The wind velocity is made of two components, one acting along the take-off direction called the headwind component, and the other acting across the take-off direction called the crosswind component.

It is possible to calculate the crosswind component taking the sine and the cosine of the angle difference between the take-off direction and the wind direction:

• Head/Tailwind component = Wind Speed x cos(Take off - Wind direction)
• Crosswind component = Wind Speed x sin(Take off - Wind direction)

Headwind component = 20 kt x cos (360° - 315°) = 14 kt.

According to CAT.POL.H.105 - General:

When showing compliance with the requirements, among others, account shall be taken of the environmental conditions, concerning the wind conditions:

(A) except as provided in (C), for take-off, take-off flight path and landing requirements, accountability for wind shall be no more than 50% of any reported steady headwind component of 5 kt or more;

Since, the reported headwind component is 14 kt, then 7 kt should be taken into account for performance purposes.

NOTE:

Reported wind is always magnetic.