How high do you think a pilot in an open cockpit plane would be able to fly? There must a be a point at which the altitude does not contain enough oxygen. Maybe an hour or so at a high altitude otherwise I have no idea. I know for example the the Tiger Moth could in theory fly at altitudes over 10,000 feet but without oxygen I would have thought that after an hour or two the pilot would have to descend? The limit of my knowledge is that when someone flew over Everest for the first time it was with a bottle of oxygen, I believe that one of the two planes ran into trouble when the pilot developed an oxygen leak for a short time.Any thoughts?Andrewhttp://www.gordiusfs.pwp.blueyonder.co.uk/

Andrew,Without oxygen, the upper limit is in the 13,000 foot range. After that, things get dicey depending upon pilot's health. A healthy pilot might be able to stand a higher altitude for a short period of time, but the norm for non-pressurized aircraft is a maximum of 10,000 feet.

Perfect timing Alan. Just found this on a "certain" web site with which you might be familiar ;-)AIRCRAFT OWNERS AND PILOTS ASSOCIATION (AOPA)The regulations require pilots to start using oxygen at 12,500 feet if they are going to be above that altitude for more than 30 minutes, and at all times above 14,000 (see "Pilot Counsel: Supplemental Oxygen," June Pilot).Andrew

For exapmle, In the altitude chamber I was able to remain lucid at 26,000 ft (I think, I'll have to ask, it wasn't any lower than that), while all my buddies had to put on oxygen after just a couple of minutes due to the effects of hypoxia. Infact I rather enjoyed some of the feeling it gives you, and I was still able to do math problems with absolutely no trouble at all (they give you a worksheet). Needless to say I was able to cope with the effects of altitude better than my fellow flight crew members and was the last one to put on oxygen.Jeff

I'm glad I asked. I quite happily putting along in my 1928 open cockpit plane at 12,000ft for ages and all I was thinking about was the cold. Stupid moutains! Down to 9,500ft and feeling much better :-) Better not try that again, I was wondering why I was having trouble typing just now.Andrew

Just a point of clarity Andrew.... the effects of high altitude (termed "hypoxia") will occur in *any* non-pressurized aircraft -- not just open cockpit.This may shock a few pilots but the first evidence of hypoxia occurs at 5,000 ft. The retina of the eye is actually an outcropping of the brain and as such is more dependent on an adequate supply of oxygen than any other part of the body. For this reason, above 5,000 ft you will begin to experience diminished night vision. Instruments and charts are misread; dimly lit ground features are misinterpreted.As has been stated, you are limited to 30 minutes at 10,000 to 13,000 without supplementary oxygen. Above 13,000, it's mandatory.At 14,000 ft you experience indifference, dimming of vision, tremor of the hands, clouding of thought and memory errors. Cyanosis (blue discoloring of the fingernails) is first noticed.At 16,000 ft you'll likely become disoriented, belligerent or euphoric and completely lacking in rational judgement.At 18,000 ft, primary shock sets in and you'll lose consciouness within minutes.Hypoxia is insidious -- there is no warning of any kind. One minute you feel fine, the next you don't know which way is up.Cal (CYXX)

Ah, but those of us that live in high altitude can take much more than the common low lander. :-) I grew up in Colorado so I could spend the day at 14,000 feet and do quite a lot without any side effects. Sadly now that I have moved to the low lands I have more problems when I go back home to Colorado and go over 10,000 feet, but I do adjust more quickly then most. Most people must follow the "chart" that Cal posted but please do not assume because you see someone else without oxygen that you do not need it, some people live in high altitude and can therefore stand more before problems occur.Philip Olsonhttp://www.precisionmanuals.com/images/forum/supporter.jpg

In Canada we can fly for 30 mins between 10 and 13000 after that its 0xy time.

With a separate oxygen supply (which is easy to carry of course and has been used since the 1920s or 1930s) the problem becomes cold rather than oxygen.As altitude goes up temperature decreases and your face starts to freeze. Soon you need arctic survival gear (complete with heated undies) to prevent frostbyte and hypothermia.

Same as here in NZ, over 10k its oxygen after 30 mins and mandatory oxygen if above 13kYes hypoxia is very insidious - one of its most deadly effects is to make you feel like you`re not affected...The accident that killed the golfer Payne Stewart was a very good example of how bad it can be. The Time of Useful Consciousness is very short at high altitudes.The best solution is to fly an clanky old Tomahawk which grinds its way to about 9000ft if you`re lucky (and you`re instructor stays on the ground to watch!).CheersLungs

get a fan, blow it right into your face, at max power, and fly around and keep climbing, untill you have enough of it.. should give you an idea..Johan[A HREF=http://jdserver.no-ip.com]Personal Server[/A]A LITTLE LESS CONVERSATION, AND A LITTLE MORE ACTION PLEASE!HELP:http://support.microsoft.com/?kbid=238882

WOW! Hypoxia is a lot like being married, look how well it fits if you replace the first few words of your sentances, thus:"On the way to the wedding" you experience indifference, dimming of vision, tremor of the hands, clouding of thought and memory errors. Cyanosis (blue discoloring of the fingernails) is first noticed."Standing at the wedding alter" you'll likely become disoriented, belligerent or euphoric and completely lacking in rational judgement."After you say "I Do" primary shock sets in and you'll lose consciouness within minutes."Marriage" is insidious -- there is no warning of any kind. One minute you feel fine, the next you don't know which way is up.Hmmmm, strange coincidence or.... :-lolRegards,Mike T.

18,000 feet - Loss of consciousness could occur in 15 to 30 minutes.Above 18,000 feet - Effects of hypoxia are described in terms of time of useful consciousness, (TUC) which ranges from 10 minutes at 20,000 feet to 15 seconds at 40,000 feet. I flew to 16,000 with a Flight Safety International instructor in a C310 Recurrency program without oxy. Instructor had a bag on. Took maybe 20 minuties to get up there.When he told me to descend, I could't figure out whether to pull the red, blue or black levers which I thought was pretty funny...at the time! (one of the sinister aspects of hypoxia).The instructor took the airplane and when we got lower he just smiled and said "Do you understand now?"(-:TIME OFUSEFUL CONCIOUSNESS: Consciousness Without Oxygen Table ALTITUDE TIME OF USEFUL CONSCIOUSNESS 40,000 15 seconds 35,000 20 seconds 30,000 30 seconds 28,000 1 minute 26,000 2 minutes 24,000 3 minutes 22,000 6 minutes 20,000 10 minutes 15,000 Indefinite**But with risk of physical and mental impairment.

Go that sorted then. I'll skip those rudder pedals I was going to buy and buy a small bottle of oxygen and a small freezer. I can then sit at the controls breathing the oxygen with my head in the freezer and a large fan blowing at high setting against my face. I can't wait. Oh, I'll be standing on the chair as well of course.Thanks,Andrew:-beerchug

That's just for the pilots, passenger requirements are different. So if the kids are being obnoxious, put your mask on and climb up a little. ;) j/k----------------------------------------------------------------John MorganReal World: KGEG, UND Aerospace Spokane Satillite, Private ASEL 141.2 hrs, 314 landings, 46 inst. apprs.Virtual: MSFS 2004"There is a feeling about an airport that no other piece of ground can have. No matter what the name of the country on whose land it lies, an airport is a place you can see and touch that leads to a reality that can only be thought and felt." - The Bridge Across Forever: A Love Story by Richard Bach