Do you need a LOA to repair the muffler?

[CTSW Bob]

Hello - Annual time for my CTSW.  Standard 912ULS.  I am NOT experimental.  My A&P found a small crack in my exhaust.  It appears to be where a factory weld was done.  He said it most certainly can be repaired, but needs an approval since I am factory certified LSA.  Do I need a letter?   

 

Thanks for your input.  

Bob

[Roger Lee]

No. I haven't heard of anyone getting an LOA for a small muffler repair. I've done 8-9 at my shop. You can repair that minor crack so long as you don't alter the muffler system, which you aren't.

[Tom Baker]

I sent one to Airtime for a repair, and they did not provide a MRA. I have someone local do repairs like this now. He has the third one this year to weld. All three have had the same issue, a small crack just inside the factory weld for the internal baffles in the muffler. I think there is a flange that is causing stress. All were inside the cabin heat muff. Make sure you have a good carbon monoxide detector, especially when you are using the heater.

[Madhatter]

There is always a repair standard for exhaust repairs. What is your basis for approval to reinstall? I'll bet if you asked FD or Rotax they would not have one. Most exhaust systems on all aircraft have muffler issues at 1000hrs and before. Cirrus gets about 750hrs to 1000hrs. If you have cracks now you will have more later. You can't inspect the flame cone inside the muffler for issues.  If it comes apart there is a good chance it may block the tailpipe,  this has happened a lot and the engine fails. No one in certified ever repairs cracks in mufflers anymore, those days are gone, they have them rebuilt or buy new. LSA exhaust is no different than certified. They will kill you just as easily. 

[CTSW Bob]

Thank you all for the fast replies.  I will forward to my A&P.  

Bob