News release: 3 March
Hypobaric chamber tests at Practica di Mare
Our preparation for the Everest flight continues. Richard drove 2000 Km
from England in a very nice Ducato Van provided by our sponsor FIAT to
join Angelo in Rome for some critical tests before departure for Nepal.
Yesterday Richard spent the day at the Italian Airforce Medical
institute being thoroughly checked out, the only problem; an excess of
ear-wax which was quickly solved, and he now has a certificate which
qualifies him to be a 'passagero su aviogetti militari' or passenger in
a military jet. This also means that they are satisfied he is unlikely
to be an embarrassment by dropping dead in their hypobaric chamber.
Today we spent the day at Practica di Mare air base outside Rome where
we did a 'flight' in the Italian Air Force's state-of-the-art hypobaric
chamber to 43,000 ft using all the equipment we plan to use on the
actual flight, including masks, diluter demand valves and Oxygen
bottles. After a comprehensive briefing we were wired up with saturated
O2, heartrate and respiration sensors and installed ourselves in the
chamber, Richard in one of the 10 seats and Angelo hanging from the
ceiling in his harness. We also had an instructor with us in the
chamber to assist in an emergency and a pair of spare masked plumbed
into the chamber's system in case our kit failed to work properly.
The flight profile consisted of a short 'flight' to 10,000ft and back
down to ensure sinuses and ears are clearing properly, then a 30 min
wait, on full oxygen to 'saturate' properly, to get rid of excess
nitrogen which can cause decompression sickness (the bends), and then a
rapid ascent to 43,000ft at 4500 ft /min. At this height, even on pure
pressurized oxygen one is slightly hypoxic, Richard's first symptoms are
a slight dizziness and euphoria, in other words the experience was
mildly amusing....
We then descended fairly rapidly to 25,000 ft where we were invited to
remove our masks. At this altitude the average 'TUC' or Time of Useful
Consciousness is about 5 minutes and we were given various mathematical
exercises to see how we performed. This exercise is primarily designed
so each individual learns to identify his first symptoms of hypoxia
(which are different for every person) and can react in time to prevent
permanent disability and subsequent unconsciousness by first re-fitting
the mask and selecting 'emergency' oxygen on the regulator and then
possibly making a rapid descent to a safer altitude. Richard replaced
his mask after about 4 minutes, the symptoms being a substantial
dizziness and a mild state of euphoria. Interestingly, the tunnel
vision experienced a couple of times on actual flights when the oxygen
supply failed was never apparent in the chamber.
With regulators back on we descended to 18,000 ft , the lights were
dimmed and again we were invited to remove our masks. At this height
the TUC is about 30 minutes but we did not linger that long, the purpose
of this stop was to see how one's colour vision deteriorates rapidly
with hypoxia. Viewing coloured stripes painted on the wall for this
purpose on the wall, the deterioration is not particularly evident but
once the mask is replaced and 'emergency' oxygen selected the colours
rapidly become much more evident.
We then descended to ground level and a de-briefing. It is good to
report that all our equipment performed flawlessly which is very
encouraging for our forthcoming flight tests this weekend at Guidona air
base where we will try to reach 30,000 ft.
For this test many thanks are extended to the members of the Italian
Air-force for their most gracious hospitality.
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