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Aerotoxic in the news

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Aerotoxic in the news

Old 24th Feb 2015, 19:23
  #81 (permalink)  
 
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seals from the compressors wear down over time and leak oil which is burnt.....
BS. Bleed air is taken form various compression stages BEFORE the combustion chambers. And these stages have VERY little lubricating oil and essentially no "seals" because these are axial flow compressors. You are confusing the dynamics and mechanics of an internal cumbustion engine which is NOTHING like an axial flow turbine engine.
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Old 24th Feb 2015, 20:02
  #82 (permalink)  
 
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KenV, the compressors have bearings which leak oil mist into the airstream that is then bled through the pneumatic system, including the aircon and press systems. The vapour is not combusted, but bleed air temperatures are far higher than what is needed to cause TCP to decompose into the organophosphates. You are quite right that this is not exhaust gasgetting into the cabin and cockpit, but the bleed air is most certainly contaminated with engine/APU oil. Skydrol is another source of contamination, which can be caused by overfilling the hyd reservoirs (which a re pressurised by the pneu system to prevent foaming of the fluid). Had that too (smells sweet)...
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Old 24th Feb 2015, 21:14
  #83 (permalink)  
 
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but the bleed air is most certainly contaminated with engine/APU oil.
Which makes it puzzling why the few experimental studies thus far have found nothing significant inside the cabin.
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Old 24th Feb 2015, 21:23
  #84 (permalink)  
 
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Toxic compressor air in aircraft

I think that this is blown out of proportion to reality and the occurrence of real sickness, or death, could also be influence by where pilots live.
Breathing toxic air is part of city life and I am 83 (including the toxic fumes I breathed during 8000 flights in power planes). Granted I am deaf as a doorpost, though ,
from jet and reciprocating engine noise !
I know several older pilots who have flown with airlines all their working lives and they are reaching ripe old ages o 80 and 90 plus................so what is the argument ?
If a pilot is allergic to fumes generated in a particular aircraft type, then he/she should change aircraft or get a desk job or, maybe, become a lawyer in a polluted city.
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Old 24th Feb 2015, 21:41
  #85 (permalink)  
 
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Frankly, YW would you accept that logic process in respect of ANY other safety issue? You might know several women who met Jimmy Saville and weren't raped by him ...which supposedly makes him innocent according to your reasoning. And the issue is nothing whatever to do with allergy. Where did you get that?
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Old 24th Feb 2015, 23:36
  #86 (permalink)  
 
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would you accept that logic process in respect of ANY other safety issue?
In general the risk with safety issues are done according to risk analysis. There is no absolute safe. Its just some issues can be emotive, or made to be emotive for various reasons rightly or wrongly, to effect a cause.

As such, then this can have the effect of someone taking action on a cause. This may or may not be warranted. Sadly in the case of taking action on a problem when it is not statistical warranted, that then takes resources away from where it could be better utilized.
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Old 25th Feb 2015, 01:33
  #87 (permalink)  
 
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I suspect how or if the fumes effect you badly are genetic or similar and may be coupled with other exposures like radiation, chemicals etc? Same for many other pollutants.

My father died at 96 with no lung disease. From age 14 to 60 he was daily exposed to high levels of asbestos with no problems but most of his workmates died in the 50s from lung related diseases.

Just because my father was OK doesnt mean asbestos is safe does it? I certainly dont intend to go anywhere near asbestos just because my Father didn't die from asbestosis.
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Old 25th Feb 2015, 08:30
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Wow, the number of people posting "it hasn't affected me, so it doesn't exist" is staggering. Egocentric, much?
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Old 25th Feb 2015, 14:47
  #89 (permalink)  
 
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KenV, the compressors have bearings which leak oil mist into the airstream that is then bled through the pneumatic system, including the aircon and press systems.
Modern turbo fan engines have two shafts (three on many RR turbo fans). The power turbine and the compressor turbines share the same shaft. The shaft is supported by bearings. The shaft bearings do NOT "leak oil mist into the airstream". There is simply no airpath for that to happen.

The vapour is not combusted, but bleed air temperatures are far higher than what is needed to cause TCP to decompose into the organophosphates
If it were remotely true that the engine oil "decompose into the organophosphates" at normal operating temperatures, the oil would need VERY frequent changes. That is simply NOT true.

You are quite right that this is not exhaust gasgetting into the cabin and cockpit, but the bleed air is most certainly contaminated with engine/APU oil.
ONLY if there has been some sort of serious internal failure.

Skydrol is another source of contamination, which can be caused by overfilling the hyd reservoirs (which a re pressurised by the pneu system to prevent foaming of the fluid). Had that too (smells sweet)...
It would require a serious SERIES of failures for hydraulic fluid to get into the bleed system that feeds the environmental control system. Bleed air is drawn from differnt ports and different stages of compression for the various functions it is used for. The environmental control system and the engine systems don't share a common bleed port.

Last edited by KenV; 25th Feb 2015 at 15:04.
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Old 25th Feb 2015, 15:17
  #90 (permalink)  
 
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Rolls Powered B757

I flew the old model B757 with BA from 1996-1999 and they did sometimes blow oil vapour into the flight deck on start up. It appeared briefly as a puff of blue ish smoke or vapour, smelt of oil and then dispersed.

The exact route under which it could reach the flight deck is not something I can state but it did occur.

The other point at which pilots might get exposed to oil vapour with some types was on walk round when a little oil vapour would waft out the back of an engine.

If pilots or crew were already sensitised to Organo Phosphates then a whiff of oil vapour might trigger a reaction.
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Old 25th Feb 2015, 15:18
  #91 (permalink)  
 
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Wow, the number of people posting "it hasn't affected me, so it doesn't exist" is staggering. Egocentric, much?
IF this "aerotoxic syndrome" were REMOTELY true, aircrew would be exposed to much higher levels than the general public. There is no evidence whatsoever that aircrew are suffering illness and/or dying at higher rates than the rest of the population.

And on the subject of "egocentric", what about the guy that insists HE knows "aerotoxic syndrome" is a real and present danger despite the dirth of hard data to support this myth and in the face of LOTS of contrary data. The folks pushing this agenda are often the same ones pushing the "immunizations cause autism" agenda and sound remarkably a lot like the folks who insist the Apollo moon landings were an elaborate hoax.
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Old 25th Feb 2015, 15:26
  #92 (permalink)  
 
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I flew the old model B757 with BA from 1996-1999 and they did sometimes blow oil vapour into the flight deck on start up. It appeared briefly as a puff of blue ish smoke or vapour, smelt of oil and then dispersed.
This occasional oil smell thing on start up is almost always the result of recent maintenance on the environmental control system. Once the oil residues deposited by the maintenance action are swept away on start up, that's the end of it.
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Old 25th Feb 2015, 16:27
  #93 (permalink)  
 
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I wouldn't normally get involved in these discussions but I have to reply to Kenv's statement of when we get the oil smell(exhaust gas smell)in the fd. I'm a long term captain on 320 series and this smell occour on 20-30 percent of all start-up performed on this type. Often 2-3rd sector of a 4 sector day with no maintainence performed during the day. This is a known occurrence to all Airbus pilots. Probably on other types as well.
Another common cause for encounters with "the dirty sock" smell is overfilling of oil in the apu. Common occurrence with any Airbus operaters and known to technical staff.
These are the facts. A lot of other statements in this discussion would require further investigation. Let's hope that happens
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Old 25th Feb 2015, 16:28
  #94 (permalink)  
 
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KenV
Keep dreaming that it doesn't exist!
Do you know how engine oils are tested so that its ok in case of human contact??
Let me enlighten you. The oil is spoon fed to chickens at room temperature!!
When was the last time your engine oil was at room temp when flying??
This was the answer from a certain oil manufacturer 9 years ago when we had a fumes event.
We still await our reply from the 22 different people that were spoken to at the company about this event!!
ITS ALL ABOUT COST.....
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Old 25th Feb 2015, 17:34
  #95 (permalink)  
 
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If the engine temp is lower than the point when oil degradation starts (and it is ,logically , otherwise planes would top up tonnes of oil at every stop ) then the hot oil is the very same with the one at room temp . Water is water at 20C and at 80C but the hot one is harder to spoon fed to live specimens in order to test it's toxicity.

And yes it's all about cost , otherwise we would have ejection seats and 10 times the ticket prices .
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Old 25th Feb 2015, 18:01
  #96 (permalink)  

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Gotta agree with KenV.

Organophosphates are all around us, as DNA, RNA and various commonly used pesticides. We all of us have varying levels of a variety of organophosphates - mostly from pesticides.

Chronic medium level exposure certainly creates problems (agricultural workers are the most at risk), but data on the effects of chronic low or very-low level exposure is very hard to separate from random noise.

The answer to finding out whether Aerotoxic Syndrome is real is proper scientific study and there seems to be a dearth of that.

S'easy - take new starting airstaff, get a good history (esp. diet and gardening etc., etc.) and measure their levels. Repeat after 6-12-18 months.

Put a cabin-air sampler in suspect/all aircraft and check accumulated readings weekly or monthly.

Correlate with hours/aircraft etc. and within a year or two you'll have a proper scientific answer instead of anecdotes and speculation - which mean nothing at all.
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Old 25th Feb 2015, 21:25
  #97 (permalink)  
 
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Quite a couple of german airline cabins were sampled for TCP and almost all tested positive, even newer airframes. 737 and A320.
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Old 26th Feb 2015, 00:42
  #98 (permalink)  
 
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Source?
Or hearsay?
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Old 26th Feb 2015, 03:12
  #99 (permalink)  
 
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Quite a couple of german airline cabins were sampled for TCP and almost all tested positive, even newer airframes. 737 and A320.
Not a surprise ... try it on a busy street corner.

What we need is a portable detector that we can pin to our clothes everyday. Now if only we knew what to do with the readings afterwards ......
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Old 26th Feb 2015, 08:09
  #100 (permalink)  
 
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The scant few official studies have been tiny and carried out by authorities with the same attitude and vested interests as KenV, with a coverup the outcome. Everything Ken has said on the last page is incorrect. TCP decomposes at between 80 and 90oC, bleed air temperatures are in excess of 200. Oil from the front compressor bearings can escape the seals into the airflow before the bleed valves. As for the hydraulic contamination, it is easily possible - you only need the engineers to be in the habit of overfilling the reservoirs (as was the case at my employer until memos started whizzing around about the issue) and a slightly leaky check valve and the fluid can seep into the pneumatic manifold. As I said, I've had that, and more than once.

This is a real issue, and only those profiting from others' illness are going to deny it.

The small sample in Germany (six aircraft, I believe) that was referred to was done by German media. They arguably have an interest in a crisis story, so it is debatable how unbiased their study was too, but I recall they detected organophosphates on all six aircraft, including new A320s and 737s.
I agree that a proper scientific study is needed, but not just a small scale one set up by a party determined to bury the matter - a very wide and large study by a truly independent organisation with no vested interests.
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