Results 1 to 14 of 14

Thread: PA-12 top cowl snubber?

  1. #1

    Join Date
    Sep 2003
    Posts
    5,589
    Post Thanks / Like

    PA-12 top cowl snubber?

    There is a 12 locally with an angle piece at the top center of the nose cowl where it meets the top cowl. It does not contact the engine case. IA (not me) wants it attached. I think that might be a lousy idea.

    Help? I can maybe post photos with some effort.

  2. #2
    www.SkupTech.com mike mcs repair's Avatar
    Join Date
    Aug 2004
    Location
    chugiak AK
    Posts
    8,301
    Post Thanks / Like
    if i am reading that right, you mean the piece that hangs down with the rub block on bottom?
    rarely do they (original) touch on ground, I extend them to be closer or just touch

  3. #3
    Gordon Misch's Avatar
    Join Date
    Dec 2003
    Location
    Toledo, Wa (KTDO)
    Posts
    2,571
    Post Thanks / Like
    Do NOT attach to the engine, if that's what the person wants. Vibration will tear the cowl apart.
    Gordon

    N4328M KTDO
    My SPOT: tinyurl.com/N4328M (case sensitive)
    Likes AKCRUISER liked this post

  4. #4
    skywagon8a's Avatar
    Join Date
    Mar 2008
    Location
    SE Mass
    Posts
    7,009
    Post Thanks / Like
    Quote Originally Posted by bob turner View Post
    IA (not me) wants it attached. I think that might be a lousy idea.

    Help? I can maybe post photos with some effort.
    You are correct, If attached it WILL break.
    N1PA

  5. #5

    Join Date
    Sep 2003
    Posts
    5,589
    Post Thanks / Like
    Let me see if I can attach a photo:Click image for larger version. 

Name:	PA-12 nose cowl to engine attachment   (3).JPG 
Views:	79 
Size:	1.37 MB 
ID:	31408

    Yes, that worked. Apparently something has to happen to that little angle before the IA will sign the annual. My opinion is that it is fine as-is, having made it this far without a major catastrophe. This aircraft actually made it to Europe and back like that.

    Both the owner and I are IAs, but our opinions need to be augmented. The annual has to be through a Repair Station.

  6. #6
    wireweinie's Avatar
    Join Date
    Aug 2013
    Location
    Palmer, AK
    Posts
    1,512
    Post Thanks / Like
    What, exactly, is this IA's justification for wanting to attach this bracket to the engine? I.e. why does he think that is correct?

    Web
    Life's tough . . . wear a cup.
    Likes skywagon8a, mike mcs repair liked this post

  7. #7

    Join Date
    Sep 2002
    Posts
    168
    Post Thanks / Like
    Quote Originally Posted by mike mcs repair View Post
    if i am reading that right, you mean the piece that hangs down with the rub block on bottom?
    rarely do they (original) touch on ground, I extend them to be closer or just touch
    Mike, can you attach the snubber to the case using the case bolts instead of attaching it to the cowl?

  8. #8
    skywagon8a's Avatar
    Join Date
    Mar 2008
    Location
    SE Mass
    Posts
    7,009
    Post Thanks / Like
    Quote Originally Posted by bob turner View Post
    Click image for larger version. 

Name:	PA-12 nose cowl to engine attachment   (3).JPG 
Views:	79 
Size:	1.37 MB 
ID:	31408
    Both the owner and I are IAs, but our opinions need to be augmented. The annual has to be through a Repair Station.
    Bob,
    It does look as though the rub strip is worn and ought to be replaced. Tell the other IA that the cowl is fixed to the airframe and that the engine through normal operation moves inside the cowl. If the engine were fixed to the cowl, the part which makes the connection would break. If the people in the repair station think that it needs to be attached to the engine, find another repair station because this one has no business working on a PA-12.

  9. #9
    cruiser's Avatar
    Join Date
    May 2002
    Location
    South Glens Falls, NY
    Posts
    1,240
    Post Thanks / Like
    For us amateurs, what does he see that makes the airplane not airworthy?
    Likes Hardtailjohn liked this post

  10. #10
    skywagon8a's Avatar
    Join Date
    Mar 2008
    Location
    SE Mass
    Posts
    7,009
    Post Thanks / Like
    Quote Originally Posted by cruiser View Post
    For us amateurs, what does he see that makes the airplane not airworthy?
    That L shaped bracket which is hanging down from the stiffener on the top cowl. It's only purpose is to keep the cowl from sagging too low so that the starter ring gear contacts the nose bowl. There is supposed to be an anti-chaffing block on the bottom leg of the L where it can rest on the pad on the engine case. You can see half of an anti-chaffing strip along with both rivets.
    N1PA

  11. #11
    jrussl's Avatar
    Join Date
    Jul 2005
    Location
    Madison, WI
    Posts
    383
    Post Thanks / Like
    This thread sure has caught my attention. I have been experiencing a ton of cowl wear on my PA-18 since my rebuild in 2013 (750 hours of flying) and now am seeing the root of my issue. I have a rubber piece that directly attaches the cowl to the top of the case. I can see that I have to get this piece of rubber the hell out of there.


    Does anyone have a picture of what the original "bumper" system is supposed to look like?

    Thanks for your help.

    Jeff
    Last edited by jrussl; 05-18-2017 at 03:33 PM. Reason: to clarify that I have a PA-18
    Likes mike mcs repair, 12Geezer2 liked this post

  12. #12

    Join Date
    May 2017
    Posts
    1
    Post Thanks / Like
    Thanks everyone for your replies. My second contact with Univair with more info, Mark found the nose cowl rubber pad part no. U10189-008 but did not have the pad in stock so Mark emailed me the measurements 0.063 inches thick x 2.00 inches long x 0.50 inches wide neoprene rubber.
    Thanks again,
    Bob
    Likes Hardtailjohn liked this post

  13. #13
    www.SkupTech.com mike mcs repair's Avatar
    Join Date
    Aug 2004
    Location
    chugiak AK
    Posts
    8,301
    Post Thanks / Like
    most originals rub blocks are just phenolic that i have seen, but did not touch or come close to engine... think they were just there as a oh **** limit thing...

  14. #14
    12Geezer2's Avatar
    Join Date
    Jan 2006
    Location
    Eau Claire, WI
    Posts
    1,032
    Post Thanks / Like
    Piston engines are not as smooth as electric motors---attaching to the engine would shake heck out of the cowling--cowlings are aluminum and are prone to cracking when shook--perhaps some of the younger generation of inspectors just don't have the right experience/information. Was recently involved with the repair of a nice 90 H.P. Supercub that flew like a dream when completed.. inspected and signed off by a competent cub man---the next year the planes annual was done by another inspector who did not understand the correct method of weight and balance---added a bunch of lead to the tail---just very lucky no body was hurt before the mistake was corrected. When there are doubts about cub stuff, dot org is the best place to ask questions as the experience of so many here is priceless and can be life saving----geezer Dan
    Likes Hardtailjohn liked this post

Similar Threads

  1. Metal for boot cowl and engine cowl
    By Jim Miller in forum Experimental Cubs
    Replies: 22
    Last Post: 05-13-2015, 10:30 AM
  2. Webbing on nose cowl & boot cowl
    By cubnut93 in forum Tips and Tricks
    Replies: 14
    Last Post: 05-24-2014, 10:04 PM
  3. McFarland Cowl Seal Installation and Cowl Fit
    By Darrel Starr in forum Cafe Supercub
    Replies: 0
    Last Post: 03-30-2009, 10:42 PM

Bookmarks

Bookmarks

Posting Permissions

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