The danger of heat

jesse

Touchdown! Greaser!
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Jesse
I wasn’t really planning on writing anything about this since I considered it to be not that big of a deal. But the more I thought about it the more I thought it might not be a bad idea. If I could just drive the point home with one person it would be worth it.

In aviation if there is metal bent or blood spilled there are usually a chain of events that caused it. I think carbon monoxide poisoning as a rental pilot is one of those things that has almost no chain to it. That only chain you get is the chain of symptom. The problem is that the more serious symptoms occur after your judgment and thought process has already been compromised. On a recent flight of mine I discovered the effects of carbon monoxide by experience instead of words in NTSB reports.

It was a cold night with temperatures at about 15 degrees. The winds were kicking strong out of the north and unfortunately I had to go north. With altitude the winds became unmanageable. Because of this I chose a relatively low cruising altitude for a night flight. There are increased risks as your options are very limited if the engine quits. I was cruising along at about 1700 AGL (3,000MSL) in a Diamond DA-20 with about 130 knots indicated and 85 over the ground.

I had developed a headache but didn’t really think much of it. I get headaches often without caffeine and I had not drank any all as of recent. I was looking at my sectional comparing it to the GPS and noticed that the GPS was not showing airspace. I knew that this was because the detail level was set too low on the 430. I couldn’t figure out how to change the detail level and I knew it was just a matter of pushing a button. After quite a bit of button pushing and knob turning I said screw it—I don’t need the airspace on the GPS.

As the flight continued the headache worsened and I started to feel pretty fatigued. At this same time I wanted to change radio frequencies to see if Approach could pick me up on radar for flight following. I don’t like night cross countries VFR without flight following and I really don’t like it this low. I’d like to at least get a yell for help out if the engine failed. I looked over at the Garmin 430 and wanted to change frequency. I turned the wrong knob at first and tried to push the button to go back. Next thing I knew I was DIRECT TO some airport that was like 500 nm away. I found the right knob for the COM and set it. But now I couldn’t figure out how to flip-flop it as the active frequency. I couldn’t figure out how to get back to the normal nav screen. I felt stupid and confused.

I knew right now that something was wrong. I *KNOW* how to use a Garmin 430. I’ve never had a problem and the things I’m trying to do are very simple functions. I knew it was not hypoxia because my altitude was too low. I knew what it was. I was getting poisoned by carbon monoxide. I turned the heat off and opened up the air vents. Luckily the DA-20 has some hellish air vents. As fresh air entered the cabin I started to run some random math through my head. Look at the airspeed indicator and took the indicated airspeed times the altimeter times plus the VSI. Just something random I could come up with. I was starting to feel better and math was making sense to me (at least I think I was saying the right numbers). After breathing nice fresh air for some time I looked at the GPS and knew instantly how to make the airspace show up. Press the CLR button. As I pulled the power off to land the engine started to backfire excessively. I landed and taxied back to the FBO and heard a very noticeable clicking noise the whole time.

I think the lower cruising altitude probably helped me out a LOT. If I would have been higher there would have been much less oxygen and the carbon monoxide effects would have been much more rapid.

The reason I post this isn’t really for someone to rip me apart about failure to recognize it earlier. Or failure to rip the cowling apart on preflight and inspect every single part of the exhaust like they do every single time since they are a perfect pilot and FAR 91.23.23.2 says to do it. The reason I write this is to try and get people to think about recognizing problems before it’s too late.

If something does not seem right in aviation—it’s not.
 
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The carbon monoxide detectors are very useful. My FBO puts them in all their planes for the winter season, and changes them out every with every GPS cycle, so they're always good. We've had one leak in 4 years and over a dozen airplanes, and they figure they get their money's worth. Their insurance company likes the idea too, and encourages it in other clients.
 
The reason I post this isn’t really for someone to rip me apart about failure to recognize it earlier.

No ripping here, I think you were on the ball, and saved yourself. I hope I do as well if I encounter a similar situation...
 
Yet another reason to invest in those cheapo CO detectors. Good write up, and glad you didn't end up another statistic.
 
Though if he did, the conveyer belt thread would finally die...


... no no - bad Chuck ... evil thoughts.


Satisfying...evil thoughts... ;)





(J/K Jesse!) :)
 
Though if he did, the conveyer belt thread would finally die...


... no no - bad Chuck ... evil thoughts.


Satisfying...evil thoughts... ;)





(J/K Jesse!) :)

Nah. I'd posthumously continue the thread in his honor. :D
 
Good write-up. I'm glad you recognized it early, corrected and made it down safely.

What was found to be the exact cause of CO entering the cabin? I know the common cause is cracked exhaust from fatigue, entering the heat exchanger. But, just curious what they actually found.

As much as the conveyor belt thread gives me headaches, this isn't how I want it to end! :)
 
Good write-up. I'm glad you recognized it early, corrected and made it down safely.

What was found to be the exact cause of CO entering the cabin? I know the common cause is cracked exhaust from fatigue, entering the heat exchanger. But, just curious what they actually found.

As much as the conveyor belt thread gives me headaches, this isn't how I want it to end! :)

Still awaiting details from the FBO.
 
Forget the expensive GPSs, handhelds, aviation do-dads - save your life and buy a portable battery powered CO detector! I did and the thing is great.
 
Yep, CO can be insidious. And (from personal experience) some exhaust leaks can be hard - nigh on impossible - to find, even by an experienced shop.

I am a firm believer in a CO detector... always was, but driven home by experience above.

You done good Jesse.
 
Thanks for the great write-up, Jesse. I'm really glad you decided to post it. As far as I can tell, you did everything right. It's easy to say that you should have recognized the symptoms earlier, but how do you recognize a scrambled brain when your brain is scrambled? You done good.

I've been told by a not very reliable source that it takes a very long time to get the CO back out of your system and that a precautionary landing might be in order if you detect CO in the cockpit. Your experience of your head clearing once you removed the source and provided plenty of ventilation seems to suggest otherwise. Obviously, an off airport precautionary landing would have been a poor idea at night. Did you consider diverting to another airport once you figured out what was going on, or were you already pretty close to your destination?

Chris
 
I've been told by a not very reliable source that it takes a very long time to get the CO back out of your system and that a precautionary landing might be in order if you detect CO in the cockpit. Your experience of your head clearing once you removed the source and provided plenty of ventilation seems to suggest otherwise. Obviously, an off airport precautionary landing would have been a poor idea at night. Did you consider diverting to another airport once you figured out what was going on, or were you already pretty close to your destination?

Chris

It might. I suspect that it could easily vary from person to person. I felt like **** for the entire night. The headache was mostly gone on my drive home.

I could have diverted but by the time I had everything figured out a diversion might have got me on the ground 10 minutes earlier. I didn't really think about diverting but this was probably because I wasn't thinking worth a ****. The disorientation / state of confusion was not a factor by the time I landed.
 
Jesse, that was a great writeup, and no criticism from me! You did a great job.

People shouldn't think of CO poisioning as a winter-only thing. If you're up high, you might have the heater on in the middle of summer.
 
Although I know you told me this story the other day, it deffinitly puts it into perspective when you can mentaly see whats going on. I'm very glad you noticed this quickly and I will admit that I would have noticed something was wrong but wouldn't have lead it to carbon monixide as quickly so hats off to you for that. I can deffinitly understand that it must have been a scary moment knowing that you knew how to operate the easiest functions on the airplane but couldn't seem to get it in order. I believe I would have thought it was fatigue which I'm sure would be my link to open the window anyways since thats my cure for motion sickness.

I hope you never hold back from sharing your experiences. Something seemingly small can lead to big trouble and the fact that you caught it by recognising symptoms, cured it, and then shared it with fellow aviators could have saved someones life. Remember the old saying? "Learn from others mistakes, you won't live long enough to make them all yourself."

Glad you learned something, and above all, I'm glad you're okay.
Tristan
 
The carbon monoxide detectors are very useful. My FBO puts them in all their planes for the winter season, and changes them out every with every GPS cycle, so they're always good. We've had one leak in 4 years and over a dozen airplanes, and they figure they get their money's worth. Their insurance company likes the idea too, and encourages it in other clients.
The trouble with Carbon Monoxide detectors is they do have a life limit unless its digital. The ones I've seen in most airplanes last only 90 days and in the original aircraft I recieved my private in, I believe they had been there for years! The color on the indicator had faded from the sun and there was no expiration date written on the front. Unfortunatly, the orginal thought to put it in the trainers was a great idea but hardly anyone keeps up with them (always exceptions). Other problems include throwing it on the dash or other areas where it cannot be seen. I actualy found one laying in the cockpit during my training and found out what it was, no instructor taught me about it despite it being a source of saving my life if I didn't catch the symptoms.

I do have questions on how helpfull they are too. Such as, the company indicates that it turns a slight grayish color. Would you be able to see that clearly at night or even recognise the color change links to carbon monoxide if you can't even understand what button to flip radios (not pointing fingers jess)? How gray is "slightly?" Why does it only work before 90 days is up? Shouldn't there be some sort of indicator when it would expire? I wouldn't think that would be too hard to make.

I do understand they make other types both lasting up to 18 months with the same plastic type or sportys offers others with digital read outs. I'm simply using the example I see in our trainers and also rental aircraft many of us are exposed to on a weekly basis. Just think about it, how often are you exposed to these risks and don't even think about it? After all, I've never seen "check the monoxide indicator" written anywhere (aircraft or flight center) and our students or us as students are flying countless hours each day. I guess some things are assumed a given to know.
 
All the aircraft at my aeroclub have the little card ones mounted on the panel using velcro. They expire 90 days or so after you open the plastic package, so you have to just write the expiry date on it when you open it. The better ones have two colors right next to the dot in the middle: orange (ok) and grey (bad). You can easily compare what's going on.

If you glance at it every once in a while (every time you change tanks?), that's great, but even just having it there to double check when you feel lousy would be good enough. Jesse said his first symptom was a headache. If he'd had a detector mounted on the panel, he could have checked with a flashlight to see if the headache might have been due to CO instead of lack of caffeine. My impression was that the headache came before the confusion, so that very inexpensive tool could have prevented him from descending into a dangerously befuddled condition.

The great value of Jesse putting up this discussion is that the next time I have a headache in an airplane, I'll actually think that it might be CO. Hopefully, I'll also have purchased my own CO detector if it's not already installed in the rental. I'll also divert if I'm not as close to home as Jesse was. By running through the scenario now, I don't have to think as hard when my brain's addled by CO.

Chris
 
Nice write-up. There actually is a chain of error with CO. It has two links and the first one is the pilot not utilizing a good CO detector on each flight.

I have a battery/box type that I leave right in the top of the flight bag open to the cabin air for every flight. It has a variable audio warning and the lowest detection will sound every so often, even in summer, which I don't mind because then I know the unit is working and it's not a dangerous amount of CO concentration anyway.
 
Thanks for the write-up, Jesse - NTSB reports don't tell us how it feels! :no:

Tris, those paper CO detectors are almost worthless even when they're new - You won't see any indication on them until you're well on your way to a highly impaired state.

How hard would it be for manufacturers to put a decent CO detector in the planes that's powered by the plane, rather than relying on people to change batteries (which as we all know can be highly unreliable! ;))? IIRC, Dave W ferried a new G1000-equipped Cessna that had a CO detector built in which would put an alarm right on the PFD.
 
Thanks for the write-up, Jesse - NTSB reports don't tell us how it feels! :no:

Tris, those paper CO detectors are almost worthless even when they're new - You won't see any indication on them until you're well on your way to a highly impaired state.

How hard would it be for manufacturers to put a decent CO detector in the planes that's powered by the plane, rather than relying on people to change batteries (which as we all know can be highly unreliable! ;))? IIRC, Dave W ferried a new G1000-equipped Cessna that had a CO detector built in which would put an alarm right on the PFD.

Let's see, ~$100 for state of the art audio warningdigital CO detector, plus FAA and liability lawyers, that should be about $1500 per airplane.
 
Jesse-

Thanks for the writeup. The description of symptoms is done well. I hope I don't have this problem, but if I do, I have the self-checking you have to catch the problem and fix it before I get incapacitated.

I've been told by a not very reliable source that it takes a very long time to get the CO back out of your system and that a precautionary landing might be in order if you detect CO in the cockpit. Your experience of your head clearing once you removed the source and provided plenty of ventilation seems to suggest otherwise. Obviously, an off airport precautionary landing would have been a poor idea at night. Did you consider diverting to another airport once you figured out what was going on, or were you already pretty close to your destination?

Chris

It does take a long time to get CO out of your system. The binding constant of CO with hemoglobin is much greater than that of oxygen (about 100 or 200x), so a dose of CO reduces the ability of the blood to carry oxygen for some time.

I am curious- would lean of peak (LOP) operations reduce the CO in exhaust, or do engines always make a certain amount of CO?
 
The trouble with Carbon Monoxide detectors is they do have a life limit unless its digital.

Tristan,

The truth that most people don't realize is that even the digital ones have a life limit. It's on the order of 5 years or so.

It is well worth talking to the manufacturer to find out the recommended useful life. The life you save may be your own.
 
Thanks for the write-up, Jesse - NTSB reports don't tell us how it feels! :no:

Tris, those paper CO detectors are almost worthless even when they're new - You won't see any indication on them until you're well on your way to a highly impaired state.

How hard would it be for manufacturers to put a decent CO detector in the planes that's powered by the plane, rather than relying on people to change batteries (which as we all know can be highly unreliable! ;))? IIRC, Dave W ferried a new G1000-equipped Cessna that had a CO detector built in which would put an alarm right on the PFD.

I disagree about the paper units. The "good" ones are pretty good and last no more than 60 days. Electronic ones are better, no doubt.
 
I bought one of the pulse oximeters a little while back. Can that be used to tell if you're impaired by lack of oxygen as a result of CO?
 
IIRC, Dave W ferried a new G1000-equipped Cessna that had a CO detector built in which would put an alarm right on the PFD.

Beat me to it! Yup, Garmin/Cessna were spot on with that design decision!! I think that's an awesome feature. Simple, but practical.

After a CO experience in a Mooney (was to be an IFR flight in the clouds, but we caught the problem before we got into IMC due to my co-pilot's CO detector card on his clipboard, which had been nice and yellow but was black passing through 3000 feet! :eek:), I bought and keep a CO detector card on my clipboard during every flight, right where I can see it every time I look down (it's held on to the top edge of the clipboard by one of those black binder clips).


Good write-up, Jesse. A few more minutes, you might not have been able to be discerning enough to know there was a problem.
 
I bought one of the pulse oximeters a little while back. Can that be used to tell if you're impaired by lack of oxygen as a result of CO?

No. IIRC, saturation of the blood with CO changes its color the same way that O2 does.
 
Both my wife and me were victims of CO poisoning in 1984. The heating system in our apartment in Germany malfunctioned and if my platoon sergeant had not come around to see what was wrong, neither of us would be here today. I recall very advanced flu like symptoms with an intense headache that lasted for quite a while. It was weeks before either us could ride in any sort of vehicle due to the motion sickness. Both of us were in the hospital for several days pressure breathing pure O2 to clear the effects of the poisoning. Today we have no less than four CO detectors in our home, one in each auto and one in the airplane. CO is nothing to mess around with where ever you are.
 
For $21 to $100 buy a battery operated CO detector and carry it with you. Cheap insurance. It is possible to get CO in the cabin even when not using the heat btw.
 
Beat me to it! Yup, Garmin/Cessna were spot on with that design decision!! I think that's an awesome feature. Simple, but practical.

snip....

I just got checked out in the G1000 at my FBO, and the fact that it has the CO Guardian is only briefly mentioned in the POH and the G1000 user guide. The POH also notes that it's optional, but I can't find a way to see if it's installed in a specific plane.

Anybody come across this and how to verify if it's installed or not?

I've been considering getting one of the electronic sensors to carry in my flight bag, and after hearing Jesse's story, I definately will be doing that, and soon.

As everybody else has said, thanks for sharing Jesse.
 
Probably not, as they work on the change in color of the rbc's when they uptake O2, and CO gets taken up in the same way, effectively mimicking the way O2 acts.

Of course, that right there is nothing but a WAG on my part!! :)

What's scary about CO is that it doesn't come off of the rbc once it attaches, there's such a strong bond. You have to wait for the rbc to die to get rid of it.
 
fbo said:
The exhaust pipe had become angled and was not
allowing for proper flow out which was able to be fixed quickly. Thank you
for bringing this to the attention of our people and appreciate your
business here. Thank and have a great day!


me said:


Did this exhaust pipe being angled cause the leak of exhaust?


Jesse


fbo said:
From my understanding it wasn’t allowing for proper flow out and was therefore leaking back in.

So whatever that means. That is the manager that is in charge of the aircraft rental. I doubt he's a mechanic. Maybe I'll talk to the mechanics one of these days for a better explanation. An exhaust pipe "being angled" that allowed for this to happen seems to me like the only way that could happen would be some mechanic messing up at some point.

The exhaust's flow being blocked doesn't make a whole lot of sense to me considering the very large ticking noise I could hear and the fact that the airplane seemed to have been developing full power best I could tell. I suspect that something wasn't put together properly and came apart.
 
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It may have been that the exhaust pipe bent, creating a crack, which allowed fumes into the heating system. Hard to say w/o seeing the bird.
 
Probably not, as they work on the change in color of the rbc's when they uptake O2, and CO gets taken up in the same way, effectively mimicking the way O2 acts.

Of course, that right there is nothing but a WAG on my part!! :)

What's scary about CO is that it doesn't come off of the rbc once it attaches, there's such a strong bond. You have to wait for the rbc to die to get rid of it.

Wow, IIRC, with about a 90 day RBC lifetime, that would mean about 45 days to get rid of most of it, unless it kills the cell faster than its normal lifetime, and about 90 days to get rid of all of the toxin?
 
Jesse,

When you have gotten more of the facts, you should write this up for AOPA Student Pilot. If anyone needs to hear about this, its them. Not that we all couldn't do with good reminders...
 
Change in skin tone is very rare in CO poisoning, unless you are talking about turning very pale :vomit: Almost no one turns red.

Pulse oximetry will NOT detect CO poisoning for reasons that - if I were to post them here - would bore most of you...suffice it to say that CO bonding mimics O2 bonding in the blood. Your SpO2 would look great right up to the moment you died.

I have the fancier card-type detector. I've decided that it is next to useless and I have a digital one on order as of last week. The reason is not that it doesn't work - I tested it and it does...but rather because - as Jesse's experience shows - the last thing you will think of in your impaired state is to look at the CO card. I'd rather have something beeping at me.
 
Thank you so much for posting this, Jesse. It may be that someone will benefit from your story. Bravo Zulu.

Jim
 






So whatever that means. That is the manager that is in charge of the aircraft rental. I doubt he's a mechanic. Maybe I'll talk to the mechanics one of these days for a better explanation. An exhaust pipe "being angled" that allowed for this to happen seems to me like the only way that could happen would be some mechanic messing up at some point.

The exhaust's flow being blocked doesn't make a whole lot of sense to me considering the very large ticking noise I could hear and the fact that the airplane seemed to have been developing full power best I could tell. I suspect that something wasn't put together properly and came apart.

Was there any part of their note that said "sorry you almost died up there"?
 
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