We get it, Wingnuts: You reject CO as a factor. We get it.

Clearly you haven’t spent much time in cockpits with accurate CO detectors.

LB, I tend to agree with Wingnuts. I have spend quite a few years sitting in many Beavers, never had a problem with Co2.

Me too. If nothing, the old girls I flew were quite draughty making it difficult reconcile the CO2 theory. But of course maybe the new age fully refurbished passenger carrying Beavers are more air tight?

You’d all have a bit more credibility if you got the chemical symbol for the gas correct. And hands up those who’ve done many, many hours of flying with an accurate CO detector in the cockpit.

Was any of that logged accurate CO detector time in a Beaver cockpit, LB?

No, Checkboard.

But it ain’t rocket surgery to log the CO levels in various cockpits of various piston engined aircraft during various ground operations with windows/doors/vents open/ajar/closed. There’s nothing magical or fundamentally different with a Beaver or a Walrus.

And the insidious effects of CO are supported by things called ‘science’ and ‘data’.

Then perhaps if you put one post up, detailing your experience and the results of that experience, rather than six posts with tiny hints of what you are trying to contribute, your posts would have greater effect?

Like post #328 perhaps?

There seem to be people simply rejecting what the tests say about the blood CO levels of the persons tested and simply rejecting what the science and data show about what CO does to pilot performance.

Most of us have done enough GA to know that 20 minutes of piston fumes doesn’t make us fly up a tight valley and do a split arse turn at the end! Curiosity, ego and machoism might, just a theory.

Quite so.

If the PIC had been exposed to 'piston fumes' for merely '20 minutes', you'd be on to something.

Do you know the half-life of carboxyhemoglobin in fresh air? All of the science and data about the deleterious effects of CO exposure are at your fingertips. You could try googling it.

I guess we’re all screwed then.

(note to self: blame all errors on air contamination)

I'd suggest a different note to self: Obtain and carry an accurate CO detector.

I've posted this link before. It is worth watching, if you have an interest in safety:

Point taken. That superfluous “2” was a result of muscle memory... what with being hammered by climate change experts and all that. Call it my Greta Thunberg moment if you will.

If by accurate CO detector? I presume you’re referring to that unlit, aged plastic thing with a circle which is supposed to turn dark in the presence of CO and is stuck to the lower far right side of the panel. Then the answer is yes. Many, many single pilot, night hours with the Janitrol heater going full blast. None of which makes me any the wiser on CO poisoning.

My comment was to do with the unintended excess of outside fresh air flowing through the cockpits of the Beavers I flew and the then presumed likelihood of this diluting the CO concentration.

You presume wrongly. Those aged plastic things with a circle are useless. If you'd take the time to watch the video I posted, you'd know why.

This is the type I fly with at the moment: https://www.candoitaustralia.com.au/...-ios-app-white

I've used other different types.

They measure and display CO concentration in parts per million and give an audio and visual alarm above set levels of CO concentration.
Again, a presumption. I say again (for the last time) the highest levels of CO I measured in the cockpit of the serviceable aicraft I flew for hundreds of hours (now sold) were during taxi with all the windows open. Prolonged exposure at those levels would have been deleterious. My current aircraft varies from 1 to 3 ppm in the cruise, depending on how the vents are set.

Most of what people believe about airflows through cowls and cockpits and cabins is based on mere intuition that has been disproved by actual testing.

What the ATSB should have done / do is get another Beaver, remove the same firewall fasteners, and make some measurements with an accurate CO detector during various operations and window/vent configurations.

The ATSB has done ground smoke and digital detector tests. The problem faced was there wasn’t a definitive path from exhaust crack into accessory compartment. This was solved by locating a relatively large diameter hose in the Beaver’s exhaust outlet and pumping raw, undiluted exhaust into the accessory compartment. Hose entry into the compartment was made possible by lifting an accessory cowl corner. No surprise then that CO via the missing bolts did register in the cabin.

Hardly a valid test. To get CO into the cabin, you can figure how the ‘door ajar’ theory came about.

Even so, the highest level detected was 144 ppm at pilot’s feet near the mag panel. To put that into perspective, 100 ppm will result in a slight headache in 2 – 3 hours. The CO spot detector as fitted to NOO will begin to darken at 100 ppm in 15 – 45 minuets. No head height readings are shown in the report.

You make some valid points, Wingnuts.

I'd only note that:

1. Those CO spot detectors are nigh on useless, if more than 12 months old or contaminated with e.g. cleaning chemicals, and

2. SafeWork NSW says: "... Carbon monoxide has a workplace exposure standard of 30 ppm averaged over eight hours. However, short term exposures above this are permittable to 60 ppm where total exposure at this level is less than 60 minutes in an eight-hour shift; 100 ppm where total exposure at this level is less than 30 minutes in an eight-hour shift ...".

Would you be happy to fly for e.g. 3 hours in an aircraft with the PIC exposed continuously to 100ppm of CO? Not this little black duck... (I'm not asserting those were the actual durations/levels in this case.)

Call me a dreamer if you will but I get the feeling that airflow while you’re taxiing around with windows open might, just might be slightly different than going forward at 80KIAS in a type which I’m wondering you have any experience on. But hey, don’t let that stop you banging on your beloved CO drum.

"I get the feeling that airflow while you’re taxiing around with windows open might, just might be slightly different than going forward at 80KIAS...". I get exactly the same feeling, and the output of the CO monitor confirms it to be true.

Heeeeeeyyyyyyyyy, he's pulling the old 'experience on type' line. Like 'you vill only speak on types you are endorsed on, schnell!'

schnell, surely you mean verstehen , or perhaps dummkopf

anyway I wonder if having someone snapping off photos of nothing every second sitting in the front seat might have led to a more scenic route which rapidly became a very bad idea. Which led to the scenario in Cedricks post above. I think CO is an herring rouge but would like to see the actual amounts in the pilots system compared to various benchmarks of no effect, limited effect etc. Saying the pilot would definitely have been affected should be backed up with the actual readings taken.