Muffler Repair Source
- Thread starter Sub-sonic
- Start date
Snowbirdxx
Well-Known Member
Be happy that they are gone, you do not want them. They may block the outlet.
Tango Foxtrot
Member
My wife would call me a Husky Demon .
3 annuals ago the IA told me my flame tubes were shot. I called Aviat and was told they had designed a new and improved system and my muffler could not be repaired. I talked to the Aviat IA about this issue and I was told to be airworthy it should be replaced. The new system cost $2500.00 plus shipping. I said l would fly down and pick up the new exhaust system the shipping was $600.00 The mechanic suggested that I didn’t fly the plane until it was repaired. It was lousy weather so l took a few days and drove down. Bobby gave me a tour of the place and all that did was make me want a new one. last annual a SB or an AD showed up on the exhaust Needed to check leaks. Good luck. Remember all pilots are rich.
VLB
3 annuals ago the IA told me my flame tubes were shot. I called Aviat and was told they had designed a new and improved system and my muffler could not be repaired. I talked to the Aviat IA about this issue and I was told to be airworthy it should be replaced. The new system cost $2500.00 plus shipping. I said l would fly down and pick up the new exhaust system the shipping was $600.00 The mechanic suggested that I didn’t fly the plane until it was repaired. It was lousy weather so l took a few days and drove down. Bobby gave me a tour of the place and all that did was make me want a new one. last annual a SB or an AD showed up on the exhaust Needed to check leaks. Good luck. Remember all pilots are rich.
VLB
Thanks TF
They are more money now, but the rest of the places are repairing an old design for almost the same money. Its been a SB for awhile and should be inspected every 100 hours or annually, I use a $20 borescope from Amazon. I checked with Knisley Welding, Acorn Welding, AEI, and AWI. Aero Fabricators no longer does exhaust repairs because of a lack of welders.
Hi Sub-sonic,
I am trying to understand and learn how the flame tube failure caused pin holes. Pin holes are a very specific type of corrosion and it has been about 25 years since I had a class in corrosion engineering. I am just curious about the mechanism. Do you think that it is erosion breaking down a passivation layer with the new flow path that allows the start of pits or is it strictly a thermal issue with a change in grain structure?
Some folks on this site have intentionally removed their flame tubes and this is the first I have heard of it causing a pitting issue with the shell. Again, I am just curious about the mechanism.
Hi dogday,
I'm no engineer, but I continue to seek knowledge. Heat is the enemy. Excessive heat will cause the metal to erode and change the metal itself, making the metal weak and susceptible to failure. Heating and cooling cycles, along with moisture will cause the corrosion to begin. On this design or more specific my muffler the pin holes started at the end seams. The purpose of the flame tubes is to keep the exhaust flame from directly hitting the outer corrugated can. The exhaust flame is like a torch and the flame tubes buffer that flame. Most designs, say a Citabria or a Scout, muffler you cut the end off, weld in a new flame tube and close it up... not this design, seems like you can do it one time and then there's not enough of the corrugated material. When I started as an A&P looking up the exhaust was the first thing you did because turn around time on a muffler repair was a week or two. Now you can get a $20 endoscope hook it to your cell phone and take a look, easy. But, inspecting the muffler is important, that's what I'll do. FAA FAAST team has a good video on line ALC-498, Husky SB35 and AC91-59-A are good references. Hope that make sense.