High Altitude Ballooning, hypobaric chamber visit

Before we could attempt our high altitude hot air balloon flight Lev David and I had to visit some grown ups that would frighten us.... Well me certainly. I was very pleased that, the Levster had managed to blag business class seats on BA/Commair and sitting at 31,000' on the way up eating breakfast it seemed that the trip would be very straightforward. Until Lev asked what the outside temperature was and we were told a chilly -42. We also had a tailwind that got us to our destination 10 minutes early, ah um. But, the houses didn't look too far away!! The flight also gave me a chance to look at the Greytown / Tugela area in great detail. A slight technical crisis had arisen at East Coast that was unwinding as we flew; the result was that rather than staying over in Pretoria and meeting David Mortimer, what would be right now, Lev had to quickly arrange to get us back the same day. I went to the hire car office; we then proceeded to wait almost as long as it had taken to fly up from Durban for the car. You know the story, space for five people to help with only two working. That made us fairly late onto the R21, we had been told it would take an hour to get to the Institute for Aviation medicine in Pretoria and of course there were traffic snarl ups being reported on the radio. Stress is one of the factors that affect the early onset of Hypoxia, with a problem at East Coast, complete change of arrangements, delayed hire car and journey we thought impossible to do in the available time we managed to arrive on time and feeling not in any way flustered! I was fairly amazed that Lev just uttering the words, "We are here to see Sgt Major Ross", made the gates open, it was effortless. I expected at least 20 minutes of being asked questions about my great grandparents. As it should be, in the building in which big machines are held there were plenty of echoing corridors and steps. The chambers of which there were two had the appropriate number of levers and dials. Sgt Major Ross was the man operating the controls and unfortunately I cannot remember the names of the two doctors. One a physiologist and the other a straight forward medical man. Both of them seemed just older than my eldest son who is in grade 0. We were to be taken fairly rapidly up to 12,000' sit there a while making sure all was ok and then at 2000 fpm up to 20,000' where we sat for several minutes without oxygen steadily loosing functions! Yet again sponsors HP came to the fore as the machine monitoring our health was made by them. The doc measured our blood saturation level dropping and would not let it drop below 60%. Just for Lev here's a chart explaining what range it should be in. I think, although my mind may not have got this right at 20,000', I will have to review the video carefully. Lev's saturation which was 100% at base point dropped to 65 and mine 79 although my saturation at the start was 95 I think. By the following chart that makes me indifferent normally. That can't be right ;-) Stage Altitude in Feet Saturation (%) Indifferent 0 to 10000 95 to 90 Compensatory 10000 to 15000 90 to 80 Disturbance 15000 to 20000 80 to 90 Critical 20000 to 23000 70 to 60 My slightly better performance at altitude may be the km's I have done in the gym. Or it could be that Lev had been up until two that morning preparing today's show which then all fell apart and he's sitting at the station making another plan right now! Or could also be the fact that Lev lives at sea level and I live at 4000'. I was very nervous about the chamber, Lev on the other hand took the view that there were grown ups, sort of, with us and they wouldn't let anything happen. I took no solace earlier when one of the Generals in a brief brief suggested that, "30,000' is too high and we might be best to pray!" Hum sound medical advice, I'm not sure. The chamber itself was noisy, brightly lit and with a bearded man outside at the big picture window operating levers. If you suffered from claustrophobia the closing of the door would instantly bring on panic I should think. At one point Lev asked if Sgt Major Ross could hear us and then made some off colour remarks to which the psychologist replied that, "He couldn't hear us which was just as well because he is the chap that lets us out". I personally felt the tingling at my extremities and anxiety. More than likely euphoria but its hard to tell. Lev seemed to get quieter. We obviously both survived but the stupidity of attempting anything at high altitude without the right equipment was underlined. When they bought us down at 4000' fpm my right ear very quickly became blocked and very painful. I asked them to slow the rate of descent, which Sgt Ross did and then we actually climbed back up to 18,000' again which helped. We then descended at a much slower rate with me clearing my ears best I could. We left Johannesburg in a rush to get Lev back to the station, I think neither of us really grasping what a day we had had. Only in the following week did we really start talking about our chamber ride! Gary http://www.airborneadventuresafrica.com