ACARS time
 

Where does the ACARS source its UTC time update from?

I've had a quick look at the 744 manuals and wiring diagrams, it's not 100% clear but ACARS gets it's time input from the CMC, the wiring diagram shows that the CMC gets an input from the flt deck clocks. As far as I know the clocks are set manually, but this is not accurate as it is a manual input. I would hazard a guess that there is some input from SATCOM which will be more accurate, I just can't find the input at the moment. :confused:

I believe airbus GPS equipped a/c use GPS satellite time based clocks. This is the time seen on the main panel clock provided the selector is to GPS. ACARS uses this as the time reference.

Possibly out of date now but on the B744 it used to come from the Capts clock, i.e. as in Spanners post.

737 'classic' is, I believe, the same. NG from GPS time.

Sounds like somebody's trying to ge paid early .... ;)

In the plane I used to fly it was GPS time. The one I fly now, I think it is taken from ARINC as the ACARS talks to the comm towers.

But you can input a manual time, drop the hammer, and then 5 seconds later the time resets to ARINC time. But the OFF time captured is the manually input time. :O

Anyone ever seen an ACARS manual ? Online ?