I don't understand how modern airliners, with all their advanced high-tech complicated design, operating in such a tightly controlled regulatory environment, can still be having trouble with this. Crazy.
Notice it became a problem when pilots began getting sick and it could not be hidden anymore. At the same time pilots are the most exposed, as they are airborne the most. You, the passenger, probably don’t fly enough for it to necessitate an immediate response
I feel like you are implying conspiracy-like behavior, instead of recognizing the absurd rarity of the event:
> "Over a two-year period, nearly 400 pilots, flight attendants and passengers reported receiving medical attention after these “fume events,” and four dozen pilots were described as impaired to the point of being unable to perform their duties, The Times found."
This same two year period flew about 280 million "passengers", obviously not unique, but 400 / 280 000 000 ~= 1 in 15000
I don't think that this is about being covered up so much as obfuscated. That's a low-frequency event.
If you told me that if I leave my house at 10:00 PM to-nite and I had a probability 1/15000 chance of dying or become incapacitated I would more than likely wait five or ten mins before leaving.
50-year-old males have a 1/75000 chance of dying on any given day. 70-year-old males have a 1/15000 chance of dying on any given day. See https://www.ssa.gov/oact/STATS/table4c6.html
We really don't address air pollution anywhere if the levels are low enough that there aren't any severe acute effects. Aviation actually has exemptions that allow them to pollute more in the name of mechanical reliability, e.g. 100LL
This shouldn't be that surprising. A jet engine that operates across temperature ranges of hundreds of degrees, with air shuffling through it at near the speed of sound and burning huge amounts of fuel every second may occasionally have something break every few thousand hours. Mechanical components (including oil tubes and cylinders) can fail.
Curious whether this is typically APU or primary engine-related. (I find that the APU fumes are noticeable when the rear doors are open during loading.)
Both. You smell fumes while rear doors are open because the APU is not moving (or there is another plane in close proximity). From the main engines, it should not be noticeable in flight
I think the concern is generally air coming from the bleed air system (air that has been redirected from the engine core's compressor stages, prior to combustion) which is used to pressurize the plane. This can come from either the main engines or the APU, but in-flight it's almost always going to be the main engines and the APU will be shut down. During a potential fume event, if the APU is supplying bleed air the packs could generally just be turned off, the APU shut down, or the aircraft deplaned, since it's probably on the ground. Obviously you don't have any of those options in the air.
Exhaust, which is what you're smelling when the doors are open, seems like it'd be much less of a problem. Any fumes will be much more dilute from all the uncontaminated air pushed by the fan through the bypass ducts, and of course diffusion into the environment. Not to mention probably decomposed by the temps in the combustion chamber. The bleed air though comes from the engine core's compressor stages (before combustion), and it's the only source of air for the cabin, so if it's contaminated you won't have any dilution effect.
Is this not more applicable to the (yes of course, many) 1-previous generation of bleed-air based planes where the AC packs are linked to the jet exhaust?
I thought that 787 etc. now use purely electrical power that are now (and for the future generation of planes) a no-bleed-air-anymore system.
The newer generation of planes are using pumps instead of bleed air and add humidity.
I sort of recall reading something that not having metal bodies helped with the increased pressure (787 is like 6000ft pressure altitude instead of 8000ft) and reducing corrosion?
Some new designs are 'bleedless' and use electric compressors sourcing from outside air to pressurize the cabin, and these designs shouldn't have significant fume event issues.
However not all recent cleansheet designs use this methodology, for example the A350 (launched 2013, after 787) and Bombardier CSeries (now A220, also 2013) both use the traditional bleed air design, as do the modernized 777X, 737MAX and A320neo families. I think even among modern designs, only the 787 is bleedless.
So we're at least another generation away from going bleedless, and it seems that Airbus and some other Boeing design teams have decided the tradeoffs aren't worth it. Maybe the new regulatory environment will put more pressure in that direction.
What people don't take into account is that human effort is both limited and fungible. Even if we restrict ourselves to only activities that improve health and/or environment, any effort spent on this could have been spent on something else. Is this the BEST way to spend that effort? I don't know, maybe it is. But would it be better spent on recycling, solar power, species protection, cancer research, etc?
I hope someone is trying to do some level of analysis of this so that we don't spend a lot of effort on a tiny problem when there might be larger problems we could be going after.
This implies a command economy, which we definitely don't have. Certainly people are doing these analyses within firms and agencies. Nobody is doing it on a society-wide basis except maybe in China.
Someone is deciding that it's a good idea to pass legislation that would require airlines to remediate this. It would be nice if those people consider how much effort will be required to do so, and whether that is a good trade-off or not compared to the [presumed] health benefits. It would require airlines to indirectly pull labor from the production of things like housing, shoes, tweets, solar panels, etc. Every hour spent improving the safety of the air in planes could be spent doing other things.
I'm not sure if you would call this a command economy or not, but the force of law is a pretty strong command.
Ah well the answer is definitely no. Nobody in government or even the airline industry is considering 4th or 5th order effects like this, and likely never will (again, unless we decide to have a planned economy).
I still remember the "vapor recovery" mechanisms implemented decades ago, in California, that now compete against newer car's internal recovery systems. These regulations often outlive their usefulness.
Howabout recognizing there is inherent risk in flying, and adding the pollution as a broadcast/informed risk seems like an eco-friendly way to reduce air travel (and the pollution from that travel).
There are so, so many great things we can do. Removing or mitigating toxic chemicals from airplane air is on that list for sure.
But I think it's responsible to consider things not in isolation, but with the understanding that doing any one of those awesome things come at the expense of many other things. I don't often see folks trying to quantify the level of goodness that comes from an activity or the level of effort involved in attaining it. Simply recognizing this as a trade off would be a healthy step.
Pretty gross take, given this section of the article:
> Scientists have long warned of potential dangers from breathing heated jet engine oil, which contains tricresyl phosphate, or TCP, a highly toxic chemical that can damage the nervous system. TCP can have immediate effects such as headaches and dizziness, as well as longer-term effects such as tremors and memory problems, experts say. Some pilots and flight attendants have experienced serious health problems, including brain damage, after fume events, The Times found.
> I hope someone is trying to do some level of analysis of this so that we don't spend a lot of effort on a tiny problem when there might be larger problems we could be going after.
Long term health effects are a big problem.
It's just not as sexy of a problem as the ones you mentioned. Perhaps this is more a comment on needing more people working towards the great mythical idea of capital-P Progress?
Desperate measure to advantage Boeing and its B787 (and future aircraft) which are using electrical power to pressurize the cabin (vs bleed air for Airbus).
> Boeing and its B787 (and future aircraft) which are using electrical power to pressurize the cabin
At this point any change from Boring gives me shivers. Like with MCAS I expect it to be half baked and have at least a couple of incidents before FAA steps in and they have to do something about it.
Potable water tanks are built into the plane, and they're filled from a truck at the gate. Those tanks are cleaned... occasionally. Oh, and the water is usually pumped out via the same bleed air this article is about.
Although this article says that "most airlines" serve bottled water for this reason:
Although I have seen it claimed elsewhere that often the coffee and tea are made with water from the tap and not bottled. I suspect it may vary by airline.
If the coffee pots, water tanks, etc. are cleaned as rigorously as the same at restaurants and so on, then yeah I could see the desire to only want stuff that came in sealed bottles and touched no ice.
I believe the amount of organophosphates has been studied on 'normal' flights, but considering these events are estimated to be 1/5000-1/50000 flights, you need a lot more than one person to capture a statistically significant sample. But considering the number of flights per day, that's a few events per day and is probably worth investigating.
There have been some post-facto blood tests trying to find if crew who noticed these fumes had detectable byproducts in their blood, which mostly found nothing, but this doesn't say much about whether the environment in the aircraft is safe when these events occur, especially since significant and acute harm seems relatively rare among these incidents.
Air quality monitors definitely do need to be installed on airplanes in order to measure the scope of the problem before panicking over it.
From the parent article:
"Over a two-year period, nearly 400 pilots, flight attendants and passengers reported receiving medical attention after these “fume events,” and four dozen pilots were described as impaired to the point of being unable to perform their duties, The Times found."
Now I'm not sure where 'Times' got their numbers, and I'm confident the issue is under reported. However as it stands the issue seems really minor. Let's start with air quality monitors on every aircraft and then go from there.
Some genetic conditions like factor 5 Leiden can be triggered by strong chemical exposure. Imagine your blood deciding that clotting constantly for rest of life is a good idea.
I fly a lot, and have noticed a very strong smell of fuel several times on various aircraft, while still at the gate just before taxiing to the runway. It always baffles me that passengers don't overreact to it, because it can be very pungent and will cause a mild headache.
I've always wondered how toxic this is. Apparently it's caused by wind blowing jet fuel fumes into the air conditioning intake so it's indeed fumes that make it into the cabin for a few minutes.
The air needs to be pressurized so people can breathe normally. The most convenient way to do this is to use bleed air from the turbine compressors, but no-bleed systems (e.g., https://www.boeing.com/commercial/aeromagazine/articles/qtr_...) are possible.
Most aircraft get their pressurized air from the engine bypass air, off a system called the bleed air system (air is bled off of the bypass). Since the bypass air (air that is compressed but not used for combustion, it makes jet engines more efficient) is already pressurized by engine operation it's sort of "free compressed air" and used for a few different purposes. That said, some newer aircraft are choosing to simplify design by eliminating the bleed air system and instead using electrically-driven compressors for cabin air. One advantage this has is that the air doesn't require initial cooling like bleed air does due to the engine bypass being so hot. Mostly, though, it's being done for the reduced cost/complexity and increased safety of eliminating the air lines from the engines.
The German media made a documentary about this (~2013) and I started to fly with a special mask capable of filtering the toxic fumes. People kind of stared at me, when it was not normal to fly with a mask..
Crazy, that it took more than 10 years before things are finally starting to change.
Commercial jets are not required to have Carbon Monoxide detectors? The Cessna 172 I flew for flight training had one of these $5 color-changing detectors. Surely we should have comprehensive monitoring for CO and volatiles.
54 comments
[ 3.5 ms ] story [ 92.7 ms ] thread> "Over a two-year period, nearly 400 pilots, flight attendants and passengers reported receiving medical attention after these “fume events,” and four dozen pilots were described as impaired to the point of being unable to perform their duties, The Times found."
This same two year period flew about 280 million "passengers", obviously not unique, but 400 / 280 000 000 ~= 1 in 15000
I don't think that this is about being covered up so much as obfuscated. That's a low-frequency event.
Harm caused by occupational exposure to hazardous chemicals is usually a chronic, cumulative, delayed onset type of thing.
But actually, I typo'd quite badly: the ratio is 1 in 700000, not 1 in 15000 (how did I make that mistake?)
Anyways, I hope it's clear that a 1 in 700000 event is hard to detect.
> of dying or become incapacitated
Sorry, I don't see any death in the logs, can you point me to recent aviation deaths that were caused by this?
> or become incapacitated
For instance, you have a ~1 in 366 chance of being in a car accident per 1000 miles driven.
I think you should stay home more often, or learn more about probability.
Exhaust, which is what you're smelling when the doors are open, seems like it'd be much less of a problem. Any fumes will be much more dilute from all the uncontaminated air pushed by the fan through the bypass ducts, and of course diffusion into the environment. Not to mention probably decomposed by the temps in the combustion chamber. The bleed air though comes from the engine core's compressor stages (before combustion), and it's the only source of air for the cabin, so if it's contaminated you won't have any dilution effect.
I thought that 787 etc. now use purely electrical power that are now (and for the future generation of planes) a no-bleed-air-anymore system.
I sort of recall reading something that not having metal bodies helped with the increased pressure (787 is like 6000ft pressure altitude instead of 8000ft) and reducing corrosion?
However not all recent cleansheet designs use this methodology, for example the A350 (launched 2013, after 787) and Bombardier CSeries (now A220, also 2013) both use the traditional bleed air design, as do the modernized 777X, 737MAX and A320neo families. I think even among modern designs, only the 787 is bleedless.
So we're at least another generation away from going bleedless, and it seems that Airbus and some other Boeing design teams have decided the tradeoffs aren't worth it. Maybe the new regulatory environment will put more pressure in that direction.
I hope someone is trying to do some level of analysis of this so that we don't spend a lot of effort on a tiny problem when there might be larger problems we could be going after.
I'm not sure if you would call this a command economy or not, but the force of law is a pretty strong command.
Howabout recognizing there is inherent risk in flying, and adding the pollution as a broadcast/informed risk seems like an eco-friendly way to reduce air travel (and the pollution from that travel).
There are so, so many great things we can do. Removing or mitigating toxic chemicals from airplane air is on that list for sure.
But I think it's responsible to consider things not in isolation, but with the understanding that doing any one of those awesome things come at the expense of many other things. I don't often see folks trying to quantify the level of goodness that comes from an activity or the level of effort involved in attaining it. Simply recognizing this as a trade off would be a healthy step.
> Scientists have long warned of potential dangers from breathing heated jet engine oil, which contains tricresyl phosphate, or TCP, a highly toxic chemical that can damage the nervous system. TCP can have immediate effects such as headaches and dizziness, as well as longer-term effects such as tremors and memory problems, experts say. Some pilots and flight attendants have experienced serious health problems, including brain damage, after fume events, The Times found.
> I hope someone is trying to do some level of analysis of this so that we don't spend a lot of effort on a tiny problem when there might be larger problems we could be going after.
Long term health effects are a big problem.
It's just not as sexy of a problem as the ones you mentioned. Perhaps this is more a comment on needing more people working towards the great mythical idea of capital-P Progress?
At this point any change from Boring gives me shivers. Like with MCAS I expect it to be half baked and have at least a couple of incidents before FAA steps in and they have to do something about it.
Boeing has completely tarnished its brand name
However, if we're comparing, issues with air quality within planes has contributed to accidents as well.
If a hundred people died every time a kubernetes cluster served a 503, the human race would be extinct.
The coffee/water/ice scare me more than either of those. A former FA family member told me longer term employees wouldn’t dare touch the stuff.
Although this article says that "most airlines" serve bottled water for this reason:
https://insights.globalspec.com/article/16509/airplane-water...
Although I have seen it claimed elsewhere that often the coffee and tea are made with water from the tap and not bottled. I suspect it may vary by airline.
There have been some post-facto blood tests trying to find if crew who noticed these fumes had detectable byproducts in their blood, which mostly found nothing, but this doesn't say much about whether the environment in the aircraft is safe when these events occur, especially since significant and acute harm seems relatively rare among these incidents.
From the parent article: "Over a two-year period, nearly 400 pilots, flight attendants and passengers reported receiving medical attention after these “fume events,” and four dozen pilots were described as impaired to the point of being unable to perform their duties, The Times found."
Compared to: 178 million passengers and 99 million passengers in 2022 and 2021. https://www.statista.com/statistics/193590/total-air-traffic...
Now I'm not sure where 'Times' got their numbers, and I'm confident the issue is under reported. However as it stands the issue seems really minor. Let's start with air quality monitors on every aircraft and then go from there.
I've always wondered how toxic this is. Apparently it's caused by wind blowing jet fuel fumes into the air conditioning intake so it's indeed fumes that make it into the cabin for a few minutes.
https://www.mypilotstore.com/MyPilotStore/sep/4420