I just got these pictures from the shop doing the first annual under my ownership. The exhaust muffler looks burnt internally, and they recommend replacing. It is a Gomolzig silencer.
What options do I have other than souring a new replacement ? Is repairing / welding an option ?
And dare I ask is this an item that affects airworthiness ?
Gomolzig has been reasonably fast in repairing my exhaust, when I had a leak two years ago. In the process they found a few other very thin parts.
Check, if its just the muffler or maybe a “major repair*” of the whole exhaust by Gomolzig.
Took 2 wks in my case.
*effectively a new exhaust…
they recommend replacing
And so would I. The noise absorbing sheet is breaking up. This is, but please send the pics to Golmozig first, difficult if at all repairable.
Airworthy? No.
There have been cases when a whole piece of the material broke loose and wedged itself across the exhaust tube… and this is no good.
Interesting type of failure. How many hours?
It must be normal stainless; inconel would not disappear like that.
Don’t ALL mufflers do this after ~15 years?
Only some have that perforated sheet. Mine doesn’t and looks like new after 21 years / 3000hrs.
Peter wrote:
Interesting type of failure. How many hours?
I will have to lookup the log books and report back (travelling at the moment). From memory previous owner had it installed many years ago.
Peter wrote:
It must be normal stainless; inconel would not disappear like that.
Shop is dealing with Gomolzig. Will check if inconel is a replacement option.
boscomantico wrote:
Don’t ALL mufflers do this after ~15 years?
Interesting. Maybe a poll of owner operators is worth doing: How often have you repaired / replace exhaust system on your aircraft ?
Thanks for all your quick feedback.
Update:
Rest of the exhaust system is fine, only the perforated muffler is the problem.
It was in service for just over 1000 Hours, installed 12 years ago.
Is this typical lifetime of a muffler ?
@Peter, @boscomantico, @ch.ess
My experience (sample size = 1) :
Exhaust developed a crack after 19 years and >2000hrs in service*
Gomolzig repaired it extensively and did not comment on any other particular failure/issue.
So it can/could last longer…
PS i did repack the Liese muffler with a sort of steelwool once. That was fairly brittle/burnt, but is apparently an expected maintenance step after several hundred hours with Liese’s
I have never had exhaust parts (in aircaft) which have this stuff inside but the problem is probably in the use of a poor grade of stainless steel.
SS comes in many grades, from basically crap to very good stuff.
But nothing beats Inconel. Some good reading especially in that Socata one. There is clearly money to be made by supplying substandard material.
