Had the same problem. When I replaced the heat shield plate I left
one side of the big fixing clips just a little bit loose so that the
plate can expand and contract relative to the muffler without having
to go into tension forces. 50 hours on there is no sign of the cracks
returning. By the way, I also wire locked the screws on the fixing
clips so they stay just as I want them.
Willie Harrison (G-BZNY)
On 18 Dec 2006, at 20:22, irampil@notes.cc.sunysb.edu wrote:
>
> Greetings All,
>
> I just completed my annual condition inspection of N224XS
>
> I discover that the aluminum plate strapped atop the muffler was
> cracked
> bilaterally just inside its retaining straps starting forward and
> extending
> backward. I stop drilled them.
>
> Last year it was the muffler that cracked in several places in or
> near the down-
> pipe sockets. No problems there this year.
>
> Has anyone else seen this? Since there are no apparent structural
> pressures
> on this piece of aluminum, the cracks maybe related to thermal
> stress, i.e.,
> different coefficient of expansion of plate vs muffler to which it
> is bound.
>
> I just hate cracks in aircraft!
>
> Any thoughts?
>
> Ira N224XS
>
>
|