WheelPantsOff

Because I was referenced, I'll respond directly. I do not believe I was the recipient of a 'shoddy inspection,' and more important than my feelings is my proof that I can't say I was. How many airplanes develop squawks or issues during or immediately after maintenance? Do you blame all of them on the shop either not performing the inspection correctly or willfully inflating the bill? So what am I going to do about it? I'm going to have the muffler repaired or replaced and the rest of the exhaust inspected and repaired as necessary and life goes on. Can I prove that something was or was not done relative to the muffler? No. All that can be proven is what is on the logbook sticker. Can I prove that the cracks developed in the handful of hours post-annual? No. Am I comfortable and confident in the shop's abilities, knowledge, regulatory compliance? Yes. Can I prove that something was performed incorrectly? No. Safety and regulatory compliance do not always see eye to eye. Look at all the NTSB recommendations that die on the vine because due to a variety of factors. The NTSB has no regulatory authority and strictly focus investigations, probable cause, and recommendations. I do believe your heart is in the right place when you say what should be included for inspection, but that shouldn't be mistaken for what must be included in an inspection. I can say that if a mechanic were to sit down and go over what was performed and then make recommendations above and beyond requirements, but that rarely happens in a completely comprehensive situation because the list would be never-ending for 40+ year old airplanes. And, at some point, once you independently vet a shop or mechanic, you have to trust that they're doing the work correctly. I did speak with the mechanic afterward and he explained what he did for the annual and I have to take him at his word. I will continue to use him in the future because nothing has proven to me that the outcome is his fault.

Even though few people care about this from a regulatory compliance perspective, this is an excellent thing to keep an eye out for during vetting the shop and when you pick the airplane up. And it doesn't matter if you're using a CRS, MSC, or independent shop. I don't believe that there's any meaningful difference anymore.

Sorry if this posts twice. I don't believe the first response didn't get posted. I'm highly confident that the crack didn't suddenly develop a month and less than 10 hours after the annual. Either way, I can't prove it one way or the other. Based upon the removal, I would also say that this was the first time in years that the exhaust/muffler was removed. In 30 years and overseeing hundreds of inspections, and the last few of these at MSC's, I don't think the muffler/exhaust was ever removed and the inspection goes something like, 'the muffler's there, no squawks, inspection complete.' I do see in the checklist that it's a required item.

Had the exhaust assembly removed today. Two cracks in the muffler: one you could slide a quarter through and another smaller one. The shroud appears to have been 'modified' by the prior owner and cut on one end. The adventure never ends!

I spoke with Rich earlier today and am going to send the entire exhaust assembly to him later this month or early Jan to repair. None of the other Hartzell-owned entities picked up the phones and AES's owner takes the time to spend 30 minutes with me discussing the process and knowledge. That's time and money well spent for me.

I see there is a lively discussion, much aged, in a separate thread after I sent my earlier message. Nice to see that the valves are still widely available. The outboard valves are noticeable harder to depress than the factory valves; looking at the two images, I can't see that being from the size/incorrect part number. I'm guessing something is blocking the actuation. Thanks again to all. Never a dull moment with these airplanes!

What's 9 years among friends for a bump... Now that I have time to clean the airplane while the exhaust gets repaired, I cleaned up really good under the four drain valves (I have the Monroy LR tanks). The outboard (LR) valves persistently get dirtier and leak-ier than the main valves. I cleaned them so good that now I can read the P/N and see that the outboard ones are the same P/N as the inboard drains. All four of them are F391-53S. I see that my outboard tanks require the F391-72. Anyone know the difference between the two? The 'proper' one looks taller than the factory drain. Thanks as always.

Thanks, guys. Time to get it sent out and repaired. I can't get a good look into the innards with a borescope so I'll just have the A&P remove the risers and hand me the muffler. On the exterior shroud/jacket, is it normal to have multiple rivets holding the shroud together? It looks like it may have been repaired before and looks like a 'rough repair.' Separately, researching shops, I have never seen such an incestuous business segment as aviation exhaust repair stations. It's like either Hartzell or some other VC-owned player owns all of the big ones. Thanks again to all!

Greeting all, A month out of annual and I have an exhaust leak. When using cabin heat, within 5 minutes my mechanical cat's eye goes from tan to black, and the electronic sensor reaches several hundred ppm and I stop the experiment. I performed a general visual inspection of the risers and muffler assembly and nothing was out of sorts. I checked for leaks and I was getting a lot of smoke out of the slip joints and two of the riser to exhaust port mating. I'm guessing that this is original to the airplane (~43 years). I understand that in order to take off the muffler assembly the risers have to come off and this is ending up into being a full exhaust repair. I'd like to replace the riser gaskets and have the muffler replaced. I can't open it because it has rivets all over the place on the cylindrical cone and I don't want to mess with that. Given these conditions, who would you recommend it gets sent out to for repair? Many thanks and have a safe and joyous holiday season!

Parts support, combined with the aging out of the ownership population, will be the death of this brand.

To close the loop on this, the one-piece seal the A&P installed seemed to solve the leak. I did notice that the oil return tube rubber couplings on the bottom of the engine were very loose and could be spun by hand. The hose clams holding those in were tightened and a noticeable decrease in belly/gear door blow-by was evident after a few hours.

Bumping this back from the dead. Where are people sending their D4LN-3000 magnetos for inspection/repair nowadays? Thanks in advance.

Yeah, I found that one here and have familiarized myself with it. It's a very well-written SI, considering that some I have read read like they're intended for engineers and not maintainers.

I'm going to live it, lube it, and love it before installation. And order a spare or two if it breaks it in two.

Thanks, guys. Parts on order.