| Well I found this empty little nodeshell, and thought it needed some love, so here goes.
Airspeed is generally associated with aviation, and so I will try to
explain the different types of airspeed one may encounter. In general it is the speed of an airplane (or other object) in relation to the air.
Indicated airspeed:
The airspeed displayed on the airspeed indicator in
the cockpit, also equals true airspeed at sea level.
Calibrated Airspeed:
Indicated airspeed corrected for instrument and
installation errors. Calibration errors can occur when the pressure sensed
by the static port when the angle of attack of the fuselage is changed.
True airspeed:
True airspeed can be calculated by adding 2 percent of the
indicated airspeed for each thousand feet of altitude.
Example: An indicated airspeed of 100 knots at 4000' MSL = 108 knots true
airspeed.
Equivalent Airspeed:
Calibrated airspeed corrected for compressibility.
This happens when the air entering the pitot tube is travelling too quickly
and becomes compressed, therefore the air pressure inside the pitot tube
will be greater than the sum of the free-stream Static and Dynamic
Pressures. The result being that a the airspeed indicator will register
higher than it should.
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