Precautionary Landing

[John221us]

So a friend and I had just departed my home airport in my Cherokee. Just a few minutes into the flight during the climb, we both noticed a clacking noise. I immediately turned the plane back to the airport. I did notice that the noise was more pronounced at higher RPM. I had not lost any power and all the gauges were in the green. The noise was definitely not there on run up and takeoff. It started after I already had flight following.

Here is what my exhaust pipe on my #2 cylinder looked like after I landed:

 

[BillTIZ]

Interesting that the clacking noise could be heard over the engine and headsets. A hot smell may have been next.

A good decision to turn back and check it out.
We don't always notice exhaust cracks on preflight, and depending how the cowling opens, one cannot see the exhaust or intake manifolds.

 

[Neal Howard]

Good choice to land. An exhaust system breakage like that could quickly lead to a failed cylinder... or worse, an engine fire.

 

[John221us]

Interesting that the clacking noise could be heard over the engine and headsets. A hot smell may have been next.

A good decision to turn back and check it out.
We don't always notice exhaust cracks on preflight, and depending how the cowling opens, one cannot see the exhaust or intake manifolds.

Good point. I don't normally check that side of the engine. Maybe once every 4 or 5 flights. I usually only open the cowling on the right side, where the dipstick is. I will need to modify my preflight.

 

[John221us]

Good choice to land. An exhaust system breakage like that could quickly lead to a failed cylinder... or worse, an engine fire.

A fire is one of my worst fears.

 

[Tom-D]

Any one notice how many old welds were on that pipe??

In the long run, it is cheaper to buy new.

 

[Tom-D]

Good choice to land. An exhaust system breakage like that could quickly lead to a failed cylinder.

How ? ?

 

[Old Geek]

I had a similar failure in a Flight Design CTSW. I was in the pattern with an instructor. The sound was just like a car with the muffler broken off, along with a strong smell of exhaust gas in the cabin. We landed without incident.

 

[John221us]

Any one notice how many old welds were on that pipe??

In the long run, it is cheaper to buy new.

Do you think the old welds caused it. Should it have been caught at annual? I have had the plane a little over two years and no welding has been done to the exhaust since I have owned it.

 

[John221us]

I had a similar failure in a Flight Design CTSW. I was in the pattern with an instructor. The sound was just like a car with the muffler broken off, along with a strong smell of exhaust gas in the cabin. We landed without incident.

We didn't smell any exhaust gas, but it did sound a little like a broken muffler, but I wasn't sure.

 

[CMTowner]

It may have been able to have been caught in preflight, but it's hard to say. Based on what I see in the photo, I'm thinking it would not have been caught. I know that I will occasionally grab the exhaust pipe stacks and give them a little tug to check for movement.

You made the best call, going back to investigate. Better safe than sorry.

 

[Rigged4Flight]

Good choice to land. An exhaust system breakage like that could quickly lead to a failed cylinder... or worse, an engine fire.

How ? ?

John Purner writes in his book 02 Golf about a crack in the exhaust manifold on the #3 cylinder in his C150 that was repaired with a braze (the cheapest option his mechanic suggested). It eventually failed in flight, leading to loss of oil pressure, high engine temps, oil covering the windshield, and extreme vibration from the engine. He made a safe landing, but the engine was a complete loss (would have cost as much to repair as the aircraft was worth).

 

[denverpilot]

John Purner writes in his book 02 Golf about a crack in the exhaust manifold on the #3 cylinder in his C150 that was repaired with a braze (the cheapest option his mechanic suggested). It eventually failed in flight, leading to loss of oil pressure, high engine temps, oil covering the windshield, and extreme vibration from the engine. He made a safe landing, but the engine was a complete loss (would have cost as much to repair as the aircraft was worth).

Oil from an exhaust pipe. Now I've heard everything. Care to explain that one?

(Somehow when I saw that book was $3 for Kindle or free for Prime subscribers I had a feeling there was a "you get what you pay for" going on there.)

I'm almost tempted to spend the $3 to read this train wreck now. Sigh.

 

[kgruber]

Any one notice how many old welds were on that pipe??

In the long run, it is cheaper to buy new.

Good catch!

 

[Henning]

Any one notice how many old welds were on that pipe??

In the long run, it is cheaper to buy new.

Yep, first thought, 'ain't no more welding that one up'...

 

[Henning]

How ? ?

Never figured that one out. Without a supercharger a zoomie pipe costs some power from lost scavenging, but that's about it.

 

[Rigged4Flight]

Oil from an exhaust pipe. Now I've heard everything. Care to explain that one?

(Somehow when I saw that book was $3 for Kindle or free for Prime subscribers I had a feeling there was a "you get what you pay for" going on there.)

I'm almost tempted to spend the $3 to read this train wreck now. Sigh.

I'm just the quoter, not the author.

 

[Henning]

Oil from an exhaust pipe. Now I've heard everything. Care to explain that one?

(Somehow when I saw that book was $3 for Kindle or free for Prime subscribers I had a feeling there was a "you get what you pay for" going on there.)

I'm almost tempted to spend the $3 to read this train wreck now. Sigh.

Burned through a hose?

 

[MBDiagMan]

Looks like time for a new exhaust system. That one appears to have had it's share of patching.

If you look in the picture along the right side of the pipe on the bottom segment next to the vertical tube, you will see that the edge is rusty. That means that the crack has been developing for a long time. Just sayin'.

Glad everything worked out okay.

 

[flyingron]

Interesting that the clacking noise could be heard over the engine and headsets. A hot smell may have been next.

I had an exhaust hanger break once. I could hear the clanking in the noise canceling headsets, pulling them off my ear to get a better sound made it impossible to hear it anymore.

 

[John221us]

I had an exhaust hanger break once. I could hear the clanking in the noise canceling headsets, pulling them off my ear to get a better sound made it impossible to hear it anymore.

Yes, it was a little easier to make out with the ANR headset on.

 

[Skylane81E]

Any one notice how many old welds were on that pipe??

In the long run, it is cheaper to buy new.

Split right down one of the welds too.

 

[Skylane81E]

Interesting that the clacking noise could be heard over the engine and headsets. A hot smell may have been next.

Last summer had a warrior that sounded like someone was banging on the side of the cowling with a hammer that turned out to be a broken exhaust stud. So if that small leak is that loud I can only imagine how loud a broken stack can be.

 

[AuntPeggy]

I'm not a mechanic in any way, but what I saw first was that the opening was right down the middle of an old weld and there is another old weld leading up to it. And yet another further down. Looked like a lot of repairs to my untutored eyes. I also noted that what appears to be a copper pipe next to the opening seems to be discolored, too.

Landing seems like a good idea to me. Anything noisy enough to be heard from under the cowl needs to be looked at.

 

[Henning]

If you're gonna spend money on exhaust, may as well buy a Powerflow pipe and save some fuel(or add some speed & climb) for your money. A tuned exhaust is the number one best engine performance mod bang for your buck regardless the engine.

 

[Sac Arrow]

If you're gonna spend money on exhaust, may as well buy a Powerflow ppe and save some fuel(or add some speed & climb) for your money. A tuned exhaust is the number one best engine performance mod bang for your buck regardless the engine.

A cheaper way to add speed is simply to put a Yoshimura sticker on the cowling.

 

[Henning]

A cheaper way to add speed is simply to put a Yoshimura sticker on the cowling.

But that is only for idiots who never in their lives would dream to make the bike go as fast as it could stock. Otherwise you won't see a sticker unless the sponsor is hauling the freight on the costs and then some. Stickers are for posers and sponsors.

BTW, do you think a tuned pipe is a waste of money?

 

[John221us]

If you're gonna spend money on exhaust, may as well buy a Powerflow pipe and save some fuel(or add some speed & climb) for your money. A tuned exhaust is the number one best engine performance mod bang for your buck regardless the engine.

I have looked into this before. I agree, it is a lot of bang for the buck and my plane needs the extra climb performance. I didn't pull the trigger, before, because I have been considering trading up for a Mooney or a Bo with a better panel. If I need to replace the whole exhaust, I will definately consider it, but 5 AMUs is still a lot to spend on an upgrade for a Cherokee, where you won't get it back on resale.

 

[wabower]

If "getting it back on resale" ranks high on your list for spending money on airplanes, you might to consider a different activity.

I have looked into this before. I agree, it is a lot of bang for the buck and my plane needs the extra climb performance. I didn't pull the trigger, before, because I have been considering trading up for a Mooney or a Bo with a better panel. If I need to replace the whole exhaust, I will definately consider it, but 5 AMUs is still a lot to spend on an upgrade for a Cherokee, where you won't get it back on resale.

 

[SCCutler]

Interesting.

My experience with seeing “repaired” exhaust system components (exhaust headers and mufflers) from reputable repair stations (I used Dawley) is that, while they may call it “repaired,” what you get back looks like new. My exhaust stack certainly looked so close to new that it was remarkable.

I suspect what we see there is the result of several field welds; the “repaired” stacks I got back had substantial new material, were new in appearance, very robust.

By the way, when I used Dawley, they gave mean estimate of time and cost in advance, and beat both by a good measure. Excellent service.

 

[Sac Arrow]

But that is only for idiots who never in their lives would dream to make the bike go as fast as it could stock. Otherwise you won't see a sticker unless the sponsor is hauling the freight on the costs and then some. Stickers are for posers and sponsors.

BTW, do you think a tuned pipe is a waste of money?

I don't think I could give a general answer to that. Tuned exhausts are generally most effective on engines running high BMEP's (high compression and turbo'd engines, less so aircraft engines.) But still effective. One nice thing about a tuned aircraft exhaust is it only needs to be optimized over a very narrow RPM range. There is the drag factor of a big external exhaust to consider too. Depends on the airplane and engine combination, and usage factor.

 

[Henning]

I have looked into this before. I agree, it is a lot of bang for the buck and my plane needs the extra climb performance. I didn't pull the trigger, before, because I have been considering trading up for a Mooney or a Bo with a better panel. If I need to replace the whole exhaust, I will definately consider it, but 5 AMUs is still a lot to spend on an upgrade for a Cherokee, where you won't get it back on resale.

You need to replace your exhaust as I highly doubt that it is only a rotten piece of **** in that one spot. Don't throw good money after bad trying to patch that mess up.

 

[John221us]

You need to replace your exhaust as I highly doubt that it is only a rotten piece of **** in that one spot. Don't throw good money after bad trying to patch that mess up.

I have a really good shop. They don't cut corners. They are going to take a look at it. I am certainly not an expert. He mentioned that he thought it was just old and that is why it gave out, which probably means I need to replace all of it. He did say that the welds near the header were normal and that is how they build them and he didn't think it was a former repair.

BTW, how much for the sticker and how much street cred does that buy me?

 

[Henning]

I have a really good shop. They don't cut corners. They are going to take a look at it. I am certainly not an expert. He mentioned that he thought it was just old and that is why it gave out, which probably means I need to replace all of it. He did say that the welds near the header were normal and that is how they build them and he didn't think it was a former repair.

BTW, how much for the sticker and how much street cred does that buy me?

The flange weld is the only factory one, and the welds aren't the issue, the issue is the parent material is eroded so thin that it'll break next to the new weld, and that's only if the guy is good enough with a TIG torch to not blow it out trying to get a bead.

Stickers are free and they buy you all the cred you paid for... It was funny seeing all the stickers on cars "Man, all those guys sponsoring you?" "No" "Then why are you advertising for them? BTW, that has to be the fastest tool box in the pit..."

BTW, If I was gonna put unsponsored stickers on my stuff, it would be for the worst crap on the market.

 

[dell30rb]

BTW, do you think a tuned pipe is a waste of money?

Depends on the bike / motor.

In the motocross world, you can be competitive in the 450 four stroke class with a stock motor/pipe. The bikes just have so much excess HP and torque anyway. The stock bikes come with a decent exhaust. My last yamaha yz250F came stock with a titanium header, that's not a cheap part.

Go down to the smaller 250cc Bikes, you will be at a significant disadvantage if you show up without an exhaust, higher compression, race gas burning, tuned motor.

 

[Henning]

Depends on the bike / motor.

In the motocross world, you can be competitive in the 450 four stroke class with a stock motor/pipe. The bikes just have so much excess HP and torque anyway.

Go down to the smaller 250cc Bikes, you will be at a significant disadvantage if you show up without an exhaust, higher compression, race gas burning, tuned motor.

Do tou understand the difference of what a pipe does on a single cylinder vs multi cylinder engine? As for bikes, the difference between a pipe for a 2 stroke and 4 stroke? BTW, most bike (and car for that matter) pipes today are tuned to scavenge rather than to 'log' the gas.

Also, having enough performance is not the only issue when gas is $5+ a gallon. An extra MPG adds up fast if you do some flying.

 

[dell30rb]

You need to replace your exhaust as I highly doubt that it is only a rotten piece of **** in that one spot. Don't throw good money after bad trying to patch that mess up.

Agreed unless he's really going to turn around and sell it. He won't see his 5k back.

 

[Henning]

Agreed unless he's really going to turn around and sell it. He won't see his 5k back.

If I saw that exhaust I'd figure the $5k into my offer. These days on resale it's about being able to sell it at all as much as price.

 

[dell30rb]

Do tou understand the difference of what a pipe does on a single cylinder vs multi cylinder engine? As for bikes, the difference between a pipe for a 2 stroke and 4 stroke? BTW, most bike (and car for that matter) pipes today are tuned to scavenge rather than to 'log' the gas.

Yes.. and I am talking about four strokes. Generally speaking the pipes are tuned to scavenge or actually pull the exhaust out of the motor in a certain RPM range.

On a two stroke I believe the expansion chamber is made to create backpressure at certain RPM's keeping as much fuel/air in the cylinder that would otherwise pass through.

 

[dell30rb]

If I saw that exhaust I'd figure the $5k into my offer. These days on resale it's about being able to sell it at all as much as price.

I agree if the rest of the exhaust looks all welded up and cobbled together. I didn't really look too hard at the pic.