5. TRIANGLE OF VELOCITIES

INTRODUCTIONVECTOR: Conjuction of 2 parameters:

• Module: Quantity, actual value, dimension• Direction: “Where is it going to or coming from”

TRIANGLE OF VELOCITIESDEFINITION: Triangle made up of 3 vectors

• AIR VECTOR …………………….(TAS / TH-MH-CH)• GROUND VECTOR ……………..(GS / TT-MT-CT)• WIND VECTOR ………………….(W / V)

For every flight planification we must find out all of the 6 parameters

Whenever we have 2 of those 3 vector we can calculate the other.

Two ways:

Graphicaly over a map

Using a navigation computer

TRIANGLE OF VELOCITIES

TRIANGLE OF VELOCITIES

AIR VECTORDEFINITION: Vector representing the actual path the

aircraft flies inside the airmass.

Defined by 2 parameters:

• TH = Heading the aircraft would actually fly if there where no drift

• TAS = Speed the aircraft would have above the ground if there where no wind

GROUND VECTORDEFINITION: Vector representing the actual path the

aircraft will follow over the ground taking into account wind.

Defined by 2 parameters:

• TT = Actual path the aircraft follows over the ground.

• GS = Relative speed of the aircraft and the ground

WIND VECTORDEFINITION: Vector representing the actual wind conditions.

Must take into account winds aloft are usually given as true and METAR / TAFOR are in magnetic.

• W = Direction where the wind COMES FROM (Magnetic,true or compass)

• V = Wind intensity (Velocity)

DRIFT ANGLEDEFINITION: Mesurement of the amount of degrees

the wind is pushing the aircraft on the direction opposite to the one it is coming from.

Angle between the Heading and the Track

WIND CORRECTION ANGLE (WCA)

DEFINITION: Angle and sense from the Track to the Heading. Angle you have to change the rhumb of the aircraft to keep it on the desired track

Equal amount and opposite to the Drift Angle

WIND CORRECTION ANGLE (WCA)

UPDATING A TRIANGLE OF VELOCITY

OBJECTIVE: Whenever you’ve already calculated your triangle and for any reason wind changes, there’s no need to create a new one. Instead you can

revise it.

UPDATING A TRIANGLE OF VELOCITY

TRACK ERROR

DEFINITION: Difference between the directionof the desired track (DT) and the direction of the track actualy flown (Track Made Good = TMG).

Given in degrees left or right.

NOTE: Another way of describing it is by stating how many nm your position is left or right of the desired track

TRACK ERROR

METHOD OF REGAINIG TRACK AFTER A TRACK ERROR

Whenever you realise you’ve lot your way and need to regain your track to reach a

certaing point

REGAINIG TRACK