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

(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;

(B) where take-off and landing with a tailwind component is permitted in the AFM, and in all cases for the take-off flight path, not less than 150% of any reported tailwind component shall be taken into account;

(C) where precise wind measuring equipment enables accurate measurement of wind velocity over the point of take-off and landing, wind components in excess of 50 % may be established by the operator, provided that the operator demonstrates to the competent authority that the proximity to the FATO and accuracy enhancements of the wind measuring equipment provide an equivalent level of safety.

Therefore, according to the fore mentioned performance regulation, the wind components that may be used for performance planning purposes are:

• HWC = 50% of the reported headwind (more than 5 kt) = 50% of 10 kt = 5 kt
• TWC = 150% of the reported tailwind = 150% of 8 kt = 12 kt