mm in Texas to describe artillery.

    If it's 88mm, it could be German. I think 37mm could either be Russian or US. 20mm or 40mm could be just about anybody.
     
  31. Maxnr

    Maxnr Line Up and Wait

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    A hole that is 0.5 CM converts to 0.19 inches, or about 3/16 inch. I'm betting that somebody ran some equipment into it. On top, on the side, the front? Metal or FG? Engine OK? 0.177 is an air rifle caliber.
    As 206 said, FAR 43 Appendix A, Para (C) preventive maintenance is authorized if you are the owner, pilot or operator. There is a list of the do-able things that you can do. #12 is: "Small simple repairs to fairings, cover plates, cowlings,....etc". I would go to a boater's supply store and pick up a fiber glass repair kit and don't look back.
     
    Last edited: Apr 28, 2022
  32. PastZTL

    PastZTL Pre-takeoff checklist

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  33. WDD

    WDD En-Route

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    There are two types on countries. Those that use the metric system, and those that put a man on the moon.
     
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  34. Dan Thomas

    Dan Thomas Final Approach

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  35. Dan Thomas

    Dan Thomas Final Approach

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    When America put men on the moon, Canada was still imperial. Inches and feet. The metric system wasn't mandated until about 1976 or '77, and even after 45 years we still buy lumber and plywood in inches and feet. And build houses that way. The supermarket has prices for metric weight and often in pounds and ounces as well. Us old guys still think in terms of miles and acres and stuff like that, and some of use are good at converting on the fly. When talking to young people we have to remember to give specs in metric. I can't tell a kid that my favorite lake is 1100 feet deep; got to tell him it's 330 metres deep. On POA I have to talk in 'Murican measurements. And spell words in 'Murican.

    Primacy. Whatever is first learned is really hard to break. Not until everybody born before 1977 is dead will it go away here, and even then, if the US remains a world power, we'll still have to deal with the old systems.
     
  36. DaleB

    DaleB Final Approach

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    One of the surprising things I learned during my recent trips to the UK is that the English still use feet, inches, miles per hour, etc. I'd have thought they'd gone metric by now, since their currency did back in 1971.

    The other big surprise is that those people drink coffee ALL the time... don't know that I ever saw anyone drinking tea.
     
  37. WDD

    WDD En-Route

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    To be serious for a second - yeah, the metric system is much better. Knots, nautical miles, statute miles, inches of mercury, ……. It’s odd


    Hey - we lead the work with soda in 2 liter bottles !
     
  38. PastZTL

    PastZTL Pre-takeoff checklist

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    And every auto engine is in liters.
     
  39. Jeff Oslick

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    Nautical miles and knots at least have a basis in physical geography.
     
  40. Checkout_my_Six

    Checkout_my_Six Touchdown! Greaser!

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    Yup....he needs to keep looking for the oil leak. Hasta be with that round fired into it. o_O