YAW
(yaw)
An
erratic deflection or side to side movement of a ship or
aircraft, especially on a vertical axis Common clues: Nautical
lurch; Go off course; Deviate at sea; Fishtail; Swerve off
course; Partner of pitch and roll; Pilot's problem Crossword
puzzle frequency:
once a year Frequency
in English language:
45780 / 86800 Video: How
to Fly an Airplane: Yaw Movement in an Airplane
Flight
dynamics is the science of air vehicle orientation and control in
three dimensions. The three critical flight dynamics parameters
are the angles of rotation in three dimensions about the
vehicle's center of mass, known as pitch, roll and yaw (quite
different from their use as Tait-Bryan angles).
Aircraft
engineers develop control systems for a vehicle's orientation
(attitude) about its center of mass. The control systems include
actuators, which exert forces in various directions, and generate
rotational forces or moments about the centre of gravity of the
aircraft, and thus rotate the aircraft in pitch, roll, or yaw.
For example, a pitching moment is a vertical force applied at a
distance forward or aft from the centre of gravity of the
aircraft, causing the aircraft to pitch up or down.
Roll,
pitch and yaw refer, in this context, to rotations about the
respective axes starting from a defined equilibrium state. The
equilibrium roll angle is known as wings level or zero bank
angle, equivalent to a level heeling angle on a ship. Yaw is
known as "heading". The equilibrium pitch angle in
submarine and airship parlance is known as "trim", but
in aircraft, this usually refers to angle of attack, rather than
orientation. However, common usage ignores this distinction
between equilibrium and dynamic cases.
The
most common aeronautical convention defines the roll as acting
about the longitudinal axis, positive with the starboard (right)
wing down. The yaw is about the vertical body axis, positive with
the nose to starboard. Pitch is about an axis perpendicular to
the longitudinal plane of symmetry, positive nose up.
A
fixed-wing aircraft increases or decreases the lift generated by
the wings when it pitches nose up or down by increasing or
decreasing the angle of attack (AOA). The roll angle is also
known as bank angle on a fixed wing aircraft, which usually
"banks" to change the horizontal direction of flight.
An aircraft is usually streamlined from nose to tail to reduce
drag making it typically advantageous to keep the sideslip angle
near zero, though there are instances when an aircraft may be
deliberately "sideslipped" for example a slip in a
fixed wing aircraft.
This
article is licensed under the GNU
Free Documentation License.
It uses material from the Wikipedia
article "Flight_dynamics".
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