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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 3/2/98:
Q:
On a Boeing 777, the floor seat tracks can hold the seats in place under a force
of sixteen times the force of gravity. Most of them are made of aluminum --
a metal which is relatively inexpensive, light, and easy to work with.
In the galley area, however, they are made of titanium, which is more
expensive and harder to work with. Why?
A:
Soft drink and beer spills can be corrosive. Titanium is much less prone
to corrosion than aluminum.
No correct answers!
- The Aeroquiz Editor.
Week of 3/9/98:
Q:
While taking off in a commercial passenger jet, you will sometimes feel
a slight deceleration due to a throttle reduction, followed by a decrease in
the airplane's attitude angle at a minute or so into your flight. What is
happening?
A:
Your airplane is following noise abatement procedures. After takeoff,
airplanes take off at a steep ascent angle to gain as much altitude as
possible, then they throttle back on the engines to reduce noise over outlying
parts of the airport. In order to prevent a stall, the aircraft's nose is
pitched forward until the airplane leaves the airport vicinity. Then normal
altitude climb and throttle settings are resumed.
Congratulations to Anthony Lee.
Throttle cutbacks for noise abatement are allowed under FAR part C36.7(c) to
a level that gives a four percent climb gradient).
- The Aeroquiz Editor.
Week of 3/16/98:
Q:
Last week, two "unlucky" events occured simultaneously. "Friday the
thirteenth" fell on the same day as a lunar eclipse. The odds of this
happening on any given day are on the order of one in thirty thousand. Now,
speaking of astronomical odds, what would be the odds of both a solar AND a
lunar eclipse falling on a Friday the thirteenth?
A:
Zero. A solar and lunar eclipse cannot fall on the same
day. They would have to be at least two weeks apart.
Congratulations to Arnie McCullers.
Week of 3/23/98:
Q:
According to US Federal Aviation regulations, all commercial transport jet
aircraft conducting normal operations must be quiet enough to meet strict
takeoff and approach noise requirements. All commercial jet aircraft except
one, that is. What aircraft is it?
A:
The Concorde.
Congratulations to Philip Stehno.
Under Federal Aviation Regulation (FAR) 36.301(b), "It must be shown, ...,
that the noise levels of the [Concorde] airplane are reduced to the lowest
levels that are economically reasonable, technologically practicable, and
appropriate for the Concorde type design." In other words, the Concorde must
fly the best noise abatement trajectory as is safely possible, but need not
comply with any specific noise limits. Therefore, operational techniques
like turning the afterburner off and throttling at the cutback point are
performed. Unlike the Concorde, the proposed US High Speed Civil Transport
will certify with respect to FAR36. Batman's Batplane is also exempt --
the FAA is willing to make allowances for the sake of state-of-the-art
crimefighting.
- The Aeroquiz Editor.
Week of 3/30/98:
Q:
A tip of the hat to April Fools Day!
What is the airspeed velocity of an unladen swallow?
A:
Is that a European or African Swallow?
Congratulations to Harry Pepper.
You have to know these things when you're an aeronautical engineer, you know.
- The Aeroquiz Editor.
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