Flying Petri Dishes

<...no outside air whatsoever in the cabins during flight...>

Never mind <...Petri dishes...>: the assertion does not cover the Apollo 13 situation of CO₂ building up in the cabin during flight. Were the assertion to be true, then the plane's occupants would suffer in the same way as Lovell/Haise/Swigert did on the way back from the Moon before the scrubber canister challenge was overcome.

<...allowed to dump their toilets over...unoccupied areas...>

That's exactly what trains do, so what's the problem? "Please do not flush the toilet while the train is standing at a station"

<...It seems like in these times of Pandemic that the airlines would take action to help prevent the spread of viruses....>

They have. They've stopped flying.

#1: A quote from your link:"The atmosphere at typical jetliner cruising altitudes is generally very dry and cold; the outside air pumped into the cabin on a long flight has the potential to cause condensation which might in turn cause corrosion or electrical faults, and is thus eliminated"

#2: I have never seen a train at 30,00 feet altitude.

I have never seen sewage on a railroad track,except perhaps in other countries.

#3:The airlines did not stop flying voluntarily,people stopped flying,so they could not fly empty.

I think that after this pandemic ends the economy will change drastically.

The economy of teleconferencing vs flying will become apparent,and business flights will be reduced.

People will tend to reduce impulse buying,and start saving for a rainy day,stockpiling supplies for the future,perhaps learning from the elders that survived the great depression.

Eventually the current hoarding will decrease.

There is only so much room to store things,of course one could always rent more space,or buy surplus cargo containers.

Hoarding will be replaced with a steady increase in non perishables in a more sustainable pace.

Countries will try to broaden their supply lines to prevent clogging the main arteries of world trade by any single country.

This will have a disturbing depressing effect on the economy of many countries,and a boon for others.

The new world economy will not be the same.

<...sewage on a railroad track...>

The motion of the train is usually swift enough to disperse it over a wide area. It is nothing different to what non-domesticated animals do every day in the rest of the environment.

<...after this pandemic ends the economy will change drastically...>

Something good will come out of it as well.

<...only so much room to store things...rent more space, or buy surplus cargo containers...>

Such a solution takes up a bigger volume than not doing so, thereby reducing the available <...space...>. "Having less" looks to be a way forward, a philosophy that will be uncomfortable to accommodate in some areas. "The circular economy" is another.

Until the 1990s, U.S. trains commonly flushed their waste onto the tracks, simply asking passengers not to use the bathroom while the train was in the station, and this is still common in some parts of the world. Now they store waste in an onboard holding tank.I see a lot of this talk about updating in some countries.

The trains that use the Channel Tunnel between the UK and France/Belgium have retention tanks.

Some people have the space to put a cargo container.

More space than inside their pantry or closets.

Storage lockers are everywhere now,so no additional space required.

You are misreading the Wikipedia article. The air pressurizing the cabin does come from outside cabin air just not directly from outside the cabin without conditioning for moisture. If you think about it this makes perfect sense for otherwise all of the cabin air, including the air leaked out during a delayed flight and CO2 scrubbing capabilities must be carried by the plane. Also would the doors of a direct flight plane from Denver Colorado landing at LaGuardia airport be more difficult to open.

Actually, they do bring in fresh air. The air outside is only about 3.5 psi and colder than -70F^o, but it is compressed and then cooled (due to heat of compression).

https://www.travelandleisure.com/airlines-airports/how-airplane-cabin-air-works

Now, the pull-down trays, there are your Petri dishes.

This is in disagreement with the quote from a link posted by PW Slack.

Who you gonna believe?

I would bet on the method that saves the most money for the airline.

https://nbaa.org/aircraft-operations/safety/coronavirus/aircraft-disinfection-coronavirus/

There is a rule,but who enforces the rules?

Every workforce has slackers that half-as_ the job.

And what about infected people with no symptoms?

Airlines are famous for cutting costs and cutting corners at the expense of safety.

(Boeing ring a bell?)

They should have a means of enforcement by inspections,etc.,but that will cost too much.

I am glad I don't have to fly anymore.

You know there is "fresh" air coming in when you can smell kerosene on the taxiway.

There's no way there isn't a fresh air component to the air supply.

Oh Snap! There you go making sense again. Just stop it.

Absolutely true!...and I've smelled it lots of times.

The PRV is used to limit the shock load to the backing pump and the NRV is used to prevent process contamination of the gearbox.

I stole this answer fair and square.

Recirculation of cabin air

The recirculation system uses two fans to move air from the passenger compartment to the mix manifold. This system reduces the amount of air that the packs need to supply. This part of the A/C system recycles approximately 50 percent of the cabin air for ventilation purposes. This reduces the quantity of fresh air from the pneumatic system for ventilation. The left and right recirculation fans and filters are the primary components.

See Here

And I had heard that the filters for cabin air were being replaced with HEPA units and there was talk about upping the percentage of make-up air. All subject to verification of course because this was discussed on the news in the early days of the pandemic.

There's no reason they can't have 100% fresh air (as some offices do) but they would need to add humidification otherwise there would be a plan load of mummified corpses.

There'd be quite a bit of cost involved.

I missed the old days when everyone smoked on planes. Then they upgraded to non-smokers at the back and guess which way the ventilation system flowed?

Airplanes. They are the culprit in practically every single pandemic movie out there. (save The Stand) and for good reason. Airplanes are designed and flown for maximum profit.

HEPA level air filters are insanely expensive and HEPA level air scrubbers and sanitizers. Astronomically priced and rather large, Would have to remove two rows of seats. That's not happening. Hepa Filters require heavy duty blowers to move air through them. Their go two more seats or 500 pounds of cash cargo.

Not seeing this happening in an industry plagued by overpaid executives and stock holders. In fact not seeing anything happening until we have a government again and not a greed enabling agency.

SO are airplanes "Flying Petri Dishes"? Hell yes. Not only that but they comprise the most effective contagion distribution system we have yet devised. Between the airports and the planes if your version of the CDC doesn't "catch" a bug like COVID in the first few days, its too late you've gone from epidemic (which is localized) to full Pandemic just that fast if the bug has an R-nought of 2 or higher. (covid has been ranked at a 2 to 3) It's just that fast.

Question; It's really simple exponential math, why do so few understand it?

Last question is a joke. Very few can even comprehend when you start talking "orders of magnitude." Write 1e¹¹ and heads start to explode.

It's not simple exponential math. Simple exponential math is unbounded. Contagion growth is bounded by population size among other aspects.

If you have ten ducks and a contagion takes blah days to double in size when one adds one sick duck on day zero then at day blah there should be two ducks sick. On day blah, blah there should be four ducks sick. On day blah, blah, blah there should be eight ducks sick. On day day blah, blah, blah, blah there should not be sixteen ducks sick because there are only eleven ducks in total.

Your joke is a little ambiguous as to if "e" means exponent or Euler's number. In the former the equivalent number is simply 1. In the later the number is just under 60,000. This is an engineering forum. Big numbers themselves don't scare us. Big numbers of somethings can.

Not fully understanding something and thinking you do can be quite dangerous.

"Gary Lenius and his wife Wanda, both in their 60s, drank chloroquine phosphate last month after confusing it for hydroxychloroquine - a drug touted by Donald Trump as a potential cure to treat Covid-19.

Gary, a retired mechanical engineer living in Arizona, died on March 22 and his wife was left in critical condition after ingesting the toxic chemical."

But hey, I am going to sit in the sun while bathing in Clorox, inject disinfectant and go shoot down some boats.

Wanda was crazy, she slipped the concoction to her husband without his knowledge, it was said to be 4 times the lethal dose, this guy wasn't stupid, he was a retired engineer, he was poisoned by his wife, and she took just enough to make herself sick to get away with it...it certainly had nothing to do with Trump...

https://www.redstate.com/nick-arama/2020/04/24/even-more-questions-raised-about-case-of-the-man-who-died-from-fish-tank-cleaner/

You a funny guy SE. Redstate.com? Really? And you hide it so well. LoL

just poking fun.

1. The "internet" said the 737 was safe and passed all reviews too. Deal with it.

The link I posted isn't "the internet" -- it's a site maintained by the National Center for Biotechnology Information. Real science from real scientists. Not FUDmongering from random people with access to a computer.

In view of the serious,potentially fatal nature of this pandemic,they should be using ULPA class filters.

The Corona virus can pass through the N95 filters

Of course there is always the $$ factor.

The solution for airlines and cruise ships is vaccine.

How many airlines will be able to survive long enough for a vaccine to be developed?

There MUST be other solutions, and I'm not aware of anything more promising than 222nm far-UVC.

SWA already has announced that it has HEPA filters on all the planes it is flying. I presume other airlines have followed suit...

There are no "other Solutions". Until we can test adequately, a vaccine is not going to help because its effectiveness will not be documentable. Far UV is a unicorn at the moment. I work for DuPont. IF this worked and was practical we would have it on site.

I work in a factory that makes bacteria. Very similar processes to virus prop. When a bacteria gets loose, we test, we test, we test, we test again , we test the test, we test the results, we test until it is completely gone. Then and only then is it safe to resume production. (FYI, Currently making solutions for testing of COVID at the hospitals in between production runs)

Until we have that level of testing with tests that are actually working and not some money grab like several that have come and gone recently, we cannot safely re open anything.

Like it or not the failure of America to respond appropriately to this crisis has caused most all of this crap world wide.

Hurray for Dupont!

They are doing what should always be done as a standard and probably is a federal standard or they would not spend the money for all of the testing.

So you are saying that UV does not kill viruses or bacteria?

How about all of the potable water treatment plants that use UV to kill pathogens?

I guess they should just turn them off and stop wasting their money.

Hospitals should stop using it to sterilize the surgery rooms.

IMHO:

Big corporations are psychopathic without exception.They have to be in order to please the shareholders.

And if that means breaking the rules till they get caught,so be it.

I can show plenty of cases where big corporations have blatantly polluted hundreds of miles of river and thousands of acres of drinking water wells.

When it gets too hot in the kitchen, and they see millions of dollars for cleanup looming,they spin off another company designed to go bankrupt and take the fall.

Then the taxpayers foot the bill for cleanup,and the executives of the "whipping-boy company" move on up the ladder till next time,with a few more jewels in their parachutes.

IMHO:

UVC is effective,and could be used when buildings are not occupied,like at night.

They have traveling robots to perform inventory,it would be simple to add a UVC source to them to kill 2 birds at once.

Save the Far UVC for when occupied.

Nothing,is 100% effective.

China's poor handling of the initial outbreak is the real cause of all of the trouble,and the WHO's delay in declaring a pandemic caused delays in action from many countries.

China arrested the first doctor that reported a very deadly form of pneumonia that was caused by an unknown virus.

Others were afraid to report any of their cases.

Information was suppressed until it was too late to prevent the spread.

So if you want to point fingers,point them to China.

It is hard for me to trust any information from China about their recovery/mortality rate.

Dude, Chill.

I have over 100 UVC lights to keep running 24/7. its something I know fairly well from experience. No one said UV is ineffective. Where the hell did you see that in what I wrote?

I said waiting for FAR UV is useless. the problem exists today. The answer to getting things opened back up is testing. Period. Its all we got at the moment.
If far uv was doable, it would be ramped up just like Sherman tanks. 50,000 in 3 years. Or, From having 0 tanks and 0 capacity to build them to overrunning Europe with them. Why isn't it?

As for corporate corruption, bad behavior, illegal activities, etc. you will find we are on the same side there. I work for DuPont because I needed a safe place to hunker down and wait out the '08 depression. I got in under the wire for pension and 401K match So I am going to stay put for those reasons. (and DuPont has proven again to be a safe bet in hard times) Do I agree with DuPont's current corporate philosophy, not even on paper. Do I agree with the paycheck and benefits? I am still here.

Sorry! I misread your post and thought you said that UVC was not effective.

The UVC lamps(not Far UVC) are effective in non occupied areas,so I presume these are used when trying to sterilize a room?

It does seem to me that commercial entities would be using these to help suppress the virus when the business is closed at night.

Even banks should be using them to sanitize paper money,which is handled by almost everyone.

Even a little bit is better than nothing.

No problem. I would also hold off on blaming the Chinese until after you read this and the report about our failings in the Ebola response that led to the creation of the Global Health Security Office.

https://www.usatoday.com/story/news/world/2020/03/18/coronavirus-did-president-trumps-decision-disband-global-pandemic-office-hinder-response/5064881002/

Now one caveat that is essential to understanding. West Africa is about as third world as it gets. We have more people fly in and out of Madison in a day than West Africa has in a year. Meanwhile airports in China see more international travel than almost any other.

As I said in a previous post, if the R-0 is above a 3, then as soon as patient zero enters a major international airport its game over. The airplane is by far the most effective delivery method ever devised by man.

In my opinion, even our best would have missed this one because of its 'Novel'. Unless we screen for diseases at airports prior to allowing entry and travel this will happen again. AND, how can you screen for something that doesn't yet exist?

Patient zero was in China.

It was identified as a new,dangerous,and highly contagious virus,but the reports were suppressed until it was no longer possible to keep the info inside the country.

By the time they released the info,it was too late.

So yes,I am pointing the finger at China and the WHO, that also had the information but failed to take the appropriate action.

China and the WHO were not in the dark on this,only the rest of the world,due to inaction in the critical period.

If a novel virus or bacteria somehow escaped from your DuPont location,and DuPont did not notify the proper authorities,trying to keep the information internal until hundreds of people were infected,where would you point the finger?

Would it be the fault of others failing to recognize a novel strain,or the origin of the strain itself?

First, remember I am a therapist by training. What I am saying is it was not China's fault that they are Chinese. They have a very different way of seeing the world and interacting (or not) with it.

Our previous government took the correct path and accepted as axiom, that other countries are going to be more concerned with optics than solutions. (like our current disaster) A nonpolitical group was set up to monitor the world and react to the first social media report, that first question to WHO out of China in early January, "Have you seen this before?" Those are the first rumbles of thunder so to speak. It's why we have had a rep assigned to WHO, so we would be in the loop, no one could suppress the information and could get people on the ground in the area. Make no mistake, the warnings were early and obvious had anyone in authority been listening. It is my opinion that our current administration has soured the waters with China and they would not have allowed our people in.

It is easy to point a finger, but as therapist I know the first person you point to is yourself. Once you have your house in order then you worry about others. I also understand that the world is a very complex system and it is rarely just one piece that fails. Complex systems are like that. We have a very well designed system that works well when run properly by We The People. When we drop the ball, it gets bad for the entire world, not just us.

Sucks to be a world leader.

I agree that it is not the Chinese people that are at fault,it is their government,and that is not their fault either.Most were born into it,as we were.

The ordinary Chinese citizens are like everyone else: They are good hearted people. They have many admirable traits that seem to have been forgotten in our country by many: good work ethics,honor,dignity,respect for their elders.

They just want to raise their families and enjoy their lives on a day to day basis.

The politicians and rulers over every country mess it all up.

They get into pissing contests with other super-ego leaders and one little wrong leads to another,so they chip away at peace until they have carved a glowing mushroom.

I spoke to a worker in a Chinese food restaurant and asked her if she liked being in the USA.

She said she wished she was back home picking olives.

She was happier there.

You've hit so very many nails on the head here. GA

I agree that due to the "Novel" source of this pandemic it is likely this spread would have happened to some extent regardless of any preparations. I also agree the Global Health Security Office may have appeared to be an unnecessary expense. But the optics of disbanding the very group tasked with responding to a pandemic two years before this crippling pandemic forms at best looks dumb. Worse are the denial claims that the office wasn't closed. There is plenty of blame to go around. No one group here or abroad made things inevitable or intended to harm the world. There also shouldn't be any shame in trying to tighten purse strings but getting it wrong. People should stop pointing fingers at others to apply blame and instead work on fixing this mess instead.

I still say the airplane environment itself is unlikely the incubator. I say it is more likely the airport waiting area, baggage claim, ticket taking, customs, and other population funnels at the airports that are the likely contamination areas.

As for UVC light, why stop there. Sterilize things with e-beams or gamma rays when it really counts.

Assuming that by "e-beams" you mean electron beams, they can only be produced in a rather high vacuum. Not practical for most things.

Did I say practical?

Jaguar is planning to put these new 222nm lights is their new cars....maybe other public transportation venues will follow suit...

These lights remind me of those plasma ball lights....

I wonder what wavelength of light they give off??

https://www.arborsci.com/blogs/cool/top-10-demonstrations-with-the-plasma-globe

So I'm thinking these 222nm bulbs are made using the same alternating high voltage tesla coil type voltage source with a pwm circuit and krypton/chlorine gas instead of argon and quartz instead of glass enclosure coated with a wavelength selective coating....

https://www.rmcybernetics.com/science/diy-devices/diy-plasma-globe

This is pretty cool too....a xenon bulb

Now, back to contagions in a confined space. AKA Snakes on a Plane!

Even if the cabin were HEPA filtered, since each individual is NOT breathing from a dedicated supply and return line it is safe to assume that anything exhaled is circulating around you in an ever expanding circle, sort of, depending on movement in the cabin, direction of air vents etc. Yes, some of it will be captured by the air returns and possibly filtered out. Most of it will not. It ends up on surfaces. You touch it, you touch your face, Viola! You've Been Vectored!

In most sealed systems, only a small percentage of the atmosphere is filtered at any given time, The more you try to collect the louder and larger the fans have to be. Obviously not a priority on airliners so lets just call it what it is, bare minimum required by law.

However, the airplane is NOT the main transmitter. The Airport is. Here is an over simplified example. We all get to the airport two hours early because security.

Lets call it an R-3. and its aerosol not airborne. It has an incubation time of 30 minutes and a surface life of one hour. (that's the time time it takes to takeover a cell, reproduce itself, and be exhaled and the time it can live on a surface and still be viable) Patient 0 walks into Atlanta Hartsfield.

He exhales. Of the ten people within 25 feet 3 are now infected. For simplicities sake lets have all of these people be outbound so our vector has only one direction. (we know reality is very different)

So each of these three will within thirty minutes become vectors. Meanwhile patient 0 is still infecting 3 of every ten contacted. Lets assume that there are 5000 outbound flyers. Within two hours how many will be infected? All on planes heading elsewhere. Everyone on the plane is considered exposed now, and then we land at the airport and again enter a crowded terminal only the plane now disgorges 300 vectors instead of just one into the airport. And then there are the other 130 plague ship planes that all departed Atlanta that afternoon.

We have developed a perfect system for rapid, widespread, distribution of disease.

By the time patient 0 develops symptoms and goes to the doctor three days later you have an instant pandemic. (Covid can take far longer to become symptomatic but you are still contagious that whole time as best we can tell)

Please understand this is incredibly simplistic and done only to demonstrate how this sort of thing moves in our modern connected world. Had we gotten the very first warning out of China it was already too late because of the time delay between infection, infectiousness and development of symptoms and diagnosis. The infected were already traveling. Think Cruise ships. All of those caught the virus during their trip to the ship.

Had we gotten the first warning. Had we still had the Pandemic Response agency, Had we a world class leader, we would still have a pandemic to deal with, just one where we had a better handle on it quicker and could have taken effective measures sooner and saved lives.

Well the transmission rate should be cut down by plane disinfection between flights and everybody wearing masks....and with far uvc lights soon to be deployed in the aircraft, all but eliminated....

No reason you shouldn't take matters into your own hands...

https://www.chicagotribune.com/coronavirus/sns-nyt-how-to-disinfect-airplane-space-20200304-l4dctcchrzactaikkw2ybchlvm-story.html

https://onemileatatime.com/canada-masks-traveling/

I cant remember the last time I saw more than two in a cockpit. I'd say simulator except the dirty windshield looks real.

Airbus A330....A350 also quite roomy...

This is a 747...