How safe is air quality on commercial planes? | Hacker News Reader

How safe is air quality on commercial planes?

bbc.com

45 pointsotoolep45 comments

I´m commercial pilot and from my 16 years experience, breathing toxic fumes has never been a real issue for crew members. The rate of medical discharges due to respiratory illness is equal or lower than I you can see in normal population (just my experience). We never talk about it, nor consider it a health factor.

It´s true there is a moment when the engines start (there is fuel vapor that is not being burnt at the very beginning) when you can smell strong fuel fumes, they make their way to the packs (air conditioning system) but it only smells for a minute or so.

Crews are very, very, VERY sensitive to smells, the worst emergency you can suffer in flight is a fire or smoke (electrical are the worst). We are always trying to discover and track any weird smell. We have procedures to isolate an air conditioning if it´s the cause of the smell or smoke (sometimes it happens).

So no, I don´t think air quality it´s an issue in commercial planes. The air is very dry, and the recirculation and cabin altitude of 5k to 8k feet that create a lower oxygen partial pressure, in my opinion these are bigger factors in how you feel in flight than isolated contaminations.

Also I must note that some flight attendants have some kind of urban legend were they come to cockpit and check the Flight level we are flying, then if it´s high (above FL320 or so) they start complaining about hipoxia and how tired they feel. Usually there is little difference in cabin pressure between FL320 and let´s say FL380, for example the cabin will keep around 8k feet for an Airbus A320 and 5k feet for an airbus A340 (cabin altitude is lower). I´ve tried several times to see if I can feel the difference somehow, but it´s almost impossible. I guess you need an aerobic test to feel it, or having some hipoxic condition due to an illness.

I wouldn't be surprised if the people complaining from the quality of the air is the same one that complains of cabin altitude. But maybe they are right and there is an aerotoxic syndrome, I´m interested in seeing the results of a study.

Personally I´m still more concerned about timezone changes 4-5 times a month, accumulated radiation, being bitten by malaria mosquito (when flying to Caribbean or Africa)or simply a van accident when being carried from the hotel to the airport.

Edit: typo and clarification.

A similar thing happened with the F-22A Raptor. Pilots reported breathing difficulties, and for a while the "experts" were sure it was some exotic chemical toxin in the air supply.

After much investigation, it was confirmed as a combination of a faulty BRAG(Breathing Regulator & Anti-G) valve and poor breathing technique. The proximate physical condition is known as 'Acceleration Atelectasis' which is a lung issue resulting from the incorrect breathing technique under High-Gs.

IMO a combination of fatigue, and a relatively high cabin altitude (8k feet) could easily account for the symptoms these crew are reporting.

Can I just say, this is a really well written article. Great diagrams, explanations, and it gives both sides fairly well. Even for the BBC this is top class journalism.

The diagrams are exemplary.

Small thing about the diagrams, they depict a four-engine aircraft which only make up about 5% of commercial aircraft in service

They're talking about British Airways, the world's largest operator of Boeing 747.

According to Wikipedia [1], the four-engine 747 and A380 comprise over 20% of BA's fleet, way above the worldwide average. The percentage of four-engine aircraft on BA's long-haul routes are likely to be even higher, and it's those long-haul routes that the people mentioned in the article are worried the most about.

[1] https://en.wikipedia.org/wiki/British_Airways#Fleet

>The only exception being the new Boeing 787, which uses "bleed-free technology".

More detail on this: "In the no-bleed architecture, electrically driven compressors provide the cabin pressurization function, with fresh air brought onboard via dedicated cabin air inlets." http://www.boeing.com/commercial/aeromagazine/articles/qtr_4...

Say what you will about the 787 but it has brought a number of innovations to aircraft that will probably live on eventually in future models.

Say what you will about the 787

Sounds like you've got a somewhat negative view of the 787; I'd love to hear more. I haven't read much in the way of 787 reviews, but my experience as a passenger on them have been great thus far.

See: https://en.wikipedia.org/wiki/Boeing_787_Dreamliner#Incident...

Thanks... I had forgotten about the fires etc.

Unfortunately, bleed-free won't save you from the exhaust that other planes are producing. Breathing exhaust-filled airport air can be a substantial chunk of the time spent on a short trip.

Also, I don't know if I've ever experienced a "1 in 1000 fume event" that the article mentions, but I know that about half the time the pilots start the engines on the ground, I can smell the half-burnt jet A in the cabin. It seems to happen on smaller/older aircraft more often.

Then again, the relative harm of all that vs. the high altitude radiation is very unclear.

I was on a flight recently and something smelled... wrong. So I asked the cabin crew about it.

"Oh, you're probably just smelling jet fuel. Once it burns off the smell will go away. No big deal," said the cabin crew.

I did not feel soothed by this.

They were probably messing with you.

My favorite will always be a large quarter-circle a few feet in radius taken out of the trailing corner of a control surface on the wing, visible from the cabin windows, with a large arrow & inscription in sharpie saying "WE KNOW ABOUT THIS"

That's both hilarious and terrifying. When was this? And on what airline?

Oh, many years ago, and I don't remember what airline. I wasn't especially worried, I am pretty sure it was a temporary fix to stop the spreading of damage (such as in the case of a drill stop[1]), and of course the computer would necessarily be able to compensate for a slightly less effective control surface.

[1] http://en.wikipedia.org/wiki/Fatigue_%28material%29#Stopping...

About a week ago British tabloids ran all sorts of "TERROR IN THE SKIES" stories because someone snapped a photo of a maintenance crew applying speed tape[1] to a plane, and thought they'd duct-taped a broken plane back together.

Every so often someone posts a photo of a plane with a missing winglet and asks why it was allowed to fly when "the wing was broken" (missing a winglet will do nothing except decrease fuel efficiency a bit).

Lots of really silly posts happen because people don't know much about airplanes.

[1] http://en.wikipedia.org/wiki/Speed_tape

http://edition.cnn.com/2012/08/08/travel/alaska-airlines-win...

http://wpmedia.news.nationalpost.com/2012/08/alaska-airlines...

This is an important article about the dangers of engine chemicals mixing with the cabin air. There's also the airplane air quality issue not referenced in this article about the recirculation filters against spreading airborne microbes. Who hasn't heard someone say "you always get a cold 3-5 days after taking an airflight". There must be articles about the epidemiology of airflight. (rate of appearance of novel virus serotypes around Atlanta, and Hillingdon, London, for example)

Regarding the air quality issue, there was the 17 year old who won the International Science Fair for his air circulation invention: http://www.thestar.com/news/canada/2015/05/16/bc-student-win...

While it may be possible that their is an increase in colds after flights, it's probably down to a combination of factors - the cold, dry air in planes makes the ideal conditions for cold viruses in your nose and sinus, the shared bathrooms and confined seating makes it easy to pick up the virus on common surfaces, and finally, the time period before flights is often a time of stress (getting ready, making it to the airport etc), and the increased cortisol suppresses the immune system. All that makes a perfect setup for a cold virus to take hold. I would guess that taking a set of stressed people, and making them sit in a confined space with cold, dry air for ventilation would result in an increased incidence of viruses even with a perfect ventilation system.

Hmm, as a frequent flyer once a week. I have gotten a cold maybe once so far that may be related to travel within last 12 months.

All I mainly do is wash my hands before and right after flights.

I'm generally fine with short flights, but it does seem that after every long haul flight I get the cold or flu.

Careful! In order to cut costs, airlines mix nitrogen into the air they pump into the plane, almost 50% sometimes!

(archived from vani hari, the "food babe":)

http://www.freezepage.com/1415667665TBMRBWICKU

Someone here needs to invent a mask that can filter out all that nitrogen

"food babe" == "Landover Baptist" of food.

How dare you. If it wasn't for the food babe, we wouldn't know that microwave ovens destroy the structural purity of water in the same way as demonic possession.

http://www.science20.com/cool-links/the_food_babe_took_down_...

I wonder what would happen is the nitrogen is increased to 78%?

Is that a joke? Normal breathable air is made of 78% nitrogen and 21% oxygen (http://en.wikipedia.org/wiki/Atmosphere_of_Earth). Thanks god is not all oxygen otherwise you will catch fire in practically 0 seconds. On the pressurization that compress your body. But the problem is, they pressurize the plane to the same level of between 3000-6000 feet. It is less then the pressure you usually feel. So doesn't make sense.

Catch fire? 1 bar of oxygen is on the lower end of toxicity, with the only health effects taking hours to manifest. Fires that already exist will burn faster but there's no direct physical danger.

http://www.hse.gov.uk/pubns/hse8.pdf In pure oxygen some material will start combustion autonomously. But even worst, every possible cause of fire (simple friction, sparkles, etc...) that normally are not an issue, became a deadly hazard. But my point was, no, the air we breath normally is not 100% oxygen, fortunately...

My father was navigator in B-17s. They flew at 30,000 feet, and needed to wear oxygen masks. He told me that the funny thing with that was the chain smokers who couldn't last 8 hours between smokes. A cigarette wouldn't stay lit at 30,000 feet. So the smoker would take a breath from the mask, blow on the cigarette causing it to burn like a torch, take a quick puff, then take another quick breath from the mask, blow on the sputtering cigarette to reignite it, all in an endless loop.

>In pure oxygen some material will start combustion autonomously.

What materials? That guide doesn't list any. Acetylene ignites, but that's generally what you want anyway, right?

You are so obviously a shill of Big Nitrogen. How do you sleep at night?

You cannot prove it, besides I can tell you obviously work for the airlines.

How do you know? Have you ever actually analyzed the nitrogen content of air? I think you just believe what the airlines want you to believe.

If you ask me, "Food babe" is as credible as whale.to.

Someone please tell me this is a joke site. I like this quote

"Just think about it – Airplanes thrive in places we don’t. You are traveling in a pressurized cabin, and when your body is pressurized, it gets really compressed! [...] your body’s digestive organs start to shrink [...]"

I wish it was a joke, but Ms. Hari is getting rich with this shit.

The reason it's "archived" from there is because she deleted it, for obvious reasons.

I bet they put dihydrogen monoxide in the complementary beverages as well!

If a news headline is phrased as a question, it's almost certainly click bait. If it is about politics, it definitely is.

If cabin fumes impair brain functioning, that would explain a lot of what I've seen/heard from the kinds of people who travel all the time.

What have you seen/heard?

Its even worse for your brain to sniff your own farts.

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