> An internal Boeing memo described it as a “risk” to give air sensors to even one airline, according to a deposition of a Boeing executive.
> “Flight attendant, pilot unions, and congressional supporters could use this effort as evidence that sensors are needed and ... to drive their agenda forward to have bleed air sensors required on all aircraft,” said the 2015 memo, which Boeing turned over in litigation.
> Boeing told The Times that it has not equipped its planes with air sensors because suppliers have not “demonstrated the existence” of devices that could “reliably detect contaminated bleed air.” The company said in a statement that scientific studies have not proved a link between fume events and health problems. “The cabin air inside Boeing airplanes is safe,” the company said.
That is indeed ironic, although in my defense all of my flights are going to be on 737/A320 sized aircraft. I can't remember the last time I flew on a wide bodied aircraft, and I'm not likely to do it again soon.
My issue is mostly that everything that comes out of Boeing makes me feel like they're more worried about suing them than them hurting me or killing me. Maybe Airbus isn't much better, but it sure seems hard for Boeing to get much worse.
The winking smiley should give you a clue to say I’m being deliberately provocative... I think the company culture is probably more important than any regulatory practices or geographical locations.
Several examples of fume events in the article are from Airbus planes as well, especially Jet Blue ones. I suspect because Boeing is closer to home, the journalists have more insider insight as to the internal decisions to not do anything at Boeing, thus putting them in an even more negative light. I would guess Airbus is just as bad. The actual airlines seem to be neglegent as well, fighting to not pay workers comp.
All airliners (except the 787) use the same technology when it comes to air supply. They even buy the equipment from the same suppliers (engines, heat exchanger, ozone converter, packs…).
The risk of fumes is exactly the same on all brands (again, except the 787).
The fumes come from the engine, there's nothing the bleed system can do to mitigate that. All bleed components already don't use any lubricant, they don't add any fume. Also all bleed systems across the whole industry have an extremely similar architecture.
So in the end the component that really matters for this is the engine. And both Airbus and Boeing use very similar engines from the same suppliers. And the engine manufacturer defines the maintenance tasks for it.
As I said in another comment; I don’t want to put Airbus on a pedestal here, but the internal emails from Boeing are incredibly damning towards the company culture. Painting people concerned about breathing in fumes as having an “agenda” is a perfect stereotype of corporate malice, it’s almost beyond parody.
I’ve never seen such emails out of Airbus, although it’s entirely possible that that’s because they’re in another language and therefore they haven’t made it to the English only media I consume.
Seems like they are intentionally asking for regulation, saying they have absolutely no consensus mechanism to do what is necessary until Congress forces them to
They are already regulated but apparently this is most likely a major and intentional oversight. Why? My best guess as to why you can't have a separate air intake from bleed air is that you need the pressurization and the heat. And the extra weight of a different system is cost prohibitive and maybe less reliable. I would hope you could have a primary system that was all electric and taken from a safer bleed or entire system and then use the secondary bleed air system.
I’m referring to the regulations requiring them to detect bad air with a sensor, not an actual solution. Just more data for now, they seem to be asking for that.
To be honest, even just the amount of jetfuel fumes you take in while on board waiting to push off the from the gate bothers the hell out of me. I think that's just because the jetway connector mostly has unconditioned exterior air and with the door open, that makes its way into the cabin, but it can be very nauseating.
I'd seen an ad about this in the airport but wasn't sure whether it had to do with the bleed issue. Seems not: "A jet bridge (also termed jetway, jetwalk, airgate, gangway, aerobridge/airbridge, skybridge, airtube, or its official industry name passenger boarding bridge (PBB)) is an enclosed, movable connector which most commonly extends from an airport terminal gate to an airplane"
I was not surprised this article buries the 787 deep inside where no one will read it. Honestly the bleedless air system of the 787 is one of the things that makes me enjoy flying it.
Exactly! Boeing can't claim that engine bleed air is clean on one hand, and tout that a bleed-less air system improves air quality. It's either one, or the other, not both.
I don't think Boeings primary reason for switching to no-bleed air was air quality reasons anyway. Electrically powered air is way lighter, more reliable, efficient, etc...
It's not that straightforward. I work in that domain and the general consensus is that the 787 system is about as efficient as a conventional bleed system would be. It doesn't offer any significant efficiency advantage.
The mechanical power offtake affects the engine fuel consumption less than the equivalent bleed offtake, but on the other hand their system is significantly heavier, and creates a lot more drag.
Basically, the engine compressor is the best compressor you will find aboard. To provide air supply you need pressurized air. So it makes sense to directly take the compressed air you already have with that excellent compressor.
With their bleedless system they add 2 large extra electrical compressors, and 2 large extra air intakes (to take the air to be compressed). So of course there are advantages to the electrical route, but efficiency isn't a given.
Fume events are the dark belly of the aviation industry. The stuff used to lubricate turbofan engines is incredibly toxic when breathed in, literally orders of magnitude more potent than simple kerosene fumes.
There are a variety of lubricants, but it is believed that the primary contributor to the problem is the organophosphate (Tricresyl phosphates - TCP / e.g. Durad 125[1]) added as an anti-wear additive.
TCP is a known neurotoxin:
"It is a toxic substance that causes neuropathy, paralysis in the hands and feet, and/or death for humans and animals alike. It can be ingested, inhaled, or even absorbed through the skin." [2]
Below is a presentation based on a PHD thesis on the subject with a lot of detail:
In both cases only the pilots/crew had issues, none of the passengers. In one case it was a "dirty sock" smell. If it was a bleed air problem, it would have affected passengers as well.
A lot of research has been done, and there isn't actually any evidence showing that bleed air causes any health problems:
Obviously there are some cases where the seals do break, and there is actual smoke in the cabin, but that is not what the majority of these cases are referring to.
Sounds like the Dreamliner is the only plane designed to avoid this problem. Oddly the article hardly mentions Airbus, so it isn't clear to what degree their planes suffer this problem. And I wonder why European regulators aren't addressing this issue (which seems implied by the article).
I wouldn't say "designed to avoid this problem", because I'm pretty sure that cabin air quality didn't play much of a role in the engineering trades regarding ECS architecture.
The 787 was intended as a more electric aircraft, from the very start, even called the "7E7" during development. An electrical ECS requires special cabin air compressors with big motor drives and power electronics, but there was significant savings for the engines by removing bleed air. It makes sense as a system: Electrical main engine start, generator-optimized engines/APU, electrical cabin air compressors. But the trade criteria were the typical ones: weight, installation volume, total lifecycle cost, etc.
The choice of a lower cabin altitude _was_ a big deal though, and if I had to guess, is the main source of a more pleasant experience.
The main ECS vendors (Honeywell, Hamilton Sundstrand, and Liebherr) all have cabin air quality products, which have mostly gone without interest by the aircraft manufactures and the airlines.
Well, maybe I should have said "made proposals, research projects, and demos". It takes a lot of time and money to bring an actual product to market through flight qualification, and nobody will take that on until there is sufficient interest.
Sorry, thought that was in the story: Environmental Control System, which is the aircraft subsystem responsible for pressurizing and cooling/heating the cabin.
The article states (and I have heard this independently) that the Boeing 787 is the only aircraft which does not use engine bleed air to provide air to the pressurization and air conditioning system.
Apparently to a similar degree. It seems that the European airlines are doing a good job (DHL, Lufthansa) as mentioned in the article about mandating this stuff.
I once actually briefly lost consciousness in my seat after boarding due to fumes coming in with the bleed air. I had some other things going on at the time and was physically and mentally burned out, but still as a more or less healthy young man I passed out in a plane seat for a few seconds largely because of the bad air.
The 787 also pressurizes the cabin to a lower altitude. Most aircraft pressurize to an altitude of 8,000 ft (~2,438m). The 787 pressurizes to 6,000 feet (~1,828m), which is a noticeable difference - it's like being in Denver vs. higher up on a mountain. Your blood oxygen concentrations will be higher as a result.
Does anyone else have a hard time putting up with flying (pre-pandemic) recently? 20 years ago I used to fly without any issue but since they've made the seats smaller, the food somehow got worse and the TSA pre-boarding eats another hour of time I wouldn't have spent in the airport.
I recently started trying to fly business class to actually arrive at my destination like a functioning human being and not anxious/sick to my stomach. Unfortunately it's prohibitively expensive.
Add in the toxic fumes and I'm not surprised how bad I feel after a transcontinental flight.
Airlines learned from previous mistakes and basically would not add any capacity until load factors were incredibly high and they knew they could easily fill another flight. Very rarely would someone get bumped 10 plus years ago but in the last few years it was common practice. The planes were stuffed full where even the very back rows typically left open for flight attendants were filled.
I used to take at least one trip every week for 20 years and it wasn't so bad. After 911 it became worse but the flight was still ok. The last 3-4 years have been absolutely terrible. Even 1st/Business class was a joke and always oversold. I developed anxiety every time I had to fly simply because of the nightmare of getting through the lines (TSA/Customs/DHS), fighting the crowds, no where to even sit, dirty planes, etc. Flying became like riding in a cattle car.
I still fly about once a month and ever since the pandemic it's a lot more pleasant. My last flight had over 100 empty seats and absolutely no lines or people at the airport. Reminded my of a flight I once took to YYZ from DFW on a 727 in 91. I and two more guys were the only passengers on the whole plane, 2 in coach and the other in 1st. Three of us on the whole plane. Felt like a Rock Star on my own private jet....
I'm confident that flying will become miserable again. In another year I expect everything will be back to shit/normal.
We travel around 300 miles pretty regularly to visit family. Over the years we’ve tried almost every form of transportation: train, renting a car, flying, dirt cheap buses, very fancy buses.
Bang for the buck, I’d say our preference became car, train, fancy bus, flying, bad bus.
They all pretty much take the same time, door to door, because the airports are not particularly accessible from our starting point and destination.
The key factors were autonomy and punctuality. If the train or bus hit traffic or broke down, you were totally screwed. Sometimes for hours. If the car hit traffic, we stopped for dinner. The plane is the most expensive, and provides some of the worst experiences of the three. They were rarely late, but really made you suffer for the price.
I never thought I’d become a car person, and yet here I am!
Thanks for sharing your experience. With anything under 6-8 hours of driving, if a car, train or bus is available I'd take that.
First off, getting to the airport is guaranteed time lost since airports are nowhere near where I want to end up. Second, the security theater. Take off your shoes, belt, get X-rayed.
Next come the delays. The worst is when you can be stuck on the tarmac for hours and you can't even get up to go to the toilet or stretch your legs. If a train is stuck you can get up and walk around and if you have a car you can take a break.
It’s basically a greyhound bus with 1/2 the seats, a complimentary hot meal, functional air conditioning, and comfortable chairs.
They charge a premium, but you bring as many bags as you like and the pickup locations are usually less chaotic (a hotel rather than a regional mass transit center).
They still suffer from traffic and the movement of the vehicle (trains are way better in this dimension).
They’re kind of like what I imagine flying in the 80s was like, in terms of the amenities and milieu of customers. Except with near constant turbulence.
I think 300 miles is around the inflection point where, if the transportation systems are mature and trafficked enough, it’s hard to nail down an ideal form of travel.
It’s far too long for a taxi, too short for the plane to be obvious, too short for a drive to be overly boring, and too short for a train to be mind-numbing.
Any longer (500+), I think the plane gets the obvious advantage. Any shorter and you wouldn’t consider a plane.
I guess my point is that, at this point in my life, I’d only want to fly to avoid a reliably 6+hour drive (NYC to Augusta ME, for an example).
Even then it’s a toss up, depending on how much stuff I’m bringing with me.
I used to actually really enjoy flying but the experience has severely degraded over the years. My chief complaints are insanely tight seat density, shitty food / flight amenities, and a terrible boarding process.
In the two years pre pandemic I had to do a ton of business travel. I could expense whatever I needed, fly biz class for international. It still started to wear on me. I think it's just getting older. It's more emotional effort to be away from home. I started feeling some anxiety just about being trapped in a flying tube and not being able to leave. Also because seats are narrower and I'm wider.
For a couple years I was taking 4 flights/week. I absolutely hate flying now and the conclusion I came to was that travel has a lot of anxieties, and air travel in particular involves even more. There are so many variables out of your control that have to go your way to be successful.
Sleeper cars are better than an airplane seat, but I wouldn't call them refreshing. The beds are narrow, firm, heat/AC is a crapshoot, and train noises and movement can keep you awake.
For any serious work in crowded/noisy places, bring earplugs. I used to complete my Chicago commute (train/foot) using cheap , disposable 30db earplugs.
France is 1/3rd higher, and it's centered in relatively fewer big cities - Paris alone is one quarter of the total population of France - no area in the US comes close.
In the US it's worse than the density alone would suggest... because 80% of the country right in the middle geographically has a density that is for all intents and purposes zero.
You don't think there are France-sized regions in the US that have greater-than-French density? Why don't those regions have these trains if density is the only problem?
You can drive to a bullet train station for a trip across the country just like we already drive to an airport. Density isn't the reason we don't have this stuff.
More silly urbanist "density solves all problems" nonsense.
Except even by billet train a trip across the country takes a minimum of 15 hours, instead of a 5 hour flight - and that’s assuming no stops. There is a distance where trains can potentially make sense but it’s NOT across the country.
You’re forgetting to add another two hours to get to and from the airports, another couple hours to deal with the security etc lines, and the absolutely miserable experience that is modern days flying.
A train gets you city center to city center, you have all the freedom you want to walk around, and the luggage restrictions are nowhere as drastic (plus you can keep your 250mL drink you got cheap at the supermarket on the way)
If I recall correctly the 787 bypasses the use of bleed air and similar systems by using electrical power instead to pressurize the cabin.
That comes with its own set of interesting issues but I wonder if you could get some useful data from the fact that these events shouldn't occur on that plane.
It feels much better whilst in the air, but at least some airlines don't run the air conditioning whilst on the ground, so it can feel horrible in the event of warm weather & a delay on the tarmac.
I've loved the 787 every time I've flown it, which is probably 30+ times, predicated entirely on the air + lighting (though this could just be confirmation bias).
Toxic fumes seep into the air we breathe everywhere. Coincidentally, planes are a major cause, as part of a system that has lost its value of health and safety in favor of craving and profit.
Great article. If Boeing won't install them and flight crews can't use them, is there anything stopping normal passengers from bringing detection equipment in their carry on luggage?
If the battery of the detector is not too big, there should be no problem. I did bring an oscilloscope (with probes and all) and lot of other electronics with no issues. The only piece of electronics TSA checked longly was a half broken laptop with no battery. This really intrigued them (so it got re xrayed and the full strip test plus hands and clothes).
> Belgian police has blocked off a part of downtown Brussels over a man wearing a thick coat with wires hanging out of it. The suspect turned out to be a radiation student doing research.
I have carried unusual electronics on an airplane, was expecting trouble but nobody cared. It was a small black foam box with a jumble of wires connecting various pieces of equipment for a high altitude balloon experiment carried on the plane somewhere around 2010. got nothing more than a momentary glance
OBOGS is supposed to be a relatively mature technology at this point, but many military aircraft have had significant issues with it over the last decade or so, and it's interesting to see similar issues crop up in civilian aircraft. I'm kinda mind-blown that the air quality isn't monitored on passenger aircraft, because the military has been doing it for decades.
It's cool to be able to do a back-to-back comparison. I guess I've always been more worried about cabin pressurization failing than OBOGS--oxygen lights are pretty chill, but I've heard some horrifying DCS stories.
> Senior Boeing engineers worried that data from sensors would prove damaging in lawsuits by sick passengers and crew members, according to internal emails and sworn depositions obtained by The Times.
Oh, definitely nothing to do with Boeing’s consistently poor management, an engineer thought up not implementing sound technical safeguards because of imaginary lawsuits. Bullshit.
Senior engineers frequently align with poor management.
For example, in March 2018, Jeff Dean defended Google making Tensor Flow video analysis software for the US military (to use to decide which Pakistani families to assassinate [0]). He calmly and normally presented the technology. When he presented his rationalization for the project, he blinked continuously. I think he was lying.
Having a senior engineering position in a large company does not imply integrity.
The occurrence rate on this is so small, you have a better chance of inhaling fumes from the editors car on the way to LAX then you do of this actually happening IRL.
If an engine bleed is sucking in fumes, there are much bigger issues, like the law of gravity and being 30k feet above a hard surface.
When I see articles like this written so poorly and based on crap science, I usually look for alternative motive. In this case, I can only speculate... Like what on earth?
The whole airport-and-airplanes experience always leaves me feeling like crap. Like I have the flu. My friends report similarly. I figured it's common knowledge.
Plastic vapors. Bad food. Weird solvents. Toxic af.
FAA seems like it has really let america down. The Max 8 thing and now they've sat on their hands for almost 2 decades after being ordered to assess the way pilots are being poisoned.
Oh, and now it appears something questionable went on with the recertification of the max 8. The congressional committee "concluded Federal Aviation Administration (FAA) and Boeing officials “had established a pre-determined outcome to reaffirm a long-held human factor assumption related to pilot reaction time ... It appears, in this instance, FAA and Boeing were attempting to cover up important information that may have contributed to the 737 MAX tragedies.”
And this point:
"The committee also said “multiple independent whistleblowers contacted the committee to allege FAA senior management was complicit in determining the 737 MAX training certification level prior to any evaluation.”"
The FAA delegated safety to mfgs. (ODM), which in general doesn't work as well as expected.
The actual 737 Max design problems were caused by Boeing, then false documents were filed with the FAA, so you could argue that beyond the ODM system, Boeing deliberately misled the FAA, subverting the safety certification process.
The challenge with cockpit/cabin air quality is that fundamentally air flows from high pressure to low pressure in both a local as well as a global manner. So each airplane model and perhaps each example would need to be studied for air quality. Although airliners are air-tight pressure vessels, I don't think this is as simple as one might think.
I also have noticed strange smells or emissions in the cabin on some flights, so it appears to be a real issue. What people don't understand is that an airliner is a big machine beyond human scale, so even a minor problem on the scale of an airliner can have a big effect on a row of passengers.
Source: commercially-rated pilot, study aerodynamics.
According to the article, one main culprit, known to the airline mfgs, is the typical location of the air intakes means that a leaking seal can lead to toxic organics spreading to the cabin. In fact, they cite the novel intake location on the 787 dream liners as avoiding this air quality issue.
A first step to investigating how serious of an issue the air quality is during fume events would be to actually measure the air quality during fume events, which congress instructed/mandated the FAA do in 2003, per the article. But to paraphrase, the airlines told the FAA to take a hike, and they obeyed.
If the mfg can repeatedly mislead the regulators and the airlines they are purportedly regulating can tell them to pound sand when they try to investigate, it means the regulators are failing. Yes it also means Boeing is in the wrong and the airlines, but it means the FAA has dropped the ball.
I'm not sure what you're trying to say with the statement that gas flows along pressure gradients... temperature flows along temperature gradients... why does that standard behavior change anything in the analysis.
> “Flight attendant, pilot unions, and congressional supporters could use this effort as evidence that sensors are needed and ... to drive their agenda forward to have bleed air sensors required on all aircraft,” said the 2015 memo, which Boeing turned over in litigation.
> Boeing told The Times that it has not equipped its planes with air sensors because suppliers have not “demonstrated the existence” of devices that could “reliably detect contaminated bleed air.” The company said in a statement that scientific studies have not proved a link between fume events and health problems. “The cabin air inside Boeing airplanes is safe,” the company said.
Thanks Boeing