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the stratosphere to double the normal
levels globally and increase them by as
much as ten times where there is dense
traffic'' (Stuart Auerbach,
Los Angeles
Times,
August 2, 1970).
This could raise the temperature in
the stratosphere considerably - maybe
even six or seven degrees centigrade.
Present-day aircraft have already
increased the atmospheric turbidity, or
cloud-cover frequency. In fact, one of
the most common causes of turbidity is
the exhaust from cars and aircraft,
especially the latter, since they place the
particles high in the atmosphere.
It
is calculated that the cloud cover
over the North Atlantic is already 10%
above normal, thanks to increasingly
man-made turbidity. Now, suppose by
2000 A.D. there are 3,000 SST's Bying
- the "optimistic'' forecast for the
number of
SST's
by the end of the
century. Does thís mean the Atlantíc,
together wíth much of North America
and Europe, will be permanently under
a doud?
If
so, how will this affect
climate?
No one real/y knows for JtJre.
Heat and Radiation
Najeeb E. HaJaby, President of Pan
American World Airways, offended the
Concorde engineers in 1964 when he
insisted that
they
had not given enough
thought to the problems of stress and
strain encóuntered by planes traveling at
supersonic speeds. According to Halaby,
aluminum gets hot and "creeps," much
like asphalt on a scorching day.
British engineers, however, are quite
aware of the problem. The nose of the
Concorde, when Bying at its designed
speed of 1450 miles per hour, will heat
up to 306 degrees F. The nose on a
2,000-mile-per-hour supersonic plane
would heat to better than 600 degrees
F., hot enough to broil a steak.
American scientists have developed a
stronger stainless steel and titanium
alloy to withstand the predicted heat
and stress of the Boeing version. Alumi–
num, the cooventionaJ plane-building
rnate·iaJ, would probably fail at such
high speeds.
Solving the heat problem
is
another
expensive factor in the SST race. Elabo–
rate refrigeration systems have been
developed to counteract the extreme
externa! heat of the f'<!.Ster SST's.
The
PLAIN TRUTH
There is also a concern with radi–
ation. At 60,000 feet there is twice as
much radíation as there is at 35,000,
and at least one hundred times more
than at sea level. For sorne reason, radi–
ation levels peak out at the cruising
level of the SST. This is another danger
passengers and crews must face.
Experts have suggested that there be
limits placed on the amount of time
spent at cruising altitude by SST crews
- especially women. Sorne have sug–
gested that SST hostesses should
all
be
above cbild-bearing age, a suggestíon
considered ridiculous by others!
Dr. S.
R.
Mohler, Chief of the
FAA Aeromedical Applications Divi–
sion, warns that SST crews run the risk
that high-altitude cosmic radiation " . ..
may shorten the life span by 5 to 10.
percent and the gross sigas of aging
may appear earlier than would other–
wise be anticipated." Other possible
results of exposure to radiation, accord–
ing to Dr. Mohler, are damage to sperm
cells, bone marrow, lung tissues, kidney
tissues, and the lymphatic system - and
leukemia
(SST and Sonic Boom Hand–
book,
William A. Shurcliff, p. 73).
Danger is especially high to pregnant
women who might Ay during tbe first
few weeks of undetected pregnancy.
According to Shurcliff, even a very
slight dose of this high-power radiation
might cause damage to the unborn child.
Normal cosmic radiation is a prob–
lem, but solar
fiares
compound it.
Pilots will be instructed to dive to safer
altitudes in order to escape tbem -
but this will be an obvious hazard in
the already crowded airspace, besides
causing a more intense and annoying
boom.
ln-Flight Problems
Passengers who have a tendency to
become airsick on turbulent flights may
experience real discomfort. At this alti–
tude SST's will be subjected to violent
"wind shears" caused by colliding rivers
of cold and warm air. These winds can
toss a plane like "a rat shaken by a
dog." Pilots hope to be able to detect
them with infrared heat-detection de–
vices tbat are currently being devel–
oped - but when a pilot is covering a
mile each two seconds, the infrared
detectors will have to be able to give a
May 1971
150-mile advance warning. Engineers
are working
to
solve the problem.
Fire is another concern.
Because of the greater amounts of
fuel SST's carry and the speeds at which
they travel, fire is an especially dan–
gerous prospect.
According to one report: "A broader
safety problem exists, arising from the
presence of ignitable fuel-air mixtures
in the tanks and venting systems.
"Possible sources of ignition are:
electrostatic discharges, unusuaJ light–
ning strikes, ground fires, unforeseen
arcing and sparking from electrical
components, and hot metal fragments
from engine disintegration. This poten–
tia! Jire and explosion hazard is not
unique to the SST; however, it rep–
resents a safety threat which is more
critica[ for the SST because of the broad
fuel temperature ranges likely to
be
experienced, and the greater quantities
of fuel stored in or near the fuselage
areas" ("Tentative Airworthiness Stan–
dards for Supersonic Transports," report
by Federal Aviation Administration,
Jan., 1969, p. 99).
Engineers are also faced with ozone.
Too much ozone entering the passenger
cabin could cause individual hemor–
rhaging - and even small amounts
cause irritation to the respiratory sys–
tem. The filter apparatus aboard the
Concorde will decrease the density of
ozone to .1 in a million parts - well
below the margin of safety. But should
the system fail, the plane would be
forced to a Jower altitude in order for
all aboard to survive.
Even the weather poses a problem.
Hail has been occasionally reported by
Air Force pilots at tbe altitudes these
planes will be Aying. It is rare, but
damage from large hailstones has been
reported. At supersonic speeds they
could cause dangerous damage, espe–
cially structural fatigue.
"Holding Pattern" Crisis
The SST would be unable to "hold"
for long periods of time - an absolute
necessity in today's crowded system of air·
port traffic. A subsonic plane would be
able to detour five hundred to even one
thousand miles in the event of an air–
port's being dosed due
to
bad weather
- but not the SST. The SST uses a