Carbon Monoxide incident - Mooney No longer Stranded

[carusoam]

Great follow-up John!

At least with a high number it will make it a bit easier to find….

The common CO monitor many MSers use has device that helps search for the CO source…. A tube / sensor combination….

Makes it easy to point the tube at various locations around the cockpit…

 

Good luck with the hunt!

Best regards,

-a-

[DanM20C]

On 7/17/2022 at 6:33 PM, carusoam said:

Inviting @DanM20C our CO measuring guru… Dan has done a great job bringing this topic to the mainstream…

Thanks Anthony! 

Lots of good suggestions in this post.   I would examine the examine the exhaust carefully.  137ppm does seem very high for a normally operating exhaust system and a leak into the cabin someplace.  @Junkman had 200+ppm with a broken/loose V-band on his Bravo.

Thanks for posting and please let us know what you find!

Cheers,

Dan

 

[Ragsf15e]

Hopefully they’ve found it by now.  There’s only 3 areas it can come from:

1. Exhaust leak into engine compartment.  Possibly broken, disconnected or leaking exhaust.  It’ll then leak through the firewall.

2. Heater muff exhaust leak.  It’ll then get in through your heater vent.  Depending on how well your heater valve is adjusted, it may come in with the heat off.

3. Cabin leaks let in exhaust from outside.  Bad door seal, rat socks, etc.

Personally, my CO issue (caught with high Sensorcon reading) was #1.  Exhaust stack bolts not torqued, exhaust stack disconnected.

#2 is well known and can definitely happen in many airplanes.

I’ve heard people talk about #3 and I’ve seen it during runup/ground ops depending on the winds, but in cruise, my airplane definitely leaks and I show 0ppm…

[JohnB]

Update- by pressurizing the exhaust system, and applying soapy water to detect bubbles technique as suggested by the awesome Don Maxwell, mechanic found the leaks,  which were large amounts of CO leaking past my slip joints throughout my exhaust system. Since the exhaust and engine are nearly factory new, lycoming was contacted. I don’t actually know how high above 137 my ppm went, as I stopped looking at the monitors then and focused all of my concentration on landing.

I am hugely grateful for having a monitor on board or I may have never known. If I can figure out how to upload the video, I will. 

[Ragsf15e]

2 minutes ago, JohnB said:

Update- by pressurizing the exhaust system, and applying soapy water to detect bubbles technique as suggested by the awesome Don Maxwell, mechanic found the leaks,  which were large amounts of CO leaking past my slip joints throughout my exhaust system. Since the exhaust and engine are nearly factory new, lycoming was contacted. I don’t actually know how high above 137 my ppm went, as I stopped looking at the monitors then and focused all of my concentration on landing.

I am hugely grateful for having a monitor on board or I may have never known. If I can figure out how to upload the video, I will. 

Might also want to check for leaking through the firewall.  Are there open holes that need sealed?  I had an exhaust riser come off and I only got mid 50s ppm in flight.  On the ground it was higher.  I’m surprised yours got that high from leaking slip joints.

[JohnB]

On 7/20/2022 at 3:11 PM, Ragsf15e said:

Hopefully they’ve found it by now.  There’s only 3 areas it can come from:

1. Exhaust leak into engine compartment.  Possibly broken, disconnected or leaking exhaust.  It’ll then leak through the firewall.

Looks like mine was #1, exhaust leaking into engine compartment. Hmm That also probably explains why the number didn’t go down when I held the portable monitor outside of my side window. 

12 minutes ago, Ragsf15e said:

Might also want to check for leaking through the firewall.  Are there open holes that need sealed?  I had an exhaust riser come off and I only got mid 50s ppm in flight.  On the ground it was higher.  I’m surprised yours got that high from leaking slip joints.

Great point! Mechanic also found that one of the JPI probes going through my firewall wasn’t sealed properly which he did. Wouldn’t explain the high number by itself and the last probes were put in years ago, but that probably contributed 

On 7/20/2022 at 2:36 PM, DanM20C said:

Thanks Anthony! 

Lots of good suggestions in this post.   I would examine the examine the exhaust carefully.  137ppm does seem very high for a normally operating exhaust system and a leak into the cabin someplace.  @Junkman had 200+ppm with a broken/loose V-band on his Bravo.

Thanks for posting and please let us know what you find!

Cheers,

Dan

 

Yes exactly correct Dan. Exhaust issue and small leak in firewall from JPI probe. 
 

Edited July 22, 2022 by JohnB

[JohnB]

Allright update! I have learned so much about CO in the cockpit in the last 2 weeks. First, from Lycoming, slip joint leaks are common, particularly with new engines as the seals typically fill with gunk over time which seals the slip joints. So further investigation was required. 

Thanks to Al at Air San Luis in San Luis Obispo Airport, he was able to find the leak in one of my heater hoses and replaced. (See attached photo) Now no CO in my cockpit! Huge thanks to lots of people including All of Mooneyspace, and some awesome lifelong friends! 

[carusoam]

On 7/21/2022 at 11:17 PM, JohnB said:

Update- by pressurizing the exhaust system, and applying soapy water to detect bubbles technique as suggested by the awesome Don Maxwell, mechanic found the leaks,  which were large amounts of CO leaking past my slip joints throughout my exhaust system. Since the exhaust and engine are nearly factory new, lycoming was contacted. I don’t actually know how high above 137 my ppm went, as I stopped looking at the monitors then and focused all of my concentration on landing.

I am hugely grateful for having a monitor on board or I may have never known. If I can figure out how to upload the video, I will. 

Common practice… to load a video….

Use YouTube to host the video…. Post link here.

 

Great follow-up John!

Lets invite @DanM20C again to see what you found (high CO level, successfully detected, in a Bravo, now with follow-up of the cause)

 

The important part about life-long friends… successfully having a long life….  

Holy cow those CO detectors work great!   

Best regards,

-a-

[JohnB]

I now have two digital readout CO detectors in my plane and looking to replace one, as my original one only goes up to 50ppm. Looking for another CO detector that displays up to 1,000+ ppm (these are hard to find) as based on CO toxicity charts (one attached), I would do drastically different things depending on the level, i.e. < 50ppm,  I might just fly home. With increasingly higher levels, I would think about landing at nearest field with services, then nearest field, then nearest flat land based on the number. If I could find one that would go higher, for example if I ever saw a reading of 3,000 (egads) I would immediately shut down engine without any thinking about it and glide where I could, and I might be thinking that for readings over 1,000 as well. That's also why I think two are good to have as my first reaction was that there might be something wrong with the monitor but since it read over 50, wasn't going to take a chance..

Here is a chart of levels of CO toxicity, and time to unconsciousness and death which I found educational and helped me figure out what I would probably do based on a ppm number.

[MikeOH]

@JohnB

Thanks for that chart!

[Pinecone]

50 PPM is the OSHA limit for worker exposure for an 8 hour day, 5 days a week.

This is based on an 8-hour time weighted average.  So in a simple form, a worker may be exposed to 50 PPM for their entire shift.  If the level is 100 PPM, they would only be allowed to work for 4 hours.  200 PPM for 2 hours.   But you cannot go higher, as there is a Ceiling Limit of 200 PPM.  So a worker may not be exposed to over 200 PPM for any length of time.

I do not see the need for a meter that reads over 1000 PPM.

Anything over 200 PPM is a land IMMEDIATELY situation.  And over 100 PPM is a land as soon as practical.

If you have not ever been exposed to CO, you do not realize how extreme the headaches mentioned are.  They are blinding headaches.  I would not want to be flying/landing with one such headache.  And yes, I have been so exposed in my home due to furnace flue issue.

[Ragsf15e]

9 hours ago, JohnB said:

I now have two digital readout CO detectors in my plane and looking to replace one, as my original one only goes up to 50ppm. Looking for another CO detector that displays up to 1,000+ ppm (these are hard to find) as based on CO toxicity charts (one attached), I would do drastically different things depending on the level, i.e. < 50ppm,  I might just fly home. With increasingly higher levels, I would think about landing at nearest field with services, then nearest field, then nearest flat land based on the number. If I could find one that would go higher, for example if I ever saw a reading of 3,000 (egads) I would immediately shut down engine without any thinking about it and glide where I could, and I might be thinking that for readings over 1,000 as well. That's also why I think two are good to have as my first reaction was that there might be something wrong with the monitor but since it read over 50, wasn't going to take a chance..

Here is a chart of levels of CO toxicity, and time to unconsciousness and death which I found educational and helped me figure out what I would probably do based on a ppm number.

Sensorcon is a good choice.  There’s probably a discount available as well @DanM20C may know.  It goes from 0 to 2000.  
 

https://www.amazon.com/Carbon-Monoxide-Inspector-Detector-Portable/dp/B004YUEPBW/ref=asc_df_B004YUEPBW/?tag=hyprod-20&linkCode=df0&hvadid=312140380281&hvpos=&hvnetw=g&hvrand=15002458341707748687&hvpone=&hvptwo=&hvqmt=&hvdev=m&hvdvcmdl=&hvlocint=&hvlocphy=9032382&hvtargid=pla-569992736801&psc=1

[JohnB]

5 hours ago, Pinecone said:

I do not see the need for a meter that reads over 1000 PPM.

Anything over 200 PPM is a land IMMEDIATELY situation.  And over 100 PPM is a land as soon as practical.

If you have not ever been exposed to CO, you do not realize how extreme the headaches mentioned are.  They are blinding headaches.  I would not want to be flying/landing with one such headache.  And yes, I have been so exposed in my home due to furnace flue issue.

Thanks! Good to know about severity of headaches! None of these actions are written in any regulation or recommendation on what to do in flight that I’m aware of, but the reason I want one that goes a bit higher as I would like a ppm decision point where I would immediately shut the engine down in flight no matter where I was and glide in, which I probably wouldn’t shut my engine down at 200ppm, but would be looking for the nearest spot to land. 

19 minutes ago, Ragsf15e said:

Sensorcon is a good choice.  There’s probably a discount available as well @DanM20C may know.  It goes from 0 to 2000.  
 

https://www.amazon.com/Carbon-Monoxide-Inspector-Detector-Portable/dp/B004YUEPBW/ref=asc_df_B004YUEPBW/?tag=hyprod-20&linkCode=df0&hvadid=312140380281&hvpos=&hvnetw=g&hvrand=15002458341707748687&hvpone=&hvptwo=&hvqmt=&hvdev=m&hvdvcmdl=&hvlocint=&hvlocphy=9032382&hvtargid=pla-569992736801&psc=1

Thanks! I was just looking at a version of this one, and found the pro version. 
https://www.amazon.com/Sensorcon-Inspector-AV8-CO-03-Monoxide-Aviation/dp/B0986264WF/ref=sr_1_1?crid=13EES9A4BQDLL&keywords=Sensorcon+av8+pro&qid=1659193302&sprefix=sensorcon+av8+pro%2Caps%2C143&sr=8-1

Doesn’t look much difference other than the colors, but I think I’ll grab one of these. I like the portable nature of these so if I ever fly in rental or unfamiliar aircraft, I can get the same kind of notice. I’m getting one, thanks!

[Ragsf15e]

46 minutes ago, JohnB said:

Thanks! Good to know about severity of headaches! None of these actions are written in any regulation or recommendation on what to do in flight that I’m aware of, but the reason I want one that goes a bit higher as I would like a ppm decision point where I would immediately shut the engine down in flight no matter where I was and glide in, which I probably wouldn’t shut my engine down at 200ppm, but would be looking for the nearest spot to land. 

Thanks! I was just looking at a version of this one, and found the pro version. 
https://www.amazon.com/Sensorcon-Inspector-AV8-CO-03-Monoxide-Aviation/dp/B0986264WF/ref=sr_1_1?crid=13EES9A4BQDLL&keywords=Sensorcon+av8+pro&qid=1659193302&sprefix=sensorcon+av8+pro%2Caps%2C143&sr=8-1

Doesn’t look much difference other than the colors, but I think I’ll grab one of these. I like the portable nature of these so if I ever fly in rental or unfamiliar aircraft, I can get the same kind of notice. I’m getting one, thanks!

I have the older pro version and it’s great.  I have it hung on my old “microphone clip” which is in my line of sight.  The alarm is loud but not through noise canceling headsets.  
Expect to see some low values on the ground and maybe during climb (<20) but zero in flight.

[JohnB]

21 minutes ago, Ragsf15e said:

I have the older pro version and it’s great.  I have it hung on my old “microphone clip” which is in my line of sight.  The alarm is loud but not through noise canceling headsets.  
Expect to see some low values on the ground and maybe during climb (<20) but zero in flight.

@Ragsf15e Thanks for the pirep, just ordered one! 

[MikeOH]

@Ragsf15e

How old is yours? Don’t all of them have a relatively short life; like a couple of years?

Hmm, I better go check the date on mine!

[Ragsf15e]

32 minutes ago, MikeOH said:

@Ragsf15e

How old is yours? Don’t all of them have a relatively short life; like a couple of years?

Hmm, I better go check the date on mine!

Yes, it’s supposed to be recertified ~18-24 months.  Mine is about that old.  Still seems to be fine, but I think you can send them in for “factory overhaul “.

[Bolter]

I am late to this topic.  @JohnB, glad you could tell the tale with less drama than @DanM20C with his CO story.  

Aside from opening vents to get the most air (hopefully clean) circulation, I think you can consider getting to lower power and aggressively LOP.  I am rusty on combustion reactions, but I think as you get very lean, you get less CO production which will help reduce the source of the CO in the cockpit.  You will slow down, but may have clean air.  

Someone smarter than me should weigh in on this.

-dan

[ilovecornfields]

I’m curious what the safety-minded guys with mechanical knowledge like @kortopates think, but if I usually read 0 in flight and suddenly I’m reading 50 I would be concerned there is a dynamic process going on and I might be at 500 before I know it. I think if I saw anything abnormal suddenly pop up I’d be looking for a place to land to figure it out on the ground instead of flying away from possible landing sites in hopes that it doesn’t get worse over inhospitable terrain.

Bummer you got your plane back. Rod & Hammer is having their pickup party tomorrow and I’ve heard their orange bourbon is amazing. It’s also a 5 minute walk from the airport.

[carusoam]

What we have learned along the way…

Small CO numbers happen often…

Elevated numbers happen every now and then…

But, consistent elevated numbers are the time to do something different…

 

There are only a few situations that we have seen elevated numbers, but they have all turned out as an indication to find out what is wrong…

 

PP thoughts only, not a CO expert…

Best regards,

-a-

[Pinecone]

Yes, LOP operation will reduce the production of CO.

CO is produced when there is combustion without sufficient oxygen to fully burn all the fuel to end up with only H2O and CO2.  LOP is running excess air (O2) to ensure complete combustion of the fuel.  BTW, CO is flammable, so yes, it does get combusted.

My point was, 1000 is the range of thinking about shutting the engine off.  2000, you probably will not be conscious to do anything.

As mentioned, open outside vents, reduce power, lean VERY aggressively, and LAND NOW.

[GeeBee]

You need to stay on top of the units for calibration. I had a cousin who was a guide and Coast Guard licensed  Captain in Alaska. He became ill with the flu and returned to his boat to warm up and sleep. He never woke up. He ran the generator unit to operate the heat and he had a CO monitor. However it was 5 years old, never re-calibrated and basically was inoperative despite the power light on and a green light showing good air. In my boat I have 5 different monitors of different makes and the two marine ones I recalibrate annually although lately it has gotten to the price point where I just buy a new unit.

The airplane I buy a new Sensorcon every two years. I consider them "wearable parts" like tires.

 

[JohnB]

51 minutes ago, GeeBee said:

 

The airplane I buy a new Sensorcon every two years. I consider them "wearable parts" like tires.

 

@GeeBee, +1 on that. I think that’s what I’m going do from now on, as the portable ones are not that expensive, and big decisions rely on their accuracy, and me remembering to change them out at annuals I’m sure I can manage. 
My panel installed guardian CO unit is now out of date and inoperable, so getting a shop to remove, send out, recalibrate, receive and reinstall when it comes  back is likely more costly then  replacing 2 portable units. 

[Pinecone]

Each unit should have a life limit from first use in the instructions.   Home units these days typically have 5 or 7 year sensor life.

I suggest putting the CO monitor replacement (or sensor replacement) in your list of time related service requirements.

For home units, I suggest writing the replacement date on the unit with a Sharpie.

[Will.iam]

On 7/30/2022 at 12:51 PM, Ragsf15e said:

Yes, it’s supposed to be recertified ~18-24 months.  Mine is about that old.  Still seems to be fine, but I think you can send them in for “factory overhaul “.

Doesn’t mooney summit have a sensorcon  tester/calibration unit that they will check and calibrate your sensorcon if you bring it? I’m coming up on 1.5 years so need to get mine checked.