Instinctively I'm so not sure that AtoB is right about his assertion that most airliners are usually being pressurised to 6500 feet. I would bet that they're not - but would be more than happy to look at any evidence that this is the case.
You're instincts are correct. But it's a major cover-up that you can only expose through infiltration followed by whistleblowing. So you must get yourself licensed and buy yourself a Boeing or Airbus type-rating. Then, you can check to see for yourself and log the results/readings. Don't worry, you'll undoubtedly recoup your $50,000+ investment when people are lining-up to buy your book instead of the next Harry Potter installment. Blow the cover off this thing. Go take out your loan today.
Apart from the Dreamliner - which we've already mentioned here - it must cost more to crank up the pressure above the "accepted" 8000 level - not just in power but in ensuring the aircraft will remain robust enough, over its long service life, to withstand the repeated pressurisation cycles to contain a 6500 ft pressure at - say 35,000 feet.
It only stands to reason it must cost more to crank up the pressure. In a house it costs more to crank up the heat in winter or crank up the AirCond in summer, so why would an airpcraft be any different with air? An airplane has a kitchen, bathrooms, the cabin has chairs you sit on while you watch movies holding a thing you can switch channels with, and up front is an office with books and pens and stuff.
We all know about the incidents in which the skins of high-cycle aircraft have failed . 8000 ft pressure was enough to peel back the roof of that Aloha airlines 737 in 1988. ......Just imagine what the pressure equivalent of 6500 feet would have done.
It's too incredible to even imagine. You could almost say it's unimaginable.
Another factor in crew (and passenger) alertness - or lack of it after, say, 4 hours at 35,000 feet (pressurised to the equivalent of 8000feet) is something that hasn't been discussed here so far - the temperature of the air. When cold rarified air is drawn in at 35,000 feet AND heated to 70 degrees F (to say nothing of its subsequently being recycled) it must further reduce the concentration of oxygen molecules. Ergo - there may well be less oxygen available in this heated rarified air than people might think.
Ok, I can't maintain silence any longer now that you've gotten this close re the temperature thing, but it's much worse than you thought. If the ill- effects of heating that cold, 35,000' air to 70 degrees concern you, just how much does it scare the holy bejeezus crap out of you to find out that the rarified air is heated not from "cold to 70", but in fact is heated from cold to....HUNDREDS OF DEGREES! You didnt' read that wrong, it's heated to 100s of degrees by compression inside the engines, then COOLED DOWN AGAIN to cold, but then WARMED UP again to only 70. This may fool the unwary, but there is major abuse of the air happening that even liquid couldn't sustain. This information strengthens your case.
In summary I think we need some hard evidence to prove the often-made but totally unproven assertion that the performance of pilots and passengers is NOT degraded after sustained (3 hours or more) flight at 35,000 feet.
Yes we do. I may as well feed you some evidence since I've said so much I'm probably marked for death anyway: Ask any pilot if he/she has ever shared a cockpit with a rambling idiot who droned-on for hours about something stupid while cruising at 35,000'. You'll find almost all of them will confirm they have. Coincidence? How could it be, when the common denominator in every instance is the existence of weak air in the cockpit? Feel free to use that information. You don't even have to pay me.
The way to establish what's really going on here is for the CAA to carry out cognitive ability tests of pilots (and passengers) . Test them on the ground at sea level - and then see how they perform after flying for at least three hours at 35,000 feet in an aircraft pressurised to 8000 feet. It would be a safe bet that performance would be worse at 35,000 feet.
The Powers behind the cover-up wouldn't allow objective testing, or would finesse the results to maintain it. You'll have to conduct tests on your own, I'm afraid. I'd suggest a fold-out Skinner Box maze disguised as a carry-on, with a live rat smuggled down your pants. Since you'll have already conducted sea level tests at home to establish the cognitive baseline, all you have to do is wait for 3 hrs to elapse at 35,000', then release the rat and observe the behavior of the rat and those around you and ask yourself; "is this normal"?
.......Such tests would settle the issue once and for all - and may well result in far reaching changes and safer flying.
Indeed they would. So spend the money, get the ratings, use the rat, write the book, and my instincts tell me you're on your way to a real breakthrough.
heating that cold, 35,000' air to 70 degrees .... it's heated to 100s of degrees by compression inside the engines, then COOLED DOWN AGAIN to cold, but then WARMED UP again to only 70.
Is this what they mean when they say that global warming has gone to local warming?
It is STILL the case that I am more likely to die on the roads. When driving to an appointment this morning (a funeral as it happens) on the motorway, I was overtaken by a car who then realised that they wanted the next exit. They went from the outside (3rd) lane, across the 2nd and the 1st and went up the exit road at 70mph with no signal, or indication. Just swerved across all the lanes. THAT driver was drinking air at only a few hundred feet above sea level and could have killed and maimed several of us.
Fortunately, everone else - consuming the same air - was being watchful and we all avoided that twit. That's the job of driving.
Perhaps the drinking of rarefied air helps pilots concentrate better.
OK - fair enough . Some very funny comments here . When you have PD, TightSlot and Paxboy on your tail you know you are in trouble....... But I really wasn't looking for a fight with anyone. All I'm suggesting is that maybe the "universally adopted" cabin pressure of the equivalent of 8000ft altitude isn't enough - and that's why it's no longer "universal".
Here's a quote from Boeing test pilot Heather Ross who's logged 1000 hours in the , 787 which has, as we know, a minimum cabin altitude of 6000ft (and has higher humidity than aluminium aircraft). After a 14 hour flight to India she said "You don't feel like you've been beaten up.You're not dry and thirsty all the time."
At 38,000 feet the 787 had a cabin pressure of equivalent of 5,400 feet (about the equivalent of living in Denver) .When the aircraft climbed to 43,000 feet the cabin altitude was at the 787 comfortable minimum of 6,000 feet.
So why has Boeing gone to all the trouble to rock the boat and increase cabin pressure on the 787 when passengers and aircrew are (to judge from this thread) apparently so happy to fly at a cabin-altitude of 8000ft? The simple answer is that they aren't.
Blake Emery - director of cabin design - says Boeing's research shows what's described as "passenger discomfort" on ordinary non-787 flights with cabin pressure at 8000ft . This shows up (according to Boeing) in the form of headaches, muscle cramps, and feelings of fatigue after three to five hours in the air - and there's no evidence that, on an ordinary airliner, the pilots are feeling any better than the passengers. (The FAA found that pilots' nighttime vision deteriorates once cabin altitude drops to 5000 feet - never mind 8000)
Lastly - just to return to the question of the lower amount of oxygen in heated rarified air which amused Magnus P . A cubic metre of warm air, as Magnus P will remember from his Form 1 Physics classes, contains fewer molecules of oxygen (and all other gases come to that) than does cold air. The proportion of oxygen is the same - 23% or thereabouts - but it's less dense..
........And, what's more, remember that 60% of cabin air has already been recycled (i.e. breathed). - but we won't go there.
I spend a lot of time in the mountains. At heights below 10000 feet, all of the symptoms you describe are solved by drinking more water, ie its dehydration increasing with altitude, not the number of oxygen molecules.
By an amzing coincidence, drinking more water on long haul flights seems to have the same beneficial effects, as maintaining hydration in the mountains.
I'm afraid I can't contribute to this thread anymore because having to read it is causing blood to gush from my eyes and then I have lie down for a short nap. I'm beginning to wonder if this isn't some frightening new genetic mutation of trolling? We'd better count the Lab Rats and make sure.
There is a lot of 'informed' rubbish here. Try putting breathing 100% oxygen after a couple of hours in cruise at night and look out of the window. From a black hole the scenery changes to millions of stars! Obviously the lack of oxygen affects the brain especially if the packs are on recirc..... Used to suffer migraines but only on long high altitude flights - get stuck below Nat tracks and the symptoms disappear. Even as SLF I can feel the effects. Roll on the Dreamliner with fresh air. Similar effects flying sailplanes over 10000 ft.
The various articles would seem to suggest there is indeed an adverse effect at 8000ft - but it is minimal and has no operational effect. A fact, I would suggest, born out by empirical evidence gained over the last sixty years or so.
Aren't we overlooking the mental stimulation caused by purer cosmic rays at 35000' that counteract oxygen deprivation? Empirically, it's clear that the real reason ground-level drivers are so much more accident prone is because the cosmic rays have been weakened, reflected and defracted all over the place and our human brains, originating as snippets of DNA on a meteor, can't function properly.
One of the reasons that I think Boeing are making so much of the air-con for the 787 is simple publicity.
They have heard the complaints over the years and have claculated a way that they can increase fresh air without a penalty on fuel consumption. So they want everyone to know that is a big part of the 787.
Of course, my cynical mind says that they will tell everyone enough times so that folks believe it ... they HAVE to make a success of the 787 as they have bet the farm on it. They saw that the word Jumbo was theirs and then became public property as the 'Hoover' word as a generic for large pax aircraft.
You will have seen that, this time, they chose the word and branded it all over the place. All the publicity has this and lauch carriers are also splashing the name - just look at Thompson inviting you to name their Dreamliner not their 787.
Boeing hope that pax will want to travel on the Dreamliner and not the super-jumbo that could be a 744 or 748 or 787 or 380. In idle conversation with a friend yesterday about aircraft, they mentioned the Dreamliner - even though they had no idea what size/capacity it had or what duration it would operate. So Boeing appear to be succeeding and all strength to them for having found a new angle. Personally, I'll wait for it work through it's teething problems for a few years.
So, to return to the topic () if you tell folks you've fixed the air-con problem and the fix is called 'Dreamliner' you have a chance of getting your money back.
Whether there is a problem is another matter but I'm sure that Boeing could line up a 727 full of 'experts' to tell me all about it.
PAXboy is right of course - Boeing is using the 6000ft cabin altitude as a means of differentiating the Dreamliner from "ordinary" airliners (including - ironically - their own)
But let's also remember that Airbus - after a lot of hesitation - are now on the same path with the A350 XWB which will also offer 6000ft max cabin altitude - and 20% humidity..
Soon all airliners will be like this. It'll be like jets versus pistons. The 6000ft cabins will win. 8000ft airliners will collapse in value. The cosy assumption that a well-maintained 747 could fly for 30-40 years will be shown up as just plain wrong. Sure it'll still fly just fine - but no one will want to fly in it. Watch those 8000ft cabin seat-prices slide and those used aluminium aircraft residuals start to crumble.
The days when passengers had no option but to endure being reduced to a semi-comotose state of virtual anaesthesia at the fag-end of a long-haul could be coming to an end sooner than we all think.
Of course this is isn't going to be popular with traditionalists and knuckle-dragging neanderthals - and it's certainly going to be traumatic for the aviation industry. .....But it will be good for passengers and good for pilots.
Well korrol ... my last post was because you mentioned the 787 and I put forward what I thought was a more realistic reason for the 6,000ft cabin NOT that they think there is a prob with flight deck air.
Since we used to have cigarette smoke and, I think, worse recirculation rates until it reached public discussion - we are already better than we were. When did they ban smoking on the flight deck? In the cabins?
If I had to list the things that make me anxious about commercial flight these days, flight deck air quality would not be in the top five.