Originally Posted by
afterburn81
I have always wondered about CO2 in the cabin. Unless something is burning I'm not sure where it would come from in a jet aircraft. Bleed air from the engines is extracted from the compressor. Simple physics shows that a gas will go from a higher pressure to a low pressure so I'm not sure how the combustion could flow back into the compressor on a high bypass turbofan. In no way am I doubting this situation. Clearly they had some type of contamination. Does anyone have an idea as to where this sort of thing could come from if nothing was actually burning?
Yes, something would have had to burn to produce CO. I can think of a few remote possibilities...
Oil leak in a compressor bearing ahead of the 10th stage might get heated enough by compression to burn and create CO...but you'd think it would also make smoke and bad smells.
Another possibility would be an oil leak in the left pack at a point where it could come in contact with hot bleed air. Since it seemed to affect the cockpit only that would mean it would have to come from the left bleed or pack. But again, no smoke?
They were on climb out, so engine power (and bleed temps) would be high.
I would rule out something in the cargo compartment since it only seemed to affect the cockpit.
Actually this is really weird...I can't imagine how there would be any trace of CO left by the time they shut down th engines, opened the doors, unloaded, and got somebody out there with a gas analyzer. The cockpit fans should have flushed it all out. I almost suspect that the CO was from a nearby operating GPU?
Maybe they were poisoned by burning oil additives, not CO.