So, what would happen if the hull of a passenger aircraft were not pressurized???
- Jinx
Everyone passes out when they get to a certain altitude for a certain period of time?
Being at commercial jet cruising altitude without special protection is not unlike being outside the International Space Station without protection. There’s atmosphere up there but it’s very thin. Unless you grew up in Cuzco or Lhasa, you’d quickly suffocate, if your body didn’t burst first.
Well- they haven’t always been so. In the Ford Trimotor, there was a pamphlet that I saw a copy of- it said something along the lines of “We are flying at speeds of over 100MPH, if you don’t believe this, open the window and put your hand out.”!!! :eek:
But yes, Brutus is correct for modern jet airliners. Death could result, even.
Death could result? Isn’t that more of a death will result?
Depends on how long you fly at altitude. Don’t forget, cruising altitude of a jetliner is between 30,000 and 40,000 feet. Mt. Everest is around 29,000 feet (too lazy to look up the exact number) and a number of people have climbed it without oxygen.
11,000 feet is simply the altitude at which most people lose consciousness due to hypoxia. It isn’t a vacuum and it isn’t instant death. The biggest risk is having your flight crew pass out and fail to revive in time to avoid crashing.
Pilot type here …
At 10,000 feet, you can be perfectly fine for hours sitting in a seat.
At 20,000 feet, you’ll be too stupid to stand or talk within a few minutes. Elderly or those with bad lungs will pass out, and eventually suffer brtain damage from lack of oxygen.
At 30,000 feet, healthy young people will pass out within a minute or two, faster if standing up or walking. Again, brain damage will ensue in a couple to a few minutes.
At 40,000 feet, make that 15-30 seconds.
Airliners generally cruise between 30,000 and 40,000 feet. Clearly lifespans measured in minutes aren’t compatible with trip times measured in hours.
Don’t forget the pilots would be exposed to the same lack of breathable air as the passengers. Losing the pilots really shortens the ride.
One other thing: at 40,000 feet, the temperature is around -60F. Damn chilly. You could heat the plane without pressurizing it, but once you’re pumping all that warm air in there, it isn’t that hard to keep a little more inside to increase the pressure.
Isn’t that what happened to that golfer Payne Stewart? His plane depressurized and everyone passed out then expired.
Higher than that. I was in an altitude chamber at ‘18,000 feet’ without supplemental oxygen, and nobody passed out. (The drill was we were to concentrate on a colour wheel. After a while, they had us put on the masks. Suddenly the colours were more vibrant.) You might pass out after a while at 18,000 feet, but you should be fine for the duration of your flight at 11,000 .
And for what it’s worth, I took my skydiving altimeter up on a commercial flight once to see what altitude the cabin was pressurized to - read about 8000 feet.
I’ll bet your group in the altitude chamber had been cleared for medical problems and fitness though, right? I mean, maybe not an in-depth physical but at least a questionaire or waiver. Commercial airline passengers aren’t screened at all.
11,000 feet is really not that high. I go skiing at 11,000 feet routinely. I agree that some people might have problems at lesser altitude. But 11,00 feet is nowhere close to fast scary death.
Yes, we had a quick checkup by an Air Force medico.
I’ve repeatedly heard that if a person were to be suddenly plopped on top of Mt. Everest, they would die in 5 minutes. They always talk about this on Everest TV specials when they are discussing the acclimazation process. If this is true, then at 30,000 feet everybody is toast, right?
Everything that LSLGuy said accords with what I have been instructed during training for private and commercial pilots’ licences in the UK.
These figures are given as an average for the population. I too have spent a whole day snowboarding at 11,500 feet with no noticeable effect - but I am still prohibited from flying passengers above 10,000 without oxygen. (That’s for the pilot not the pax!)
The figure we are given in the UK ATPLs is 11 seconds to blackout at 40,000ft. We are also told to get the plane down to below 14,000 feet during that period but to make sure we don’t overstress it!
The answer to the OP is simple enough though - if the plane were not pressurised it would fly at 10,000 ft and below. It would probably use more fuel and have a smaller range as well. I say probably because if aircraft were limited to 10,000ft I guess designers would work within those constraints when building engines.
FYI, commercial aircraft are designed to have the oxygen system automatically deploy at 14,400 feet or higher if there is a loss of cabin pressure. I run the functional test everyday on every brand new 737 built.
You know that people travel to Cuzco all the time, from lower altitudes even, and manage not to suffocate or burst.
I live at 11,200. People routinely climb the ‘fourteeners’ (14,000’ peaks in Colorado)
Most people adjust to it without any problems, but I keep my eye on older folks and kids. Altitude sickness is not fun.
I think NattoGuy is off by a factor of two here. Between my house and Yellowstone is the 10,974 foot Beartooth Pass, which tens (hundreds?) of thousands of tourists drive over every year. I can guarantee that an extra 26 feet wouldn’t cause “most people” to lose consciousness.
Growing up in Colorado, we drove to the top of Pike’s Peak (14,110 feet) a number of times. I never saw anyone (much less “most people”) pass out up there.
You don’t have to just sit in a seat, either, LSLGuy. I hike at 10,000 to 14,000 feet in Colorado and Montana and do just fine. Granted, you get winded a lot easier, but I certainly don’t see hikers passing out all over the mountainsides.
I’m willing to bet that being on top of a mountain at 11,000 feet is nothing like being in an unpressurized aircraft at the same altitude. At the very least, the air pressure in an aircraft would be lower, because the air passing around the airframe would encourage a lower pressure inside the plane. Oh yeah, and I’d imagine that having the ground under your feet on a mountaintop would make a difference with oxygen content of air, as compared to being aloft.
Further, I recall that my flight instructor told me to be extra careful when flying at somewhat higher altitudes (as in, between 5,000 and 10,000 feet) at night. Anyone have any dope on if there’s something to that?
Also, found a discussion on effects of hypoxia: http://www.avweb.com/news/aeromed/181893-1.html