Suzuki Burgman USA Forum banner

1 - 11 of 11 Posts

·
Registered
Joined
·
1,111 Posts
Discussion Starter #1
who really believes the air circulation systems on planes is good enough to purify all virus particles to keep you safe?

I heard this on the news and havent had such a hard laugh in a long time.
there is no way any plane has such a good purifying system that it can filter out virus particles . no way in hell is the system good enough to do that. but more so, the air the next person near you breathes isnt connected to some vacuum hose that gets sucked into the system to be "purified" in mere seconds. its all over. from behind you to the one in front. its not pulled from their body and right into the system. its airborne.

if you gave me a free round the world flight, I wouldnt fly right now. the thought to be in the hospital proning on my stomach with hoses in my body to keep me alive scares me too much. id rather take a bullet or die in my sleep.
 

·
Premium Member
Joined
·
2,738 Posts
  • Like
Reactions: s-steel

·
Registered
Joined
·
1,111 Posts
Discussion Starter #3
my ex wife was a travel agent, so have flown to enough places. people on long flight with sleep let it rip constantly. people remove shoes and it gets stinky. ask the stewardesses who work on planes and theyll tell you of the stink and reek they need to put up constantly.

this is what they do...
they give you no touch stations for check in, distance people in the waiting areas, give you gel and masks, but what the hell does that matter once youre on a flight with so many crammed together with everyone expelling air one to another for hours and hours? its not like the air comes out from your nose and mouth and the ventilation system suck it all right away and purifies it. no way in hell. if you could shoot it in infrared I think wed see it bouncing off the back of the seat in front and some overflowing to the back of the head of that passenger and many vortices of it flying all over when people pass in the aisle and the blow vent just pushing it everywhere. its not getting purified and this is just pr bs to the nth degree to calm people because...they need flight money badly.

yea, I think it would be best to stop travel altogether. its unheard of? yea, well is this virus where we specifically never went through. sure we have history of it. but nothing even remotely close to these numbers. when they spoke of sars numbers, I said, wow thats a lot of dead people. befoe I realized how many die from flu a year, then I was shocked. then I heard Italy deaths jumping through the roof I got very scared.I though 50000-100000 infected and 10000 dead around the world. I wish. we should be so lucky.
 

·
Registered
Joined
·
2,370 Posts
I'm old enough to recall airplanes with smoking sections. Maybe some of you do, too.

If you could smell the smoke then, you'd have been in range of exhaled 'rona particles now.

And these days they don't scoop as much fresh air into the cabin as they did back then in large part because they don't have to flush out cigarette smoke any more. Reduces drag, saves fuel, and they weren't thinking about pandemics.
 

·
Registered
Joined
·
3,086 Posts
Not all airliners use recirculated air, some are 100% air from outside.

Those modern aircraft that do partially recirculate have HEPA filters down to 0.01 micron so they can indeed filter out a virus. So that part is true.
In terms of air quality it is better than an office etc (apart from being very dry, but that is bad news for an envelope virus too)


However, if somebody coughs or breathes on you - that is going to hit you before it gets filtered, so in that case it doesn’t matter how good the filter is.

I have much more of a problem with touching surfaces and airport queues and lounges rarher than the aircraft filtration.


This year I should have been in US, France, Australia, Japan and Scandinavia + tram and train locally. I won’t be doing any of those trips for at least another 12 months no matter what happens.
I do feel lucky that I can make that choic. It must be bad for people in the early stages of their career who don’t get to call the shots.
 

·
Registered
Joined
·
3,086 Posts
If anybody is interested in cabin airflow etc:

The air does not travel along the cabin.
It is pumped in overhead and exits at floor level - the flow is is downward, not fore/aft.

On the ground there isn’t enough air coming through the doors.
Airliners have an small, extra jet engine called an APU which powers a generator for electrical power on the ground. Sometimes this also drives a conditioned air supply or an external air conditioning unit is plugged in by the groundcrew.

On the move the aircraft uses “bleed air”, this is air compressed by the first stages of jet engines that gets diverted away from the later combustion stages. This has to be temp and pressure adjusted before it can be fed into the cabin.
It is common to mix this 50/50 with recirculated, filtered air.

The air is pressurised because you can’t breath at 35,000 ft., people tend to feel unwell above 10,000.
The cabin “pressure altitude” is normally 8,000 ft (ie what you would experience at 8,000 in the open) not ground level pressure.
 

·
Premium Member
Joined
·
2,738 Posts
If anybody is interested in cabin airflow etc:

The air does not travel along the cabin.
It is pumped in overhead and exits at floor level - the flow is is downward, not fore/aft.

On the ground there isn’t enough air coming through the doors.
Airliners have an small, extra jet engine called an APU which powers a generator for electrical power on the ground. Sometimes this also drives a conditioned air supply or an external air conditioning unit is plugged in by the groundcrew.

On the move the aircraft uses “bleed air”, this is air compressed by the first stages of jet engines that gets diverted away from the later combustion stages. This has to be temp and pressure adjusted before it can be fed into the cabin.
It is common to mix this 50/50 with recirculated, filtered air.

The air is pressurised because you can’t breath at 35,000 ft., people tend to feel unwell above 10,000.
The cabin “pressure altitude” is normally 8,000 ft (ie what you would experience at 8,000 in the open) not ground level pressure.

At flight altitude is it enriched with any oxygen ? At what levels would the oxygen masks deploy ? Does the plane carry high pressure oxygen tanks or a maker ?
 

·
Administrator
Joined
·
18,161 Posts
At flight altitude is it enriched with any oxygen ?
No. It is pressurized 78% Nitrogen/21%Oxygen and 1% trashy stuff in normal air.

At what levels would the oxygen masks deploy ?
At about 7-8 PSI. Also Flight Crew can deploy them.

Does the plane carry high pressure oxygen tanks or a maker ?
Depending on the aircraft, some have Liquid Oxy tanks but most plains, the masks are hooked up to a Oxygen Generator. It gives about 15 minuets of mixed air. But the flight crew have a few bottles of compressed Oxy on board for emergency medical use only.
 

·
Registered
Joined
·
3,086 Posts
No, as Dave says, most airliners do not carry oxygen. It would be too bulky and too heavy.

They have chemical reaction generators, usually sodium chlorate and iron or barium peroxide (burns at a lower temp). Pulling the mask operates a firing pin to start the reaction.

I know some masks release at 14,000 ft altitude density but not sure if it is the same for others
(I’m almost exclusively helicopters which are very rarely pressurised, if you are in a pressurised helicopter it is Russian and carrying serious firepower - Havoc or Hind.
I was once had an offer to fly an operational Hind but it didn’t happen in the end. A shame, it’s an amazing machine.

 

·
Premium Member
Joined
·
2,738 Posts
Thanks to you both, that’s a mean looking bird .
 

·
Registered
Joined
·
1,114 Posts
THE TRUTH ABOUT CABIN AIR
Filthy, germ-laden, rotten, disgusting, wretched, skanky, rancid, putrid, fetid, and fart-filled are just a few of the adjectives used to describe cabin air, and legion are the accounts of flyers allegedly made ill by microscopic pathogens circulating throughout a plane. In reality, the air is very clean.
On all modern aircraft, passengers and crew breathe a mixture of fresh and recirculated air. Using this combination rather than fresh air only makes it easier to regulate temperature and helps maintain a bit of humidity (more on the humidity in a moment). The supply is bled from the compressor sections of the engines. Compressed air is very hot, but the compressors only compress; there is no contact with combustion gasses. From there it is plumbed into air conditioning units for cooling. It’s then ducted into the cabin through louvers, vents, and the eyeball gaspers above your seat. The AC units are known to pilots as “packs.” That’s an acronym for pneumatic air cycle kit. Usually there are two per plane.
The air circulates until eventually it is drawn into the lower fuselage, where about half of it is vented overboard—sucked out by the pressurization outflow valve. The remaining portion is remixed with a fresh supply from the engines and run through filters, and the cycle begins again.
Studies have shown that a crowded airplane is no more germ-laden than other enclosed spaces—and usually less. Those underfloor filters are described by manufacturers as being of hospital quality. I needn’t be reminded that hospitals are notorious viral incubators, but Boeing says that between 94 and 99.9 percent of airborne microbes are captured, and there’s a total changeover of air every two or three minutes — far more frequently than occurs in offices, movie theaters, or classrooms.
One persistent urban myth holds that pilots routinely cut back on the volume airflow as a means of saving fuel. It’s especially regrettable when even our most august and reliable news sources parrot this baseless assertion. Case in point: the following is from a 2009 issue of The Economist: “Typically an airline will strike a balance by using a 50:50 mixture of fresh and recirculated air,” says the magazine. “Although pilots can reduce the amount of fresh air to save fuel. Some are thought to cut it back to only 20 percent.” My mouth dropped open when I read this. I love that sentence, “Some are thought to cut it back to only 20 percent,” with its oily overtones of conspiracy.
To start with, pilots cannot tinker with a plane’s air-conditioning systems to modify the ratio of fresh to recirculated air. This ratio is predetermined by the manufacturer and is not adjustable from the cockpit. On the Boeings I fly, we have direct and accurate control over temperature, but only indirect control over flow. If you asked me to please “cut it back to 20 percent,” I would politely inform you that this is impossible. The switches are set to automatic mode prior to flight, and the packs more or less take care of themselves. So long as both engines are turning and everything is operating normally, the flow is perfectly adequate. Only when there’s a malfunction are the settings changed.
I am not as familiar with Airbus models, but let’s talk to somebody who is.
“Airbus series aircraft, from the A320 through the much larger A380, do provide a way for pilots to vary airflow,” says Dave English, an A320 captain and aviation writer. “But not in the way characterized by The Economist.”
English explains that the Airbus controllers have three positions, labeled HI, NORM, and LO. “Almost all the time you’re in the NORM position, and flow control is automatic. The HI position is used when you need a rapid change in temperature. The LO position does as the name implies. It reduces flow and provides some fuel savings, but they are minimal and this isn’t used very often. Company guidance is to use LO whenever the passenger load is below a hundred. It’s not a big change. Sitting in the cabin, it’s almost impossible to notice the difference.”
You’ll occasionally notice a strong odor when the plane is on the ground—a pungent smell similar to the exhaust from an old car or bus that fills the cabin shortly after pushback. Usually this happens when exhaust gases are drawn into the air conditioning packs during engine start. The wind is often to blame, causing air to backflow or blowing fumes through the pack inlets. It normally lasts only a minute or so, until the engine is running and stabilized. It’s unpleasant but little different from the fumes you occasionally breathe in your car while stuck in traffic.
 
1 - 11 of 11 Posts
Top