We installed both the old fashioned black dot card CO detector and (this past week) a digital detector with visual and audio alarm on our recently acquired RV6A. Interestingly, this past Sunday the digital detector rose from 0 to 15ppm after about a 10 minute take-off/climb. Both the heat vent and fresh air vent (nearest the detector) were partially open (I was a bit warm - son was a bit cool) during this time. After seeing the 15ppm reading I then closed both vents and the detector dropped back down to zero within a few minutes. I then experimented by turning the heat fully back on in cruise flight for about 15 minutes and the detector remained at 0. I then turned off the heat and opened the fresh air vent - same story - detector remained at 0. Stayed at 0 for the remainder of 90 minute flight with heat on and outside air occasionally partially open. This has us scratching our head and wondering if the dynamics of our taxi/take-off/climb somehow caused some CO to get drawn in the fresh air intakes - but subsided in cruise flight. Anyone have any thoughts/insights?
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RV6A Carbon Monoxide mystery...
- Thread starter dbier99
- Start date
jneves
Well Known Member
My detector picks up some readings, 20 to 35 PPM during start up, taxi and shutdown if the canopy or air vents are open. I haven't paid attention to the reading during climb, but I know it's at zero by the time I finish my cruise check list.
If you're getting these low readings only in climb and then it's back to zero, I wouldn't stress too much. Many next time climb longer and run the same checks you did to verify where is is coming from. Also keep in mind there are many other gaps to the outside (other than the vents and heat) that can let in some CO. Found this chart to help understand the PPM and the effects on us.
If you're getting these low readings only in climb and then it's back to zero, I wouldn't stress too much. Many next time climb longer and run the same checks you did to verify where is is coming from. Also keep in mind there are many other gaps to the outside (other than the vents and heat) that can let in some CO. Found this chart to help understand the PPM and the effects on us.
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Thanks for the insights and chart!
Thanks for the reply. I'll check those spots but am realizing the current situation isn't a worry - but nice peace of mind to have a digital detector in operation.
jneves
Well Known Member
You went down the road I did when I picked up my digital meter, finding that chart helped calm my nerves. Try taking it for a drive with the windows rolled down, you'll be surprised how much CO is in the environment around us daily.
BoydBirchler
Well Known Member
Sounds like high AOA versus low AOA. The higher angle of attack during climb could possibly be reduced by reducing the climb rate to 300 or so FPM at the same power setting (cruise climb after obstacle clearance). Give it a try and see if the PPM drops.
koupster
Well Known Member
My RV-6A digital CO detector sometimes alarms during a downwind taxi, a slower climb with a rich mixture, or when the fuel truck pulls up. The first two instances are in the 15ppm range.
Wing root seals and aileron pushrod seals may help, but some air may come in through the tail and make it's way forward.
You may try increasing your climb speed if you're headed in the desired direction, and leaning as you climb. Richer mixtures produce more CO.
Wing root seals and aileron pushrod seals may help, but some air may come in through the tail and make it's way forward.
You may try increasing your climb speed if you're headed in the desired direction, and leaning as you climb. Richer mixtures produce more CO.
Jetmart
Well Known Member
I would recommend all to watch this.
https://www.youtube.com/watch?v=pOEBoeuyR0U&feature=youtu.be
I found it very enlightening and certainly opened my eyes. Different views than historical thinking.
Draker
Well Known Member
Timely thread. I've been chasing an intermittent CO reading that shows up only in my EFIS log (no alert from the detector). Entire flight is zero ppm, except very very occasionally I see a 5-15 second burst of 10-1000 ppm, then it goes back to zero. Can't pinpoint these episodes to any particular phase of flight, altitude, airspeed, or other activity. Very bizarre. I'm troubleshooting with the detector manufacturer. From what I read, if the high ppm reading is not sustained, I'm not in real danger, but I have a habit of chasing down every fault, no matter how minor.
EDIT: That was fast. According to the CO detector manufacturer (FDS), the detector is sensitive to VHF transmissions, and upon checking my logs, sure enough my unexplained "bursts" of CO correspond exactly 1 to 1 with each of my radio calls. Probably a long shot but maybe check whether your device is outputting elevated CO readings due to RF interference?
EDIT: That was fast. According to the CO detector manufacturer (FDS), the detector is sensitive to VHF transmissions, and upon checking my logs, sure enough my unexplained "bursts" of CO correspond exactly 1 to 1 with each of my radio calls. Probably a long shot but maybe check whether your device is outputting elevated CO readings due to RF interference?
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Indeed - very good video. Also check out his interview with oil guru Ed Kollin.
