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Fatal Carbon Monoxide Crash


DanM20C

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So there has not been a great deal of discussion what to do if the worst.

What if a dangerously high CO reading occurs in flight - so high as to make headaches and clear risk of loosing cognitive ability and consciousness - but I become aware because my alarm alerts me in time.  What action to take?

Obviously if I have my o2 system at the handy then use it!  But it is not always readily handy.

Obviously declare an emergency and divert to the nearest practical landing point.

But what else?  Open the side window - open the vents - close the heater.

What else?

Open the door?  Probably yes? (and slow to a speed where opening the door is reasonable.

And monitor engine monitor for other even more pressing problems?  Like engine fire, or whatever else can be the cause?

Edited by aviatoreb
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I've got two CO sensors. If either of them go off showing dangerous levels of CO, I'm doing all of the above.

  1. Shut off the heater... if it's on.
  2. Open all ceiling vents.
  3. If that solves the problem, then I'd likely continue to destination. But not fly again until fixing the problem.
  4. If not...
  5. Slow to below 130 knots IAS.
  6. Open the window.
  7. If that solves the CO level, then find an airport and land.
  8. If not, then keep slowing and open the door.
  9. Find an airport and land.
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Things to consider...

1) sources of air, where they come from...

2) The heater is expected to be the primary source of CO. So it gets turned off first...

3) The outside air vent may be sharing the same ducts as the heat... it could be on the suspect list... unless the heat can be really shut off tight. This is the knobs on the panel...

4) Outside air vents independent of the heat system are OK.  It would take them being in the exhaust stream to accidently pick up exhaust... if you have a monitor, use it in the stream of the air supply to see what it is delivering...

5) open the pilot side window... it is running A vacuum service...pulling air away from the pilot... the eyeball vents are a good supply of expected fresh air...

6) Doing this is going to be extremely cold.  You want to be on the ground to find out what the problem is... and not freeze to death before doing so...

7) Any decisions you make with an elevated level of CO in the cabin, may not be your own best work... even low levels of CO are accumulating quickly in your bloodstream... without practice, it is going to be very difficult to calibrate yourself...

8) you may get the alarm at 10 ppm? You may have a few minutes to experiment with air flow...

9) Unfortunately, you might have a crack in the exhaust pipe growing at an unknown rate.  

9.5) in a turbo plane, it might not be contained to inside the heat muff... it could be the warning you need to get on the ground now.... broken pipe, or loose V-clamp... could be the blow torch effect up front...

10) Improve conversion from CO to CO2... deep LOP, low power, slow RPM...

11) The heart, when extremely short of O2, doesn’t work very well... people may have thought the pilot was having a hear-attack, or possibly he was... caused by CO poisoning...

12) Dan has posted the limits of CO that can be ingested over time in his presentation... and that is how the alarm limit / warning is set... @DanM20C see if Dan can point us to that slide...  there is probably a get home limit, vs. the land now limit... Best to be in the know for the situation you have...

Quick Review... Minimize CO production, don’t let the CO in the plane, blow lots of non-suspect air into the cabin, evacuate the cabin to improve air changeover... there is an exit air vent at the bottom of the baggage compartment make sure it is working/not blocked, get on the ground to sort things out...

Being short on O2 is similar in some ways as having many alcoholic drinks...in a very short period of time... with the inability to stop imbibing... short because CO is binding with, and blocking, the O2 receivers in the blood stream, you can’t use José’s magic whiz tube to unload the CO from your blood stream, the liver doesn’t help with the disposal of CO... decision and motor skills are going to be affected making flying really difficult...

Until you know the source of the CO, you want to be on the ground before it gets worse...

From my firebird experiments... the exhaust pipe separated from the engine block on the way home from the muffler shop... applied some throttle, I heard a bolt snap, smelled the exhaust, and felt some unusual effects within15minutes... used my CO meter after I got home... it was reading the number 80 on the device, blaring a warning...  the monitor was from CO experts.

I bought the CO Experts one before Dan did his aviation CO study...  Aging gracefully/quickly/overnight one day..., I lost a few key senses like the ability to smell/taste fine notes... so I went on a buying spree for the plane and house... CO and nat gas detectors... everywhere...

I have had a nat gas leak in the house before... a cracked pipe elbow after the install of a new heater.... got the new heater because we were afraid of it leaking nat gas.  The new installation assured the leak we were fearing....

Lesson learned, pipes crack and let bad stuff out... cracks don’t heal themselves, and might get worse, quickly.... turbo engines have more opportunities for cracked pipes to become disastrous...

Having a broken exhaust pipe is going to lead to a bad day.   Enjoy the bad day on the ground... it’s like a failed PPI that went horribly wrong... sure it’s expensive and inconvenient. But the alternatives are much worse... :)

 

PP thinking out loud, I only ran out of oxygen once... aviation taught me the meaning of the phrase TUC... you never know when that will be a useful lesson...

At least when you are on the ground, you can make a friend to help with your decisions...

If you wonder what it’s like to run out of oxygen on the ground... review the recent recording of the ATC controller having a stroke... with a stroke, O2 stops being delivered, when blood goes outside of the usual circulatory route... and can effect the brain more in one area than others... CO will be being delivered evenly throughout the entire body... more general, less acute...?

You might get the feeling of something going wrong, you might not... or it might be too late to get on the ground safely...

 

How about telling somebody? On Flight following? Hello ATC? Keep an eye on me, we are having a small CO situation... I want to be on the ground to figure this out....   you will sound perfectly fine to yourself... but you have advised help if you need it... If they ask you to perform a 10 count in reverse, you will know, you don’t sound fine to everyone else...

PP thoughts only, not a CO expert, or a doctor, and my firebird no longer moves pending exhaust work....  :)

Best regards,

-a-

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Anthony! I think that is my favorite post of yours.  I couldn't put it any better. 

I could dig out those charts but I don't like them.  I think everyone behaves so differently to exposure that they don't have much value in the real world.  They could lull someone into a false sense of security, "the chart said 200ppm will only give me a headache after 2-3hrs and I'm only 1hr from my destination, I'll continue on" 

Those charts also assume sea level.  I have been trying to find data for CO at altitude and there isn't much out there.  The only study I have found suggested that the effects of hypoxia due to CO and due to altitude have at minimum, an additive effect.  Altitude hypoxia can have a physiological response increased breathing rates(hyperventilation) to try to get more 02 in your system.  If CO is present this compounds the problem as the CO and Oxygen are fighting for the same spot on your hemoglobin and generally the CO wins.

 

13 hours ago, gsxrpilot said:

I've got two CO sensors. If either of them go off showing dangerous levels of CO, I'm doing all of the above.

  1. Shut off the heater... if it's on.
  2. Open all ceiling vents.
  3. If that solves the problem, then I'd likely continue to destination. But not fly again until fixing the problem.
  4. If not...
  5. Slow to below 130 knots IAS.
  6. Open the window.
  7. If that solves the CO level, then find an airport and land.
  8. If not, then keep slowing and open the door.
  9. Find an airport and land.

I don't know why I haven't thought of a checklist for a CO alarm.  This one is perfect.  Thanks Paul!

I might change #3 for us turbo guys if the ppm is remotely high, maybe 100 or more.  We don't have mufflers so I get my heat (at least the 231) from 2 heat shrouds around each (L&R) exhaust header.  If I"m getting CO through the heater I'm probably more worried about fire than CO at this point.

Cheers,

Dan 

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30 minutes ago, Yetti said:

Would you not want to add?  Descend to MVA

I wouldn't put it on my list.

If I'm IFR... I'd let ATC know either that I needed to land ASAP and find me the closest. Or I'd have already decided I'm landing and would have pick out my airfield of choice and asked ATC to get me there ASAP. In either case, I'd be descending on their orders.  If I'm VFR, then I don't care about MVA anyway and I'm just looking for a normal landing at whatever my GPS considers NRST.

At least that's my thoughts on it today... open to suggestions/education.

 

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6 minutes ago, Jim Peace said:

Carry a Pbe?

what are the highest acceptable numbers on a CO detector?

is there always 5 or 10 Ppm in a plane with the heat on or off? Or should it always show zero?

Not sure what's "normal" in the cockpit, but I suspect numerical readouts down to 1 ppm might be TMI and a bit of an unnecessary distraction.  The exhaled breath of a regular smoker has about 10ppm before their first cigarette of the day, and about 20ppm 5 minutes after a cigarette, so these levels in the ambient air probably do not indicate imminent danger.     I ended up going with the Guardian avionics 12V plug in that gives an amber light and alarm at 50ppm and a red light and louder alarm at 100ppm.  As long as the light is green, I'll ignore.  However if it goes off at 50ppm in flight, it might be nice to have some numerical trend data while you try to address the issue, so that may be a disadvantage of that particular device.  

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12 minutes ago, DXB said:

Not sure what's "normal" in the cockpit, but I suspect numerical readouts down to 1 ppm might be TMI and a bit of an unnecessary distraction.  The exhaled breath of a regular smoker has about 10ppm before their first cigarette of the day, and about 20ppm 5 minutes after a cigarette, so these levels in the ambient air probably do not indicate imminent danger.     I ended up going with the Guardian avionics 12V plug in that gives an amber light and alarm at 50ppm and a red light and louder alarm at 100ppm.  As long as the light is green, I'll ignore.  However if it goes off at 50ppm in flight, it might be nice to have some numerical trend data while you try to address the issue, so that may be a disadvantage of that particular device.  

Yes, but if you wanted trend data you'd have to repeatedly look at the display, which would be a distraction.

Ideally, someone would come up with a CO monitor that will display a trend bar graph or some other visual way of representing trend data.

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I just bought what I thought was a CO monitor from Sensorcon, only to find out that I messed up and got a H2S version instead.  A quick call got the correct one underway, with a comment of “no big deal, the correct one is on the way, just ship the incorrect one back”

Great customer service from them!

Clarence

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13 minutes ago, M20Doc said:

I just bought what I thought was a CO monitor from Sensorcon, only to find out that I messed up and got a H2S version instead.  A quick call got the correct one underway, with a comment of “no big deal, the correct one is on the way, just ship the incorrect one back”

Great customer service from them!

Clarence

Could have kept both- then you’d have had a toxic passenger fart detector as well

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Speaking of which....I finally got mine (Sensorcon) and clipped to the pocket right below the trim/flap indicator. Yesterday, I started the engine after multiple attempts (my mistake...) and the thing started beeping. The "pill" was ok (my backup CO2 detector!). I vented the cabin, started taxing and the number was going down. At altitude went back to zero. I opened the cabin air, still zero. Does it happen to you guys too?

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Speaking of which....I finally got mine (Sensorcon) and clipped to the pocket right below the trim/flap indicator. Yesterday, I started the engine after multiple attempts (my mistake...) and the thing started beeping. The "pill" was ok (my backup CO2 detector!). I vented the cabin, started taxing and the number was going down. At altitude went back to zero. I opened the cabin air, still zero. Does it happen to you guys too?


Nope. Mine will show less than 10 on startup (windows, vents and door closed).


Sent from my iPad using Tapatalk Pro
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5 hours ago, FastTex said:

Speaking of which....I finally got mine (Sensorcon) and clipped to the pocket right below the trim/flap indicator. Yesterday, I started the engine after multiple attempts (my mistake...) and the thing started beeping. The "pill" was ok (my backup CO2 detector!). I vented the cabin, started taxing and the number was going down. At altitude went back to zero. I opened the cabin air, still zero. Does it happen to you guys too?

 

3 hours ago, Marauder said:


Nope. Mine will show less than 10 on startup (windows, vents and door closed).


Sent from my iPad using Tapatalk Pro

 

Mine will show zero at startup but I will see anywhere up to 10 or so on taxi (Door/window open). If I am not pointing into the wind at run-up I have seen up into the 20's. I sometimes see the number come up on climb out but it drops back down to zero in cruise.

Your backup "pill" will not react as quickly as the sensorcon. It requires elevated levels for a period of time before it shows a reaction. If you are talking about the standard dot that a lot of people have it lists this on the AS site.

What is the threshold in PPM for this detector to turn to black? 
100 PPM 15-45 minutes / 200 PPM 4-5 minutes / 300 PPM 2-4 minutes / 400 PPM 1-4 minutes

Your Sensorcon should start beeping at you at I think around 35? That gives you a lot of time to make adjustments, open/close vents, heater, door, window, etc... and correct it long before that dot is going to show anything.

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Just now, flyboy0681 said:

My Sensorcon consistently shows 5 during flight. I have it mounted on the center console near the fuel selector.

In flight the highest I have seen is 1, it is normally at zero.  On the ground it varies depending on how many window/door/fresh air openings there are the wind direction.  I have had it alarm as well, but only when taxiing with 50 other Mooneys...

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7 hours ago, FastTex said:

Speaking of which....I finally got mine (Sensorcon) and clipped to the pocket right below the trim/flap indicator. Yesterday, I started the engine after multiple attempts (my mistake...) and the thing started beeping. The "pill" was ok (my backup CO2 detector!). I vented the cabin, started taxing and the number was going down. At altitude went back to zero. I opened the cabin air, still zero. Does it happen to you guys too?

Mine used to go off sometimes on final in approach configuration, and then would clear up during taxi.   I've since done some work on the cowl and cowl flaps and it hasn't done that for a long time.

The only other times it has alarmed was on the ground while taxiing with the door open.

Usually during flight it wanders around between zero and 6 or so.

 

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If you’ve ever wondered why you long body Mooney heater sucks, this might explain it.  This cold air valve shares a common plenum with the heat system.  Even when selected closed the valve let’s four jets of cold air from the right air vent into the heat plenum.

Clarence

8BE0713F-2F35-4B35-8610-28E671A99014.jpeg

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  • 2 weeks later...
3 minutes ago, Jim Peace said:

installed it and it works great.  I showed 0-2 on the ground in the air I showed 0 and when I turned the cabin heat on it went to 4.  Should it be 0 even with the heat on or is it expected to get a slight PPM.

Mine shows 0 in the air with heat off or on.

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2 minutes ago, mike_elliott said:

Do you keep the "quantum Eye" stuck on the panel to cover up a scratch or something?

Quantum dot. https://en.wikipedia.org/wiki/Quantum_dot

I always thought those sticker CO monitors were more than useless.  Useless would be not having one.  More than useless is thinking you solved a problem thus leaving yourself satisfied as protected versus a risk and you are not.

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