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. :-)

u2 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.

helmet and mask 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.

the chamber 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.

chamber seats 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.

oxygen panel 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.

u2 pilot in his oxygen suit 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

Reader Comments
# Michael Slater said:

I think the origin of these classes was after a commercial airliner in Britain had one of its cockpit windows pop free, nearly sucking the pilot out with it. The other pilot heroically managed to get the plane down to a level where he could breathe and not be frozen to death, safely landing the plane. Even the other pilot survived due to some stewardii and an engineer cling to his legs for thirty minutes.

Anyway, after that, they began a class to help pilots appreciate the effects of low oxygen on their mental acuity.

I think you should write what you learned about the U2 pilots as well. Would be an interesting article.

on March 22, 2006 07:16 AM
# Nick Arnett said:

Flying at altitude at night without oxygen really diminishes night vision. Even at fairly low altitudes, getting a good breath of O2 is like turning up the dimmer switch.

I think these kinds of orientations are really good to do. Have you ever gone for a spin in the FAA's Vertigon (or Vomitron, as some call it)? It's low-tech, but very effective at inducing vertigo.

And by the way, perhaps before you came to this area, we used to see NASA's U-2 coming into Moffett regularly. There were a lot of interesting NASA planes in our airspace occasionally before they moved them all down south somewhere.

on March 22, 2006 11:10 AM
# Jeffrey Friedl said:

To put some perspective into this, consider that your "high altitude" mark was still almost a MILE lower than the top of Everest, where people climb all the time (and, often enough, die, but never more than once each). It seems appropriate at this point to recommend Jon Krakauer's excellent "Into Thin Air".

on March 22, 2006 03:05 PM
# Brian said:

Great story, very cool stuff. I had no idea that they let civilians onto AFB like that to use their training equipment.

on March 23, 2006 12:07 PM
# gack said:

People take weeks climbing to the top of Everest. Doing it in minutes instead of weeks is an entirely different ballgame.

Helicopter pilots who fly rescue missions on Everest face a big risk because, if they get stranded up there after flying up from near sea level, they will die.

on March 24, 2006 02:02 PM
# Jason Z said:

Luck stiff! Looks like this was a blast.

on April 2, 2006 03:46 PM
# david barry said:

extremely cool post, Jeremy. I visited Beale in the 1980s when they still had the SR71s deployed there. I got to watch both a U2 take off, and an SR71 take off -- something not to many civilians got to witness. The U2 was amazing. It ran a very short takeoff roll, and then appeared to climb almost straight up -- not going terribly fast but with an amazing angle of attack --

the SR71 was altogether different. It's takeoff was thunderous -- thrilling -- then, a KC135 took off, to go up and meet it at 35 or 40,000 feet to refuel it. Then the KC135 cme back down and the SR71 made a pass at altitude -- that meant well over 60,000 feet. I think maybe above 70,000 feet. To mark its travel, it made a fuel dump -- so we could see very thin contrails -- moving at an unreal speed -= even for commercial airliners -- thse contrails -- they were four -of them - sour separate dumps moved fast -- it was almost dizzying to extrapolate that into the speed at which the Blackbird was travelling. As I recall, we heard two very loud sonic booms when the plane passed ovehread.

Then another KC135 went up to refuel the SR71 on the way down. Quite a production for one flyover. An unforgettable experience. D

Do you have any info on U2 pilots stationed in the Philippines in 1964 who made observation flights from there to Phu Bai? Or any general roster on U2 pilots in '64? It's possible that the guys I'm looking for would have been part of the Black Cat Squadron, but I believe they flew out of a base on Taiwan, not the Philippines.

Any info will be appreciated.


on May 30, 2006 09:03 AM
# Chris said:

Saw the chamber pics - neat!

For those interested - here is a link to get some gear to brag about surviving 'The Chamber" -

Or for other FAA chamber - visit

Great website! -

on April 2, 2007 05:28 PM
# karel zeman said:

A while ago, myself and good friend (and instructor at the time), Mike K, decided to take a road-trip to experience the faa’s flight physiology program. The faa offers this program for free to all pilots or those with an faa medical certificate at their home base in Oklahoma, or, for a nominal fee (we paid $50) at an authorized training center. We decided to make a road trip to Andrew’s Air Force Base in Maryland to check it out.

Now why would a helicopter pilot want to experience high altitude training you ask? Well, for one thing, this is a controlled environment that actually lets you experience the first stages of hypoxia, which can occur at any altitude if you have some means of restricting oxygen. Everyone’s symptoms are different, and this is a way for you to feel what the onset is like to you. Also, the program covers some really cool demonstrations of spatial disorientation that very clearly drive home why us instrument rated helicopter pilots should always trust our instruments. Oh, and finally, who wouldn’t want to strap on a fighter helmet and feel like a top-gun for a short while, right?

The chamber flight was conducted in a pressurized chamber with oxygen stations for each pilot. We were brought to various altitudes and asked to do tasks with our masks off. I’ll spare the details but suffice it to say that some rather unexpected and funny things happened when the masks came off for a bit. We all had different symptoms…some of us were unresponsive, others were just plain giddy.
Our crew and commander were awesome…kept it really fun if you can’t tell. We also got to do a rapid decompression, and some night-vision training and a night chamber flight at 5000 feet. That was a real eye opener, because we got to see first hand just how poor your color vision is at night.
In the spatial disorientation portion of the day, I learned not to trust my ear canals, and Mike (no, he is not sleeping) saw that moving your head around rapidly in the cockpit can produce alarming results (that’s him throwing himself into the wall after the spinning stopped!)

on October 20, 2008 10:02 PM
# David Filose said:

The U2s military air-craft are somewhat similar to gliders. Flying such aircrafts on greater heights that is above 40,000 feet can be troublesome due to the high intensity of noise. It’s been instructed that flying-individuals should wear helmet and oxygen masks and that’s too tightly. Gravitational force gets reduced as the altitude increases and pilots have to be cautious about the necessary adjustments for smooth flying.
Some of the health specialists checks whether any body is having sinus or any other ear-problem or not. Lectures on depressurization and oxygen-system have been provided by the experts. Without oxygen-marks the flying persons can feel blurred vision. At night peripheral vision gets affected. Flying in the sky is adventurous.

on May 28, 2010 02:30 AM
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