CO Poisoning: It really could happen!

[Sig600]

The scariest thing about this post is that the OP spent the money on a CO detector, and when it did it's job, it was rationalized away or brushed off.

Aviation is ones and zeros folks. I'm beyond double digits with friends I've lost, and there's no room for stuff like this.

That said, I applaud the OP for sharing the story and owning up to it. One of the biggest sources of learning in aviation is hearing from others mistakes. If we're too proud or too ashamed to do that, we lose the sole greatest source of knowledge/experience.

So if you've got a CO detector, and it turns black or beeps, ground that plane until you figure out why!

I will be putting this device on my "must" have list because of this pilots experience, at the cost of other cushy things if need be.

Edit: Maybe the mods could start a section devoted entirely to "I learned about flying from that" stories. Yes I ripped that off, I'm not motivated enough to think of a better name.

[chuckwn]

Originally Posted by erich weaver

Anything wrong with going cheap and using a $20 hardware store CO detector?

The alarms are pretty loud - I would think it would still be plenty audible

erich

There are two reasons not to use a household CO detector in an aircraft.

1) They are not altitude or temperature compensated. As altitude goes up, sensitivity goes down. As temperature goes down CO sensor sensitivity also goes down. This means that at low temperature and/or high altitudes dangerous levels of CO may not be detected.

2) They do not perform a periodic self test to confirm the sensor is within spec. CO sensors are life limited and must be replaced periodically (every 5 or so years).

The Flight Data Systems GD-40 is temperature and altitude compensated and performs a test of the sensor every hour to confirm the sensor is operating normally. The sensor can be replaced and the unit recalibrated once the life of the sensor is over.

[richas]

Originally Posted by glenn654

Is CO heavier or lighter than ordinary air or does it blend evenly with existing air?

Glenn Wilkinson

CO has approximately the same density as air so it blends evenly.

[n5lp]

Originally Posted by Bavafa

Good catch Scott.

My experience has been that if there is a smell, there is a reason.

I also had a faint sense of fume time to time and every time I investigated it, nothing was found. Till one day I decided to really not give up till it was found. Well, after some more looking I found a very small trace of fuel dye that was seeping thru my fuel gauge screws (on the inboard of the tank). This was enough to come thru the wing root area. I end up installing on of these which detects both fume and CO2 and have had great result with it.

http://www.fireboy-xintex.com/M2A.html

I believe you meant to say it detects gasoline vapors and CO rather than CO2, buit in the pdf file I can find no mention of CO detection with that unit.

[n5lp]

CO can be a serious flight hazard but it is nothing like we are going to lose consciousness because there is some CO present. The normal problem that causes difficulties for pilots are damaged exhaust/heat exchanger systems. That can cause vision problems headaches and loss of consciousness.

A friend and I did some testing with both of our airplanes. They are both RV-6 tip-ups that were built before any instructions about sealing the firewall and I don't believe either of them had any firewall sealing, although I have done some since.

Using a scientific gas monitor we found that there was CO present in very detectable concentrations just about all the time in these airplanes. I believe it tended to be the worst during taxiing and low speed climbs and best in cruise flight. I think the concentration was in the range of 5 to 15 ppm most of the time with some higher and lower spikes. This CO concentration, all day long, would not produce the blood level CO that a regular smoker has all the time. The FAA standard for cabin air is 50 PPM.

Sealing the firewall sounds like a good idea to me but there are many more possible sources for CO than that. My guess is that cabin vents and open canopies would be a likely source on the ground and that belly seams and holes back in the tail would be a likely source during low speed climb. Just think of all the places the smoke goes during air shows. CO goes all those places too.

I don't really think it is necessary to worry about every seam or all CO though. If the exhaust system is intact, you have pretty much eliminated the problem. If an aircraft CO monitor can alert you to such a problem, that is great.

[turbo]

i bought mine a couple of weeks ago. Velcro to the panel and portable it registers in parts / million. usually 1 or 2 p/m in flight. taxing out behind a twin was enough to get it going though. im sure my old 57 chevy would have drivin this thing crazy. small and expensive. $140.

http://www.detectcarbonmonoxide.com/