Flying without oxygen

Two weeks ago I had really good day flying. It didn’t start well, I even turned back to the airfiled as I couldn’t find enough lift to get away. But I flew into a thrmal on the way. A really good thermal, almost got sucked into a cloud! It got me to 8500’ and I was comfortable to fly further. The weather was great, I was finding thermals everywhere and never dropped below 6000’.

Soaring under clouds

Two hours later I was 50km away from the airfield at 8000’ and I could have stayed up for another couple of hours, but I started feeling drowsy and could sense an early sign of a headache. So I decided to do 50km run at 100knots straight home… and it was good decision because within an hour after landing I was in the club house, knocked out on a couch, with one of the worst headaches in my life.

So what happened? I came up with two possible reasons. Firstly, a possible dehydration. I know I tend to get headaches in hot weather, so I start drinking water as soon as I wake up. By the time I get into a glider, I usually down 2-3L and well hydrated. The downside is whatever goes in must come out, but it’s another story about how I handle that during the flight. That day, however, I started drinking water only an hour before flying. So I though that could be a possible reason for the headache.

The second possibility is my glasses. I usually fly with cheap $10 subglasses from Aldi (or, how we sometimes call it, “Aldi Aero” ;) ). That day I decided to try my prescription multifocal sunglasses. While my eyes are still good enough to not require prescription to drive and fly, they are not as good as 10 years ago and I find that porescription glasses allow me to see better, especially at night. My optometrist made me a multifocal sunglasses which I find very convenient while driving: I can see both dashboard and the phone as well as signs in the distance. I thought it would be a good idea to try them in a glider and they helped a lot. However, I noticed that the picture at a particular angle would become wobbly. So I suspected this “wobbliness” contributed to the headache.

After discussing this with other experienced pilots somebody mentioned a likely third reason: lack of oxygen. While I was flying well below 10,000’ legal limit, all the signs (drowsiness, headache) were pointing to that possibility.

So the following weekend I decided to eliminate what I can and see if I still get the headache. I started drinking water early, I had 3L on the grond and another 2L while in the air. I wore my usual Aldi Aero sunnies. I flew up to 9,000’… and I still go the headache, although not as as bad as the previous week.

I spent a few days researching hypoxemia (a condition of low levels of oxygen in your blood). Found a very good talk, by a doctor, who is also a glider pilot. The key takeaway is: just use the oxygen, even if you don’t plan flying high, especially if you are getting older.

I also looked at getting an oxygen system… but I really didn’t want to spend $1000+. Luckily for me, somebody was offloading their system on eBay. So I managed to get a second hand one for $500.

Can’t wait for a free weekend with good weather to try it out. But in the meantime I was thinking… I might as well try it at work and see if I get better results when breathing pure O2! ;)