Altimeter Mode -
Effects on Lower Air Density
14.5.1
Effects of lower air density on people
Effects of lower air density on engines
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If you go high enough by climbing a
mountain, about 3658 meters high, the air's
pressure is about 40% lower than at sea
level.
This means that with each breath you are
getting about 40% less oxygen than at sea
level.
When the air's density decreases, the lifting
force on an aircraft's wings or helicopter's
rotor decreases, the power produced by the
engine decreases, and the thrust of a
propeller, rotor or jet engine decreases.
When the air's density is low, airplanes need
longer runways to take off and land and they
don't climb as quickly as when the air's
density is high.
Air density also affects the performance of
automobiles; with lower density decreasing
performance in the same way it decreases
the performance of aircraft engines.
Density Altitude
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As air's density varies by altitude (the
c o m b i n a t i o n
e f f e c t
o f
p r e s s u r e
a n d
temperature), hence the performance of
aircrafts or
automobile engines will be
affected in different altitude (air density).
Pilots need to take the above facts into
account because the lift, power and thrust
would be different between the standard
atmosphere and the real atmosphere (the
Density altitude).
