Originally Posted by
trex450
beatnik,
dangerous one yours, a wind that is 30 deg off runway heading simply gives a crosswind component of half the wind speed. Your example gives a 2 kt crosswind when it should be 6. Mathematically it is the sin of the angle multiplied by the windspeed. Rules of thumb work but not this one.
Stick with the clock face and you can't go wrong. Failing that if it feels to strong it probably is.
trex, you misread the table, Wind 30 on RWY 20 is 10 degrees off runway heading (not 30) - hence beatnick's result of 2 kts x-wind component.