I did something stupid today and I'm man enough to admit it. (Or stupid enough, take your pick). There are clearly not enough posts in this section.
I was planning a flight from Florida to New Jersey today. The weather south of my airport was VFR. The weather at my destination was severe clear as well. Only problem was a system covering about 300 miles of ground that I didn't feel comfortable bobbing and weaving from underneath. I thought I would have to cancel but realized there was a chance I could go over the top. (Controversial to some of course). With the threat of worse weather over the next several days my getthereitis started to kick in. I figured I could take a local hop and see if I could get on top.
Usual departure, climbed out and found blue skies through some large broken areas. I was on top by 5000' or so. I climbed to 8500 to take advantage of some stronger tailwinds. So far so good. It was quite beautiful and smooth up there. I came upon some towering clouds and decided I could hop over. Up to 10,500 I went. Looking good. But the clouds kept rising...and me with them. I was lured on by some broken opaque holes where I could see the ground if I needed to escape. Next thing I know I'm flirting with 16,000 to rise above a small area. I was able to dip back down into thicker air but only to have to climb over some towers again. I had only gone this high before to top some remnants of the Rocky Mountains but was able to descend quite quickly after clearing the terrain. I remembered the rules about O2 and hypoxia but couldn't recite them verbatim. They are as follows for anyone needing a refresher:
(a) General. No person may operate a civil aircraft of U.S. registry --
(1) At cabin pressure altitudes above 12,500 feet (MSL) up to and including 14,000 feet (MSL) unless the required minimum flight crew is provided with and uses supplemental oxygen for that part of the flight at those altitudes that is of more than 30 minutes duration;
(2) At cabin pressure altitudes above 14,000 feet (MSL) unless the required minimum flight crew is provided with and uses supplemental oxygen during the entire flight time at those altitudes; and
(3) At cabin pressure altitudes above 15,000 feet (MSL) unless each occupant of the aircraft is provided with supplemental oxygen.
Anyway, I was above 15,000 for a substantial amount of time without oxygen. Bad move on my part and I could think of no better place to confess my sins. This mistake was fortunate for me as I returned home to NJ safely but I figure this post would be a good reminder for others to prepare properly so you won't sin in a similar fashion. Please feel free to discuss...
I live at 11500 and run at 12500, but that day gave me a healthy respect... Each person has a limit, my girl friend has been to 8000meters three times without oxygen...they call it "The Death Zone"
Here's a sobering atc audio clip of a very close call with hypoxia:
http://www.natca.org/ULWSiteResources/natcaweb/Resources/media/ArchieLeague2013Audio/SouthwestZFW.wav
Here's a sobering atc audio clip of a very close call with hypoxia:
http://www.natca.org/ULWSiteResources/natcaweb/Resources/media/ArchieLeague2013Audio/SouthwestZFW.wav
It sounds like a slow depressurization up in the high 20's, although the effects can be experienced in the teens. This guy probably had just a few minutes of useful conciousness. In the high teens it might be closer to 30 minutes, but as others have mentioned, factors such as age, illness, smoking, or carbon monixide in the cockpit can significantly increase your chances of experiencing hypoxia at RV altitudes.
....I think the ones that record your 'sats' for later reference are the most valuable, 'cause we are unlikely to religiously check it during our flights....
I read all the post here today and I hear alot of people say they use oxygen at or above even 9000msl. The truth is if you are in great shape, don't smoke your safty margin is very high. my airport in wyoming is at 7200msl. I fly quite aften around that 15000 to 16000' with out oxygen. I might be used to it a little more since I live at a higher altitude, but if you are crusing around at 12000' I wouldn't even worry about using oxygen. I think a lot of people worry about it to much that it starts playing with there mind. I always have it though on hand. To fly IFR you have to be at 12500' min. The clouds often times don't look as high as they really are and can suck you into thinking o just a little more; glad you made it back.
My hangar is at 7200' also. I'm at the low point for my neighborhood. Should I carry oxygen in my car? I have to go to at least 9000' to get out of here in 3 out of 4 directions. I suppose I could dig a tunnel. Stamper is right. You get used to it. Either that, or else all of us living up here are too stupid to solve 2 digit math problems.
but on top we were still mumbling idiots.
Sometime when you are up high with a pulse ox try taking off the oxygen and let the PO2 stabilize, then do a couple of minutes of grunt breathing.
You will be amazed at how much you can raise the blood PO2 by just grunting hard each breath.
Not recommended for long time periods, but might be helpful in some situations.
maintain the executive brain functions needed to fly a plane.
I dunno. I still maintain a monkey can fly an airplane. I remember when Sonny Bono's executive brain function failed him into a pine tree. Is decision making in an airplane more critical than on Everest or a black diamond hill? Or, is it the airplane ego thing popping up again.