T
RAINING
M
ANUAL
–
L
ANCAIR
IV/IVP
•
14,000 Feet:
Your blood saturation will be down to 84 percent. If
you continue at this height for any period of time you will become appreciably
handicapped. Your vision will dim. Your hands may shake, and your thought,
memory, and judgment will be seriously degraded. An objective observer likely
would notice some or all of these symptoms after one or two hours at this
altitude, but you would feel just fine, possibly better than normal due to the
euphoric effects of oxygen deprivation.
•
16,000 Feet:
This level is particularly meaningful to pilots in the
western United States because it is close to the MEA across several areas of
mountainous terrain. Operations at 16,000 feet without oxygen are dangerous
because you will not notice your dramatic deterioration. Those who have
survived such flights are living proof that the real impairment associated with this
altitude is virtually undetectable by the victim. At 16,000 feet, your blood
saturation is only 79 percent. You will be considerably handicapped. Depending
on your temperament and other personal traits, you will be disoriented,
belligerent, euphoric, or all three.
Your judgment will be decidedly unreliable.
This level of hypoxia is similar to serious intoxication
.
•
18,000 Feet:
Here the oxygen partial pressure to the lungs is a
mere 70 mm H, and the blood saturation is approximately 70 percent. At this
altitude, without supplemental oxygen, you will be seriously impaired and
incapable of functioning in any useful manner for more than a few minutes. You
are likely to feel confident, comfortable and happy due to the euphoric response
of oxygen deprivation
. Your time of useful consciousness (TUC) is about 30
minutes.
After that, you will simply pass out.
•
20,000 Feet:
If your altimeter shows 20,000 feet and you’re not
using supplemental oxygen, you probably won’t ever see it. At this altitude, you
are in the brink of collapse, if you’re not already unconscious. Although
extremely rare, there are documented instances of death from hypoxia at this
altitude.
TUC is 5 to 15 minutes.
•
25,000 Feet:
Due to complex physiological factors, blood saturation
falls very rapidly above 22,000 feet. At 25,000 feet, your blood will have only a
37 percent load of oxygen,
and you will be unconscious in 3 to 6 minutes
.
During one air carrier decompression at 23,000 feet, the flight attendants had
great difficulty even plugging their oxygen mass to the walk around bottles after
only one to two minutes of exposure.
•
Above 25,000 Feet:
Your TUC drops rapidly.
At 30,000 feet, it is
a mere two minutes.
At 35,000 feet, it is 60 seconds, and at about 37,000 feet,
it drops to 20 seconds. Further, above 25,000 feet and with a sudden
decompression, you may suffer from aeroembolism or “the bends”, a condition
caused by nitrogen bubbling out of the blood and tissues. Pain is detected first in
the joints, then in the chest and abdomen and along nerve trunks. Only
increased ambient pressure (lower altitude) can reverse the process.
Supplemental oxygen has no effect on this decompression sickness, but it is
important to sustain consciousness so that you can quickly descend to a lower
altitude. The Lancair pilot SCUBA diving before pressurized flight is particularly
vulnerable.
‐
22
–
©
Copyright
2007
LOBO
May
not
be
copied
without
permission.
