The Wind Triangle or Vector Analysis
If there is no wind, the aircraft's ground track is the same as
the heading and the GS is the same as the true airspeed. This
condition rarely exists. A wind triangle, the pilot's version
of vector analysis, is the basis of dead reckoning.
The wind triangle is a graphic explanation of the effect of
wind upon flight GS, heading, and time for any flight can be
determined by using the wind triangle. It can be applied to
the simplest kind of cross-country flight as well as the most
complicated instrument flight The experienced pilot becomes
so familiar with the fundamental principles that estimates can
be made which are adequate for visual flight without actually
drawing the diagrams. The beginning student, however, needs
to develop skill in constructing these diagrams as an aid to the
complete understanding of wind effect. Either consciously or
unconsciously, every good pilot thinks of the flight in terms
of wind triangle. |
If fight is to be made on a course to the east, with a wind
blowing from the northeast, the aircraft must be headed
somewhat to the north of east to counteract drift. This can
be represented by a diagram as shown in Figure 15-19. Each
line represents direction and speed. The long blue and white
hashed line shows the direction the aircraft is heading, and
its length represents the distance the airspeed for 1 hour. The
short blue arrow at the right shows the wind direction, and
its length represents the wind velocity for 1 hour. The solid
yellow line shows the direction of the track or the path of the
aircraft as measured over the earth, and its length represents
the distance traveled in 1 hour, or the GS.
In actual practice, the triangle illustrated in Figure 15-19 is
not drawn; instead, construct a similar triangle as shown by
the blue, yellow, and black lines in Figure 15-20, which is
explained in the following example. |
