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DHC Beaver down in Hawkesbury

Old 13th Feb 2021, 01:52
  #401 (permalink)  
 
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Originally Posted by Cedrik View Post
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?
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Old 13th Feb 2021, 02:40
  #402 (permalink)  
 
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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.
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Old 13th Feb 2021, 08:40
  #403 (permalink)  
 
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Was any of that logged accurate CO detector time in a Beaver cockpit, LB?
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Old 13th Feb 2021, 12:55
  #404 (permalink)  
 
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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’.
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Old 13th Feb 2021, 13:39
  #405 (permalink)  
 
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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?
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Old 13th Feb 2021, 22:21
  #406 (permalink)  
 
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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.
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Old 14th Feb 2021, 21:31
  #407 (permalink)  
 
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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.

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Old 14th Feb 2021, 22:11
  #408 (permalink)  
 
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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.
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Old 14th Feb 2021, 23:00
  #409 (permalink)  
 
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I guess we’re all screwed then.

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

Last edited by hoss; 14th Feb 2021 at 23:15.
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Old 15th Feb 2021, 00:23
  #410 (permalink)  
 
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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:
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Old 15th Feb 2021, 20:54
  #411 (permalink)  
 
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Originally Posted by Lead Balloon View Post
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.

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.
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Old 15th Feb 2021, 22:39
  #412 (permalink)  
 
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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.
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.
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.
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.

Last edited by Lead Balloon; 16th Feb 2021 at 04:42.
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Old 18th Feb 2021, 10:51
  #413 (permalink)  
 
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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.
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Old 18th Feb 2021, 20:24
  #414 (permalink)  
 
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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.)
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Old 19th Feb 2021, 00:33
  #415 (permalink)  
 
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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.

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Old 19th Feb 2021, 00:45
  #416 (permalink)  
 
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"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.
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Old 19th Feb 2021, 02:02
  #417 (permalink)  
 
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Heeeeeeyyyyyyyyy, he's pulling the old 'experience on type' line. Like 'you vill only speak on types you are endorsed on, schnell!'
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Old 19th Feb 2021, 05:24
  #418 (permalink)  
 
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Originally Posted by McLimit View Post
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.

Last edited by Foxxster; 19th Feb 2021 at 05:50.
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Old 19th Feb 2021, 06:57
  #419 (permalink)  
 
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Originally Posted by Foxxster View Post
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.
NOO's pilot had flown in and out of Cottage Point literally hundreds of times. I doubt having an enthusiastic photographer in the front seat would have been unusual.
Pilot incapacitation, on the other hand..
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Old 20th Feb 2021, 12:48
  #420 (permalink)  
 
Join Date: Feb 2007
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A couple of comments from a seaplane pilot.

When the engine is running in a seaplane, the aircraft is moving. When taxiing downwind it may be at the same speed as the wind - you can end up sitting in your exhaust gases. The other main use in Aus for beavers was ag, however I would expect they would have spent most of their ground time (loading) facing into the wind.

I don't recall many pilots leaning the mixture on the water - rich mixture equals a greater percentage of CO in the exhaust gases.

The only times I remember closing the window in the Beaver whilst taxiiing was in rain.

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