Kitfox Aircraft Stick and Rudder Stein Air Grove Aircraft TCW Technologies Dynon Avionics AeroLED MGL Avionics Leading Edge Airfoils Desser EarthX Batteries Garmin G3X Touch
Results 1 to 3 of 3

Thread: Crack in engine mount gusset

  1. #1
    Senior Member kmach's Avatar
    Join Date
    Nov 2009
    Location
    Cupar, SK, Canada CLC4 Loon Creek Airfield
    Posts
    641

    Default Crack in engine mount gusset

    Hi all,

    while doing my annual I found a 5/8" crack in a gusset on the engine mount of my model 5 outback.

    I believe this mount is made of 4130 chrome moly, can anyone confirm this.

    I think this should be weldable with out removing the mount.

    Any thoughts, tips appreciated. 20170914_211839.jpg
    Attached Images Attached Images
    Kevin,

    Kitfox Outback
    912 ULS
    Airmaster AP332CTFH-WWR70W
    Summit Aircraft Wheel Skis
    C-FOXW

  2. #2
    Senior Member rv9ralph's Avatar
    Join Date
    Aug 2014
    Location
    Greenleaf, ID
    Posts
    618

    Default Re: Crack in engine mount gusset

    If the mount is powder coated, see if it will chip away from the crack. Sometimes a crack like that can just be the powder coating. If is more, the powder coating will have to be removed from the area to repair anyway.

    Ralph

  3. #3
    Senior Member PapuaPilot's Avatar
    Join Date
    Nov 2013
    Location
    Nampa, Idaho
    Posts
    1,225

    Default Re: Crack in engine mount gusset

    If no one is certain that it is 4130 it would be best to contact the factory. Find out what type of metal it is and have it professionally welded. It looks like you will have to remove your engine and mount from the plane. Then you need to remove the coating and have it welded. After that clean the mount up (bead blasting or similar) and prep it for primer/paint or powder coating.

    Don't cut corners on an engine mount, they are too critical. If you talk to to factory ask them for advice too. Maybe this gusset isn't that critical and the crack could be stop drilled and monitored, but I wouldn't make that decision without their input.

    There is also the possibility the crack could be welded without removing the engine and mount. That would depend on access for the welder and the ability to clean up the area well enough to get a coat of primer & paint on it after it is welded.

    After the repairs are done it would be advisable to have a dynamic balance done to your prop; vibrations from the engine/prop are the leading cause of cracks on aircraft.
    Last edited by PapuaPilot; 09-17-2017 at 06:55 AM.
    Phil Nelson
    A&P-IA, Maintenance Instructor
    KF 5 Outback, Cont. IO-240
    Flying since 2016

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •