Today I took the day off work to attend one of the FAA sponsored high altitude physiology training classes. They're offered at about a dozen locations around the country, the nearest to me being Beale Air Force Base northeast of Sacramento.
Though about eight or ten people has signed up and pre-paid $50 for the class, only two of us showed. The other was a guy named Dale who is also a glider pilot flying from Byron with NCSA. That meant the training was, shall we say, highly personalized. :-)
Beale AFB is home to the U2 spy plane, one of the oldest and most impressive military aircraft still flying.
Part of the fun of being on the base, aside from getting lost, is watching the U2s fly around. They look like big old gliders with F-16 engines in them. And that's not too far from the truth. There were several practicing approaches while we were there, but we also got to watch one going on a "high flight" (above 45,000 feet) take off and climb out of sight while making a hell of a lot of noise.
The first thing we really did was get fitted for our helmet and oxygen mask. I'll likely never wear a helmet like that when flying, but I do have a mask that costs several thousand dollars less that the military training model I was using.
After that, the morning instruction began. We spent a lot of time reviewing the specifics of pressure changes with altitude increase, how that affects oxygen absorption in the bloodstream, and so on. We covered related matters like G forces, disorientation, low lighting and night flying, etc.
A far amount of it was review, but there was a lot of new stuff included too.
After lunch we watched a quick FAA video on oxygen systems and then headed to the chamber.
The chamber at Beale has 18 seats in it. Two are always in use by military observers who are there to help with the training and make sure nobody gets hurt. Each seat has an oxygen control console, a "walk around" emergency bottle (the yellow ones), and a clipboard with some mental exercises on it.
Our routine for the afternoon was to perform a test ascent to 5,000 feet and make sure that nobody has sinus or ear problems. Once back at ground level, we'd go on 100% oxygen for 30 minutes while listening to a more detailed lecture on oxygen systems and depressurization (both rapid and slow). The 30 minutes on pure oxygen gave our bodies time to get rid of a fair amount of nitrogen gas.
Once that time was up, we ascended to 8,000 feet and were asked to remove our masks for a bit. Then we simulated a rapid ascent from 8,000 to 18,000 feet without oxygen.
From there, we put the oxygen back on and ascended to 25,000 feet where the real fun began. At FL250, we removed our masks and then worked on the mental puzzles on the clipboard, all the while monitoring ourselves for the onset of hypoxia.
I was able to do maybe a minute of the questions before I started to feel myself getting stupid. And as I looked around the chamber, I noticed that my vision wasn't working so well. Finally, I just started to feel odd. The rule was that we'd put our oxygen systems on the "emergency" setting and put the mask back on after noticing three symptoms, so I did.
Wow! I noticed right away how much my vision improved. I hadn't really realized the extent to which it had diminished until I witnessed the recovery. It was shocking.
After our fun at 25,000, we descended back to 18,000 and removed our masks once again. This time they lowered the lights to simulate night flying and asked us to stare at a color wheel. The idea was to notice our peripheral vision decreasing and the nearby colors all blending together. I did notice the color blending but not much of a decrease in peripheral vision. Again, when I went back on pure oxygen, I immediately noticed a dramatic improvement.
After a final summary and some paperwork, our training was complete. We then got the chance to go watch a U2 pilot getting suited up for a high altitude flight and learn about the suits they wear.
The process of getting dressed was complex. It required a team of people to help him get the suit on, hook up, test the systems, and so on. I could write a lot more about what the U2 pilots go through but it's getting late. Suffice it to say that I have a new found respect for those guys.
Pictures are in my Chamber Ride set on Flickr.
Posted by jzawodn at March 21, 2006 10:58 PM