I have been seeing low CO levels present at various key points of operation in our plane. During climbout we have been seeing around 10-15 ppm co in the cockpit using a small portable co monitor. I’ve attributed this to higher angle of attack and airflow pushing a tiny bit of exhaust gas near the vent inlets, but at this point it is just a theory. Stranger though, in cruise I see a steady 9 ppm BUT only at full throttle. Pulling back the power causes a drop to zero. Turning on the heat does appear to make it go up a few ppm, but again only at full throttle.
I suspect the heater valve likely doesn’t seal all the way, but what I can’t figure out is why throttle position matters. Any ideas?
I suspect the heater valve likely doesn’t seal all the way, but what I can’t figure out is why throttle position matters. Any ideas?