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Multidisciplinary
Design, Analysis, and
Optimization Branch
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EDUCATIONAL ACTIVITIES: THE NASA AEROQUIZ
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Week of 1/4/99:
Fourth in a series of aerospace logic problems!
Q:
Lightweight composite parts are replacing heavier steel and aluminum
parts in modern aircraft structures. Suppose you had ten bins full of
wing cutout covers. One bin is full of new composite covers, and the other
bins are full of conventional aluminum covers. The bins are not labeled, and
you can't tell by sight or by touch what the covers are made of. You do,
however, know that the aluminum covers weigh ten pounds and the composite
covers weigh nine pounds. Your major subcontractor bills you each time
you use his weighing scale. How can you definitively tell (without relying
on luck, that is) which bin contains the composite covers by using the
scale only one time?
A:
You could take one cover from the first bin, two from the second bin,
three from the third, and so on. You would end up with 55 covers. If all
of the covers were aluminum, they would weigh 550 pounds. But since you
have some number of composite covers, it will weigh somewhat less. For
example, if they weighed 545 pounds, then five covers must be composite, so
the fifth bin must contain the composite parts. If they weighed 547 pounds,
the third bin must contain the composite parts. And so on.
No one got the correct answer!
- The Aeroquiz Editor
And this week's extra credit question:
Q:
Problem: Lightweight composite parts are replacing heavier steel parts in
modern aircraft structures. Suppose you had twelve aircraft parts,
eleven of one material and one of the other. All of the parts are
identical in appearance and you want to separate the "odd" part from the
other eleven. Using a set of balancing scales, the kind with two trays
that do not necessarily "weigh" objects, what is the minimum number
of balancings you need in order to guarantee that you can determine the
"odd" part and whether it is made of steel or composite?
Click here for the answer!
Week of 1/11/99:
Q:
Many people fantasize about using a time machine to go back in time
and, for example, buy stock in McDonald's or place a bet on the New York Jets in
Super Bowl III. If you could travel back to 1920, would it be a good
idea to invest in the Loughead Aircraft Manufacturing Company?
A:
This is sort of a trick question. The Loughead brothers established
their aircraft company in 1916. They pronounced their name "Lockheed."
Unfortunately, due to the glut of cheap war surplus airplanes, the
company folded in 1920. It would have been better to invest in the
Lockheed Aircraft Company, which opened for business in 1926, renamed
amidst concern that the former spelling would invite pronunciations
like "Loghead" or "Loafhead."
Congratulations to Dale J. Martin.
Week of 1/18/99:
Q:
In 1978, mountain climbers Reinhold Messner and Peter Habeler were the
first to climb Mount Everest entirely without supplemental oxygen. Everest's
peak is 29028 feet above sea level -- the approximate cruising altitude of
many commercial jet aircraft. Since air travel is much less strenuous than
climbing Everest, is it really necessary to pressurize the cabins of passenger
aircraft?
A:
Yes! For the general population, any altitude above 8000 feet can result
in hypoxia, and heart and respiratory complications. For the flight crew,
it is especially important that they maintain a high enough blood oxygen
content. At 18,000, the atmosphere is one half the density at sea level.
If the passengers were given weeks to aclimate to the reduced oxygen
available, then pressurization would be unnecessary. There is also the
pulmonary and respiratory edema, which is fatal, to consider.
Congratulations to Ed Wahler.
In fact, climbers Messner and Habeler were quoted as saying,
"Every 15 steps we collapsed into the snow to rest as we approached
the summit - then we crawled on again." If you avoided the acclimatization
process and flew without oxygen to 29028 feet, you would pass out quickly.
The altitude can also be deadly. High-altitude pulmonary edema (HAPE) and
high-altitude cerebral edema (HACE) can affect mountain climbers.
Interestingly, the first time anyone reached such a high altitude was in
the first turbocharged aircraft. In February, 1920, Major Rudolf Schroeder
of the U.S. Army flew a small biplane powered by a new turbocharged Liberty
engine to 33,130 feet. His oxygen system unexpectedly failed, he blacked
out, and his plane went into a steep dive. Luckily, the denser air revived
him as he fell and he landed safely.
-The Aeroquiz Editor
Week of 1/25/99:
Q:
Generally speaking, what would be a better workout regimen for
a high-performance fighter pilot -- long distance running or weight lifting?
A:
Weight lifting, because of the enormous amount of gees the pilot must sustain
when doing pull ups and push overs.
Congratulations to Kiran Ahmed.
Pilots flex their lower body muscles for all they're worth to keep blood
from draining from their heads and going into "gee lock" (pilotspeak for
passing out) during high-load maneuvers. Weight lifting, which increases
muscle strength, is a part of all high-performance fighter pilots' workout
regimens. And although it's difficult to discredit long distance running,
aerobic exercise can lower blood pressure, which is counterproductive
to staying conscious while maneuvering!
-The Aeroquiz Editor
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