FMC winds page help

[rwy12 16]

HiCan somebody please help me with understanding the fmc progress sceen 2-where the 3 different readings for the winds are shown.The setting is like this h/wind wind x/wind 13K 270/20 R 15ktI understand the middle reading-it's the current wind direction/force.I am confused about the left and right hand readings.Are these values for the landing runway-if so than how can you have headon wind and a x wind present at the same time?Looking forward to your help.Qas

[Jim Harnes 13]

Unless your course is directly into or away from the wind, you will have a head/tail wind component and a cross wind component. The flight management system does the computations for you.So in your example you have a 13kt headwind slowing the groundspeed and a 15Kt crosswind from the right which requires a heading compensation to stay on course. Again, the FMS/AP take care of that for you.At 3000 ft in a Cessna it's wizwheel time :).Jim Harnes

[rwy12 16]

Hi JimThanks for the help-I still can't undersatnd how is it possible to have both x winds and head winds present at the same time.Qas

[SAS263 1]

You

[rwy12 16]

HiThanks for the reply-I take it than the center reading in the FMC is thecombined effect of the head on and xwind vectors-and it's the currentwind direction/magnitude.Not the wind conditions at the landing runway?Qas