Grnd-51 Basic Navigation 3 Velocity Triangles

Path of an aircraft over ground is depenedent on what?

The motion of the aircraft through the airmass, and the motion of the airmass (wind)

Air Masses on the Move

When an aircraft is flying in an air mass that is moving, wind affects the speed and the path (track) of the aircraft over the ground.

Magnitude of effect depends on direction and speed of wind.

Track

The actual path of the aircraft over the earth

Drift

The angle between the aircraft's heading and the aircraft's track.

Correcting for Drift

To maintain the required track, the aircraft is flying into wind an amount equal to the amount of drift

called the drift correction angle or drift correction

Groundspeed affected by wind

the rate of travel relative to the earth's surface is known as the groundspeed.

Flying with head or tailwind causes considerable difference in groundspeed.

Three parts of Velocity Triangle

Air vector, wind vector, ground vector

Air Vector

Showing the direction (true heading) and speed (true airspeed) of the aircraft

Wind Vector

Showing the direction and speed of the wind (W/V), and the

Ground Vector

Showing the direction (track) and speed (ground- speed) of the aircraft over the ground.