GateHold
May 8, 09, 2:51 pm
This week in Patrick Smith's ASK THE PILOT on Salon.com:
Cabin Air & Disease
From swine flu to malaria, jetliners can spread deadly pathogens...
“…Arriving from Africa, we noticed a lone mosquito in the cockpit. How easily it would be, I thought, for the that tiny stowaway to escape onto the tarmac, or into the terminal, and bite somebody. Imagine an unsuspecting airport worker or passenger who has never before left the country, and suddenly he’s in the throes of some exotic tropical malady. It is instructive, fascinating, and frankly a little scary, to see just how efficiently global air travel is able to spread pathogens from continent to continent. Throw in the long-term effects of climate change, and the term ‘tropical disease’ may eventually lose its meaning. On the other hand, it’s fear and hysteria, not illness, that is more easily contagious -- and in some ways more dangerous. …”
Yet, is the air on planes really as dirty as people think? ...
“…Passengers breathe a mixture of fresh and recirculated air. The supply is bled from the compressor sections of the engines. Compressed air is very hot, but there is no contact with fuel, oil, or combustion gasses. From there, it is plumbed into air conditioning units, known to pilots as “packs,” for cooling. It’s then ducted into the cabin through louvers and vents. The air circulates until eventually it is drawn into the lower fuselage, where about half of it is vented overboard. The remaining portion is run through hopital-quality filters, then re-mixed with a fresh supply from the engines, and the cycle begins again. Between 94 and 99.9 percent of airborne microbes are captured, and there’s a total change-over of volume every two or three minutes -- far more frequently than occurs in classrooms or buildings. Though if passengers have one very legitimate gripe, it’s about the dryness. Indeed the typical cabin is exceptionally dry and dehydrating – at around 12 percent humidity, it is drier than you will find in most deserts. Humidifying a cabin would seem a simple and sensible solution, but it’s avoided for different reasons…..:
The full story is here:
http://www.salon.com/tech/col/smith/2009/05/07/askthepilot319/
(Access to Salon is free. Watch for the “skip this ad” or “enter Salon” links on the gateway page.)
Recently in ASK THE PILOT: This is your captain sleeping. Is pilot fatigue a menace to airline safety?
http://www.salon.com/tech/col/smith/2009/04/17/askthepilot317/
Cabin Air & Disease
From swine flu to malaria, jetliners can spread deadly pathogens...
“…Arriving from Africa, we noticed a lone mosquito in the cockpit. How easily it would be, I thought, for the that tiny stowaway to escape onto the tarmac, or into the terminal, and bite somebody. Imagine an unsuspecting airport worker or passenger who has never before left the country, and suddenly he’s in the throes of some exotic tropical malady. It is instructive, fascinating, and frankly a little scary, to see just how efficiently global air travel is able to spread pathogens from continent to continent. Throw in the long-term effects of climate change, and the term ‘tropical disease’ may eventually lose its meaning. On the other hand, it’s fear and hysteria, not illness, that is more easily contagious -- and in some ways more dangerous. …”
Yet, is the air on planes really as dirty as people think? ...
“…Passengers breathe a mixture of fresh and recirculated air. The supply is bled from the compressor sections of the engines. Compressed air is very hot, but there is no contact with fuel, oil, or combustion gasses. From there, it is plumbed into air conditioning units, known to pilots as “packs,” for cooling. It’s then ducted into the cabin through louvers and vents. The air circulates until eventually it is drawn into the lower fuselage, where about half of it is vented overboard. The remaining portion is run through hopital-quality filters, then re-mixed with a fresh supply from the engines, and the cycle begins again. Between 94 and 99.9 percent of airborne microbes are captured, and there’s a total change-over of volume every two or three minutes -- far more frequently than occurs in classrooms or buildings. Though if passengers have one very legitimate gripe, it’s about the dryness. Indeed the typical cabin is exceptionally dry and dehydrating – at around 12 percent humidity, it is drier than you will find in most deserts. Humidifying a cabin would seem a simple and sensible solution, but it’s avoided for different reasons…..:
The full story is here:
http://www.salon.com/tech/col/smith/2009/05/07/askthepilot319/
(Access to Salon is free. Watch for the “skip this ad” or “enter Salon” links on the gateway page.)
Recently in ASK THE PILOT: This is your captain sleeping. Is pilot fatigue a menace to airline safety?
http://www.salon.com/tech/col/smith/2009/04/17/askthepilot317/