Hi  and merry Christmas to all B)

 

I was just wondering why the "Actual wind" on the CRZ page in the FMC is not identical to what ND is showing.

 

Is this normal ?

 

CRZ page has 277/66

ND has 267/66

 

10 degrees between them

 

Thanks everyone

 

 

Update:

 

Hmm it must have something to do with track vs heading i guess. Maybe it is explained in the FCOM....otherwise feel free to educate me  B) heading is 10 degrees of vs track because of the wind.

 

Michael 

Hi and merry Christmas to all B)

 

I was just wondering why the "Actual wind" on the CRZ page in the FMC is not identical to what ND is showing.

 

Is this normal ?

 

CRZ page has 277/66

ND has 267/66

 

10 degrees between them

 

Thanks everyone

 

 

Update:

 

Hmm it must have something to do with track vs heading i guess. Maybe it is explained in the FCOM....otherwise feel free to educate me B) heading is 10 degrees of vs track because of the wind.

 

Michael

The calculated wind direction shown in the FMS is referenced to true north. However, unless flying in far northern regions, the aircraft's ND heading is referenced to magnetic north. The 10-degree difference you see in the ND vs. FMS wind direction is due to the magnetic variation at the particular location your aircraft was flying when you made the comparison.

Thanks alot,

 

I do still get confused with those true north, true heading, true track etc. It can be overwhelming but as time moves on i am quiet sure one of your guys would show me , when true track or something like it is in place .

 

Thanks over all

 

Michael

I believe there is a switch from magnetic to true north at 70 degrees north latitude or several degrees above that.